Bunyavirus, any virus belonging to the family Bunyaviridae. Bunyaviridae is a family of arthropod-borne or rodent-borne, spherical, enveloped RNA viruses. Bunyaviruses are responsible for a number of febrile diseases in humans and other vertebrates. They have either a rodent host or an arthropod vector and a vertebrate host.
Bunyavirus, any virus belonging to the family Bunyaviridae. Bunyaviridae is a family of arthropod-borne or rodent-borne, spherical, enveloped RNA viruses. Bunyaviruses are responsible for a number of febrile diseases in humans and other vertebrates. They have either a rodent host or an arthropod vector and a vertebrate host.
The Paramyxoviridae is a family of single-stranded RNA viruses known to cause different types of infections in vertebrates. Examples of these infections in humans include the measles virus, mumps virus, parainfluenza virus, and respiratory syncytial virus (RSV).
A picornavirus is a virus belonging to the family Picornaviridae, a family of viruses in the order Picornavirales. Vertebrates, including humans, serve as natural hosts. Picornaviruses are nonenveloped viruses that represent a large family of small, cytoplasmic, plus-strand RNA viruses with a 30-nm icosahedral capsid.
Adenoviridae is a group of medium sized, non-enveloped, double stranded DNA viruses that replicate and produce disease in the eye and in the respiratory, gastrointestinal and urinary tracts;
Poxviruses are brick or oval-shaped viruses with large double-stranded DNA genomes. Poxviruses exist throughout the world and cause disease in humans and many other types of animals. Poxvirus infections typically result in the formation of lesions, skin nodules, or disseminated rash.
The rhinovirus (from the Greek ῥίς rhis "nose", gen ῥινός rhinos "of the nose", and the Latin vīrus) is the most common viral infectious agent in humans and is the predominant cause of the common cold. Rhinovirus infection proliferates in temperatures of 33–35 °C (91–95 °F), the temperatures found in the nose. Rhinoviruses belong to the genus Enterovirus in the family Picornaviridae.
The three species of rhinovirus (A, B, and C) include around 160 recognized types of human rhinovirus that differ according to their surface proteins (serotypes).[1] They are lytic in nature and are among the smallest viruses, with diameters of about 30 nanometers. By comparison, other viruses, such as smallpox and vaccinia, are around ten times larger at about 300 nanometers; while flu viruses are around 80–120 nm.
Viruses that infect and parsitized bacteria is known as bacteriophage.
It was discovered by Frederick.W.Twort in Great Britian (1915) and Felix d’ Herelle in France(1917).
D’ Herelle coined the term bacteriophage meaning ‘bacterial eater’ to describe the agent’s bacteriocidal activity. He observed lysis of a broth culture of a dysentry bacillus.
The Paramyxoviridae is a family of single-stranded RNA viruses known to cause different types of infections in vertebrates. Examples of these infections in humans include the measles virus, mumps virus, parainfluenza virus, and respiratory syncytial virus (RSV).
A picornavirus is a virus belonging to the family Picornaviridae, a family of viruses in the order Picornavirales. Vertebrates, including humans, serve as natural hosts. Picornaviruses are nonenveloped viruses that represent a large family of small, cytoplasmic, plus-strand RNA viruses with a 30-nm icosahedral capsid.
Adenoviridae is a group of medium sized, non-enveloped, double stranded DNA viruses that replicate and produce disease in the eye and in the respiratory, gastrointestinal and urinary tracts;
Poxviruses are brick or oval-shaped viruses with large double-stranded DNA genomes. Poxviruses exist throughout the world and cause disease in humans and many other types of animals. Poxvirus infections typically result in the formation of lesions, skin nodules, or disseminated rash.
The rhinovirus (from the Greek ῥίς rhis "nose", gen ῥινός rhinos "of the nose", and the Latin vīrus) is the most common viral infectious agent in humans and is the predominant cause of the common cold. Rhinovirus infection proliferates in temperatures of 33–35 °C (91–95 °F), the temperatures found in the nose. Rhinoviruses belong to the genus Enterovirus in the family Picornaviridae.
The three species of rhinovirus (A, B, and C) include around 160 recognized types of human rhinovirus that differ according to their surface proteins (serotypes).[1] They are lytic in nature and are among the smallest viruses, with diameters of about 30 nanometers. By comparison, other viruses, such as smallpox and vaccinia, are around ten times larger at about 300 nanometers; while flu viruses are around 80–120 nm.
Viruses that infect and parsitized bacteria is known as bacteriophage.
It was discovered by Frederick.W.Twort in Great Britian (1915) and Felix d’ Herelle in France(1917).
D’ Herelle coined the term bacteriophage meaning ‘bacterial eater’ to describe the agent’s bacteriocidal activity. He observed lysis of a broth culture of a dysentry bacillus.
Slideshow is from the University of Michigan Medical
School's M1 Infectious Disease / Microbiology sequence
View additional course materials on Open.Michigan:
openmi.ch/med-M1IDM
orthomyxovirus, any virus belonging to the family Orthomyxoviridae. Orthomyxoviruses have enveloped virions (virus particles) that measure between 80 and 120 nm (1 nm = 10−9 metre) in diameter. The nucleocapsid, which consists of a protein shell, or capsid, and contains the viral nucleic acids, has helical symmetry.
Picornaviruses presentation for medical student created by: Farhang Shapouran
References : Moray medical microbiology, Jawetz medical microbiology, ICTV
Mechanisms to correct damaged DNA.
Replication errors that have escaped the proof-reading process.
Damage that may occur in non-replicating DNA
Mismatch repair
Excision repair
Recombination(post-replication) repair
S.O.S. repair
A bacteriophage (informally, phage) is a virus that infects and replicates within a bacterium. The term is derived from "bacteria" and the Greek (phagein), "to devour". Bacteriophages are composed of proteins that encapsulate a DNA or RNA genome, and may have relatively simple or elaborate structures. Their genomes may encode as few as four genes, and as many as hundreds of genes. Phages replicate within the bacterium following the injection of their genome into its cytoplasm. Bacteriophages are among the most common and diverse entities in the biosphere.
Phages are widely distributed in locations populated by bacterial hosts, such as soil or the intestines of animals. One of the densest natural sources for phages and other viruses is sea water, where up to 9×108 virions per milliliter have been found in microbial mats at the surface,] and up to 70% of marine bacteria may be infected by phages. They have been used for over 90 years as an alternative to antibiotics in the former Soviet Union and Central Europe, as well as in France. They are seen as a possible therapy against multi-drug-resistant strains of many bacteria (see phage therapy). Nevertheless, phages of Inoviridae have been shown to complicate biofilms involved in pneumonia and cystic fibrosis, shelter the bacteria from drugs meant to eradicate disease and promote persistent infection
An introduction to Rhabdoviridae.Rabies is a viral disease that causes acute inflammation of the brain in humans and other mammals. Early symptoms can include fever and tingling at the site of exposure. These symptoms are followed by one or more of the following symptoms: violent movements, uncontrolled excitement, fear of water, an inability to move parts of the body, confusion, and loss of consciousness. Once symptoms appear, the result is nearly always death. The time period between contracting the disease and the start of symptoms is usually one to three months; however, this time period can vary from less than one week to more than one year. The time is dependent on the distance the virus must travel to reach the central nervous system.
A introduction on Viral vaccine for medical students.Although most attenuated vaccines are viral, some are bacterial in nature. Examples include the viral diseases yellow fever, measles, rubella, and mumps, and the bacterial disease typhoid.
a double-stranded DNA virus : human herpesvirus-3 subfamily Alphaherpersvirinae
only one serotype is known
humans are the only reservoir
VZV enters the host through the nasopharyngeal mucosa, and almost invariably produces clinical disease in susceptible individuals
Following varicella, the virus persists in sensory nerve ganglia, from where it may later be reactivated to cause herpes zoster (Shingles)
It might be thought that viruses as a class represent the ultimate in parasitism.
Reliant as they are on their host cells to provide most of the machinery or replication.
The Parvoviruses, show a still further degree of dependence .
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
2. A 22-year old man suddenly experienced
headache, myalgia, malaise, dry cough, and
fever. He basically felt “lousy”. After a couple
of days, he had a sore throat, his cough had
worsened, and he started to feel nauseated
and vomited. Several of his family members
had experienced similar symptoms during the
previous two weeks.
2
3. Characteristics:
• Influenza A, B and C the only members
• Enveloped virion; inactivated by detergents
• Segmented negative-sense RNA genome
with eight nucleocapsid segments
• Genetic instability responsible for annual
epidemics (mutation:drift) and periodic
pandemics (reassortment: shift)
3
4. Structure & Replication:
• Envelope with two group-specific glycoproteins:
1. Hemagglutinin (HA)
Functions:
a. Viral attachment protein – bind to sialic
acid on epithelial cell surface
receptors
b. Promotes fusion of the envelope to the
cell membrane
c. Hemagglutinates human, chicken and
guinea pig rbc
d. Elicits protective neutralizing antibody
response
4
5. Structure & Replication:
• Envelope with two group-specific glycoproteins:
2. Neuraminidase (NA)
With enzyme activity
Cleaves the sialic acid on glycoproteins,
including the cell receptor prevents
clumping & facilitates release of virus
from infected cells
Target for two antiviral drugs: zanamivir
(Relenza) and oseltamivir (Tamiflu)
5
6. Structure & Replication:
• Type-specific proteins: used to differentiate
among influenza A, B, and C viruses
1. Matrix protein (M1)
Viral structural protein
Interacts with nucleocapsid & envelope
promotes assembly
2. Membrane protein (M2)
Forms membrane channel
Facilitates uncoating & HA production
Target for amantadine
3. Nucleocapsid proteins (NP)
6
7. Structure & Replication:
• Transcribes and replicates its genome in the
target cell nucleus
• Assembles and buds from the plasma
membrane
7
8. Pathogenesis & Immunity:
• Virus first targets & kills mucus-secreting, ciliated,
and other epithelial cells loss of primary
defense system
• Cleavage of sialic acid residues of mucus by NA
provide access to tissues
• Preferential release of the virus at the apical
surface of epithelial cells and into the lungs
promote cell-to-cell spread & transmission to other
hosts
8
9. Pathogenesis & Immunity:
• Spread to lower respiratory tract shedding of
bronchial or alveolar epithelium
• Promotes bacterial adhesion to the epithelial cells
pneumonia
• Histologic: inflammatory response of mucosal
membrane (primarily monocytes & lymphocytes)
with submucosal edema
9
10. Pathogenesis & Immunity:
• Systemic symptoms due to the interferon and
lymphokine response to the virus
• Local symptoms due to epithelial cell damage
• Interferon & CMI responses (NK & T cell)
important for immune resolution and
immunopathogenesis classic symptoms
associated with interferon induction
• Antibody important for future protection against
infection
10
11. Pneumonia Secondary bacterial pneumonia
Primary viral pneumonia
CNS/muscle involvement
Antibody
T-cell
response
Future protection
Interferon
induction
Aerosol
inoculation
of virus
Replication
in resp. tract
Desquamation
of mucus-
secreting and
ciliated cells
Influenza
syndrome
Major contributors to pathogenesis
Immune response
Less frequent outcomes
11
12. Why is influenza difficult to
control even when there is
vaccination available?
12
13. Antigenic Changes:
1. Antigenic drift
• Minor change
• Mutation of the HA and NA genes
• Occurs every 2 to 3 years
• Cause local outbreaks of influenza A & B
2. Antigenic shift
• Major change
• Result from re-assortment of genomes
among different strains, including animal
strains
• Associated with pandemics
• Occurs only with influenza A
13
16. • Virus is spread by inhalation of aerosol
droplets expelled during talking, breathing,
and coughing.
• Virus likes cool, less humid atmosphere
• Virus is extensively spread by school
children.
16
18. Seronegative people.
Adults: classic “flu” syndrome
Children: asymptomatic to severe respiratory
tract infection
High-risk Groups:
Elderly
Immunocompromised people
People with underlying cardiac or
respiratory problems (including people
with asthma and smokers)
18
19. What are the clinical
syndromes associated with
the virus? What are the
possible complications?
19
20. Diseases Associated with Influenza Virus Infections
Disorder Symptoms
Acute infection in adults Rapid onset of fever, malaise, myalgia,
sore throat, and non-productive cough
Acute infection in children Acute disease similar to that in adults
but with higher fever, gastrointestinal
tract symptoms (abdominal pain,
vomiting), otitis media, myositis, and
more frequent croup
Complications Primary viral pneumonia
Secondary bacterial pneumonia
Myositis & cardiac involvement
Neurologic syndromes:
Guillain-Barre syndrome
Encephalopathy
Encephalitis
Reye’s syndrome
20
22. Laboratory Diagnosis of Influenza Virus Infection
Test Detects
Cell culture
Hemadsorption to
infected cells
Hemagglutination
Hemagglutination inhi-
bition
Antibody inhibition of
hemadsorption
Immunofluorescence,
ELISA
Serology: HI, headsorp-
tion inhibition, ELISA,
immunofluorescence,
complement fixation
Presence of virus, limited cytopathologic
effects
Presence of HA protein on cell surface
Presence of virus in secretions
Type and strain of influenza virus or
specificity of antibody
Identification of influenza type and strain
Influenza virus antigens in respiratory
secretions or tissue culture
Seroepidemiology
22
23. Which antiviral drugs are
effective for the treatment of
influenza virus infection? What
are the targets & mechanisms of
action of these drugs?
23
24. Amantadine, Rimantadine
• Target: M2 protein inhibit an uncoating
step
• Do not affect influenza B or C virus
Zanamivir (Relenza) & Oseltamivir (Tamiflu)
• Target: neuraminidase prevent release of
virus from infected cells
• Inhibit both influenza A and B
• Effective for prophylaxis and for treatment
during the first 24 to 48 hours after the
onset of influenza A illness
24
26. The best way to control the virus is through
IMMUNIZATION!
• Killed vaccine representing the “strains of the
year”
o Killed (formalin-inactivated) whole-virus
vaccine
o Detergent-treated virion preparations and
HA- and NA-containing detergent extracts
of virus
• Vaccination routinely recommended for the
elderly and people with chronic pulmonary or
heart disease.
26
28. Properties of Orthomyxoviruses and Paramyxoviruses
Property Orthomyxoviruses Paramyxoviruses
Viruses Influenza A, B, and C Measles, mumps, RSV, and
parainfluenza viruses
Genome Segmented (8 pieces) ssRNA
of negative polarity
Non-segmented ssRNA of
negative polarity
Virion RNA
polymerase
Yes Yes
Capsid Helical Helical
Envelope Yes Yes
Size Smaller (110 nm) Larger (150 nm)
Surface spikes HA and NA on different
spikes
Hemagglutinin &
neuraminidase on same
spikes
Giant cell
formation
No Yes
28
29. Members of the Family Paramyxoviridae
Genus Human pathogens
Morbillivirus
Paramyxovirus
Pneumovirus
Measles virus
Parainfluenza viruses 1 to 4
Mumps virus
Respiratory syncytial virus
Nipah virus (1998, Malaysia and
Singapore)
Hendra virus (1994, Australia)
29
31. Unique Features of the Paramyxoviridae
• Large virion with helical nucleocapsid
• Negative RNA genome
• Envelope containing viral attachment protein (HN,
paramyxovirus and mumps virus; H, measles
virus, and G, RSV) and a fusion protein (F)
o HN with hemagglutinin & neuraminidase activity
o H with hemagglutinin activity
o G without hemagglutinin or neuraminidase acvitity
• Replicates in cytoplasm
• Penetrate the cell by fusion with and exit by
budding from the plasma membrane
• Induce cell-to-cell fusion multinucleated giant
cells
31
32. Envelope Spikes of Paramyxoviruses
Virus Hemagglutinin Neuraminidase Fusion
protein1
Measles virus + - +
Mumps virus2 + + +
Respiratory
syncytial virus
- - +
Parainfluenza
virus2
+ + +
1The measles and mumps fusion proteins are also hemolysins.
2In mumps and parainfluenza viruses, the hemagglutinin and
neuraminidase are on the same spike and the fusion protein is on a
different spike.
32
33. An 18-year old college freshman
complained of a cough, runny nose, and
conjunctivitis. The physician in the
campus health center noticed small
white lesions inside the patient’s mouth.
The next day, a confluent red rash
covered his face and neck.
33
34. • How is the disease
transmitted?
• What clinical characteristics
of this case were diagnostic
for measles?
• When was the patient
contagious?
34
36. Transmission:
• Inhalation of large-droplet aerosols
Disease Mechanisms:
• Infect epithelial cells of respiratory tract
• Spread systemically in lymphocytes and
by viremia
• Replicate in cells of conjunctivae,
respiratory tract, lymphatic system,
blood vessels, and CNS
• Characteristic rash caused by immune T
cells targeted to measles-infected
endothelial cells lining small blood
vessels 36
37. Mechanisms of spread and pathogenesis of measles
Inoculation of
respiratory tract
Local replication
in respiratory
tract
Lymphatic
spread
Viremia
Wide
dissemination
Conjunctivae
Respiratory tract
Urinary tract
Small blood vessels
Lymphatic system
CNS
Virus-infected
cell + immune
T cells
RASH
Recovery
(lifelong
immunity)
Post-infectious
encephalitis
(immunopathological;
etiology)
Subacute sclerosing
panencephalitis
(defective measles
virus infection of CNS)
No resolution of acute
infection due to
defective CMI
(frequently fatal
outcome)
37
38. • Incubation period: 7 to 13 days
• Prodrome: high fever + 3C’s + P most infectious
• Koplik’s spots after 2 days of illness last 24 to
48 hours
• Appearance of exanthem within 12 to 24 hours of
the appearance of Koplik’s spots
• Rashes undergo brawny desquamation
38
43. Post-exposure: Immune serum globulin given
within six days of exposure
Pre-exposure:
1. Live, attenuated vaccine
2. MMR
• Composition:
a. Measles – Schwartz or Moraten substrains of
Edmonton B strain
b. Mumps – Jeryl Lynn strain
c. Rubella – RA/27-3 strain
• Schedule: at 15-24 months and at 4-6 years
• Efficacy: 95% lifelong immunization with a
single dose
43
44. A 13-month-old child had a runny nose,
mild cough, and low-grade fever for several
days. The cough got worse and sounded
like “barking.” The child made a wheezing
sound when agitated. The child appeared
well except for the cough. A lateral
radiograph of the neck showed a sub-
glottic narrowing.
44
45. What is the specific and
common name for these
symptoms?
45
46. What other agents would cause
a similar clinical presentation
(differential diagnosis)?
What is the most common
cause?
46
47. How was the virus
transmitted?
Answer: Droplet inhalation
47
48. Parainfluenza Viruses
Characteristics:
• Four serotypes
• Infection limited to upper respiratory tract
Upper respiratory tract disease most
common, but significant disease can occur
with lower respiratory tract infection
• Not systemic and do not cause viremia
• Infection induces protective immunity of short
duration
48
49. Parainfluenza Viruses
Four serologic types
• Types 1, 2, and 3
Second only to RSV as important causes of
severe lower respiratory tract infection in
infants and young children
Cause respiratory tract syndromes ranging
from a mild cold-like URTI to bronchiolitis to
pneumonia
Especially associated with croup
• Type 4
Mild upper respiratory tract infection in
children and adults
49
50. Parainfluenza Viruses
• Clinical:
• Main cause of croup in children < 5 y/o
• Characterized by harsh cough (“seal bark
cough” and hoarseness due to subglottal
swelling
• Other clinical conditions: common cold,
pharyngitis, otitis media, bronchitis, and
pneumonia
50
51. Respiratory Syncytial Virus
• Most important cause of pneumonia and
bronchiolitis in infants
• Fusion protein causes formation of
multinucleated giant cells syncytia
• Humans and chimpanzees are the natural
hosts
• Two serotypes – subgroup A and B
51
52. Respiratory Syncytial Virus
• MOT:
1. Respiratory droplets
2. Direct contact of contaminated hands with the
nose or mouth
• Infection in infants more severe and usually
involves lower respiratory tract than in older
children and adults
• No viremia occurs
52
53. Respiratory Syncytial Virus
• Severe disease in infants with
immunopathogenic mechanism
o Maternal antibody passed to infant react with
the virus form immune complexes damage
respiratory tract cells
• Most individuals with multiple infections indicate
incomplete immunity
• IgA respiratory antibody reduces the frequency of
infection as a person ages
53
54. Respiratory Syncytial Virus
• Clinical:
1. Bronchiolitis
2. Pneumonia
3. Otitis media in young children
4. Croup
5. Upper respiratory tract infection similar to
common cold in older children and adults
54
55. Respiratory Syncytial Virus
• Treatment:
Aerosolized ribavirin (Virazole) for
severely ill hospitalized infants
Combination ribavirin + hyperimmune
globulin may be more effective
55
56. A 7 year-old boy developed fever, body
malaise, and loss of appetite. This was
followed by tender swelling around the
right mandibular area, with increase in
the pain everytime he drinks calamansi
juice. The condition spontaneously
resolved after one week.
56
57. Mumps Virus
• Two types of envelope spikes:
1. With both hemagglutinin and neuraminidase
activities
2. With cell-fusing and hemolytic activities
• Only one serotype
• Neutralizing antibodies directed against the
hemagglutinin
• Humans are natural hosts
57
58. Mumps Virus
• MOT: respiratory droplets
• Infects both upper and lower respiratory
tracts spread through blood parotid
glands, testes, ovaries, pancreas, and in
some cases, meninges
• Occurs only once subsequent cases may
be caused by parainfluenza viruses,
bacteria, and by duct stones
58
61. Mumps Virus
• Complications:
1. Orchitis in post-pubertal males may lead to
sterility if bilateral
2. Meningitis – usually benign, self-limited, and
without sequelae
61
62. Mumps Virus
• Prevention:
Live, attenuated vaccine given subcutaneously to
children at 15 months of age (MMR)
Immune globulin not useful for preventing or
mitigating mumps orchitis.
62