Identification of virus Prepared by: Putri Shareen Binti Rosman
Types of viral infectionAcute infections -relatively short duration with rapid discovery. Most viruses that infect humans, such as those that cause routine respiratory infections (e.g., cold viruses, influenza viruses) and gastrointestinal infections (e.g., Rotaviruses, Noroviruses),skin infection(e.g.,Varicella zoster virus) cause acute infections.
Types of viral infectionsPersistent infections - Viruses continually present in the body. - Late complications following acute infections. Also known as latent infection. Eg:HSV-1(fever blister),HSV-2(genital herpes). Chronic infection - the virus can be demonstrated in the body at all times and the disease may be present or absent for an extended period of time. - Eg: hepatitis B (caused by HBV) and hepatitis C (caused by HCV).
Slow infections - are ones in which the infectious agents gradually increase in number over a very long period of time during which no significant symptoms are seen. - Eg: include AIDS (caused by HIV-1 and HIV-2) and certain lentiviruses that cause tumors in animals.
Portals of entry and exit of virusesVirus can enter into our body at many different sites and these are called portals of entry.Respiratory TractGenitourinary TractGastrointestinal TractSkin/Mucous MembraneTransplacental (mother to fetus)Blood
Modes of TransmissionThe mechanism for transfer of an infectious agent from a reservoir to a susceptible host. Dr.M.ElBashaar
Means of Transmission Five Main RoutesDropletAirborneCommon Vehicle (Food, blood)Vector-borneContact Direct Contact Indirect Contact (Objects) Dr.M.ElBashaar
Sources and modes of transmission of infection1. Person-to-Person Spread Skin-to-skin contact, clothes, (viral as HSV1) Droplets during coughing, sneezing (common cold, flu, swine flu, smallpox,measles,SARS) Stool-to-mouth (fecal-oral) spread, usually via dirty hands or utensils (hepatitis A,poliomyelitis) Dr.M.ElBashaar
Sources and modes of transmission of infectionSexually transmitted (gonorrhea, genital HSV2, genital warts (human papillomavirus – HPV).Blood-to-blood contact by: contaminated needles, usually by drug addicts or health workers (hepatitis B, C, AIDS) blood transfusion (hepatitis B,C, AIDS, viral hemorrhagic fevers) Vectors: rabies anthropod:mosquitoes (Malaria, Dengue,Yellow fever) Dr.M.ElBashaar
Sources and modes of transmission of infectionSpread from mother to fetus during pregnancy (hepatitis B, C, HIV, HSV-1, HSV-2, rubella, varicella, bird flu).Food poisoning is an infection of the gastrointestinal tract caused by microbes from contaminated food:Eg: Enterovirus Dr.M.ElBashaar
Viral DiseasesDiseases caused by viruses has been known for thousand years ago.Antibiotics are not effective in killing virusesCertain viruses are also linked to cancer in human such as Hepatitis B (liver cancer),Epstein-Barr virus (Burkitt’s Lymphoma) and Human Papilomavirus (cervical cancer).
Important viral diseasesAIDS:Immune system failureCommon cold:Sinus congestionEbola:High fever,uncontrolled bleedingHepatitis A:Flu like symptom,swollen liverHepatitis B:Flu-like symptom,swollen liver.Influenza (flu):Fever,chills,sneezing,body aches.Mumps:Painful swelling of saliva glandsPolio:Fever,headachenstiff neck,paralysisRabies: Mental depression,madness,paralysis
Assignment 1Per group have 4-5 per group = 16 groupsPresentation after CNY holidayEach group have 5 minutes for presentationRepresent 5% marks for assessmentExplain the genome content, viral morphology, modes of transmission, infection in human,treatment. MIC208 - VIROLOGY 18