Waking up to reality?

A woman lies dying in a small rural village in southeast Uganda. Her family does not want to talk about it and they seek no treatment for her. They believe she has AIDS. But Uganda is the one country in sub-Saharan Africa where HIV infection rates are falling. The cause of her illness is not through contact with her partner but through living in close proximity to the cattle that are kept in the village. This woman, has sleeping sickness - a disease, which could have been treated but, more tragically, should perhaps have been prevented.

Sleeping sickness is endemic in southeast Uganda and western Kenya and has, in the past, given rise to horrendous epidemics. At the turn of the last century it is estimated that over 300,000 Africans living around the shore of Lake Victoria died during an epidemic of the disease, which was previously unknown in the region. Caused by the trypanosome parasite Trypanosoma brucei rhodesiense, which is carried by the tsetse fly, the disease is fatal if not treated. But even treatment is associated with severe side effects and up to 5% of people suffering in the later-stages of sleeping sickness will die as a result of the chemotherapy. Even if the drugs are available, it costs US$250 to treat one person over a one-month period in hospital. Second only to the cost of treating malaria, the treatment of human sleeping sickness is currently a drain not only on the health services but on the resources of families who stay in the hospital to help care for their sick relations.

credit: Sue Welburn, CTVM, Univ. of Edinburgh

In southeast Uganda, it has been shown that domestic livestock are the principle reservoir of T.b.rhodesiense. Treatment of the disease in cattle is relatively inexpensive and straightforward - dependent only on the correct application of a single shot of an appropriate trypanosome drug. However, underdosing is common and could increase with the privatisation of veterinary services. With the potential for drug resistance to develop and no back-up drugs likely to be made available, the possible impact on rural people is severe, both through the effect of the disease on their livestock and also on their own health.

The impact of sleeping sickness is not just of concern for areas where the disease is endemic. During the last two years, there have been serious concerns about the geographical spread of sleeping sickness, north of the traditional disease focus in southeast Uganda, to areas previously free of the disease. The first case of human sleeping sickness was detected in Soroti District, Teso region in December 1998. There have since been over 100 recorded cases but this is probably only a small proportion of the true number. Sleeping sickness is now present in the area. It is not going to go away and it is spreading: in two years the disease has spread over 80km from the original focus.

But, in a previously unaffected area that is over 150km away from the original sleeping sickness focus in Busoga, why are people now at risk from this disease? The answer lies in the movement of infected animals linked to the essential livestock restocking activities being promoted in the area. The restocking of livestock in the Teso area has been identified as a central activity for the development of the region and 250 million Ugandan shillings have been allocated to carry out this process. However, animals being brought in from the south are being sold and moved without any precautionary measures to prevent T.b.rhodesiense from becoming introduced in new areas. Further expansion of the disease to Masindi District, north-west of the traditional sleeping sickness focus, has already been recorded. Although the involvement of cattle in the spread of the disease has yet to be investigated, scientists are concerned that this is the most probable cause. And, with several markets in the southeast selling cattle to the north, it is only time before the parasite invades other areas and more people become infected.

credit: Sue Welburn, CTVM, Univ. of Edinburgh

The involvement of cattle movements in spreading sleeping sickness to the Soroti district has been confirmed through the use of hospital records, which have been used to map the spread of the disease. It was immediately evident that early cases were centered on the main cattle market. Investigations at the Livestock Research Institute (LIRI) at Tororo used isoenzyme analysis to determine that the strain of the parasite circulating in Soroti was the same predominant strain in the area from which over 50% of the cattle originated.

Although LIRI has already provided training to medical staff and drugs for treating sleeping sickness, further research is being conducted with the support of scientists at CTVM in the UK to assess parasite prevalence; quantify the risk and burden of sleeping sickness; and determine the cost-effectiveness of control measures. The resulting information should aid policy-makers to identify suitable control strategies, to minimize the risk of restocking programmes and disseminate appropriate information to farmers, veterinarians and health service staff. Without such action, the re-stocking programme intended to revitalize livestock production in Teso will result in the further undermining of the health and vulnerable livelihoods of the rural poor.

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