Eliminating Human African Trypanosomiasis: Where Do We Stand and What Comes Next>

I n the early part of the twentieth century, human African trypanosomiasis (HAT), also known as sleeping sickness, decimated the population in many parts of sub-Saharan Africa. In the 1930s, the colonial administrations, conscious of the negative impact of the disease on its territories, established disease control programmes. Systematic screening, treatment, and follow-up of millions of individuals in the whole continent led to transmission coming to a near halt by the 1960s. With the advent of independence in most countries where HAT was endemic, the newly independent authorities had other priorities to deal with. The rarity of HAT cases, and a decline in awareness of how the disease could return, led to a lack of interest in disease surveillance. Over time the disease slowly returned, and some thirty years later, flare-ups were observed throughout past endemic areas (Figure 1). Since 1995, the World Health Organization (WHO) has on many occasions expressed its concern about the rise in HAT cases. The World Health Assembly has passed several resolutions in an attempt to stem this rise. However, social upheavals, wars, and population movements, combined with lack of awareness and shortage of funds, prevented any progress in interrupting transmission, and the disease continued to evolve and spread. In a 1997 resolution, WHO strongly advocated access to diagnosis and treatment and the reinforcement of surveillance and control activities, concurrently setting up a network to strengthen coordination among all those actively concerned by the problem [1]. As a consequence, the public and private sector granted stronger support to HAT surveillance, control, and research. HAT is a vector-borne parasitic disease that is fatal if left untreated. It is caused by a single-celled protozoa belonging to the Trypanosoma genus. Parasites are transmitted to humans by the bite of a tsetse fly (Glossina genus) that has acquired the infection from human beings or from animals harbouring the human pathogenic parasites (Figure 2). Tsetse flies, and subsequently sleeping sickness, are usually found in remote sub-Saharan rural areas where health systems are weak or non-existent. For reasons that are so far unexplained, there are many regions where tsetse flies are found but sleeping sickness is not. Sleeping sickness, coupled with nagana, the animal form of African trypanosomiasis, has been a major obstacle to sub-Saharan African rural development and a stumbling block to agricultural production. On the one hand, human infections reduce labour resources, while on the other, the animal disease …