Survival and failure to thrive in the SIV-infected juvenile rhesus monkey

In AIDS patients, wasting in adults and failure to thrive in children are c ommon and devastating problems. Weight loss in rhesus macaques infected wit h simian immunodeficiency virus (SIV) has not been well characterized. The purpose of this study was to determine growth curves in SIV-infected juveni le macaques to determine the effects of SIV infection on body weight and gr owth. Medical records of seven juvenile male SIV-infected macaques were ret rospectively reviewed to determine body weights, survival time, CD4 count, and viral load. Mean age and body weight at the time of inoculation were 63 .3 weeks and 2.4 kg, respectively. Mean survival was 73.7 weeks, and mean b ody weight at the time of death was 3.0 kg, whereas the published mean body weight for this age of male rhesus macaque is 4.1 kg. Compared with the li near growth pattern of normal animals, the growth pattern for the SIV-infec ted animals exhibited strong nonlinearity with an inflection point at the m ean survival of 74 weeks. After this time point, the discrepancy between gr owth curves for infected and healthy animals increased at a greater rate. B ody weight correlated inversely with viral load (r = -0.368; p = .003) but there was no correlation between body weight and CD4 count. The results of this study suggest that failure to thrive is a consequence of SIV infection and may be related to severity of infection.