Recent reports draw attention that Guinea Worm persisted in small numbers in 2017 in two countries, Chad and Ethiopia. Mali and South Sudan were the only other two countries monitored because of recent cases, but each reported none for 2017.
We recall that 32 and 23 years have passed since the challenge to eradicate the disease was posed and the hoped for date of eradication was to be achieved. There is no doubt that the 30 cases reported in 2017 is a gigantic drop from the 3.5 million estimated globally when the war on the worm started in 1986.
To date eradication has been achieved for only small pox (though its reemergence from labs as a potential biological war agent is feared). Could it return as global warming melts permafrost (and bodies) in the permafrost of northern latitudes?
Besides Guinea Worm, only polio and malaria have received calls for eradication (malaria for the second time in history). One wonders if even small pox could be eradicated in today’s world of conflicted and failed states – the last case of smallpox was in Somalia. Both Ethiopia and Chad border South Sudan’s civil conflicts.
What had made guinea worm, like smallpox, imminently eradicable was the fact that humans were the main reservoirs of infection (not counting the defenseless crustacean, the cyclops, that served as an intermediate host for work larvae). That has not changed. WHO observed that in Ethiopia both baboons and dogs have been infected with guinea worm in the same communities where humans suffer from the disease. While it was possible to ‘contain’ the infection in dogs, that is preventing them from contaminating water supplies, it was not surprisingly difficult to do the same for baboons. The dog problem has existed in Chad for at least 5 years.
Another problem in Ethiopia was the infection of seasonal laborers who could potentially take the disease back to other areas of the country. Although a system of rewards had been put in place this did not lead to the timely identification of all cases by either community members or health workers.
The road to disease eradication is clearly not a straight line from A to B. The twists and turns should be expected as time passes because ideally an eradication should be a short-term effort that is time-limited in order to provide a clear focus and adequate funding on the end goal.
What are the implications for malaria and polio? Conflict led to the hiding of polio cases in Nigeria and longer term efforts allowed vaccine derived poliovirus to emerge. Malaria is now found in Monkeys in Malaysia and Brazil, and parasite resistance to medicines and vector resistance to pesticides threatens effective interventions.
Time is not a commodity that favors eradication. In these days of plateauing financial support for global health, the call for eradicating deadly and economically debilitating infections needs to be louder.