Central, East, and West Africa: Angola, Benin, Burkina Faso, Burundi, Cameroon, Cape Verde Islands, Central African Republic, Chad, Comoros, Congo (Brazzaville), Democratic Republic of Congo, Côte d'Ivoire, Djibouti, Equatorial Guinea, Eritrea, Ethiopia, Gabon, The Gambia, Ghana, Guinea, Guinea-Bissau, Kenya, Liberia, Madagascar, Malawi, Mali, Mauritania, Mauritius, Mayotte, Mozambique, Niger, Nigeria, Réunion, Rwanda, São Tomé and Principe, Senegal, Seychelles, Sierra Leone, Somalia, St. Helena (UK), Sudan, Togo, Uganda, Tanzania, and Zambia. In this area, entirely within the tropics, the vegetation varies from the tropical rain forests of the west and center to the wooded steppes of the east, and from the desert of the north through the Sahel and Sudan savannahs to the moist orchard savannah and woodlands north and south of the equator. Many of the diseases listed in the following section occur in localized foci and are confined to rural areas. They are mentioned so that the international traveler and the medical practitioner concerned can be aware of the diseases that can occur.
Anthropod Borne Diseases
Arthropod-borne diseases are a major cause of morbidity. Malaria in the severe Plasmodium falciparum form occurs throughout the area, except at altitudes over 2,600 meters (8,530 feet) and in the islands of Réunion and the Seychelles. Various forms of filariasis are widespread; endemic foci of onchocerciasis (river blindness) exist in all the countries listed except in the greater part of Kenya and in Djibouti, The Gambia, Mauritania, Mozambique, Somalia, Zambia, and the island countries of the Atlantic and Indian Oceans. However, onchocerciasis exists on the island of Bioko, Equatorial Guinea. Both cutaneous and visceral leishmaniasis can be found, particularly in the drier areas. Visceral leishmaniasis is epidemic in eastern and southern Sudan. Dengue fever occurs within this region. African sleeping sickness (African trypanosomiasis), in discrete foci, is reported in all countries except Djibouti, Eritrea, The Gambia, Mauritania, Niger, Somalia, and the island countries of the Atlantic and Indian Oceans. The transmission rate of trypanosomiasis is high in northwestern Uganda and very high in northern Angola, Democratic Republic of the Congo (mostly Equateur and Bandundu), and southern Sudan, and there is significant risk of infection for travelers visiting or working in rural areas. Relapsing fever and louse-, flea-, and tickborne typhus occur. Natural foci of plague6 have been reported in Angola, Democratic Republic of the Congo, Kenya, Madagascar, Malawi, Mozambique, Uganda, Tanzania, and Zambia. Tungiasis (skin penetration by larva of the female sand flea) is widespread. Many viral diseases, some presenting as severe hemorrhagic fevers, are transmitted by mosquitoes, ticks, and sand flies, which are found throughout this region. Large outbreaks of yellow fever occur periodically in the unvaccinated population.
Foodborne and Waterborne Diseases
Foodborne and waterborne diseases are highly endemic. Alimentary helminthic infections; the dysenteries; typhoid fever; hepatitis A and E; and diarrheal diseases, including giardiasis, are widespread. Cholera is actively transmitted in many countries in this area. Dracunculiasis (Guinea worm) infection occurs in isolated foci. Paragonimiasis (oriental lung fluke) has been reported from Cameroon, Gabon, Liberia, and, most recently, from Equatorial Guinea. Echinococcosis (hydatid disease) is widespread in animal-breeding areas. In 2002, only three African countries reported laboratory-confirmed wild poliovirus transmission: Nigeria, which accounts for 95% of all polio cases on the African continent; Niger; and Somalia. In addition, two polio cases among Angolan refugees in western Zambia demonstrate ongoing transmission in Angola. Schistosomiasis is present throughout the area except in Cape Verde, Comoros, Djibouti, Réunion, and the Seychelles.
Hepatitis B is hyperendemic. Trachoma is widespread. Among other diseases, certain Arenavirus hemorrhagic fevers have attained notoriety because of their high case-fatality rates. Lassa fever has a virus reservoir in a common multimammate rat. Studies have shown that an appreciable reservoir exists in some rural areas of West Africa; travelers visiting these areas should be advised to take particular care to avoid rat-contaminated food or food containers, but the extent of the disease should not be exaggerated. Ebola and Marburg hemorrhagic fevers are present but reported only infrequently.
Epidemics of meningococcal disease can occur throughout tropical Africa, particularly in the savannah areas during the dry season. For example, in recent years, epidemic outbreaks of meningitis from Neisseria meningitidis type A have occurred in Rwanda. In 2002, a major meningitis epidemic due to serogroup W135 occurred in Burkina Faso. Rabies is also a hazard in some areas.
Other hazards include snake bites.