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

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.

Viruses in acute gastroenteritis in children in Pune, India.

A 2-year study from January 1981 to December 1982 was undertaken to determine the role of viruses in the causation of diarrhoea in hospitalized children in Pune, Maharashtra State, India. The stool samples of 426 children (213 diarrhoeal and 213 non-diarrhoeal controls) were investigated by electron microscopy and ELISA for the presence of viruses. Six morphologically distinct viruses were visualized: rotavirus, coronavirus-like particles (CVLP), adenovirus, astrovirus, calicivirus and small round virus-like particles (SRV). Rotavirus was detected in 28.6% of the diarrhoeal patients and in 1.4% of the controls. The frequency of infection with rotavirus was highest in the children aged less than 5 years. The mean age of rotavirus-positive patients was 11 months. Although rotavirus was detected in almost every month, there has a seasonal trend for colder months when CVLP cases were fewest. However, the prevalence of CVLP was greater in the control group (23.0%) rather than in those with diarrhoea (8.9%). In the control group, CVLP were detected more frequently during the summer months. An inverse relationship between CVLP and rotavirus was observed in children. Adenovirus, astrovirus, calicivirus and SRV were detected in a small proportion of children with and without clinical symptoms of gastroenteritis.

Aetiological association of a virus-like particle with enterically transmitted non-A, non-B hepatitis.

Virus-like particles, approximately 27 nm in diameter, were identified in faeces from an Indian patient with enterically transmitted non-A, non-B (ENANB) hepatitis. They were serologically distinct from hepatitis A virus (HAV). Nucleic acid extracted from the particles did not hybridize with cDNA probes representing the genomes of HAV, enteroviruses, and cardioviruses. Chimpanzees were experimentally inoculated with faecal suspensions containing this 27 nm particle or with faeces from another case of ENANB hepatitis. Mild histological and biochemical hepatitis developed in these animals and there was serological evidence of infection with the virus-like particle as shown by immunoelectronmicroscopy (IEM). Serological analysis by IEM suggested that this agent or an antigenically similar virus was the aetiological agent of two epidemics and a sporadic case of ENANB hepatitis in India and of an epidemic of the illness in the USSR. Antibody to the particle was found in sera from patients with ENANB hepatitis from various geographic areas over a 30-year period.

The epizootics of Kyasanur Forest disease in wild monkeys during 1964 to 1973.

In the Kyasanur Forest disease area two species of wild monkeys, Presbytis entellus and Macaca radiata, succumb to the natural infection with Kyasanur Forest disease (KFD) virus (family Flaviviridae). Between October 1964 and September 1973, 1046 monkeys (860 P. entellus and 186 M. radiata) died. Of these, KFD virus was isolated from 118 P. entellus and 13 M. radiata. Maximum mortality of monkeys was reported during December through May coinciding with the season of activity of immature stages of Haemaphysalis ticks, incriminated vectors of KFD. The epizootic showed an initial spread of the disease to the areas contiguous with the original focus of infection. This was followed by the recognition of epizootics and epidemics in three new foci, removed from the original focus, by the end of 1973. It was also observed that, in certain localities in the original focus, KFD virus activity persisted over several years.

A sero-epidemiologic study of a water-borne epidemic of viral hepatitis in Kolhapur City, India.

Between February and March 1981 an epidemic of hepatitis occurred in Kolhapur City, Maharashtra State, India. Approximately 1200 cases of jaundice were reported; more than 300 patients were hospitalized and three died. The epidemiological investigations showed a distinct concentration of cases in municipal ward E of the city. Investigations of the ward E water supply system disclosed gross contamination of raw water with sewage at source. The serological studies revealed that the aetiological agent responsible for this epidemic was neither hepatitis A virus nor hepatitis B virus but was likely to have been due to a non-A, non-B hepatitis virus.

Non-A, non-B epidemic hepatitis: visualization of virus-like particles in the stool by immune electron microscopy.

Acute-phase stool samples collected from hepatitis cases during outbreaks of water-borne epidemic hepatitis were examined by immune electron microscopy (IEM). Spherical virus-like particles (27 nm in diameter) were visualized in the stool of a hepatitis patient with serological evidence of non-A, non-B (NANB) hepatitis. The IEM demonstrated serological specificity of the antigen with the patient's own convalescent serum as well as a known pool of NANB hepatitis convalescent sera. It is suggested that these virus-like particles may be the aetiological agent of faeco -orally transmitted NANB epidemic hepatitis in India.

Epidemic and endemic hepatitis in India: evidence for a non-A, non-B hepatitis virus aetiology.

69 serum pairs from two common-source water-borne outbreaks and one series of endemic cases of hepatitis in three parts of India were tested for hepatitis A and hepatitis B virus infections. None of the patients had evidence of HAV infection and only 10.1% had evidence of HBV infection. A large proportion of hepatitis in India seems to be caused by previously unrecognised agents.