Fecal shedding of hepatitis A virus in Indian patients with hepatitis A and in experimentally infected Rhesus monkey

Abstract

Hepatitis A is highly endemic in India. The surveillance reports for the disease from this region are primarily based on the demonstration of hepatitis A virus (HAV) specific serum IgM and IgG antibodies. The present study was conducted to assess the presence and duration of fecal shedding of HAV in patients with hepatitis A and in an experimentally infected rhesus monkey. Nested reverse transcription polymerase chain reaction (RT-PCR) was applied to fecal specimens from 67 sporadic cases of hepatitis A. Recent infection with HAV in these cases was evidenced by the presence of serum anti-HAV IgM. Fecal HAV RNA positivity was observed in nearly 40% patients. The proportion of HAV RNA positivity in fecal specimens obtained within the first week (36.58%) was not different from those collected in 2-12 weeks post onset (42.42%) (P > 0.05). A significant number of HAV RNA positive stool specimens showed presence of full virus particles by immune electron microscopy (IEM). Extended fecal shedding of HAV could be a major contributory factor for high circulation of virus thereby maintaining hyperendemicity of the disease. One of the IEM positive samples was inoculated into an anti-HAV negative rhesus monkey. Serum alanine amino transferase levels of the monkey remained within the normal limits. However, HAV RNA positivity in the feces was noted from 3 to 50 days post inoculation. The monkey seroconverted to anti-HAV IgM on day 31. This study records prolonged excretion of HAV in humans as well as in experimentally infected rhesus monkey.