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Background: Little is known about changes in hepatitis B viral load (HBV DNA) in relation to age in Africa. The aim of this study is to determine the natural course of HBV chronic infection, particularly in relation to sequential changes in serum HBV DNA levels and hepatitis B surface (HBsAg) antigen/hepatitis e antigen (HBeAg) status by age. Methods: The study was conducted on 190 HBV chronic carriers, aged 1-19 years who were followed for 19 years. 160, 99 and 123 were traced at 5, 9 and 19 years later. All available samples were tested for HBsAg and HBeAg, whilst 170, 61, 63 and 81 were tested for HBV DNA at the baseline, and at 5, 9 and 19 years following recruitment. Results: In general HBeAg which correlated with high levels of HBV DNA was lost at a much faster rate than HBsAg. 86% of the carriers who were recruited at the age of 1-4 yrs lost HBeAg by the age of 19 years compared to 30% who lost HBsAg. HBeAg negative carriers had serum HBV DNA levels of < 105 copies per mL, HBV DNA positivity declined from 100% in 1-4 yrs old carriers at recruitment to 62.5%,60% and 88% at 5, 9 and 19 years respectively following recruitment. Conclusion: After 19 years of follow up, the majority of HBV surface antigen carriers had lost HBeAg positivity and had low levels of viral replication. However small proportions (10-20%) retained HBeAg and continue to have high levels of viral replication. [ABSTRACT FROM AUTHOR]

Reports on the potential risks involved with antiretroviral therapy to combat the HIV epidemic in Africa. Potential for short term gains such as reducing individual morbidity and mortality to be outweighed by the potential for the long term spread of drug resistance in the virus; Principal factors leading to drug resistance include intermittent therapy and poor adherence to therapy; Implications of drug resistance by the HIV virus; Suggestion of evidence that drug treatment in Africa is low compared with that in industrialized nations; Difficulties with antiretroviral programs in Africa.

Most human cytomegalovirus (HCMV) genes are highly conserved in sequence among strains, but some exhibit a substantial degree of variation. Two of these genes are UL146, which encodes a CXC chemokine, and UL139, which is predicted to encode a membrane glycoprotein. The sequences of these genes were determined from a collection of 184 HCMV samples obtained from Africa, Australia, Asia, Europe, and North America. UL146 is hypervariable throughout, whereas variation in UL139 is concentrated in a sequence encoding a potentially highly glycosylated region. The UL146 sequences fell into 14 genotypes, as did all previously reported sequences. The UL139 sequences grouped into 8 genotypes, and all previously reported sequences fell into a subset of these. There were minor differences among continents in genotypic frequencies for UL146 and UL139, but no clear geographical separation, and identical nucleotide sequences were represented among communities distant from each other. The frequent detection of multiple genotypes indicated that mixed infections are common. For both genes, the degree of divergence was sufficient to preclude reliable sequence alignments between genotypes in the most variable regions, and the mode of evolution involved in generating the genotypes could not be discerned. Within genotypes, constraint appears to have been the predominant mode, and positive selection was detected marginally at best. No evidence was found for linkage disequilibrium. The emerging scenario is that the HCMV genotypes developed in early human populations (or even earlier), becoming established via founder or bottleneck effects, and have spread, recombined and mixed worldwide in more recent times.

We studied mortality among subjects with human immunodeficiency virus (HIV)-1 and HIV-2 infection in relation to GB virus (GBV)-C coinfection. No significant differences in mortality were seen between subjects with and subjects without GBV-C coinfection who also had either HIV-1 or HIV-2 infection. No association between GBV-C and HIV plasma virus loads or CD4 cell count was observed.