Quick review Quiz 1 BIO 1023

Only Influenza A causes pandemics. Influenza possesses the ability to undergo genetic drift, genetic shift, and genetic reassortment shuffling of DNA between viruses, 18 kinds of H. Genetic reassortment does not have to result in new H and N. Hemaglutinin attaches to the respiratory cell. N cuts virus. There is lysing and budding (two ways). H binds to sialic acid and its bound by galactose. Avian likes 2-3 (lower tract). Zika and West Nile are the most neurotropic. Yellow fever is tropical south america and equatorial africa (tropical). In Africa reservoirs are humans and aedes. South America is monkeys and aedes. Yellow fever has a live attenuated vaccine. Zika you get fever and rash if symptomatic. A very short period of viremia in people with west nile means it was likely brought to other continents by bird or mosquito. WND can be meningitis, encephalitis, or myelitis. IgG lasts for life, IgM is short (3 months). 5-10% of women with zika during pregnancy have birth defects. A man has to wait 3 months before having sex to prevent Zika. A woman has to wait 8 weeks after onset of symptoms before pregnancy. Two manifestations with dengue, primary phase (first infection) and critical phase (second infection). Dengue is mediated by ADE. Dengue critical phase you can get plasma leakage**, low platelet count, hemorrhagic, and myocardial involvement, liver, renal, CNS. Chikungunya means to be contorted (arthritis). 85% have symptoms, arthralgias and frank arthritis (severe). Only virus to give arthritis is chikungunya. ADE happens when there is non neutralizing antibody to viral serotype. Neutralizing antibody clusters around virus so it cant get into macrophage. Receptors are on macrophages**. Extrinsic is an increase in infections in macrophages. Intrinsic is more virus being replicated. Monkeypox is double stranded DNA. Lymphadenopathy can be seen in monkeypox and chickenpox but not spox. Monkeypox can be treated with smallpox vaccine. Can come from rodent bite, or preparation of bush meat. Person to person can be from sores, fomites, sexual transmission, respiratory spread is possible, transplacental. (Unclear if semen can be a form of transmission). There is a live vaccine that can't be given to AIDS patients for Monkeypox. Two outbreaks in the DRC 1a (animals), 1b close intimate contact (hetero), 2b (homosexual). Smallpox in 1980 was vaccinated with cowpox. The cowpox vaccine changed into a new virus. Smallpox was used for bioterrorism. Fever first and then lesions with smallpox and monkeypox. Norovirus is nonenveloped (alcohol doesn't work well, you need to use bleach on surfaces and handwashing). Ten genogroups 49 genotypes, its spread through the fecal oral route, droplet spread when there is vomitus in the air, fomite contamination, food and water can be contaminated. Patients get nausea and vomiting, (vomiting is more common than diarrhea). 24-48 hour incubation, half people get fever. There is an antigen test and PCR test. There is asymptomatic shedding. Shedding means you can be contagious but not symptomatic (doesn't prove persons symptoms are related to virus). Smallpox is uniquely a human pathogen, a human reservoir.