Opioid addicts account for around a third of new cases of AIDS reported in the United States. Needle sharing cannot explain the high levels of infection in people who are addicted, says an article in the Journal of Infectious Diseases (2002;185:1826-9). It offers another possible explanation, reporting research on Rhesus monkeys which showed that those given opioids long term were more susceptible to simian immunodeficiency virus than those not given the drugs.

Scabies is known to be a pointer to the diagnosis of AIDS, and the association has been studied further in Brazil (AIDS 2002;16:1292-3). Severe, crusted scabies and Norwegian scabies should both arouse suspicion of retroviral infection with either HIV or HTLV1, or both.

Visitors to Mexico expect to get traveller's diarrhoea but they may not realise that one source of the infecting bacteria may be the sauces found on tables in most restaurants. Tests on green and red sauces in Guadalajara (Annals of Internal Medicine 2002;136:884-7) found that 47 of 71 specimens were contaminated with Escherichia coli. As a control, 25 specimens of sauces from restaurants in Houston, …