Urinary schistosomiasis questionnaires on Zanzibar (Unguja)

From 2nd June to 15th July, 2005, James Rudge, an MSc Modern Epidemiology student at Imperial College, worked with the Helminth Control Laboratory in Zanzibar (Unguja) with funding from the SCI.

From 2nd June to 15th July, 2005, James Rudge, an MSc Modern Epidemiology student at Imperial College, worked with the Helminth Control Laboratory in Zanzibar (Unguja) with funding from the SCI. This is a brief account of his experience of fieldwork on the island.

“Welcome to our beautiful island!” - I hear the friendly greeting familiar to most westerners strolling through Stone Town, the principle town on Unguja island of the Zanzibar archipelago. As usual, a local tout is trying to enrol me on a tour. After explaining that I’m here for research rather than recreation, he seems happy to make small talk instead of money: “What kind of research?” “Kichocho”, I reply, using the local term for schistosomiasis. “I see. But I think there is no problem of kichocho in Zanzibar?”

This typifies the response of several people I meet in Stone Town. Indeed, in the town, and on the on the idyllic beaches for which Zanzibar is famous, with their tourist resorts and clear turquoise waters, it is easy to believe that there is no problem. Take a trip further inland however, and it’s a different story. In these poor rural communities, where urinary schistosomiasis is endemic, passing blood in your urine is a ‘normal’ part of growing up.

As an epidemiology masters student at Imperial College London, I spent 6 weeks in Zanzibar working with the team at the recently opened Helminth Control Laboratory Unguja (HCLU) – the hub of activity for the Ministry of Health’s “Kick Out Kichocho” campaign. My project focused on Chaani, a village in the north of the island where 50% of school children are infected. Using a combination of foot-mapping, snail surveys, and questionnaires, the main objective of my fieldwork was to pinpoint foci of transmission in Chaani, and investigate behavioural patterns which could be predisposing certain individuals to higher risks of infection.

The most obvious suspect as a source of infection was a stream running through the area, along which human contact was immediately apparent. Despite the availability of well and tap water, many still choose the stream for washing clothes as the softer water allows them to economise on soap. In the hot climate, children playing in the stream was to be expected – some sites looked so inviting I was tempted to jump in and cool down myself!

Out in the field we were always warmly welcomed by the community, and often accumulated a sizeable audience of children understandably bewildered to see a strange white guy, clad in rubber waders and marigold gloves, rooting around for snails in their back garden. The snails initially proved to be surprisingly elusive, however. Luckily the local school children were much more cooperative, not to mention delightful to work with. Questionnaires proved a simple and effective tool for obtaining information on their water contact behaviour. Moreover, locations frequently reported by children diagnosed with schistosomiasis in a recent screening survey allowed us to focus our search for transmission sites, and in fact led us to a large and infected Bulinus snail colony.

GPS was an invaluable tool for mapping the location of such sitesThis process of pinpointing transmission sites not only facilitates more targeted control strategies, but will hopefully also reveal sites suitable for future studies aimed at testing the effectiveness of novel interventions, such as the introduction of refractory snail species as a form of biological control. Such strategies may be necessary alongside the current mass drug administrations in the pursuit to “Kick Out Kichocho” to ensure that the positive effects of chemotherapy are longer lasting.