In patients with HIV infection, total energy expenditure is reduced during episodes of weight loss. Reduced energy intake, not elevated energy expenditure, is the prime determinant of weight loss in HIV-associated wasting.

SUMMARY Sixty faecal samples, 39 from adults and 21 from neonates, were investigated by means of a simple scheme to isolate and identify any group D streptococci present. A number of differences were found between the two groups. Group D streptococci were absent from 43 % of the neonates compared with only 13 % of the adults; Streptococcus bovis was commoner in the neonates (23-8 %) than in the adults (5 %), and Streptococcus faecium was not isolated from any of the infant samples although it was common in the adult samples (25 %). The viable counts of Strep. faecium were found to be, on average, 100-fold lower than those of Streptococcus faecalis.The methods and results are discussed with reference to the clinical significance of group D streptococci, especially in bacterial endocarditis and carcinoma of the colon.Group D streptococci form part of the normal gut flora of man and animals, but the distribution of the various species within the group is still imperfectly understood (Medrek and Barnes, 1962). Most studies show that Streptococcus faecalis and Streptococcus faecium are common human gut commensals, while Streptococcus bovis and other species are less frequently present. Recently, attention has been focused on Strep. bovis, which has been shown to be an important cause of endocarditis. In a three-year study of streptococcal isolates, Parker and Ball (1976) showed that Strep. bovis was associated with 17i3 % of 317 cases of endocarditis, and that in the over-55 age group this organism was associated with nearly onequarter of the cases.More recently, Klein et al. (1977) have shown that the incidence of gut carriage of Strep. bovis is greatly increased in patients with carcinoma of the colon. Gross et al. (1975) devised a relatively simple scheme for identifying and speciating group D streptococci, which was shown by Facklam (1976) to give an accuracy of speciation of 98 5% in one large series.The present study is an investigation of group D streptococci isolated from faecal samples from three groups of patients-hospital neonates, adult inpatients, and adult outpatients-at Dulwich Hospital. The streptococci were identified by means of

Weight loss is a major manifestation of infection with the human immunodeficiency virus (HIV). Prospective analysis of weight change was performed in 30 male subjects with stage IV HIV infection over a period of 9-49 mo and weight change events (> 4 kg) related to contemporaneous clinical events. Two distinct patterns of weight loss were observed: episodes of acute severe weight loss and episodes of chronic unremitting progressive weight loss. Thirty-three acute episodes (median 9.1 kg in 1.7 mo) and 23 chronic episodes (13.2 kg in 9.5 mo) were identified. Twenty-seven of 33 (82%) acute weight-loss episodes were associated with nongastrointestinal opportunistic infections and 15 of 23 (65%) chronic episodes with gastrointestinal disease (P < 0.01). Weight loss was neither inevitable nor unremitting. Periods of weight stability (> 4 mo) occurred in 13 individuals (43%); 35 episodes of weight gain were identified, mostly related to recovery from opportunistic infection. These findings have important implications for our understanding of the natural history of weight loss in HIV infection.