Seroepidemiology of hepatitis A infection in India: changing pattern.

OBJECTIVE: Recent changes in the epidemiology of hepatitis A virus (HAV) infection and the availability of effective vaccines have renewed interest in this infection. We determined the age-related prevalence of anti-HAV antibodies in India and looked for differences by known risk factors for HAV infection. METHODS: In this prospective study, serum samples obtained from 1612 subjects aged 1 to 60 at six centers in five cities (Calcutta, Cochin, Indore, Jaipur and Patna) during the period February to August 1998 were tested for anti-HAV antibodies. Demographic and socio-economic information was obtained by questionnaire. RESULTS: The overall seroprevalence rate was 65.9%, varying from 26.2% to 85.3% in various cities; there was no difference between males and females. Seropositivity increased with age from 52.2% in the 1-5 year age group to 80.8% in those aged 16 years or more. Seroprevalence rates were significantly lower in those aged 1-5 years compared with other age groups (p<0.0001). There was no difference in seroprevalence between those with monthly family income <Rs 5000 and >Rs 5001. Multivariate analysis showed that anti-HAV seroprevalence varied significantly by source of water supply, being highest when the supply was municipal. CONCLUSION: Our results indicate an epidemiological pattern of intermediate endemicity. This finding has public health implications as it indicates that a significant proportion of the Indian adolescent and adult population is at risk of HAV infection.

Seroepidemiology of varicella-zoster in Pakistan.

The availability of safe and effective vaccines has renewed interest in the epidemiology of varicella worldwide. To date published data on the epidemiology of varicella in Pakistan is very scarce. Therefore, we conducted a study to determine the age-specific seroprevalence rate of varicella-zoster virus (VZV) antibodies in Pakistan. Between December 1997 and March 1998, 1,509 healthy volunteers aged between 1 month and 30 years were recruited from the Islamabad, Karachi, Lahore and Rawalpindi areas. Demographic information, socioeconomic status and past medical history were obtained by questionnaire. Serum samples were assayed for IgG antibodies against VZV by enzyme-linked immunosorbent assay. Overall 41.8% (600/1,435) of those tested were found to be seropositive for VZV antibodies. No difference was found in results obtained from the different cities. A higher seroprevalence was observed among women (45.2%) compared to men (39.6%). Seroprevalence rates increased with age and were 28.4% in those aged 0-5 years, 41.5% in the 6-10 year age group, 42.5% in the 11-15 year age group, 46.7% in the 16-20 year age group and 53.6% in those aged 21-30 years. Socioeconomic status was not a significant risk factor for VZV seropositivity. This is the first report of the seroepidemiology of VZV in Pakistan. The results indicate that seroprevalence of VZV increases with age in the Pakistani population studied. As in other tropical countries, there is greater susceptibility to varicella among the adolescent and young adult population. The results of this study suggest that these at-risk groups should be included in vaccination programs aimed at reducing the public health impact of varicella.

Age related seroprevalence of antibodies to varicella in India.

OBJECTIVE: To determine the age related prevalence of Varicella Zoster Virus (VZV) antibodies in India. SETTING: This was a cross sectional multicentric study performed in 4 major cities of India: Calcutta (outpatients), Mumbai (outpatients), Lucknow (walk-in patients to a diagnostic laboratory, orphanage and factory workers) and Bangalore (outpatients and walk-in patients to a diagnostic laboratory). METHODS: A total of 1609 volunteers from birth to 40 years of age were included into the study. IgG antibodies against VZV were determined using commercial kits (ELISA-Enzygnost). RESULTS: Overall seroprevalence of anti VZV antibodies was 68. 22percnt. The age related seroprevalence rate of anti VZV antibodies was 29percnt in the age group of 1-5 years, 51.1percnt in 5-10 years, 71.7percnt in 11-15 years, 79.8percnt in 16-20 years, 88.1percnt in 21-30 years and 91.1percnt in 31-40 years. CONCLUSION: A significant proportion of adolescents and adults are susceptible to varicella in India, as in other tropical countries

Seroprevalence of hepatitis A virus and varicella zoster antibodies in a Javanese community (Yogyakarta, Indonesia).

Hepatitis A virus (HAV) cause an acute inflammation of the liver. Varicella-zoster virus (VZV) cause chickenpox (varicella) and herpes zoster. Effective vaccines against hepatitis A and varicella are available for children, adolescents and adults. In order to implement an appropriate vaccination policy, a baseline to assess the potential benefits and sections of the population who would benefit most are required. We investigated seroprevalence of hepatitis A virus and varicella zoster antibodies in a Javanese community. A total of 1,103 subjects were studied. The 600 subjects aged 4 to 9 years were sampled between 23 October and 2 November, 1995. The other subjects were sampled between 12 October and 1 November, 1996. The overall prevalence of anti-HAV in cohort was 28.7%. Anti-HAV seroprevalence rates were below 30% until the age of 15 and below 40% until the age of 25. The anti-varicella seroprevalence showed only in two thirds of seropositive population at the age of 15. The results of the study have implications for vaccination strategies for both hepatitis A and varicella zoster.