Viruses Flashcards
Common Cold Outline
Upper Respiratory Infection. Caused by rhinovirus (RNA), adenovirus (DNA) and coronavirus (RNA). Keeps reinfecting frequently as viruses undergo rapid mutation. Mild coughing, sneezing, throat irritation, sneezing, rhinorrhea and malaise. Not systemically ill (no fever, ect)
Malaise Def
tiredness due to illness
Common Cold Treatment
Self limiting. Only addressed if economic burden is severe (typically supportive eg analgesics) .Can’t be vaccinated due to rate of mutation
Differences between influenza and common cold
Influenza’s symptoms are more severe. Influenza can be vaccinated against
Haemophillus Influenza
Gram negative, motile bacteria that causes local bronchitis and systemically causes arthiritis
Influenza Outline
Acute upper respiratory virus. Caused by influenza A,B or C (orthomyxovirus, RNA). Occurs in seasonal outbreaks (Oct-May). Occasional pandemics. Abrupt fever and cough, followed by persistent weakness (some systemic). Transfered via droplets in contact with mucus membranes
Influenza A Outline
Virus infects mammalian and avian species. Annual epidemics and occasional pandemics. Main reservoirs = birds. Envelope, capsid and flagella
Influenza B Outline
Restricted to humans. Cause outbreaks every 2-4 years. Not associated with pandemics
Influenza C Outline
Restricted to humans. Not associated with outbreaks. Causes milder diseases
Antigenic Drift Outline
Viral DNA polymerase makes replication errors. Results in change in glycoprotein antigens. Epidemics
Antigenic Shift Outline
Genes swapped between different strains when 2 viruses (of different strains) infect the same host cell.This results in a novel virus with new antigens causing a pandemic
Hemagglutin Outline
Substance on virus that ligand-ligand binds with receptors on host cells
Progression of Influenza
Secondary bacterial infection. Streptococcus pneumonia , haemophiles pneumonia and staphylococcus aures (MRSA). May progress to Reye’s Syndrome
Reye’s Syndrome Outline
Encephalopathy and liver failure (inflammation in brain and liver). Results in death
Influenza Diagnosis Outline
Nasopharyngel apirates, nose/throats swabs bronchoalveolar sputum. PCR, immunofluorescence, serology, Monkey Kidney Agar
Influenza Vaccination
Inactivated virus given every Oct as prophylaxis. Administered to at risk groups (healthcare workers, < 6 months, immunosuppressed, >65 years, pregnant women and morbidly obese
Influenzas Treatment
Supportive: analgesics, antipyretics (reduce fever), Hospitalised: oxygen and antivirals: oseltamivir (neuramininidase inhibitors, salicylic acid) and zanamivir
Coronavirus Outline
Upper respiratory infection. Ranges from mild to severe. Incubation period = 14 days. Phylogenetically related to SARs. Symptom: fever, myalgia, cough and loss taste/smell. Thrombosis, long Covid and organ failure
Coronavirus Management
Oxygen, monoclonal antibodies, dexmathasone and remdesovir
Diarrheal Illness
Rotavirus, calicivirus, astrovirus, norwalk virus, norovirus and adenovirus
5 Groups of Picroviruses (enterovirus)
Poliovirus, CoxScakie A virus, CoxScakie B Virus, ECHO virus and Others
Enterovirus Transmission
Fecal-oral (direct, indirect), oral-oral, aerosol and peri-natal transmission
Enterovirus Pathogenesis Infection
Innate infection of upper respiratory infection. Virus spreads to lymphoid tissues, viraemia (virus in blood). Damage to target organ
Viremia Outline
Minor = systemic lymphoid tissue and Major = CNS infection
Viral Meningitis Outline
Enterococci systemic infection
Enetrococci Infection Treatment
Self limiting, antivirals not recommended. supportive: antipyretics, rehydration, anelsgia;
CoxSackie Virus Outline
2 antigenic types (A and B). Faecal-oral, inhlation and vesicle contact.
Coxsackie Virus Disease
Meningitis +/- rash, Bornholm’s Disease (fever, unilateral chest pain), herpangia (mouth ulcers), neonatal myocarditis
Coxsackie Virus Treatment
Ibuprofin and rehydration
Poliovirus Outline
3 distinct serotypes. Humans are only natural host. Source is person with acute infection fecal-oral route. 95% asymptomatic, non-specific viral symptoms, aseptic meningitis and paralytic poliomyelitis (CNA paralysis)
Polio Vaccine Outline
Live Attuned (orally, IgA humoral immunity, 3 doses = primary) and Inactivated Polioviris (3 polio, administered 3 times)
Gastroentiritis Viral Cause
Rotavirus (ds RNA, reoviridae), norovirus (RNA, calciviridae), Astrovirus (RNA, astroviridae) and adenovirus (DNA, adenoviridae). Fecal-oral, food contamination
Rotavirus Outline
Acute diahorrea in children, 7 serotypes, infectous dose is small. Oral vaccine (up to 24 months of age) and rehydration
Norovirus Outline
acute diahorrea and vomiting. Short incubation
