Investigation of a hepatitis A outbreak from Shimla Himachal Pradesh.

Background & objective: Hepatitis A is an enterically transmitted viral disease, highly prevalent in India and mainly presents as a paediatric sporadic disease. This study investigated an outbreak of viral hepatitis at Shimla, Himachal Pradesh, India, during January-March 2007. Methods: Eighty seven blood samples, 3 water samples and 2 sewage samples were collected. Serum samples were tested for IgM and IgG anti HAV and IgM and IgG anti HEV antibodies. Serum, sewage and water samples were tested for HAV-RNA by nested RT- PCR. Nearly complete full genome (excluding extreme 5’ end) was amplified from one serum sample. Results: The hepatitis cases were mainly seen among children and young adults and 63.2 per cent (55/88) were positive for anti-HAV IgM. These cases were reported from the areas getting water supply from Ashwani Khud water supply system. This water purification system received water from a natural stream in which treated sewage water was let into 4 km upstream the collection point since one year. HAV-RNA present in serum, sewage and water samples showed 100 per cent sequence homology. Phylogenetic analysis based on 5’ non coding (5’ NC) and nearly complete genome showed the evidence of HAV genotype IIIA in all the samples. Interpretation and conclusion: The aetiological agent of the present outbreak was hepatitis A virus which is emerging in an outbreak form in India, emphasizing a definite need for formulating vaccination / control strategies.

Hepatitis G virus infection in India: prevalence and phylogenetic analysis based on 5' non-coding region.

OBJECTIVES: To determine the prevalence of hepatitis G virus (HGV) infection in western India and to carry out phylogenetic analysis of HGV isolates. METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) assay was used to detect HGV RNA in serum samples obtained from paid plasma donors, patients with hemophilia and voluntary blood donors. Nine Indian and one Kenyan HGV RNA-positive samples were sequenced in the 5' non-coding region (5'-NCR). Phylogenetic analysis based on the comparison of a 101 nucleotide fragment from a large number of HGV isolates from 22 countries (including Indian and Kenyan sequences obtained during the present study) was carried out. RESULTS: HGV RNA positivity rates among paid plasma donors from a commercial plasmapheresis unit (7/43, 16.3%) and patients with hemophilia (5/44, 11.4%) were significantly higher than that in voluntary blood donors (0/51; p=0.003 and 0.019, respectively). Among patients with acute non-A to E hepatitis and fulminant hepatic failure, 1 of 50 and 1 of 28 were HGV RNA-positive, whereas 6 of 49 (12%) patients with chronic liver disease had circulating HGV RNA. All Indian isolates belonged to genotype 2, whereas the Kenyan isolate formed a distinct branch within genotype 1 consisting of African isolates. CONCLUSION: Our results suggest existence of parenteral transmission of HGV in the Indian population. HGV was not an important cause of acute non-A to E hepatitis or fulminant hepatic failure among the patients investigated. Genotype 2 seems to be the most prevalent genotype in western India.

Hepatitis E virus infection in pregnant rhesus monkeys.

Ten non-pregnant female monkeys and four pregnant monkeys (all Macaca mulatta) in the last third of their gestation period were infected intravenously with the stool sample of a patient with hepatitis E virus infection (immuno-electronmicroscopy positive for hepatitis E virus). Four more non-pregnant monkeys were inoculated with a lower dose (less number of virus particles by IEM) of a stool sample collected on a different day from the same patient. The average incubation period as evidenced by the rise of serum alanine transferase in the non-pregnant monkeys, was 36.4 +/- 4.9 days. The dose of the virus did not affect the incubation period. Two of the pregnant monkeys had incubation periods of 9 and 13 days respectively. They delivered healthy babies on 40th and 53rd day respectively after inoculation. At the age of 11 months, both babies were negative for anti-HEV antibodies. One monkey which delivered a healthy baby on the 2nd day after inoculation had incubation period of 36 days. The baby of this monkey was anti-HEV positive at the age of 11 months. The incubation period was 41 days in the fourth monkey which delivered a macerated foetus on the 36th day after infection. No fatality was recorded in the infected monkeys. Bile samples collected from all monkeys showed strong signals in nested polymerase chain reaction (PCR). It seems that the incubation period in pregnant monkeys was determined by the state of pregnancy.

Hepatitis B infection among dental personnel in Pune & Bombay (India).

To assess the risk of hepatitis B infection among dental personnel, serum samples were collected from dentists of Pune and students, staff, auxiliary staff and class D staff of a dental college in Bombay. Dentists (32.02%), dental auxiliary staff (35.89%), clinical assistants and post-graduate students (19.56%) were found to have significantly higher prevalence of HBV infection as compared to undergraduate dental students (3.94%). The prevalence of HBV infection was high among the dentists as compared to voluntary donors. A positive linear association was observed in the positivity of HBV seromarkers with increasing age and number of years spent by the workers in the dental environment. The rate of increase in HBV seropositivity with age was higher (P less than 0.05) among dental personnel when compared to voluntary donors. Vaccination against hepatitis B is recommended for all the dental students before they start their clinical phase and for susceptible dentists and dental auxillary staff.