Hepatitis B virus (HBV) infection among children and adults in the Solomon Islands.

A total of 593 inhabitants of Graciosa Bay, Santa Cruz, the Solomon Islands were tested for HBsAg and anti-HBs in 1974 and again in 1977. An additional 102 children born during this study period were tested for HBsAg and anti-HBs in 1977. Loss of HBsAg was observed in 20% of the 66 HBsAg-positive individuals identified in 1974 and retested in 1977. Conversely, acquisition of HBV infection, as documented by seroconversion on HBsAg or anti-HBs, was observed in 38% of the individuals identified as negative for all HBV markers in 1974. Acquisition of HBsAg was noted in 22 individuals, eight of whom were born after 1974. Acquisition of HBsAg was noted in 66 individuals, two of whom were born after 1974. Males and females acquired HBV infection at somewhat similar rates (42% vs. 34%), except between ages 15 and 29 years, when males were infected at a much higher rate (53%) than females (11%) (p = 0.008). Contact with a carrier appears to be the predominant mode of transmission of the virus. Acquisition of HBV by children and females was strongly correlated with the presence of an HBsAg-positive individual among the household contacts. Adult males, on the other hand, tended to acquire HBV infections from sources outside their family or household setting. The relationship between the patterns of acquisition of HBV infection and the cultural practices in this Melanesian population is discussed.