HIV vertical transmission rate determinations are subject to differing definitions and therefore different rates. The Pediatric Pulmonary and Cardiovascular Complications of Vertically Transmitted HIV Infection Study Group

CD4/CD8 T-cell ratio predicts HIV infection in infants: the National Heart, Lung, and Blood Institute P2C2 Study

BACKGROUND

In resource-poor regions of the world, HIV virologic testing is not available.

OBJECTIVE

We sought to evaluate the diagnostic usefulness of the CD4/CD8 T-cell ratio in predicting HIV infection in infants.

METHODS

Data from the 3- and 9-month visits for non-breast-fed infants born to HIV-infected mothers enrolled (1990-1994) in the Pediatric Pulmonary and Cardiac Complications of Vertically Transmitted HIV Infection Study (mother-to-child transmission of HIV, 17%) were analyzed. Data from the 3-month visit for infants enrolled (1985-1996) in the Perinatal AIDS Collaborative Transmission Study (mother-to-child transmission of HIV, 18%) were used for validation.

RESULTS

At 3 months of age, data were available on 79 HIV-infected and 409 uninfected non-breast-fed infants in the Pediatric Pulmonary and Cardiac Complications of Vertically Transmitted HIV Infection Study. The area under the curve (AUC) of the receiver operating characteristic curve at 3 months was higher for the CD4/CD8 ratio compared with the CD4(+) T-cell count (AUC, 0.83 and 0.75; P = .03). The mean CD4/CD8 ratio at the 3-month visit was 1.7 for HIV-infected infants and 3.0 for uninfected infants. A CD4/CD8 ratio of 2.4 at 3 months of age was almost 2.5 times more likely to occur in an HIV-infected infant compared with an uninfected infant (test sensitivity, 81%; posttest probability of HIV, 33%). Model performance in the Centers for Disease Control and Prevention Perinatal AIDS Collaborative Transmission Study validation test (224 HIV-infected and 1015 uninfected 3-month-old infants) was equally good (AUC, 0.78 for CD4/CD8 ratio).

CONCLUSION

The CD4/CD8 T-cell ratio is a more sensitive predictor of HIV infection in infants than the CD4(+) T-cell count.

CLINICAL IMPLICATIONS

The CD4/CD8 T-cell ratio can be used with caution to predict HIV infection in children.

Simian immunodeficiency virus infection in wild-caught chimpanzees from cameroon

Simian immunodeficiency viruses (SIVcpz) infecting chimpanzees (Pan troglodytes) in west central Africa are the closest relatives to all major variants of human immunodeficiency virus type 1 ([HIV-1]; groups M, N and O), and have thus been implicated as the source of the human infections; however, information concerning the prevalence, geographic distribution, and subspecies association of SIVcpz still remains limited. In this study, we tested 71 wild-caught chimpanzees from Cameroon for evidence of SIVcpz infection. Thirty-nine of these were of the central subspecies (Pan troglodytes troglodytes), and 32 were of the Nigerian subspecies (Pan troglodytes vellerosus), as determined by mitochondrial DNA analysis. Serological analysis determined that one P. t. troglodytes ape (CAM13) harbored serum antibodies that cross-reacted strongly with HIV-1 antigens; all other apes were seronegative. To characterize the newly identified virus, 14 partially overlapping viral fragments were amplified from fecal virion RNA and concatenated to yield a complete SIVcpz genome (9,284 bp). Phylogenetic analyses revealed that SIVcpzCAM13 fell well within the radiation of the SIVcpzPtt group of viruses, as part of a clade including all other SIVcpzPtt strains as well as HIV-1 groups M and N. However, SIVcpzCAM13 clustered most closely with SIVcpzGAB1 from Gabon rather than with SIVcpzCAM3 and SIVcpzCAM5 from Cameroon, indicating the existence of divergent SIVcpzPtt lineages within the same geographic region. These data, together with evidence of recombination among ancestral SIVcpzPtt lineages, indicate long-standing endemic infection of central chimpanzees and reaffirm a west central African origin of HIV-1. Whether P. t. vellerosus apes are naturally infected with SIVcpz requires further study.

Nutrition in paediatric human immunodeficiency virus infection

The nutritional condition of children with human immunodeficiency virus (HIV) infection continues to be a problem both in developed and developing countries. HIV-infected children grow below normal standards in both height and weight when compared with HIV-exposed non-infected children. These patterns persist over time. It is possible that acute infectious episodes and increased HIV viral burden contribute to decrements in all growth variables. Potential aetiologies for abnormal growth include inadequate dietary intake, gastrointestinal malabsorption, increased energy utilization and psycho-social problems. It is likely that all these factors contribute to the growth problems of these children to some extent. With the development of protease inhibitor anti-retroviral therapy and highly-active anti-retroviral treatment regimens, children with HIV infection in developed countries are living longer with a chronic illness. New nutritional problems have arisen with the development of the fat redistribution syndrome or lipodystrophy. Emerging problems are now being recognized, with the development of insulin resistance and truncal obesity which may potentially lead to premature cardiovascular disease.