LLH partner Felix Lankester on how a project integrating rabies and human intestinal worm control could also benefit livestock health.
Earlier this year we began our first field season for the Gates-funded Grand Challenges project, ‘Integrating community-directed interventions against neglected tropical diseases in Tanzania’. In short, we are investigating whether it is cost effective to couple mass dog rabies vaccination with mass worming of people in hard-to-reach communities such as Maasai villages in northern Tanzania.
In the developing world, rabies and worms continue to exert significant impacts on public health, with rabies alone killing more than 60,000 people (mainly children) every year. Intestinal worms, which infect more than a billion people, are the world’s biggest causes of physical and intellectual growth retardation.
If our research shows that control programmes are improved by being coupled together, then this could have an impact on global efforts to eliminate these two diseases.
Straddling the rather separate worlds of human and veterinary medicine, the project falls under the heading of a One Health initiative as we are trying to link together interventions targeting animals and people. For this reason, the project has been incredibly complicated to organise, with many introductory meetings to introduce the concept to the various, rather doubtful, stakeholders.
Consequently when we held our first day of field activities, having set up our dual clinic in the centre of Oldonyowas, a Maasai village in the Loliondo District (just to the east of the Serengeti National Park), we were doubtful whether anybody would to turn up. However, with the rain holding off and a blue sky overhead, we were surprised and delighted to see scores of Maasai villagers turning up for treatment, many bringing their children and their dogs with them. And by the end of the first day we had vaccinated just under 100 dogs and wormed over 400 people. Not bad for a first day.
The project will target 24 villages, some of which will receive dog vaccination and worming separately whilst the rest will receive the integrated approach. This will allow us to investigate whether linking the interventions together has an impact on coverage.
We are also collecting socio-economic data that will enable us to quantify any savings in time and cost that may result from the integrated approach.
We are now approaching the half way mark for the project and, although we are some way off analysing the data to see what impact the integrated strategy has on the delivery of these two important health interventions, we have noticed one really interesting finding: that many primary-school age children, whose parents have not been able to afford to enroll them in school, are bringing their dogs to our clinics.
As a result their dogs are being vaccinated and, importantly, these children who would have been missed by the school-based national control programmes, have received treatment for worms.
This preliminary data is encouraging as local elimination of worms will depend on a large proportion of residents being treated regularly. If there are large numbers of children who are not attending school, the programmes will need to find a way of targeting them too. This new community-based integrated approach may be one way to do that.
Furthermore, integrating the delivery of drugs to control some of the other prevalent human and veterinary health problems can also be considered.
For example, in the pastoralist areas where this project is being carried out we have heard numerous reports of sheep and goats suffering a central nervous system disease called coenurosis. The disease is caused by the larval stage of the Taenia multiceps tapeworm, which infects the small intestines of carnivores such as dogs.
Consequently, including worming of dogs within the integrated programme would likely bring further benefits, as it would have a dramatic impact on a livestock disease that is causing significant losses to pastoralists in northern Tanzania.