Tackling land-use conflicts around game parks must form part of the national strategy to stop the spread of sleeping sickness, warn doctors fighting the disease in Tanzania.
Tanzania’s booming tourism industry has been driven largely by its wildlife parks, which contribute almost US$1.8 billion a year to the economy. But the expansion of these areas, which now cover more than a third of the country, has major consequences for the rural population.
A growing number of communities find their villages "squeezed" between wildlife areas, putting them at risk from tsetse flies that spread Trypanosomiasis or sleeping sickness, a debilitating and often fatal disease.
The impala, wildebeest, buffalo, giraffe, zebra and rhino in the parks are seen as excellent reservoirs for the disease, which is most prevalent from Kigoma at Lake Tanganyika to Arusha in the northern part of the country.
Imna Malele, researcher at the Tsetse & Trypanosomiasis Research Institute (TTRI) in Tanga, wants planning to form part of the national strategy to tackle the disease. “Proper plans on land use could help in sleeping sickness control. I would suggest that parks be surrounded by buffer zones, and wildlife management areas, and in these areas tsetse control should be stepped up [to stop the flies reaching the villages].”
Sleeping sickness is endemic in Tanzania. In advanced stages, the disease attacks the central nervous system and people experience changes in personality, alteration of the biological clock - hence its name - and difficulty walking and talking. These problems can develop over many years and if not treated, result in death.
Furaha Mramba, director of TTRI, said efforts to stamp out the disease faced numerous challenges in Tanzania - from scarce resources to the laborious process needed to develop traps and targets and poaching, which disturbs animal populations and transfers the fly larvae outside the parks.
In addition, one of the biggest challenges is the increasing population, expected to grow by 2 percent in 2012, according to the World Bank, with more than 75 percent of the total 37 million living in rural areas.
Mramba said: “All the huts are concentrated right along the borders of the parks, which is aggravating the problem. There are ‘hedge effects’ of people living head-to-toe with the border of national parks. Land use is a real problem.”
Ignas Lejora, ecology manager at the Tanzania National Park Authority (TANAPA), said: “There’s no clear-cut solution – maybe the way forward is to plan [land use] in these infested areas.”
Experts fear the scale of the problem in Tanzania may be far greater than previously thought, due to widespread misdiagnosis and its prevalence in the most rural parts of the country. Malaria and hepatitis are often diagnosed as the cause of severe illness, particularly in children, when in fact the cause may well be sleeping sickness.
Photo: Mrs B/Flickr
|The buffalo is among the reservoirs for Trypanosomiasis or sleeping sickness|
While the World Health Organization (WHO) says reported cases of sleeping sickness in Tanzania have dropped to fewer than 100 a year, Mramba said it was very difficult to say whether mortality rates had gone down or not. “It’s very deceptive. It’s a disease of ‘remote people’ who will often go to local healers for treatment; we don’t have hospitals in these areas. The symptoms look the same as HIV and malaria. We cannot say how many are dying in the endemic areas because we don’t have the data. We need to make sure that we are training numbers of medical people to go to these remote areas from the hospitals and give them microscopes [crucial for analyzing blood samples]. There is still a long way to go to address the problem.”
One of the biggest challenges Tanzanian health authorities face is the sheer scale of the areas they need to cover. The Serengeti, for example, covers more than 15,000 sqkm. So, in addition to using Nze traps, which use blue targets treated with insecticide that attract flies, in principle it would be possible to cover large areas of land by spraying insecticides from aircraft.
However, use of strong chemicals and the impact this might have on the local eco-system are major concerns. This method was used fairly effectively in both Namibia and Botswana. It was tested in some parts of Tanzania in areas of Babati near Lake Manyara in the northwest and Magugu, nearer to the central capital Dodoma.
Malele said while aerial spray was possible in Tanzania it would depend on the authorities’ view and funding. She said: "Tsetse control, even by traps, is still an issue with TANAPA and the Ministry of Natural Resources and Tourism, as they believe tsetse are an important part of the ecology.”
Another controversial control method is SIT, an insect birth control. The tsetse are mass bred in a specially designed fly factory. Male flies are then sterilized with low doses of gamma radiation and released over infested areas. When sterile males mate with wild females, no offspring are produced and the pest is steadily eliminated. SIT's potential was successfully demonstrated on Zanzibar where sleeping sickness has been totally eradicated.
Any method designed to address the problem on a national scale needs considerable funding, but there is increasing optimism worldwide that the disease can be wiped out in the next eight years. At a meeting in London in January, Margaret Chan, WHO Director-General, announced a “road map” for dealing with 17 neglected diseases in a co-coordinated effort with 13 drug companies, the Gates Foundation, and others. Sleeping sickness is one of the 10 it believes can be eliminated or controlled by 2020.