No abstract

The age- and race-specific seroprevalence of hepatitis A virus (HAV) infection was determined by radioimmunoassay (RIA) in 786 subjects between the ages of 6 months to 60 years. More than 50% of African children were seropositive by the age of 5 years. In blood donors (17-60 years), 50% (93/187) of Whites, 67% (110/163) of Indians, 85% (117/137) of Coloureds, and 91% (115/127) of Africans were seropositive. There was a significant difference in the seroprevalence of HAV infection between White blood donors and blood donors from the other three racial groups [Coloureds (P < 0.0001), Africans (P < 0.0001), and Indians (P < 0.001)] and between Indians and Coloureds (P < 0.0001) and Indians and Africans (P < 0.0001). There was no significance difference in HAV infection between Coloureds and Africans (P < 0.200). Eighty-seven per cent (32/37) of rural Africans had previous infection. In the African population HAV infection is acquired in childhood. There are significant racial differences in the seroprevalence of HAV infection. The surveillance of HAV infection may be used as a valuable yardstick to monitor the changing standards of hygiene and socioeconomic conditions of a community in transition in South Africa and to make rational public health decisions regarding a hepatitis A vaccination policy.

The prevalence of anti-HCV was studied in a South African area endemic for hepatitis B virus. A total of 35,685 volunteer blood donors (22,034 whites, 9,218 Asians, 3,077 Africans, 1,356 coloureds), 71 haemophiliacs, 84 chronic dialysis patients, 100 antenatal attenders, 212 nurses, and 20 HIV-positive male homosexuals were tested for anti-HCV. Repeat positive second generation Ortho HCV EIA was used to determine HCV status for the blood donors; Abbott-II HCV EIA combined with a neutralisation test was used for the other risk groups. Antibody to hepatitis B core antigen (anti-HBc) was also tested in the haemophiliacs, nurses, and chronic dialysis patients. Seroprevalence for the blood donor population was 0.16, 0.34, 0.75, and 0.22% for whites, Asians, Africans, and coloureds, respectively. Of the risk groups tested, 39.4% of haemophiliacs and 4.8% of chronic dialysis patients were positive; of the remainder tested none was positive. Fifty percent of nurses, 47.9% of haemophiliacs, and 22.6% of dialysis patients had serological evidence of past exposure to hepatitis B virus (anti-HBc positive). These findings indicate a low prevalence of anti-HCV in the blood donor population, thus probably resulting in a low prevalence in groups exposed to blood and blood derivatives. The overall difference in prevalence between the race groups was significant (P < 0.0001). The high prevalence of hepatitis B virus compared to the low prevalence of HCV suggests that the main modes of transmission of the two viruses are probably different.

Bread fortified to contain a daily dose of 900 mug folic acid was administered to patients in late pregnancy. The patients receiving the bread showed significant rise in red cell folate concentration. The rise was similar to that observed in women receiving a daily dose of 300 mug of folic acid in tablet form. It is concluded that bread may be used as a vehicle for folic acid fortification.