Which of the following is a DNA virus?
High-Yield Explanation
Ans. b (Hepatitis B virus). (Ref. Harrison's medicine 17th/Table 16-4; Anantanarayan, 6th/511)Clinical situationLab findingProtective antibody against HBVHBsAgAcute HBV infection, highly infectiousHBsAg, HBeAg, IgM anti-HBC absChronic HBV infection or carrier state, highly infectiousHBsAg, HBeAg, IgG anti-HBC absChronic HBV infection, low infectivityHBsAg, IgM anti-HBC abs, anti-HBe +/-Remote HBV infection, infectivity very low or nilIgG anti-HBC abs, anti HBs +/-, anti-HBe +/-Viral HepatitisVirusHepatitis AHepatitis BHepatitis CHepatitis DHepatitis EType of virusViral familyssRNAHepatovirus; related to picornavirusPartially dsDNAHepadnavirusssRNAFlaviviridaeCircular defective ssRNA Subviral particle in Deltaviridae familyssRNA CalicivirusRoute of transmissionFecal-oral (contaminated food or water)Parenteral, sexual contact, perinatalParenteral; intranasal cocaine use is a risk factorParenteralFecal-oralMean incubation period2-4 weeks1-4 months7-8 weeksSame as HBV4-5 weeksFrequency of chronic liver diseaseNever10%>80%5% (coinfection); >70% for superinfectionNeverDiagnosisDetection of serum IgM antibodiesDetection of HBsAg or antibody to HBcAgPCR for HCV RNA; 3rd-generation ELISA for antibody detectionDetection of IgM and IgG antibodies; HDV RNA serum; HDAg in liverPCR for HEV RNA; detection of serum IgM and IgG antibodiesCarrier-++--Oncogenicity-++--