13. Emerging Viruses Flashcards
Distinguish between resurgent and emergent infections, and give examples.
Resurgent: lab test available for many years, widespread, often severe, may cause epidemics, ususally diagnosed by conventional isolation or serological methods. E.g. influenza (swine H1N1), viral haemorrhagic fevers, dengue, HIV1, HIV2, rabies, west nile
Emergent: viruses identified realatively recently, some infections silent/mild, usually diagnosed by molecular techniques. E.g. human herpesviruses 6,7,8, hep D (delta agent), papillomaviruses, SARS, hendra
List some factors influencing the resurgence of viral infections:
a) viral factors
b) host factors
What happened with H7N9 (avian flu) and MERS?
a) breakdown of spp barriers, genetic
b) ecology and modern agriculture, medial/surgical interventions, human behaviour, intermediate hosts, population increase, global warming, defects in public health infrastructure
H7N9: live bird markets IDd as transmission route to humans, so speedily controlled. Route for MERS coronavirus remains elusive. Camels?
Influenza
Family, origin, causes
Type, structure
Vaccine type
Drugs against it
Orthomyxovirus, wild birds (zoonosis), respiratory tract infections
ssRNA -ve polariry, enveloped, spikes, HA (docking) and NA (shedding)
Inactivated whole, strains change every year
Amantidine, rimantadine, ribavirin, NA inhibitors
HIV
Family, origin, causes
Type, structure
Drugs against it
Retroviridae, chimps, immune deficiency (AIDS) - infects CD4 T-cells, pts die of multiple infections
ssRNA +ve polarity, enveloped
RT inhibitors (nucleoside/tide analogues/non), protease inhibitors, integrase inhibitors, fusion inhibitors, entry inhibitors. PrEP, ART, PEP
Hendra virus
Family, origin, causes
Paramyxovirus, Australian fruit bat -> horses and humans, pulmonary symptoms +/- viral meningitis and renal failure
Nipah virus
Family, origin, causes
Transmitted human->human by?
Paramyxovirus, fruit bat -> pigs and humans via saliva/urine, respiratory symptoms and meningitis/encephalitis.
Respiratory droplets
Ebola
Family, origin, causes
Transmitted human->human by?
Filovirus, bats -> primates, haemorrhagic fever: fever, malaise, muscle pains, sore throat, cough, dyspnoea, abdo pain, vomiting, doarrhoea, agitation, confusion, fatigue, depression, seizure, coma, rash, DIC, coagulation defects
Bodily fluids, blood, needles
Marburg virus
Family, origin, causes
Filovirus, fruit bats -> monkeys, humans, haemorrhagic fever
Rift valley fever virus
Family, origin, causes
Bunyavirus, bats? Transmitted by mosquitos (abovirus), haemorrhagic fever
Hantaan virus
Family, origin, causes
Sir Nombra virus
Family, origin, causes
Hantvirus (kind of bunyavirus), Transmitted by rodent body fluids, haemorrhagic fever with renal syndrome
Hantvirus, Transmitted by rodent body fluids (inc. deer mice), hantavirus pulmonary syndrome: fever, cough, malaise, myalgia, headache, lethargy, SoB, pulmonary oedema
West Nile virus
Family, origin, causes
Flavivirus, birds -> mosquitos (arbovirus), febrile illness, fever, myalgia, malaise, encephalitis, meningitis, myelitis of SC
Zika
Family, origin, causes
Flavivirus, transmitted by mosquitos (arbovirus), fever, malaise, aches, pains. Can be complicated by Guillain-Barre syndrome and microencephaly and other brain damage in foetuses (can be infected transplacentally)
Human meta-pneumovirus
Family, causes
Paramyxovirus, respiratory tract infection
Monkey-pox
Family, origin, causes
Transmitted human->human by?
Poxvirus, moneys and rodents, similar to mild smallpox
Respiratory droplets, bodily fluids
SARS
Family, origin, causes
Transmitted human->human by?
Coronavirus, bats -> rats, civet cats (?), (Severe Acquired Respiratory Syndrome), fever, sore throat, cough, malaise, lethargy, myalgia, SoB, pneumonitis/viral pneumonia.
Respiratory droplets, bodily fluids
