The long-term impact of annual case-finding and chemotherapy with praziquantel on schistosomiasis japonica was examined in an 8-year longitudinal study in the Philippines. The prevalence, incidence, and intensity of infection and schistosome-induced hepatomegaly significantly decreased within 3-4 years of treatment and then stabilized despite continual population-based chemotherapy. Hepatomegaly rapidly developed in acutely infected persons, with 82% of subjects developing hepatic enlargement within 2 years of reinfection. These data suggest that abrupt discontinuation of current control measures in the Philippines may result in a rapid rebound in morbidity. Age-dependent acquired resistance to reinfection also developed in subjects chronically exposed to schistosomiasis japonica, suggesting that a vaccine may represent an alternative approach for control of this parasitic infection.

No abstract

No abstract

The complete nucleotide sequence was determined for a hepatitis B virus genome of subtype adw (pFDW294) isolated and cloned from the plasma sample of a Philippino. The genome was 3221 base‐pair long with a point mutation at the 1376th nucleotide that affected the coding capacity of the P and X genes. There was a wide range of sequence divergence among pFDW294 and the reported three genomes of the same subtype (1.1–9.9%), occurring more often in the pre‐S region and the S gene than in the pre‐C region and the C gene.