Abstract:
African trypanosomiasis, also known as sleeping sickness, is a neglected tropical disease caused by the protozoan parasites Trypanosoma brucei. The disease is transmitted to humans and animals by the tsetse fly, a bloodsucking insect found only in sub-Saharan Africa. African trypanosomiasis is characterized by two distinct stages: an early hemolymphatic stage and a late meningoencephalitic stage, which can be fatal if left untreated. Diagnosis of African trypanosomiasis is challenging, and treatment options are limited, with many drugs having toxic side effects. There is an urgent need for new diagnostic tools and treatments for this disease.
Introduction:
African trypanosomiasis is a parasitic disease that affects humans and animals in sub-Saharan Africa. The disease is caused by the protozoan parasites Trypanosoma brucei, which are transmitted by the tsetse fly. There are two subspecies of T. brucei that cause human African trypanosomiasis: T. b. gambiense, which is responsible for over 95% of cases, and T. b. rhodesiense, which accounts for the remaining cases.
Epidemiology:
African trypanosomiasis is endemic in 36 countries in sub-Saharan Africa, where an estimated 69 million people are at risk of infection. The disease is most prevalent in rural areas where there is a high density of tsetse flies. The World Health Organization (WHO) estimates that there were approximately 9779 cases of African trypanosomiasis in 2020, with 92% of cases reported in the Democratic Republic of the Congo.
Clinical features:
The clinical features of African trypanosomiasis can be divided into two distinct stages: an early hemolymphatic stage and a late meningoencephalitic stage. In the early stage, patients may experience non-specific symptoms such as fever, headache, joint pain, and malaise. As the disease progresses to the late stage, patients may develop neurological symptoms such as confusion, behavioral changes, and sleep disturbances. The late stage is also characterized by the presence of trypanosomes in the cerebrospinal fluid, which can lead to coma and death if left untreated.
Diagnosis:
Diagnosis of African trypanosomiasis can be challenging, as the clinical symptoms are non-specific and can be similar to those of other diseases. The diagnosis is usually confirmed by the detection of trypanosomes in blood or cerebrospinal fluid using microscopy or other diagnostic tests such as the card agglutination test for trypanosomiasis (CATT).
Treatment:
Treatment options for African trypanosomiasis are limited, and many drugs have toxic side effects. The drugs used for the treatment of the early stage of the disease include pentamidine and suramin, while the drugs used for the late stage include melarsoprol and eflornithine. However, these drugs have limitations, and the emergence of drug-resistant trypanosomes is a major concern. There is an urgent need for new drugs with better efficacy and safety profiles.
Prevention and control:
Prevention and control of African trypanosomiasis rely on a combination of strategies, including the control of tsetse fly populations, the use of insecticide-treated bed nets, and the screening of blood donors. The WHO has set a goal to eliminate African trypanosomiasis as a public health problem by 2030, and progress is being made towards achieving this goal.
