DeltavirusEnveloped, Θ single-stranded and circular RNA HDV is a "defective" virus that requires the presence of HBV (for HbSAg) to replicate.
Segmented virusesAll are RNA viruses. - Orthomyxoviruses- Arenaviruses- Bunyaviruses- Reoviruses
Extrahepatic manifestations of hepatitis B and CHepatitis B:- Hematologic: Aplastic anemia- Renal: Membranous GN > membranoproliferative GN- Vascular: Polyarteritis nodosa Hepatitis C:- Hematologic: Essential mixed cryoglobulinemia, ↑ risk B-cell ...
Dengue feverFlavivirus (enveloped, ⊕ ssRNA)- Transmitted by Aedes aegypti mosquito- Distribution: tropical regions worldwide, particularly Asia (eg, Thailand) Classic dengue fever:- Flu-like febrile illness with ...
West Nile virusFlavivirus (enveloped ⊕ ssRNA) Clinical syndrome:- West Nile fever: fever, headache, rash (maculopapular/morbilliform) on back and chest- Neuroinvasive: meningitis, encephalitis, acute asymmetric flaccid ...
Hepatitis B/C- Dramatically increases the risk of hepatocellular carcinoma- Ongoing infection with Hepatitis B or C virus leads to increased hepatocyte turnover and the generation of local inflammatory cytokines, ...
Naked viral genome infectivityPurified acids of most dsDNA (except poxvirus and HBV) and ⊕ strand ssRNA (≈mRNA) viruses are infectious. Naked nucleic acids of ⊝ strans ssRNA and dsRNA virses are not infectious. They require ...
Negative-stranded virusesMust transcribe ⊝ stand to ⊕. Virion brings its own RNA-dependent RNA polymerase. They include arenaviruses, bunyaviruses, paramyxoviruses, orthomyxoviruses, filoviruses, and rhabdoviruses.
Hepatitis virusesSigns and symptoms of all hepatitis viruses: - Episodes of fever- Jaundice- ↑ ALT and AST - Naked viruses (HAV, HEV) lack an envelope and are not destroyed by the gut. - HBV DNA polymerase has DNA- ...
Hepatitis A virusPicornavirus (naked, ⊕ ssRNA) Transmission: Fecal-oral (shellfish, travelers, day care) Incubation: Short (weeks) Clinical course: Usually asymptomatic, acute No HCC risk. Liver biopsy: Hepatocyte ...
Hepatitis B virusHepadnavirus (enveloped, dsDNA) Transmission: Parenteral (blood), sexual, perinatal - Binds to a bile salt transporter on hepatocytes. Uncoats in host cytoplasm. Single-stranded DNA portion is completed ...
Hepatitis C virusFlavivirus (enveloped, ⊕ ssRNA) Transmission: Primarily blood (IVDU, post-transfusion) Incubation: Long Clinical course: May progress to cirrhosis or carcioma Prognosis: Majority develop stable, chronic ...
Hepatitis E virusHepevirus (nonenveloped, ⊕ssRNA) Transmission: Fecal-oral, especially waterborne. Incubation: Short Clinical couse: - Prodromal: Fever, myalgia, nausea, vomiting- Icteric phase: Jaundice, dark urine, ...
Perinatal hepatitis B infectionRisk factors:- Maternal viral load- Maternal HBeAg positive Clinical findings:- Infants usually immune-tolerant (normal or mildly elevated liver enzymes, no symptoms)- High risk for chronic infection- ...
HantavirusBunyavirus Reservoir: Deer mouseTransmission: Exposure to its droppings and urine Clinical presentation: Hantavirus pulmonary syndrome- Starts with fevers, headaches, severe mylagias, GI upset, dizziness, ...
PoliomyelitisPicornavirus. Unenveloped, ⊕ ssRNA. - Spread via fecal-oral transmission- Still endemic in Afghanistan, Nigeria, and Pakistan Clinical features:- Gastroenteritis, fever, nausea, sore throat, myalgia, ...
