Genetic substructure in South African Bantu-speakers: evidence from autosomal DNA and Y-chromosome studies.

The extent of genetic differentiation between seven South African Bantu-speaking groups (Zulu, Xhosa, Tsonga/Shangaan, Southern Sotho, Pedi, Tswana, and Venda) was assessed from coancestry coefficients (F(ST)) estimated from autosomal serogenetic, DNA, and Y-chromosome DNA haplotypes. The overall F(ST) obtained from the autosomal data was 0.002, and that from the Y chromosome data was 0.

An evaluation of two indirect fluorescent antibody tests for the diagnosis of Legionnaire's disease in South Africa.

The specificity and sensitivity of the indirect fluorescent antibody test (IFA) for the diagnosis of Legionnaires' disease in South African patients is unknown. Heat-treated and formalin-treated antigen preparations from 456 normal blood transfusion donors and from 34 confirmed patients with the disease (3 culture-positive cases and 31 cases of seroconversion) were assessed. Tests using both antigens showed a relatively high degree of positivity at low titres in normal individuals with an age-related increasing frequency of positive tests.