<prompt> Hepatitis C virus high efficacy testing in blood bank is by:NS1NS2NS3El  <response>: Ans.C.NS3ExplanationHepatitis C virus: Most common cause of Post-transfusion hepatitis in developing countries.Morphology: ve sense ssRNA and proteins 3 structural proteins like core protein, El and E2 glycoproteins; 6 non-structural proteins like NS1, NS2, NS3, NS4A, NS4B, NS5A, NS5B.Genetic diversity:Higher rate of mutation seen in E2 envelope protein NS5B.E2 is target against most neutralizing antibodies, genetic diversity of E2 results in mutant strains escaping bodys immunity.HCV genotypes:Genotype 1 is most common type worldwideGenotype 4 seen in EgyptGenotype 5 seen in South AfricaGenotype 6 seen in Hong KongGenotype 1 and 3 common in India.Transmission:Parenteral blood transfusion, blood products, organ transplantation, injection drug users, contaminated needles and sharpsVertical from mother to fetus lower rate 6 than HBV 20Sexual rareIt doesnt spread by breast feedingfoodcasual contacts of hugging, shaking hands.Extrahepatic: mixed cryoglobulinemia, arthritis, glomerulonephritis.Epidemiology:Worldwide infections every year 3-4 million people, are infected with HCV with more than 3.5 lakhs deaths.Prevalence rate: India 1Africa 10 South America, Asia World 3.Laboratory diagnosis.Serum antibody detectionAntigen detection Anti-HCV antibodies are detected by Third- generation ELISAs using Core antigens, NS3, NS4, NS5 to detect anti-HCV antibodies Hepatitis C virus RNA is most sensitive and gold standard test. Acute diagnosis: Anti-HCV C33c, C22-3, NS5 are detected. Branched-chain DNA bDNA assay Chronic diagnosis: Anti-HCV C100-3, C33c, C22-3, NS5 are elevated.a.-Reverse transcriptase PCRb.-Real time RTPCRc.-Transcription mediated Amplification TMA.Treatment:Combined therapy with pegylated interferon plus ribavirin.Start treatment within 2-3 months after onset of disease and continued till 24 weeks. 