For those new to the deworming debate, see here, here, here, here and here (Macartan’s response is worth reading in detail). The famous original deworming study was conducted in western Kenya, so it’s nice to get the perspective of Kenyan scientist Dr. Charles Mwandawiro. Dr Mwandawiro is the Chief Research Officer and Assistant Director of Partnership and Collaboration at the Kenya Medical Research Institute (KEMRI). He writes:

I have studied and seen myself the negative effects chronic parasitic worm infections have on childhood development. Children with severe or recurring infections have impaired growth and cognitive development because the worms lodge in their bodies, stealing the nutrients a child is able to take in. Heavy infections can result in serious clinical disease. To combat infection and give our children a chance at good health, many countries, including Kenya, run school-based mass deworming programmes that have been shown to be a simple and cost-effective strategy to reduce the disease burden of parasitic worms in school-age children, the group at highest risk.

Safe, low-cost drugs are available to treat intestinal worm infections and are the standard of medical care. The World Health Organization (WHO) recommends periodic mass treatment in areas where worm infections are above certain thresholds. Some have challenged this WHO policy, accepting that those who are known to be infected should be treated, but questioning whether the existing evidence base is strong enough to support mass treatment.

Let me say unequivocally: Mass school-based deworming works. Just three years ago, Kenya launched a national deworming program. Prevalence of parasitic worms has been reduced from 35% to 17% and as low as 6% right after a deworming round. Our focus in the National Deworming Programme in Kenya is on the reduction of infection and possibly even elimination of the public health threat of worms.

More on this here.

The WormWars are a fantastic lesson on the complications of policymaking. Contributors have weighed in from different perspectives: Does school-based mass deworming work in reducing the prevalence of parasitic worms?; what is the opportunity cost of deworming kids, thereby improving their developmental prospects?; Does a kid’s health trump everything?; did the Busia intervention increase school attendance?; did the authors adequately address the methodological challenges involved in the study? What is a policymaker to make of all of this?

Because of the complicated nature of the questions involved, the original study is being asked to bear more weight than it can withstand. Like Macartan, I think the focus should be on the school attendance outcomes, which was the primary goal of the original study. This, of course, does not mean we should completely disregard the very important questions relating to the health and developmental prospects of kids in locales with high prevalence rates of parasitic worms. Because of the long-term effects of malnutrition on cognitive development, it is reasonable to make the case that deworming kids should trump most competing uses of resources.

Policymakers, if you can, Please. Deworm. All. The. Kids.

H/T Chris Blattman