Zinc supplements are a safe, simple, and cost-effective method of reducing diarrhoea and pneumonia in children infected with HIV, concludes a randomised trial in this week's issue of The Lancet.
Previous studies have shown that zinc supplements can reduce the incidence of diarrhoea and pneumonia in children in resource-poor settings. However, the HIV virus requires zinc for its structure and function, and zinc activates lymphocytes that are target cells for HIV-1 replication, leading to fears that zinc supplementation might stimulate HIV replication. For these reasons the safety of zinc supplementation in children with HIV-infection has been uncertain.
To study the effect of zinc supplementation, William Moss (Johns Hopkins School of Public Health, Baltimore, MD, USA) and colleagues recruited 96 children, aged between 6 months and 5 years, from Grey's Hospital in Pietermaritzburg, South Africa. The team randomly assigned 96 children to receive 10mg of zinc or a placebo daily for six months. All children in the study were receiving cotrimoxazole, an antibiotic which can reduce the incidence of bacterial infections in children and adults with HIV infection.
The investigators found that zinc supplementation did not result in an increase in HIV viral load. However, children receiving zinc had less watery diarrhoea, one of the most common infections seen in children with HIV (diagnosed at 7.4% of clinic visits in the zinc group, compared to 14.5% of the placebo group, p=0.001). Diarrhoea is one of the main causes of weight loss, wasting and stunted growth in children with HIV.
Children who received zinc experienced a median weight gain of 7% over six months of follow-up, compared to a 2% gain in the placebo group (p=0.02).
The incidence of pneumonia was also lower in the zinc group, although the difference was not quite statistically significant.
Fewer children who received zinc died during follow-up, although the difference was not significant.
The authors state that zinc supplementation should be used as an adjunct therapy for children with HIV-1 infection.
Dr Moss states: "Few interventions are available to reduce morbidity in children with HIV-1 infection in resource-poor countries. Although UNAIDS, WHO, and their partners are committed to providing antiretroviral therapy to three million people by the end of 2005, antiretroviral therapy and prophylaxis for opportunistic infections are not accessible for many children. Consequently, more than half these children die before the age of three years, most commonly of respiratory tract infections and diarrhoeal diseases…Zinc supplementation could be a simple and cost-effective intervention to reduce morbidity and mortality in children with HIV-1 infection…Programmes to enhance zinc intake in deficient populations with a high prevalence of HIV-1 infection can be implemented without concern for adverse effects on virus replication."
Babat R et al. Safety and efficacy of zinc supplementation for children with HIV-1 infection in South Africa: a randomised double-blind placebo-controlled trial. The Lancet 366: 1862-1867, 2005.