Travellers arriving in South Africa from infected areas require a yellow fever vaccination certificate. Otherwise no vaccinations are required. There is a malaria risk in the low-lying areas of the Northern Province and Mpumalanga (including the Kruger National Park) and northeastern Kwa-Zulu Natal, and precautions are advised when travelling to these areas. There is a high prevalence of HIV/AIDS. Tap water is safe in urban areas but sterilisation is advisable elsewhere, as there are periodic outbreaks of cholera in the poor communities of rural South Africa, particularly in Northern KwaZulu Natal, Mpumalanga, and Limpopo provinces. Food poisoning is rare. Medical facilities in South Africa are good, but medical insurance is strongly advised as private hospitals expect cash upfront and public hospitals are best avoided.