Influenza is a highly contagious viral infection that causes fever, body aches, and respiratory symptoms. It spreads easily and can cause severe illness especially in young children, elderly adults, and those with weakened immune systems. The influenza virus is classified into types A, B, and C. Type A causes the most serious disease. Symptoms are diagnosed through viral testing of respiratory samples. Complications can include pneumonia, which is especially dangerous for high-risk groups. Treatment focuses on antiviral drugs that target the virus's neuraminidase or M2 proteins.
This document provides an overview of Acquired Immunodeficiency Syndrome (AIDS) and the Human Immunodeficiency Virus (HIV) that causes it. It discusses how HIV breaks down the immune system, leaving those infected vulnerable to life-threatening infections. The document outlines the history of the HIV epidemic and how it has affected both developed and developing countries. It also summarizes HIV transmission routes, clinical stages of infection from initial exposure to AIDS, diagnostic testing approaches, treatment options including antiretroviral drugs, prevention strategies, and healthcare follow-up for those living with HIV/AIDS.
The document provides information about HIV/AIDS, including:
- HIV is a virus that causes AIDS by infecting helper T cells. There is no cure for HIV/AIDS.
- AIDS is the late stage of HIV infection where the immune system is severely damaged and people are vulnerable to opportunistic infections.
- HIV is transmitted through bodily fluids and can be contracted through unprotected sex, needle sharing, or from mother to child during birth or breastfeeding.
- The stages of HIV infection progress from initial infection, to asymptomatic infection where the virus is dormant, to symptomatic infection where AIDS develops without treatment.
1. HIV attacks T-cells in the immune system, leading to AIDS in advanced stages. Children progress more rapidly than adults, with half of untreated children dying within 2 years.
2. In India, around 2.4 million people live with HIV, with 25,000 new infections annually in children, most occurring during pregnancy or birth. Approximately 5,000 infected children progress to AIDS each year.
3. HIV is diagnosed through PCR testing in children under 18 months or antibody testing along with clinical symptoms in older children. Management includes cotrimoxazole prophylaxis, antiretroviral therapy, treatment of opportunistic infections, adequate nutrition and immunization.
This document discusses the epidemiology and pathogenesis of HIV. It begins with global epidemiology statistics, including that there are 35.3 million people living with HIV worldwide. It then provides more specific statistics on new infections, deaths, at-risk groups, and prevalence by region. Regarding pathogenesis, it explains that HIV primarily attaches to CD4 receptors on cells and integrates its genetic material, leading to infection. It also discusses the body's immune response and how HIV evades detection through high mutation rates. Prevention methods discussed include behavior change, condoms, testing, and antiretroviral treatment and prophylaxis.
The document discusses influenza, also known as seasonal flu. It is an acute respiratory infection caused by influenza viruses that causes symptoms like fever, cough, and muscle pain. Influenza occurs seasonally as well as sporadically, and can sometimes cause pandemics every 10-40 years when the virus undergoes major antigenic changes. Influenza viruses are classified into types A, B, and C. Type A is responsible for epidemics and pandemics. The document outlines the epidemiology, transmission, clinical features, diagnosis, treatment and prevention of influenza. Vaccination is recommended for high-risk groups to reduce complications.
Rhabdoviruses are bullet-shaped viruses with a helical nucleocapsid and a single-stranded, negative-sense RNA genome. They infect mammals, fish, insects, and plants. Mammalian rhabdoviruses are classified into the Vesiculovirus and Lyssavirus genera, with rabies virus being the most important lyssavirus. Rabies virus is transmitted via bites or scratches from infected animals and causes fatal encephalitis in humans. Upon entry through a bite, the virus travels through peripheral nerves to the central nervous system. In the brain, it causes symptoms like aggression, hallucinations, and hydrophobia. Post-mortem diagnosis involves detecting Negri bodies
Three subfamilies (genome structure, tissue tropism, cytopathologic effect, site of latent infection)
Alphaherpesvirinae:
Human herpesvirus 1 Herpes simplex type 1 HSV-1
Human herpesvirus 2 Herpes simplex type 2 HSV-2
Human herpesvirus 3 Varicella-zoster virus VZV
Gammaherpesvirinae
Human herpesvirus 4 Epstein-Barr virus EBV
Human herpesvirus 8 Kaposi’s sarcoma related virus HHV-8
Betaherpesvirinae
Human herpesvirus 5 Cytomegalovirus CMV
Human herpesvirus 6 Herpes lymphotropic virus HHV-6
Human herpesvirus 7 Human herpesvirus 7 HHV-7
Influenza is a highly contagious viral infection that causes fever, body aches, and respiratory symptoms. It spreads easily and can cause severe illness especially in young children, elderly adults, and those with weakened immune systems. The influenza virus is classified into types A, B, and C. Type A causes the most serious disease. Symptoms are diagnosed through viral testing of respiratory samples. Complications can include pneumonia, which is especially dangerous for high-risk groups. Treatment focuses on antiviral drugs that target the virus's neuraminidase or M2 proteins.
This document provides an overview of Acquired Immunodeficiency Syndrome (AIDS) and the Human Immunodeficiency Virus (HIV) that causes it. It discusses how HIV breaks down the immune system, leaving those infected vulnerable to life-threatening infections. The document outlines the history of the HIV epidemic and how it has affected both developed and developing countries. It also summarizes HIV transmission routes, clinical stages of infection from initial exposure to AIDS, diagnostic testing approaches, treatment options including antiretroviral drugs, prevention strategies, and healthcare follow-up for those living with HIV/AIDS.
The document provides information about HIV/AIDS, including:
- HIV is a virus that causes AIDS by infecting helper T cells. There is no cure for HIV/AIDS.
- AIDS is the late stage of HIV infection where the immune system is severely damaged and people are vulnerable to opportunistic infections.
- HIV is transmitted through bodily fluids and can be contracted through unprotected sex, needle sharing, or from mother to child during birth or breastfeeding.
- The stages of HIV infection progress from initial infection, to asymptomatic infection where the virus is dormant, to symptomatic infection where AIDS develops without treatment.
1. HIV attacks T-cells in the immune system, leading to AIDS in advanced stages. Children progress more rapidly than adults, with half of untreated children dying within 2 years.
2. In India, around 2.4 million people live with HIV, with 25,000 new infections annually in children, most occurring during pregnancy or birth. Approximately 5,000 infected children progress to AIDS each year.
3. HIV is diagnosed through PCR testing in children under 18 months or antibody testing along with clinical symptoms in older children. Management includes cotrimoxazole prophylaxis, antiretroviral therapy, treatment of opportunistic infections, adequate nutrition and immunization.
This document discusses the epidemiology and pathogenesis of HIV. It begins with global epidemiology statistics, including that there are 35.3 million people living with HIV worldwide. It then provides more specific statistics on new infections, deaths, at-risk groups, and prevalence by region. Regarding pathogenesis, it explains that HIV primarily attaches to CD4 receptors on cells and integrates its genetic material, leading to infection. It also discusses the body's immune response and how HIV evades detection through high mutation rates. Prevention methods discussed include behavior change, condoms, testing, and antiretroviral treatment and prophylaxis.
The document discusses influenza, also known as seasonal flu. It is an acute respiratory infection caused by influenza viruses that causes symptoms like fever, cough, and muscle pain. Influenza occurs seasonally as well as sporadically, and can sometimes cause pandemics every 10-40 years when the virus undergoes major antigenic changes. Influenza viruses are classified into types A, B, and C. Type A is responsible for epidemics and pandemics. The document outlines the epidemiology, transmission, clinical features, diagnosis, treatment and prevention of influenza. Vaccination is recommended for high-risk groups to reduce complications.
Rhabdoviruses are bullet-shaped viruses with a helical nucleocapsid and a single-stranded, negative-sense RNA genome. They infect mammals, fish, insects, and plants. Mammalian rhabdoviruses are classified into the Vesiculovirus and Lyssavirus genera, with rabies virus being the most important lyssavirus. Rabies virus is transmitted via bites or scratches from infected animals and causes fatal encephalitis in humans. Upon entry through a bite, the virus travels through peripheral nerves to the central nervous system. In the brain, it causes symptoms like aggression, hallucinations, and hydrophobia. Post-mortem diagnosis involves detecting Negri bodies
Three subfamilies (genome structure, tissue tropism, cytopathologic effect, site of latent infection)
Alphaherpesvirinae:
Human herpesvirus 1 Herpes simplex type 1 HSV-1
Human herpesvirus 2 Herpes simplex type 2 HSV-2
Human herpesvirus 3 Varicella-zoster virus VZV
Gammaherpesvirinae
Human herpesvirus 4 Epstein-Barr virus EBV
Human herpesvirus 8 Kaposi’s sarcoma related virus HHV-8
Betaherpesvirinae
Human herpesvirus 5 Cytomegalovirus CMV
Human herpesvirus 6 Herpes lymphotropic virus HHV-6
Human herpesvirus 7 Human herpesvirus 7 HHV-7
The document discusses the epidemiology of AIDS, including:
- HIV originated from chimpanzees in central Africa and spread to humans in the early 20th century.
- AIDS is caused by HIV which attacks CD4 cells and leads to immunosuppression. There are 3 stages - asymptomatic, AIDS-related complex, and AIDS.
- India's HIV epidemic varies by state with some northeastern states having over 1% prevalence while southern states are lower. HIV transmission is mainly through unprotected sex and sharing of needles.
HIV enters the host cell by binding to CD4 receptors and co-receptors on T-cells. It then fuses with and releases its RNA into the cell. The RNA is converted to DNA by reverse transcriptase and integrated into the host cell's DNA by integrase. The integrated DNA is then transcribed to produce new HIV proteins which assemble and bud from the host cell to infect others.
Smallpox is a highly contagious and often fatal viral disease caused by the variola virus. It was responsible for hundreds of millions of deaths in the 20th century before being eradicated. The disease originated in Africa and spread worldwide. Symptoms include fever, body aches and a distinctive pustular rash. Transmission occurs through respiratory droplets. Vaccination with the smallpox vaccine, developed by Edward Jenner in 1796, was critical to controlling and eventually eradicating the disease globally by 1980. While there is no treatment for smallpox, vaccination provided immunity and mass vaccination programs were important in its eradication.
This document summarizes information about the epidemiology of influenza. It describes the three types of influenza viruses (A, B, C) and their antigens. It discusses the major reservoirs, transmission, incubation period, clinical features, diagnosis, prevention including vaccines, antiviral drugs, treatment recommendations, and prophylaxis. Influenza spreads mainly via respiratory droplets from infected individuals and affects people of all ages. Prevention focuses on vaccination, antiviral drugs, and limiting transmission through isolation of infected individuals and hand hygiene.
This document provides information on the management of patients with AIDS. It defines AIDS and describes the history and spread of HIV/AIDS. It discusses the global prevalence of HIV/AIDS, the virus itself, modes of transmission, pathogenesis and clinical manifestations in the different stages of infection. It also covers diagnosis, opportunistic infections, treatment goals, antiretroviral therapy and the management of HIV/AIDS patients.
The document summarizes key information about HIV/AIDS, including:
1) HIV is a lentivirus that causes AIDS by progressively destroying the immune system, allowing other infections to thrive. Once infected, the body cannot rid itself of HIV.
2) Scientists believe HIV originated from chimpanzees in West Africa and was transmitted to humans through contact with their blood.
3) HIV is classified as a retrovirus and exists as two types, HIV-1 and HIV-2. HIV-1 is more widespread and virulent.
4) There is no cure for HIV, but treatment with antiretroviral drugs can control the virus and prevent transmission.
This document discusses several types of hepatitis viruses. It covers hepatitis A virus, hepatitis B virus, hepatitis C virus, hepatitis D virus, and hepatitis E virus. For each virus, it describes key aspects such as transmission, pathogenesis, clinical manifestations, diagnosis, and prevention. Hepatitis viruses can cause liver inflammation and damage, and some may lead to chronic infection or liver cancer if not addressed. Vaccines exist to prevent hepatitis A and B.
This document provides an overview of influenza (the flu) including:
- Differences between colds and flu in terms of symptoms and severity
- Types of influenza viruses (A, B, C) and their characteristics including ability to cause pandemics
- Structure and proteins (hemagglutinin and neuraminidase) of influenza viruses
- Seasonal flu, pandemic flu, avian flu, and potential complications of flu infection
- Methods of prevention including vaccination and hygiene practices
- Treatments including antiviral medications
HIV is a virus that attacks the human immune system. It belongs to a class of viruses called retroviruses that contain RNA rather than DNA. HIV infects and kills CD4+ T cells, weakening the immune system and allowing opportunistic infections. The virus is transmitted via blood, semen, vaginal fluids and breast milk. While there is no vaccine or cure, treatment with antiretroviral drugs can control the virus. Prevention focuses on avoiding contact with infected bodily fluids through safe sex practices and not sharing needles.
Opportunistic infections are infections that occur more frequently and are more severe in people with weakened immune systems such as those with HIV/AIDS. These infections include fungal, bacterial, viral, and parasitic infections that typically do not seriously affect those with healthy immune systems. Common opportunistic infections in HIV/AIDS patients include Pneumocystis pneumonia, tuberculosis, candidiasis, toxoplasmosis, cryptococcus, and cytomegalovirus. Antiretroviral therapy has significantly reduced the rates of opportunistic infections by suppressing HIV and allowing immune recovery. HIV/AIDS remains a major global public health challenge.
This document provides an overview of picornaviruses, with a focus on poliovirus. It begins by outlining the objectives of discussing picornavirus morphology, classification, pathogenesis, and the clinical manifestations, diagnosis, treatment and prevention of poliomyelitis and other diseases caused by echoviruses and rhinoviruses. It then provides details on picornavirus morphology, classification, the history of poliovirus research and discovery, epidemiology, characteristics, cultivation, pathogenesis, and clinical features of poliomyelitis. Key points covered include that poliovirus is an enterovirus that can cause paralysis, replication in the gastrointestinal tract and nervous system, and that infection may be asymptomatic, minor
This document provides information on HIV/AIDS, including its history, epidemiology, definition, characteristics, transmission, pathogenesis, clinical manifestations by system, opportunistic infections, diagnosis, and treatment. Some key points are:
- HIV was first identified in the 1980s and has since infected over 38 million people worldwide. India has the third largest epidemic with over 2 million cases.
- Advanced HIV is defined as CD4 count <350 or WHO stage 3/4 disease. AIDS is defined as CD4 <200 or WHO stage 4 disease.
- HIV is transmitted sexually, through blood/blood products, or mother-to-child. It primarily targets CD4 cells and causes immunosuppression.
- Clinical
This document summarizes key information about HIV and AIDS. It describes HIV as a lentivirus that causes AIDS by destroying CD4 cells and weakening the immune system. The virus is able to infect non-dividing cells. It originated in West-Central Africa and is transmitted through bodily fluids. While there is no cure for HIV/AIDS, antiretroviral treatment can suppress the virus and prevent the onset of AIDS, allowing those infected to live long lives. Early diagnosis and preventative measures like safe sex and clean needles are important to prevent transmission of HIV.
The document provides information on HIV/AIDS, including:
1. HIV was first identified in 1981 and there have been two major strains identified, HIV-1 and HIV-2.
2. HIV is transmitted through bodily fluids and can be transmitted sexually or through contact with infected blood.
3. There are three phases of HIV infection eventually resulting in AIDS if not treated. Antiretroviral treatment can suppress the virus and prevent AIDS.
- Influenza viruses are divided into types A, B, and C. Type A is further divided into subtypes based on the H and N surface proteins, with 16 H and 9 N combinations possible.
- Wild birds are the natural reservoir for all influenza A subtypes. Antigenic drift causes small changes in circulating strains over time, necessitating annual vaccine updates. Antigenic shift involves genetic reassortment between human and animal viruses and can cause pandemics.
- Seasonal influenza causes annual epidemics that typically infect 10-20% of the population. While most recover without treatment, influenza can cause severe illness or death in high-risk groups. Avian influenza viruses usually do not
Hepatitis C is a global problem caused by the hepatitis C virus (HCV). HCV is a blood-borne virus that infects approximately 200 million people worldwide. Laboratory testing plays an important role in diagnosing HCV, evaluating patients for treatment, monitoring patients during treatment, and following up after treatment. There are 6 major genotypes of HCV with genotypes 1 and 4 being more difficult to treat and less responsive to interferon-based therapy.
The document discusses the transmission of HIV/AIDS through various modes:
1) Sexual transmission is the most common mode, occurring through unprotected vaginal, anal and oral sex. Anal intercourse poses the highest risk while oral sex has a lower but present risk.
2) Transmission can also occur through blood, such as transfusions or sharing needles. Procedures involving piercing of skin like tattoos or circumcision can also transmit HIV.
3) Mother-to-child transmission is another mode, where the virus can be passed during pregnancy, delivery or through breastfeeding. The risk of transmission from an HIV-positive mother to her newborn ranges from 12-35%.
Viruses are infectious agents that can cause disease in humans, animals and plants. They range from those that cause minor illnesses like the common cold to more serious diseases like HIV/AIDS. Viruses insert their genetic material into host cells and use the cell's machinery to replicate. They are host specific and thought to have originated from host cell genetic material. While some viruses can be beneficial for controlling pests, viruses overall are responsible for a wide range of diseases through disrupting normal host functioning. Prevention through vaccines is crucial given viruses cannot be treated with antibiotics.
The document discusses the epidemiology of AIDS, including:
- HIV originated from chimpanzees in central Africa and spread to humans in the early 20th century.
- AIDS is caused by HIV which attacks CD4 cells and leads to immunosuppression. There are 3 stages - asymptomatic, AIDS-related complex, and AIDS.
- India's HIV epidemic varies by state with some northeastern states having over 1% prevalence while southern states are lower. HIV transmission is mainly through unprotected sex and sharing of needles.
HIV enters the host cell by binding to CD4 receptors and co-receptors on T-cells. It then fuses with and releases its RNA into the cell. The RNA is converted to DNA by reverse transcriptase and integrated into the host cell's DNA by integrase. The integrated DNA is then transcribed to produce new HIV proteins which assemble and bud from the host cell to infect others.
Smallpox is a highly contagious and often fatal viral disease caused by the variola virus. It was responsible for hundreds of millions of deaths in the 20th century before being eradicated. The disease originated in Africa and spread worldwide. Symptoms include fever, body aches and a distinctive pustular rash. Transmission occurs through respiratory droplets. Vaccination with the smallpox vaccine, developed by Edward Jenner in 1796, was critical to controlling and eventually eradicating the disease globally by 1980. While there is no treatment for smallpox, vaccination provided immunity and mass vaccination programs were important in its eradication.
This document summarizes information about the epidemiology of influenza. It describes the three types of influenza viruses (A, B, C) and their antigens. It discusses the major reservoirs, transmission, incubation period, clinical features, diagnosis, prevention including vaccines, antiviral drugs, treatment recommendations, and prophylaxis. Influenza spreads mainly via respiratory droplets from infected individuals and affects people of all ages. Prevention focuses on vaccination, antiviral drugs, and limiting transmission through isolation of infected individuals and hand hygiene.
This document provides information on the management of patients with AIDS. It defines AIDS and describes the history and spread of HIV/AIDS. It discusses the global prevalence of HIV/AIDS, the virus itself, modes of transmission, pathogenesis and clinical manifestations in the different stages of infection. It also covers diagnosis, opportunistic infections, treatment goals, antiretroviral therapy and the management of HIV/AIDS patients.
The document summarizes key information about HIV/AIDS, including:
1) HIV is a lentivirus that causes AIDS by progressively destroying the immune system, allowing other infections to thrive. Once infected, the body cannot rid itself of HIV.
2) Scientists believe HIV originated from chimpanzees in West Africa and was transmitted to humans through contact with their blood.
3) HIV is classified as a retrovirus and exists as two types, HIV-1 and HIV-2. HIV-1 is more widespread and virulent.
4) There is no cure for HIV, but treatment with antiretroviral drugs can control the virus and prevent transmission.
This document discusses several types of hepatitis viruses. It covers hepatitis A virus, hepatitis B virus, hepatitis C virus, hepatitis D virus, and hepatitis E virus. For each virus, it describes key aspects such as transmission, pathogenesis, clinical manifestations, diagnosis, and prevention. Hepatitis viruses can cause liver inflammation and damage, and some may lead to chronic infection or liver cancer if not addressed. Vaccines exist to prevent hepatitis A and B.
This document provides an overview of influenza (the flu) including:
- Differences between colds and flu in terms of symptoms and severity
- Types of influenza viruses (A, B, C) and their characteristics including ability to cause pandemics
- Structure and proteins (hemagglutinin and neuraminidase) of influenza viruses
- Seasonal flu, pandemic flu, avian flu, and potential complications of flu infection
- Methods of prevention including vaccination and hygiene practices
- Treatments including antiviral medications
HIV is a virus that attacks the human immune system. It belongs to a class of viruses called retroviruses that contain RNA rather than DNA. HIV infects and kills CD4+ T cells, weakening the immune system and allowing opportunistic infections. The virus is transmitted via blood, semen, vaginal fluids and breast milk. While there is no vaccine or cure, treatment with antiretroviral drugs can control the virus. Prevention focuses on avoiding contact with infected bodily fluids through safe sex practices and not sharing needles.
Opportunistic infections are infections that occur more frequently and are more severe in people with weakened immune systems such as those with HIV/AIDS. These infections include fungal, bacterial, viral, and parasitic infections that typically do not seriously affect those with healthy immune systems. Common opportunistic infections in HIV/AIDS patients include Pneumocystis pneumonia, tuberculosis, candidiasis, toxoplasmosis, cryptococcus, and cytomegalovirus. Antiretroviral therapy has significantly reduced the rates of opportunistic infections by suppressing HIV and allowing immune recovery. HIV/AIDS remains a major global public health challenge.
This document provides an overview of picornaviruses, with a focus on poliovirus. It begins by outlining the objectives of discussing picornavirus morphology, classification, pathogenesis, and the clinical manifestations, diagnosis, treatment and prevention of poliomyelitis and other diseases caused by echoviruses and rhinoviruses. It then provides details on picornavirus morphology, classification, the history of poliovirus research and discovery, epidemiology, characteristics, cultivation, pathogenesis, and clinical features of poliomyelitis. Key points covered include that poliovirus is an enterovirus that can cause paralysis, replication in the gastrointestinal tract and nervous system, and that infection may be asymptomatic, minor
This document provides information on HIV/AIDS, including its history, epidemiology, definition, characteristics, transmission, pathogenesis, clinical manifestations by system, opportunistic infections, diagnosis, and treatment. Some key points are:
- HIV was first identified in the 1980s and has since infected over 38 million people worldwide. India has the third largest epidemic with over 2 million cases.
- Advanced HIV is defined as CD4 count <350 or WHO stage 3/4 disease. AIDS is defined as CD4 <200 or WHO stage 4 disease.
- HIV is transmitted sexually, through blood/blood products, or mother-to-child. It primarily targets CD4 cells and causes immunosuppression.
- Clinical
This document summarizes key information about HIV and AIDS. It describes HIV as a lentivirus that causes AIDS by destroying CD4 cells and weakening the immune system. The virus is able to infect non-dividing cells. It originated in West-Central Africa and is transmitted through bodily fluids. While there is no cure for HIV/AIDS, antiretroviral treatment can suppress the virus and prevent the onset of AIDS, allowing those infected to live long lives. Early diagnosis and preventative measures like safe sex and clean needles are important to prevent transmission of HIV.
The document provides information on HIV/AIDS, including:
1. HIV was first identified in 1981 and there have been two major strains identified, HIV-1 and HIV-2.
2. HIV is transmitted through bodily fluids and can be transmitted sexually or through contact with infected blood.
3. There are three phases of HIV infection eventually resulting in AIDS if not treated. Antiretroviral treatment can suppress the virus and prevent AIDS.
- Influenza viruses are divided into types A, B, and C. Type A is further divided into subtypes based on the H and N surface proteins, with 16 H and 9 N combinations possible.
- Wild birds are the natural reservoir for all influenza A subtypes. Antigenic drift causes small changes in circulating strains over time, necessitating annual vaccine updates. Antigenic shift involves genetic reassortment between human and animal viruses and can cause pandemics.
- Seasonal influenza causes annual epidemics that typically infect 10-20% of the population. While most recover without treatment, influenza can cause severe illness or death in high-risk groups. Avian influenza viruses usually do not
Hepatitis C is a global problem caused by the hepatitis C virus (HCV). HCV is a blood-borne virus that infects approximately 200 million people worldwide. Laboratory testing plays an important role in diagnosing HCV, evaluating patients for treatment, monitoring patients during treatment, and following up after treatment. There are 6 major genotypes of HCV with genotypes 1 and 4 being more difficult to treat and less responsive to interferon-based therapy.
The document discusses the transmission of HIV/AIDS through various modes:
1) Sexual transmission is the most common mode, occurring through unprotected vaginal, anal and oral sex. Anal intercourse poses the highest risk while oral sex has a lower but present risk.
2) Transmission can also occur through blood, such as transfusions or sharing needles. Procedures involving piercing of skin like tattoos or circumcision can also transmit HIV.
3) Mother-to-child transmission is another mode, where the virus can be passed during pregnancy, delivery or through breastfeeding. The risk of transmission from an HIV-positive mother to her newborn ranges from 12-35%.
Viruses are infectious agents that can cause disease in humans, animals and plants. They range from those that cause minor illnesses like the common cold to more serious diseases like HIV/AIDS. Viruses insert their genetic material into host cells and use the cell's machinery to replicate. They are host specific and thought to have originated from host cell genetic material. While some viruses can be beneficial for controlling pests, viruses overall are responsible for a wide range of diseases through disrupting normal host functioning. Prevention through vaccines is crucial given viruses cannot be treated with antibiotics.
This document provides an overview of infectious diseases and the agents that cause them. It discusses the historical perspective of major infectious diseases like smallpox, plague, and influenza. It describes Robert Koch's pioneering work in the late 19th century that established the germ theory of disease and his criteria (known as Koch's postulates) for identifying disease-causing agents. The document then covers viruses, bacteria, fungi, protozoa, helminths, prions, and ectoparasites as causes of infectious disease, describing their characteristics, life cycles, modes of transmission, and examples of diseases they cause.
The document discusses three major diseases prevalent in Africa: Ebola, HIV, and malaria. Ebola is spread through contact with bodily fluids and causes hemorrhagic fever. HIV is transmitted through bodily fluids and progressively destroys immune cells. Malaria is transmitted through mosquito bites and causes fever, nausea, and fatigue. While there are no approved vaccines for Ebola, experimental treatments are being tested.
Orthomyxovirus is a family of negative-sense RNA viruses that includes influenza viruses A, B, C, and D. It has seven genera that infect various hosts like humans, birds, pigs, cattle, and fish. The virus particle is pleomorphic with surface projections and a segmented negative-sense RNA genome. The replication cycle involves binding to host cells, releasing RNA into the cytoplasm, forming new viral proteins and RNA, and releasing progeny virus to infect other cells. Influenza A is the most virulent type in humans and causes pandemics through antigenic drift and shift. Vaccines and antiviral drugs are used for prophylaxis but escape mutants can evolve.
This document provides information about HIV/AIDS, including:
- HIV causes AIDS by breaking down the immune system. AIDS is the most advanced stage of HIV disease.
- Scientists believe HIV originated from chimpanzees in Western Africa and jumped to humans through contact with infected animals.
- The earliest known case of HIV in humans was in 1959 in the Congo. The epidemic then spread among high-risk groups and an estimated 5% of gay men in New York and San Francisco had HIV by 1978.
- AIDS was first observed clinically in 1981 in the US in drug users and gay men with rare infections. Soon the CDC formed a task force to monitor the outbreak.
Viruses are very small infectious agents that can only replicate inside host cells. They contain genetic material (DNA or RNA) surrounded by a protein coat. There are many types of viral infections that affect different body systems like the respiratory, gastrointestinal, liver, nervous and skin. Respiratory viruses commonly cause infections like influenza and COVID-19. Some viruses are also associated with certain cancers through their ability to insert their genetic material into host cells. Proper hygiene practices, vaccination and antiviral treatment can help prevent and treat viral infections.
HIV stands for Human Immunodeficiency Virus and can be transmitted through sexual contact, blood transmission, or from mother to child. There are two types of HIV, HIV-1 being more prevalent. HIV progresses to AIDS by weakening the immune system over time. Prevention of mother-to-child transmission (PMTCT) aims to prevent HIV transmission from mother to child during pregnancy, birth, or breastfeeding through testing, treatment, and replacement feeding. Antiretroviral therapy can suppress HIV and slow disease progression.
This document provides an overview of HIV/AIDS, including its types, epidemiology, structure and life cycle, transmission, diagnosis, stages of infection, and treatment. It describes how HIV infects and destroys CD4 cells, progressively weakening the immune system until opportunistic infections define AIDS. Laboratory tests for diagnosis include antibody and viral detection assays, with CD4 counts and viral load used to monitor disease progression and response to antiretroviral therapy.
human papilloma Virus ,measles,HIV and hepatitis virusesIkram Ullah
Human Papillomavirus, Measles, HIV and Hepatitis Viruses
The document summarizes several viruses including HPV, measles, HIV, and hepatitis viruses. It describes the structure, transmission, pathogenesis, diagnosis, and prevention of each virus. HPV is a common sexually transmitted infection that can cause genital warts and cancers. Measles is a highly contagious airborne virus prevented by vaccination. HIV weakens the immune system over time if untreated. The hepatitis viruses are transmitted through blood or fecal-oral routes and can cause acute or chronic liver disease.
human papilloma Virus ,measles,HIV and hepatitis virusesIkram Ullah
Human Papillomavirus, Measles, HIV and Hepatitis Viruses
The document summarizes several viruses including HPV, measles, HIV, and hepatitis viruses. It describes the structure, transmission, pathogenesis, diagnosis, and prevention of each virus. HPV is a common sexually transmitted infection that can cause genital warts and cancers. Measles is a highly contagious airborne virus prevented by the MMR vaccine. HIV attacks CD4 cells and leads to AIDS if untreated. The hepatitis viruses are transmitted through blood or feces and can cause acute or chronic liver disease or liver cancer. Vaccines and hygiene practices can prevent transmission of these viruses.
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Наука, изучающая закономерности возникновения и распространения заболеваний различной этиологии среди населения с целью разработки профилактических мероприятий, называется эпидемиологией.
Эпидемический процесс имеет разное проявление:
- спорадическая заболеваемость – это низкий уровень заболеваемости данной инфекцией на данной территории в данный период (сезон) времени (единичные случаи заболеваний или групповые вспышки, не связанные между собой);
- эпидемия – это такой уровень заболеваемости данной инфекцией на данной территории в конкретный отрезок времени, который в несколько раз превышает уровень спорадической заболеваемости, прогрессирует по времени и имеет тенд
This document provides information on arthropod-borne viral diseases. It defines arboviruses as viruses transmitted between vertebrate hosts by blood-feeding arthropods like mosquitoes and ticks. The document discusses the classification, properties, transmission cycles involving vectors and reservoir hosts, pathogenesis and examples of important arboviruses including alphaviruses like Chikungunya virus, flaviviruses like Dengue virus, and bunyaviruses. It summarizes the clinical manifestations and treatment approaches for major arboviral diseases.
A disease is a particular abnormal condition, a disorder of a structure or function, that affects part or all of an organism. The study of disease is called pathology which includes the causal study of etiology. Disease is often construed as a medical condition associated with specific symptoms and signs.[1] It may be caused by external factors such as pathogens, or it may be caused by internal dysfunctions particularly of the immune system such as an immunodeficiency, or a hypersensitivity including allergies and autoimmunity.
The document discusses various common infectious diseases affecting humans including their causes, symptoms, treatment and prevention. It covers bacterial diseases like typhoid and pneumonia, viral diseases like common cold, fungal disease ringworm, parasitic diseases like malaria, amoebiasis, ascariasis and elephantiasis. It also discusses immune system, AIDS, cancer, commonly abused drugs and alcohol and their prevention. Overall, the document provides a comprehensive overview of major infectious diseases, their transmission, affected age groups and approach towards prevention and treatment.
Vector-borne diseases are infections transmitted by arthropods like mosquitoes and ticks. They account for over 17% of infectious diseases worldwide and cause 700,000 deaths annually. Malaria is a major vector-borne disease caused by Plasmodium parasites and transmitted via Anopheles mosquitoes. In 2021, there were an estimated 247 million malaria cases and 619,000 deaths. Dengue is another significant vector-borne disease spread by Aedes mosquitoes. The global incidence of dengue has increased dramatically, with an estimated 100-400 million infections annually. Japanese encephalitis, transmitted by Culex mosquitoes, is a leading cause of viral encephalitis in Asia, with an estimated 68,000 cases
Monoclonal antibodies are produced by clones of single B cells that are directed against a single antigen or epitope. Polyclonal antibodies represent a mixture produced by various B cell clones, recognizing multiple epitopes. The hybridoma technology developed by Milstein and Kohler in 1975 involves fusing antibody-producing B cells with myeloma cells to form immortal hybridomas. This allows for the mass production of monoclonal antibodies through selection in HAT medium, where hybridomas survive due to inheriting genes from both parent cells. Monoclonal antibodies have various applications including disease diagnosis, antigen purification, and studying the immune system.
There are 5 major antibody isotypes - IgM, IgD, IgG, IgE, and IgA - which differ based on their heavy chain. The heavy chain determines the isotype and can be mu, delta, gamma, epsilon, or alpha. Light chains can be either kappa or lambda with any isotype. IgG is the most abundant in humans while IgE is the least. Isotypes are located in the constant region of the heavy and light chains. Allotypes are specified by allelic forms of immunoglobulin genes and are also in the constant regions. Idiotypes are unique epitopes located in the variable regions of individual antibody molecules.
Stem cells in the bone marrow can develop into three lineages - lymphoid, myeloid, and erythroid. The lymphoid lineage develops into T lymphocytes and B lymphocytes, which mediate cell-mediated and humoral immunity, respectively. B lymphocytes mature in the bone marrow or bursa of fabricius and express antibodies on their surface. When activated, they differentiate into memory B cells or plasma cells. T lymphocytes mature in the thymus and include helper T cells, suppressor T cells, cytotoxic T cells, and delayed type hypersensitivity T cells. The myeloid lineage develops into monocytes, granulocytes like neutrophils, eosinophils and basophils, mast cells,
ELISA is an immunological technique used to quantitatively determine the concentration of antigens or antibodies. It was first introduced in 1971 and is similar to radioimmunoassay but uses an enzyme-linked antibody rather than a radioactive label. There are several types of ELISA including indirect ELISA, which detects antibodies; direct/sandwich ELISA, which detects antigens using two antibodies; and competitive ELISA, which measures antigen concentration by detecting free antibody binding. ELISA has many applications such as detecting antigens or antibodies in samples, determining antibody levels, and tracking disease spread.
Antibody affinity is a measure of the strength of interaction between an antibody's antigen binding site and its target epitope. It is quantified by the affinity constant Ka, with higher values indicating tighter binding. A high affinity antibody binds its antigen more strongly and for longer than a low affinity antibody. Antibody avidity takes into account not just affinity but also the multivalency of antibodies and antigens, which allows for multiple binding interactions that further strengthen complex formation. High avidity can compensate for low individual binding affinities through cooperative multivalent binding effects.
Hypersensitivity, also known as allergies, occurs when the immune system overreacts to substances that are normally harmless. There are four main types of hypersensitivity reactions: immediate hypersensitivity (Type I) involves IgE antibodies and mast cells/basophils; antibody-dependent cytotoxic hypersensitivity (Type II) occurs when antibodies bind to antigens on cell surfaces; immune complex-mediated hypersensitivity (Type III) involves soluble antigen-antibody complexes activating the complement system; and cell-mediated hypersensitivity (Type IV) is a delayed reaction mediated by T cells. Common examples include allergic reactions, transfusion reactions, and contact dermatitis.
The document discusses vitamins, which are organic compounds required in small amounts for growth and health. Vitamins are classified as either fat-soluble (A, D, E, K) or water-soluble (C, B vitamins). Fat-soluble vitamins can be stored in the body, while water-soluble vitamins cannot be stored and must be continuously replenished. Each vitamin is then described in more detail, including its chemistry, sources, requirements, functions, deficiency and toxicity symptoms. The document provides an overview of the major vitamins and their roles and properties.
The document discusses the cell cycle and its key stages and processes. It notes that the cell cycle consists of interphase, where the cell grows and DNA replicates, and the M phase where the cell divides. Interphase contains the G1, S, and G2 phases where the cell prepares for division. The M phase contains mitosis, where the nucleus and cytoplasm divide. Mitosis further consists of prophase, prometaphase, metaphase, anaphase and telophase stages. Meiosis is also discussed, which reduces the chromosome number in germ cells and involves two cell divisions.
The document discusses the basics of lasers. It explains that lasers work via the process of stimulated emission, where photons stimulate excited electrons to emit additional photons of the same frequency and direction. This leads to coherent, highly directional light that is monochromatic and has high intensity and brightness. The key aspects that enable lasers are population inversion, where more atoms are in excited states than ground states, and stimulated emission, where incident photons cause excited electrons to emit additional photons coherently.
- Metals make up about 91 of the 118 known elements. Non-metals include gases, liquids, and solids like carbon and phosphorus. Metalloids have properties between metals and non-metals.
- Metals are characterized by properties like lustre, high melting points, conductivity of heat and electricity, malleability, and ductility. They form metallic bonds and crystalline structures.
- Theories like free electron theory and molecular orbital theory explain metallic bonding and properties. Free electron theory describes delocalized electrons within metallic bonds. Molecular orbital theory describes overlapping atomic orbitals that form energy bands in metals.
Spectroscopy is the study of the interaction between electromagnetic radiation and matter. A spectrometer is used to measure the presence of compounds in a molecule by analyzing the spectrum produced when matter interacts with different wavelengths of light. Absorption spectroscopy involves matter absorbing radiation and undergoing an electronic transition to a higher energy state. UV/visible spectroscopy uses this technique to study electronic transitions in atoms and molecules in the ultraviolet and visible light ranges.
CELL CYCLE , MITOSIS ,MEIOSIS AND CELL REGULATIONLIFE SCIENCES
The document discusses the cell cycle and its regulation. It describes the main phases of the cell cycle including interphase with G1, S, and G2 phases, and mitosis. It also covers meiosis and the key differences between mitosis and meiosis. Cell cycle checkpoints are mentioned which allow the cell cycle to be halted at certain points if conditions are not favorable for progression.
MITOCHONDRIA ,STRUCTURE ,Mt DNA ,PROTEIN TRANSPORT,ETC,OXIDATIVE PHOSPHORYLATIONLIFE SCIENCES
introduction, structure , functions,how proteins are transported into mitochondria,functions,electron transport chain,oxidative phosphorylation with animated videos
The normal flora are microorganisms that commonly live on and inside the healthy human body in different areas without causing issues. They can be divided into transient microbes that vary over time and resident microbes that persist. The types of microbes vary by body site, such as Staphylococcus and Streptococcus on the skin, Streptococcus and anaerobes in the mouth, and a diverse array of bacteria including E. coli in the large intestine. The composition of the normal flora is influenced by factors like age, hygiene, and diet.
The immune system consists of primary and secondary lymphoid organs that work together. Primary lymphoid organs include the thymus, bone marrow, and bursa of fabricus, where immune cells mature and develop. Secondary lymphoid organs, such as lymph nodes and the spleen, expose mature immune cells to antigens in circulation and further activate the immune response. The thymus educates T cells, while the bone marrow produces B cells and other immune cells through hematopoiesis. Lymph nodes and the spleen then filter antigens from lymph and blood to activate mature B and T cells.
Antibiotics are substances that kill or inhibit the growth of bacteria. They have no effect on viruses. Penicillin was the first widely used antibiotic, discovered accidentally in 1928 by Alexander Fleming. It was isolated in 1941 and used to successfully treat infections. Penicillin works by inhibiting the enzyme transpeptidase, disrupting the formation of peptidoglycan in bacterial cell walls. This prevents cell wall synthesis in growing bacteria, making them "burst" and die. Penicillin's discovery revolutionized medicine and treatment of bacterial infections.
A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
How to Add Chatter in the odoo 17 ERP ModuleCeline George
In Odoo, the chatter is like a chat tool that helps you work together on records. You can leave notes and track things, making it easier to talk with your team and partners. Inside chatter, all communication history, activity, and changes will be displayed.
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
Executive Directors Chat Leveraging AI for Diversity, Equity, and InclusionTechSoup
Let’s explore the intersection of technology and equity in the final session of our DEI series. Discover how AI tools, like ChatGPT, can be used to support and enhance your nonprofit's DEI initiatives. Participants will gain insights into practical AI applications and get tips for leveraging technology to advance their DEI goals.
This presentation was provided by Steph Pollock of The American Psychological Association’s Journals Program, and Damita Snow, of The American Society of Civil Engineers (ASCE), for the initial session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session One: 'Setting Expectations: a DEIA Primer,' was held June 6, 2024.
Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
By Dr. Vinod Kumar Kanvaria
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
2. CONTENTS…
• Retroviruses
• Terminology and definitions
• History
• Morphology
• Signs and symptoms
• Epidemiology
• Pathogenesis
• Treatment
• Prevention
3. RETROVIRUSES
• These are RNA viruses that belong to family retroviridae
• Members of this family possess reverse transcriptase(RNA
directed DNA polymerase) enzyme which prepares a DNA copy of
the RNA genome in the host cell
• discovered independently in 1971 by American virologists Howard
Temin and David Baltimore
• The presence of enzyme reverse transcriptase is a characteristic
feature
5. • Infection: infection is the entry and development or multiplication of an infectious
agent in the body of man or animals.
• Contamination : The presence of an infectious agent on a body surface
• Infestation: is the state of being invaded or overrun by pests or parasites. It can
also refer to the actual organisms living on or within a host.
• Host : A person or an animal that affords subsistence or lodgement to an infectious
agent under natural conditions.
• Contagious disease :A contagious disease is the one that is transmitted through
contact.
• Epidemic: An epidemic is the rapid spread of infectious disease to a large number
of people in a given population within a short period of time, usually two weeks or
less.
6. • Endemic: It refers to the constant presence of a disease or infectious agent within
a given geographic area or population group.
• Pandemic: A pandemic is an epidemic of infectious disease that has spread
across a large region; for instance multiple continents, or even worldwide
• Sporadic: occasional cases occuring in regular intervals
• Zoonosis : is an infection that is transmissible under natural conditions from
vertebrate animals to man
• Epizootic: is an outbreak (epidemic) of disease in an animal population, e.g. Rift
valley fever, Anthrax.
• Enzootic: is an endemic occurring in animals, e.g. Bovine TB.
7. • Exotic: diseases are those which are imported into a country in which they do
not otherwise occur, as for e.g., rabies in the UK, Yellow fever in India,
• Nosocomial infections : (hospital acquired) is an infection originating in a patient
while in a hospital or another health care facility.
• Opportunistic infection : This is infection by organisms that take the opportunity
provided by a defect in host defense (e.g. immunity) to infect the host and thus
cause disease
• Pathogenesis: The development of a disease and the chain of events leading to
that disease.
• Epidemiology : is the study and analysis of the distribution and determinants of
health and disease conditions in defined populations
9. The link between HIV and SIV?
Did HIV come from monkeys?
How did HIV cross from chimps to humans?
How did HIV-2 get passed to humans?
When and where did HIV start in humans?
Did HIV start in Africa?
How did HIV spread from Kinshasa?
What happened in the 1980s in the USA?
What is HIV?
Where did AIDS come from?
10. • HIV is a type of lentivirus, which means it attacks the immune system.
• In a similar way, the Simian Immunodeficiency Virus (SIV) attacks the immune systems of
monkeys and apes.
• Research found that HIV is related to SIV and there are many similarities between the two
viruses.
• HIV-1 is closely related to a strain of SIV found in chimpanzees, and HIV-2 is closely related to a
strain of SIV found in sooty mangabeys.
• They discovered that the chimps had hunted and eaten two smaller species of monkeys (red-
capped mangabeys and greater spot-nosed monkeys).
• These smaller monkeys infected the chimps with two different strains of SIV.
• The two different SIV strains then joined together to form a third virus (SIVcpz) that could be
passed on to other chimps. This is the strain that can also infect humans.
11. • The most commonly accepted theory is that of the 'hunter'.
• SIVcpz was transferred to humans as a result of chimps being killed and eaten,
or their blood getting into cuts or wounds on people in the course of hunting.
• There are four main groups of HIV strains (M, N, O and P), each with a slightly
different genetic make-up.
• HIV-2 comes from SIVsmm in sooty mangabey monkeys rather than
chimpanzees.
• The crossover to humans is believed to have happened in a similar way
(consumption of monkey meat).
• It is far rarer, and less infectious than HIV-1.
13. • . The first verified case of HIV is from a blood sample taken in 1959 from a man
living in what is now Kinshasa in the Democratic Republic of Congo. The
sample was retrospectively analysed and HIV detected.
• the first transmission of SIV to HIV in humans took place around 1920 in
Kinshasa in the Democratic Republic of Congo
• In 1981, a few cases of rare diseases were being reported among gay men in
New York and California, such as Kaposi's Sarcoma (a rare cancer) and a
lung infection called PCP.
14. • At first the disease was called all sorts of names relating to the word 'gay'.
• scientists realised the 'disease' was also spreading among other populations such as
haemophiliacs and heroin users.
• By September that year, the 'disease' was finally named AIDS.
• It was only in 1983 Luc Montagnier and colleagues from the pasteur institive paris isolated a
retrovirus from a west african patient with persistent generalised lymphadenopathy which is a
manigestatin of AIDS and called it lymphadenopathy associated virus (LAV)
• In 1984 Robert gallo and colleagues from the national institutes of health reported the isolation
of a retrovirus from AIDS patients and called it human T cell lymphotropic virus III
• International committee on virus nomenclature in 1986 decided on the generic name human
immunodeficiency virus for those viruses
15. CLASSIFICATION
• Family : Retroviridae
• Subfamily : Orthoretrovirinae
• Genus : Lentivirus
• Species : HIV 1 / HIV 2
• HIV 1- Isolated in America, Europe & central Africa
• HIV 2- In West Africa – Less virulent and not spread as widely and
rapidly as HIV 1
16. MORPHOLOGY
• It is roughly spherical
• diameter of about 120nm around 60times smaller than a red blood cell
• envelop enclosing two copies of positive single stranded RNA (Held
together by protein P7) enclosed by a conical capsid composed of viral
protein P24
• It is enclosed by a conical capsid composed of 2,000 copies of the viral
protein p24
• The RNA genome consists of 9 genes - Three of these genes: gag, pol, and
env, contain information needed to make the structural proteins for new virus
particles.
•
17. • Inside of capsid are three enzymes required for HIV replication: reverse
transcriptase, integrase and protease
• A matrix composed of the viral protein p17 surrounds the capsid ensuring
the integrity of the virion particle.
• This is, in turn, surrounded by the viral envelope, that is composed of
the lipid bilayer that contains a number of glycoproteins such as gp41
and gp120 these proteins bind to cell surface receptors during
infection.
18. RESISTANCE
• HIV doesn't survive well outside the body
• Temperature :
• HIV is thermo labile , being inactivated at 56C in 30 minutes and in
seconds at 100C.
• At room temperature it may survive up to seven days
• Disinfectants:
• It is inactivated in 10 minutes by treatment with 35% isopropyl alcohol,
70% ethanol, 0.5% sodium hypochlorite and 3% hydrogen peroxide.
19.
20. RESISTANCE
• For treatment of contaminated medical instruments a 2% glutaraldehyde
solution is useful
• Detergents:
• because of presence of lipid membrane therefore washing with
detergents is adequat for decontaminating clothes and household
utensils
• Lyophilisation:
• The virus withstand lyophilisation
21. RESISTANCE
• In dried blood it may survive for up to seven days
• At autopsy or necropsy , HIV has been isolated from various tissues
up to 16 days after dealth
22. MODES OF TRANSMISSION
• There are three modes of transmission:
• 1.sexual contact:
• Occurs among homosexual as well as heterosexual individuals
• HIV has been isolated from semen, vaginal and cervical secretions and breast
milk which are important vehicles of transmission
• Risk is also greatly enhanced if the sexual partners are more than one
• Parenteral transmission:
• Receiving infected blood transfusions, blood products
• Sharing contaminated syringes and needles
23. MODES OF TRANSMISSION
• Donated organs, tissue
• Perinatal transmission:
• Transmitted form an infected mother to her child either transplacentally
or perinatally
• During birth, infection may also develop from the genital secretions and
from mother milk after birth
27. EPIDEMIOLOGY
• Due to its large population size, India has the third largest HIV epidemic
in the world.
• Overall, India’s HIV epidemic is slowing down, with a 32% decline in new HIV
infections (80,000 in 2016), and a 54% decline in AIDS-related deaths
between 2007 and 2015.
• The three states with the highest HIV prevalence (Manipur, Mizoram,
Nagaland)
• 2.2% of female sex workers in India were living with HIV,
• 4.3% of men who have sex with men in India are living with HIV
28. EPIDEMOLOGY
• NACO estimates HIV prevalence among hijras to be 7.2%
• The number of people who inject drugs living with HIV in India is rising.
• 2.59% of the two million truckers in India are living with HIV.
• 40.5% of total HIV infections are among females.
29. PATHOGENEIS
• After entry into blood stream, HIV infect CD4 immune cells chiefly T helper lymphocytes. Other
cells like B-lymphocytes, monocytes, dendritic cells are also infected
• Glycoprotein GP120 present on surface has affinity for CD4 molecules present on surface of
immune cells.
• Co- receptor such as CXCR4 present on lymphocyte & CCR5 present on monocytes are also
needed for binding
• After fusion, HIV genome is uncouted and internalised into the cell
30. • Its genomic RNA is released in to cytoplasm & converted in to viral DNA (provirus) by
reverse transcriptase
• The viral DNA is integrated into host cells DNA by an enzyme integrase causing a latent
infection & captures the genetic machinery of host cells.
• This leads to rapid production of viral genome, which attains the shape of full virus with the
help of protease enzyme
• The new copies of HIV can now move on to infect other cells
31.
32.
33. IMMUNOLOGICAL ABNORMALITIES IN
HIV INFECTION
• Lymphopenia
• Selective T cell deficiency : reduction in number of T4 cells
• Hypergammaglobulinemia –predominantly IgG and IgA , IgM in children
• Decreased in vitro lymphocyte proliferative response to antigens
• Decreased cytotoxic response by T cells and NK cells
• Decreased antibody response to new antigens
• Altered monocyte/macrophage function
• Elevated levels of immune complexed in serum
34. In an infected person, HIV can be isolated from
blood, lymphocytes, cell-free plasma, cervical
secretions, semen, saliva, urine, tears and breast
milk
35. CLINICAL FEATURES
• Many people with HIV do not know they are infected. The clinical course of HIV
infection can present as follows:
• 1.Acute HIV infection:
• Withing 3-6 weeks of infection with HIV about 50% of persons experiene low
grade fever, malaise, headache,lymphadenopathy, rashes, swollen lymph
nodes, weight loss, fatigue, sweating, ulcers in the mouth, sour throat.
• HIV antibodies are usually negative at the onset of illness but become positive
during its course
• Hence this syndrome has been called sero conversion illness
36. ASYMPTOMATIC OR LATENT INFECTION
• After acute infection, the virus appears to become dormant, and the person feels
normal.
• This stage of HIV infection may last an average of eight to 10 years,
• During the latent period, the virus continues to multiply actively. It infects and kills
critical infection fighting cells, a type of white blood cell called CD4 cells or T
helper cells (T cells).
• Even though the person has no symptoms, he or she is contagious and can pass
HIV to others
• . At the end of this phase, the HIV viral load starts to rise, and the CD4 cell count
begins to drop.
38. AIDS-RELATED COMPLEX(ARS)
• When CD4+ T lymphocyte count falls below 400 per mm3, the patient may
develop symptoms
• live fever
• diarrhoea
• weight loss
• night sweats
• opportunistic infections like oral candidiasis, herpes zoster, hairy cell
leucoplakia, salmonellosis or tuberculosis
• ARC patients are usually severely ill and may of them progress to AIDS in a
few months
39. AIDS
• When CD4+ cells fall below 200 per mm3 the titre of viruses
increases markedly and there is irreversible breakdown of
immune defence mechanisms
• Most of the patients with HIV disease die of infections other
than HIV eg: opportunistic infections and malignancies
• AIDS is the end stage of HIV infection
40. OPPORTUNISTIC INFECTIONS AND
MALIGNANCIES TYPICALLY ASSOCIATED WITH
HIV INFECTION
• Parasites:
• Toxoplasmosis (fever, muscle pain)
• Cryptosporidiosis ( diarrheal disease)
• Isosporiasis ( intestinal disease)
• Mycotic:
• Pneumocystis jirovecii (pneumonia)
• Candidiasis
• Cryptococcosis (tumours in lungs)
• Aspergillosis
• Histoplasmosis (lungs)
41. OPPORTUNISTIC INFECTIONS AND
MALIGNANCIES TYPICALLY ASSOCIATED WITH
HIV INFECTION
• Bacteria:
• Tuberculosis
• Salmonellosis
• Legionellosis (penumonia)
• Malignancies:
• Kaposi sarcoma (cancer)
• Lymphomas(blood cancer)
42. AIDS
• A = not inherited
• I = immune system
• D = deficiency – inability to protect against illness
• S = syndrome, a group of symptoms or illnesses that occur as
a result of HIV infection
43. AIDS
• AIDS is not a virus but a set
of symptoms (or syndrome) caused by
the HIV virus.
• A person is said to have AIDS when their
immune system is too weak to fight off
infection,
• This is the last stage of HIV, when the
infection is very advanced, and if left
untreated will lead to death.
44. LABORATORY DIAGNOSIS
• specific tests for HIV infections
• 1.antigen detection : p24 antigen
• 2.virus isolation
• 3.detection of viral nucelic acid
• 4.antibody detection
• Non specific tests:
• 1.total and differential leucocyte
count
• 2.T lymphocyte subset assays
• 3. platelet count
• 4.IgG and IgA levels
• 5.skin tests for CMI(tuberculin test)
• Tests for opportunistic infections and
tumour
45. LABORATORY TESTS FOR DETECTION OF
SPECIFIC ANTIBODIES IN HIV INFECTION
• Screening tests:
1.ELISA
• 2.rapid tests
A. dot blot assay
B. lateral flow
assay(immunochromatography)
C. particle agglutination
D. HIV spot and comb tests
• 2.supplemental test
a. western blot test
B. indirect immunofluorescence
test
C. radio immuno precipitation
assay
46.
47. NON SPECIFIC TESTS
• Total and differential leucocyte count:
• In AIDS there is leucopenia with a lymphocyte count less than 200 per mm3
• T lymphocyte subset assays:
• The normal CD4 : CD8 T cell ratio of 2:1 is reversed to 0.5: 1 in cases of AIDS
• Platelet count:
• There is thrombocytopenia in patients of AIDS
• IgG and IgA levels:
• Both levels are raised in blood
48.
49. PREVENTION
• Health education
• Indiscriminate sex
• Use of condoms
• Avoid sharing razors, needles and tooth brushes
• Comprehensive sex education programmers in school.
• Public awareness campaigns for HIV.
50. • All mass media channels should be involved in educatingt he people on AIDS,
its nature of transmission & prevention.
• Prevention of blood borne HIV transmission
• People with high risk should not donate blood,body organs, sperm or other
tissues.
• All blood should be screened before transfusion
• Strict sterilization practice in hospitals and clinics
• Disposable needles and syringes should be used.
• Universal precautions by health care workers.
51. PROPHYLAXIS
• No effective vaccine has yet been found out
• High rate of mutation, diverse antigenic types and subtypes, long latency
and persistence in infected cells as provirus posses serious problems in
the development of vaccine
• Several stratgies have been explored for vaccine preparation
• 1.modified whole virus
• 2.subunits based on envelope glycoproteins
• 3.target cell protection by anti CD4 antibody
52. ANTIRETROVIRAL THERAPY
• It will not cure the disease but can prolong the life of severely ill patients
• Antiretroviral drugs include both nucleoside and non nucleoside inhibitors
of enzyme revere transcriptase, viral protease inhibitors, fusion
inhibitors,integrase inhibitor and entry inhibitor
53.
54.
55. POSTEXPOSURE PROPHYLAXIS(PEP)
• It refers to anti retroviral drug therapy with in hrs. Following accidental exposure to
virus.
• Following needle stick injury, the part should be thoroughly washed with soap&
water. The injured finger should not be reflex to put in the mouth.
• Open wounds should be irrigated with saline.
• Following treatment is recommended by the US center for disease control and
prevention for health care workers accidentally exposed to HIV: -• zidovudine(
200mg three times daily) +Lamivudine (150 mg twice daily) for4 weeks
56. POSTEXPOSURE PROPHYLAXIS(PEP)
• If “ source individual have advance aids : Nelfinavir(750 mg 3 times
daily)+zidovudine +lamivudine
• if “ source” individual failed on zidovudine +lamivudine therapy then
stavudine +didanosine
57. PREVENTION OF INFECTION TO BABY BY
HIV POSITIVE MOTHER
• -a) zidovudine( 300mg three times daily) –to pregnant mothers from 10-
12th week of pregnancy or immediately after diagnosis.
• b) During labour- zidovudine
• c) New born -Syrup zidovudine( three times daily for 6 weeks)
• d) Single dose of Neverpin (200 mg) at the time of labour.
58.
59.
60. “Prevention is better than cure
Especially when something has
NO CURE “
Stop HIV/ AIDS
THANK YOU