Blood, sweat and stool
In Chad, Swiss researchers are investigating parasitic diseases in humans and animals. The aim is to improve the health of vulnerable nomadic communities. By Christian Heuss
It’s with a handshake and a black goat that a research deal is sealed with the clan chief of the Foulbé nomads. "Only through long-lasting relationships and mutual respect can we research their health", says Jakob Zinsstag from the Swiss Tropical and Public Health Institute in Basel, who, over the last twenty years, has often been here on the southern banks of Lake Chad.
So with the goat safely stowed in the luggage area, ready for handover when we reach the nomads, our 4x4 vehicle drives out of the town of Gredaya, heading further and further into the green bush of the Sahel. The going is bumpy, and the puddles in the mud road testify to the recent rains. From the trees and bushes, there’s the twittering of the first migratory birds to arrive from Europe. For outsiders, every fork in the road adds to the sense of disorientation. The only person who seems to know exactly where we’re going is Ali Baye Abba Abakar. “My brain is like sat-nav”, he laughs. Along with the nurse Hadjé Falmata and the driver, Abba Abakar is a crucial member of the team led by Zinsstag’s doctoral student Helena Greter. Abba Abakar speaks the local languages and has stored on his mobile the telephone numbers of many nomadic families.
The Foulbés, the Goranes and the Kuris are very different in their nomadic lifestyles, their social structures and the routes they take, but they all belong to the most vulnerable population groups in one of the world’s poorest countries. Because they have no fixed place of residence and move from one pasture to the next along with their several hundred cattle, donkeys and carts, they fall through the gaps in the state’s net. Nomadic children have no schools, have poor access to medical services and are prone to a high rate of child mortality.
Zinsstag pursues a systematic approach. "If we want to improve the health of these people, then we have to understand how they live". Health is not just a medical problem, it’s just one aspect of the overall socio-economic picture. That is why Zinsstag, a veterinarian and epidemiologist, does not just work together with doctors of human medicine but also with geographers, ethnologists and public health experts.
Despite Abba Abakar’s sense of direction, it’s only after a difficult search that Greter and her team find the nomads. Their cattle had broken out that afternoon, which meant that they’d had to relocate their overnight camp. Now, dotted across a space families camp with their children at the base of a large tree. They have their cooking areas here, their colourful canvas tents and all their meagre belongings. Behind them, the cattle are grazing. As daylight fades, the smoke from little fires serves to ward off the malaria-carrying anopheles mosquito.
Shortly after the research team arrives, the men of the group sit with them in a circle. Over cups of bitter-sweet black tea, Greter explains her research plans. She and her team would like to visit the group three times in the coming months to examine both people and animals for parasitic worms. Her work is geared to solving a health problem that the nomads themselves have identified. Their cattle are often affected by a worm – the large liver fluke – which reduces their ability to give milk and consequently also their market price. The people also host a similar flatworm, the schistosoma haematobia. This parasite leads to schistosomiasis, an often chronic illness that weakens those who suffer from it, and that can lead to blood in the urine and even to death. Earlier examinations showed at least one in ten children to be infected.
Here, humans and animals share the same living space. So are there similarities in how they are all infected by these parasites? This is the question occupying Greter. At their watering holes, she collects water snails, which serve as intermediate hosts during the life-cycle of the flatworm. Greter determines how many of the snails carry worm larvae. Using this data and a mathematical model, she and Zinsstag want to determine the best point in time for a medical treatment to be applied simultaneously to both men and animals. Zinsstag is convinced that "this way, we hope to eliminate the parasitic infestation completely in the long term".
Greter speaks French, Abba Abakar translates. The nomads ask a lot of questions, and there is much laughter. Greter wants to examine fifteen animals and fifteen people in the next 24 hours. She keeps to a strict protocol that was agreed by ethics commissions in both Switzerland and Chad. She has medicines with her, in case she discovers any illness.
Caught with a lasso
With a clear, starry night spent under only mosquito nets, the hard manual work begins shortly after daybreak. Greter has to examine dung samples in order to find out which cattle are infected with worms. The Foulbé men catch these impressive beasts with a lasso and hold them fast by the horns. Greter plunges her arm – clad in a green plastic glove – deep into the rectum to draw out fresh dung.
In the early morning, things are already busy at the campsite. While the men are helping Greter, the children are standing around and enjoying the unusual sight of a researcher at work. Meanwhile, the women are seeing to the food. Some of them are milking cows, others are churning butter and grinding corn into a kind of polenta pulp. After a short break, Greter sits with the men to discuss the examinations she needs to carry out among their families. She picks a random sample of men and women from the group and supplies each with two white plastic cups – one for a stool sample, the other for urine. Falmata, the nurse, will then use a detailed questionnaire to ask them about their general state of health.
By ten in the morning, the sun is burning mercilessly in the sky, and time is pressing. Greter sets up her field laboratory in the shade of a bush. Her solar-powered microscope stands on a folding table. She had practised every step of the process for analysing urine and faeces back home in Basel – but now, out here in the field, everything is different. Blowflies flock to the dung samples, and Greter has to adjust both the staining method and her own timing. But with her second dung sample she immediately recognises the worm eggs with their typical, spindle-shaped silhouettes.
In the coming months, Greter will conduct hundreds of examinations, all of which will be very carefully documented and statistically evaluated. This will not just provide a more precise picture of the health situation of the nomads. Greter will also improve her overall knowledge of nomadic life in Chad. "It is an extraordinary opportunity", she says, while putting the next specimen slide under her microscope.
Christian Heuss runs the Communication Department of the Swiss Tropical and Public Health Institute in Basel.
(From "Horizons" No. 101, June 2014)