Hepatitis E virus (HEV) is a major cause of non-A, non-B hepatitis in developing countries. Factors influencing sporadic spread of hepatitis E are unclear. We examined anti-HEV seroprevalence and demographic data from 407 urban and 360 rural black South African adults living in formal housing, squatter camps, or mud huts. Anti-HEV sero-prevalence ranged from 5.8% to 19.1% (mean 10.7%) in the different regions. Mean urban and rural rates were 6.6% and 15.3%, respectively (P = 0.0001). Rural mud hut dwellers, using unchlorinated river water, were at greater risk (17.4%) than rural villagers (5.3%; P = 0.008). A linear relation was found between seroprevalence and age, suggesting sporadic spread. The high prevalence in mud hut dwellers suggests that contaminated water plays a major role in HEV spread in South Africa. Routine chlorination or boiling of river drinking water before consumption may reduce HEV infection.

Hepatitis E virus (HEV) is a major cause of non-A, non-B hepatitis in developing countries. Factors influencing sporadic spread of hepatitis E are unclear. We examined anti-HEV seroprevalence and demographic data from 407 urban and 360 rural black South African adults living in formal housing, squatter camps, or mud huts. Anti-HEV sero-prevalence ranged from 5.8% to 19.1% (mean 10.7%) in the different regions. Mean urban and rural rates were 6.6% and 15.3%, respectively (P = 0.0001). Rural mud hut dwellers, using unchlorinated river water, were at greater risk (17.4%) than rural villagers (5.3%; P = 0.008). A linear relation was found between seroprevalence and age, suggesting sporadic spread. The high prevalence in mud hut dwellers suggests that contaminated water plays a major role in HEV spread in South Africa. Routine chlorination or boiling of river drinking water before consumption may reduce HEV infection.

In an epidemiologic study of 6,359 oil shale workers, 1,664 (46.7%) of 3,566 survivors were investigated. No excess of skin disease (as reported in response to a questionnaire) was found in men exposed to oil or dust, whether compared to men who were not exposed to oil or dust or to coalminers. A low prevalence of simple pneumoconiosis was found in workers exposed to dust, while progressive massive fibrosis occurred in approximately 1% of miners and retort workers. Comparisons of responders with nonresponders revealed no serious bias in terms of age or work experience, though nonresponders were likely to have been less healthy in general.

In a case control study of 122 ex-shale workers, half of whom had simple pneumoconiosis and half of whom did not, those with pneumoconiosis were found to have the poorer lung function. Significant reductions in forced expiratory capacity (FEV1), forced vital capacity (FVC), Vmax50, lung volumes, and carbon monoxide transfer were found in men with pneumoconiosis. It is suggested that these abnormalities may represent a mixture of pulmonary fibrosis and airways obstruction related to exposure to dust and fumes in shale mines and at shale retorts.

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