Routine worming of children seems to have little effect on growth or cognitive performance and investment in mass treatment programmes in developing countries may not be necessary, according to a review in the British Medical Journal (2000;320:1697).
Dr Rumona Dickson (lecturer, Liverpool school of tropical medicine) and colleagues looked at 30 randomised, controlled trials to see whether anthelmintic drugs, which included mebendazole, piperazine and albendazole, had any effect on growth or performance in cognition tests.
They found that, for up to one year of follow-up, the estimated pooled increases in weight were 0.38kg (95 per cent confidence interval 0.01 to 0.77kg) for single dose trials and 0.43kg (–0.61 to 1.47kg) for multiple dose trials. None of the studies that assessed cognitive function showed a significant difference between children who had been treated and those who had not.
The authors say that future trials should be conducted using similar design and should look at the significance of age, worm load and exposure to infection on growth and cognitive performance.