Serological, virological and clinical markers in hepatitis A virus (HAV)-infected individuals

This paper had been presented for promotion at the University of Khartoum. To get the full text please contact the other at abumalaz2002@gmail.comHepatitis A virus (HAV), which is a common cause of acute viral infections in humans, is classified as heparnavirus genus in the family Picornaviridae. Nucleotide sequence analysis of HAV has classified the virus in seven genotypes (I, II, III, IV, V, VI, and VII). HAV has a worldwide distribution occurring in both epidemic and sporadic fashions. HAV transmission via the oro-fecal route as is excreted in feces of infected people and can produce clinical disease when susceptible individuals consume contaminated water or foods. The incubation period for HAV varies from 10 to 50 days depending upon the number of infectious particles consumed. Clinically, HAV infection is usually a mild illness characterized by sudden onset of fever, malaise, nausea, anorexia, and abdominal discomfort, followed in several days by jaundice and was not reported to evolve in chronic hepatitis in several studies and observations. The disease is more severe in adults than in children in whom it goes unnoticed and serological responses against HAV are also higher among individuals older than 10 years of age. HAV is diagnosed by detecting IgM-class anti-HAV in serum collected during the acute or early convalescent phase of disease using either ELLISA or radioimmunoassay. Virus detection from fecal extracts using immune EM was also employed. Inactivated HAV vaccine (Havrix) was used pre- and postexposure to protect against the virus. HAV is found mostly in the stools and blood of an infected person about 15 - 45 days before symptoms occur and during the first week of illness. During viremia, HAV load or persistence in both the blood and fecal excretion is exactly uncovered. However, some studies confirmed that the duration and length of viremia is dependent on the host cellular immunity levels and hemolysis while the virus genotype has no role in the clinical outcome of HAV infection