Diseases potentially acquired by travel to Southern Africa

INTRODUCTION — Southern Africa is comprised of Botswana, Eswatini, Lesotho, Namibia, St. Helena, South Africa, and Zimbabwe. This region encompasses deserts to fertile plateaus and plains.

ARTHROPOD-BORNE DISEASES

Malaria — Malaria is a risk in some areas of Southern Africa. In malarious areas, Plasmodium falciparum is the predominant cause of malaria, and chloroquine resistance is widespread. Country-specific risk areas are listed below [1]:

●Botswana – Risk exists from November to May/June in the northern parts of the country: Bobirwa, Boteti, Chobe, Ngamiland, Okavango, and Tutume districts/subdistricts.

●Eswatini – Risk exists throughout the year in all lowveld areas (mainly Big Bend, Mhlume, Simunye, and Tshaneni). Risk is highest from November to May inclusive.

●Lesotho – No risk.

●Namibia – Risk exists from November to June in Ohangwena, Omaheke, Oshana, Oshikoto, and Otjozondjupa. Risk exists throughout the year along the Kunene River in Kunene region, Zambezi River in Zambezi region, and Okavango River in Kavango regions (west and east).

●St. Helena – No risk.

●South Africa – Risk exists throughout the year in the low-altitude areas of Mpumalanga Province (including the Kruger National Park), Limpopo Province, and northeastern KwaZulu-Natal. Risk is highest from October to May inclusive.

●Zimbabwe – Risk exists from November through June below 1200 meters and throughout the year in the Zambezi valley. There is negligible risk in Harare and Bulawayo.

Issues related to prevention of malaria in travelers are discussed separately. (See "Prevention of malaria infection in travelers".)

Yellow fever — Yellow fever is not endemic within Southern Africa. However, yellow fever vaccine is required for entry into Southern African countries for travelers coming from infected areas. (See "Immunizations for travel", section on 'Yellow fever vaccine'.)

Dengue — Many areas in Southern Africa are suitable for dengue virus transmission. (See "Dengue virus infection: Prevention and treatment".)

African trypanosomiasis — African trypanosomiasis (sleeping sickness) is endemic in some northern parts of the Southern African region, although transmission has diminished significantly. (See "Human African trypanosomiasis: Treatment and prevention".)

Rickettsioses — Several rickettsioses are endemic in Southern Africa. Environments suitable for transmission of both epidemic typhus (caused by Rickettsia prowazekii) and murine typhus (caused by Rickettsia typhi) are present in sub-Saharan Africa [2].

●Epidemic typhus is transmitted by the body louse, and human conditions that favor the proliferation of lice occur during cold weather (eg, rural East African highlands) and during war or natural disasters (eg, among refugees). (See "Epidemic typhus".)

●Murine typhus is transmitted to humans by rat or cat fleas and occurs most commonly in urban settings. (See "Murine typhus".)

In addition, tick typhus, caused by Rickettsia conorii, Rickettsia africae, and others, occurs sporadically, particularly in east and southern Africa [3]. Its epidemiology is closely associated with ticks. Spotted fever group rickettsiosis was the most common individual diagnosis for travelers to South Africa in the GeoSentinel database [2].

Chikungunya fever — Chikungunya fever has been increasingly reported in the region [4]. Infection is transmitted by the bite of an Aedes mosquito, and the illness is characterized by sudden onset of fever and severe arthralgia. (See "Chikungunya fever: Epidemiology, clinical manifestations, and diagnosis".)

FOODBORNE AND WATERBORNE DISEASES

Travelers' diarrhea — Southern Africa is regarded as a high-risk area for the development of travelers' diarrhea, with enterotoxigenic Escherichia coli being the most common pathogen identified [5]. (See "Travelers' diarrhea: Epidemiology, microbiology, clinical manifestations, and diagnosis".)

Cholera — Cholera outbreaks are frequent occurrences in Southern Africa. During 2018 and 2019, Zimbabwe experienced a large outbreak of cholera, with high-level resistance to ciprofloxacin in the outbreak strain. (See "Cholera: Epidemiology, clinical features, and diagnosis".)

Typhoid — Typhoid fever is endemic throughout most of Southern Africa, although the risk is generally less than in South Asia. (See "Enteric (typhoid and paratyphoid) fever: Epidemiology, clinical manifestations, and diagnosis".)

Hepatitis A and E — Hepatitis A virus is endemic throughout Southern Africa. Hepatitis E is probably widespread in the region. (See "Hepatitis A virus infection in adults: Epidemiology, clinical manifestations, and diagnosis" and "Hepatitis E virus infection" and "Immunizations for travel", section on 'Hepatitis A vaccine'.)

Schistosomiasis — Schistosomiasis due to Schistosoma haematobium and Schistosoma mansoni is widespread in parts of Southern Africa and is recognized as a major hazard for travelers [6]. Transmission occurs through exposure to fresh water (lakes and slow-moving rivers) in endemic regions, and many travelers are only diagnosed with the disease on post-travel screening. (See "Schistosomiasis: Epidemiology and clinical manifestations".)

Echinococcosis — Hydatid disease continues to be relatively common in areas of Africa. (See "Epidemiology and control of echinococcosis".)

OTHER INFECTIONS

HIV infection — Southern Africa is the region of the world most affected by the HIV/AIDS pandemic. The main mode of transmission in the region is heterosexual contact. Unprotected sex carries the greatest risk of transmission to travelers to sub-Saharan Africa [7]. (See "Global epidemiology of HIV infection".)

Other sexually transmitted diseases — Sexually transmitted disease is a major public health problem in parts of Southern Africa. Contact with sex workers involves a high risk.

Hepatitis B and C — Hepatitis B virus is highly endemic throughout East Africa. (See "Hepatitis B virus: Clinical manifestations and natural history".)

The prevalence of hepatitis C is also high in many regions. (See "Clinical manifestations and natural history of chronic hepatitis C virus infection" and "Clinical manifestations, diagnosis, and treatment of acute hepatitis C virus infection in adults".)

Plague — The majority of the world's reported cases of plague have come from sub-Saharan Africa. (See "Epidemiology, microbiology and pathogenesis of plague (Yersinia pestis infection)".)

Rabies — Rabies is endemic throughout Southern Africa and has been reported with increasing frequency [8]. The domestic dog plays a key role in maintenance and transmission of rabies, although other animals (eg, mongoose, fox) are important in some regions. Postexposure treatment is recommended following all potential exposures, and prophylaxis should be considered by travelers spending significant periods of time in sub-Saharan Africa. (See "Immunizations for travel", section on 'Rabies vaccine'.)

Tuberculosis — Tuberculosis is relatively common in many parts of East Africa, although short-term travelers from countries of low endemicity are generally not considered at increased risk of infection.

OTHER HAZARDS

Snake bites — Venomous snakes are present throughout Southern Africa. The most important species include the saw-scaled or carpet viper (Echis spp), puff adder (Bitis arietans), and spitting cobra (Naja nigricollis, N. mossambica, and others). (See "Snakebites worldwide: Management".)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Travel medicine".)

SUMMARY

●Southern Africa is comprised of Botswana, Eswatini, Lesotho, Namibia, St. Helena, South Africa, and Zimbabwe. This region encompasses deserts to fertile plateaus and plains. (See 'Introduction' above.)

●Malaria is a risk in some areas of Southern Africa. In malarious areas, Plasmodium falciparum is the predominant cause of malaria, and chloroquine resistance is widespread. (See 'Malaria' above.)

●Other arthropod-borne diseases include yellow fever, dengue, African trypanosomiasis, and rickettsioses. (See 'Arthropod-borne diseases' above.)

●Foodborne and waterborne diseases include travelers' diarrhea, cholera, typhoid, hepatitis A, hepatitis E, schistosomiasis, and echinococcosis. (See 'Foodborne and waterborne diseases' above.)

●Other infections include HIV infection and other sexually transmitted diseases, hepatitis B, hepatitis C, plague, rabies, and tuberculosis. (See 'Other infections' above.)