Table 1. RVF outbreaks in eastern Africa, 1912–2010.
| Outbreaks | Year | Country | District/province | Diagnostic test used | Estimated number of cases in human | Number of confirmed cases in humans (deaths)a | Reference |
|---|---|---|---|---|---|---|---|
| Epizootic (localized) | 1912 | Kenya | Nakuru | Unknown | Unknown | None | 6 |
| Epizootic (localized) | 1915 | Kenya | Nakuru | Unknown | Unknown | None | 6 |
| Epizootic (national) | 1930 | Kenya | Nakuru, Naivasha, Marura, Ndabibi, Ol Magogo and Njoro | Virus isolation | None | None | 2 |
| Epizootic (national) | 1930, 1947, 1957, 1960, 1963, 1968 | Tanzania | Unknown | Unknown | Unknown | None | 5 |
| Epizootic (national) | 1936 | Kenya | Nakuru, Naivasha, Marura, Ndabibi, Ol Magogo and Njoro | Virus isolation | None | None | 6 |
| Epizootic (national) | 1951 | Kenya | Nakuru, Trans Nzoia, Uasin Gishu and Laikipia districts of Rift Valley Province; Thika, Nyeri and Maragwa districts of Central Province; Nairobi Metropolitan district of Nairobi Province | Unknown | None | None | 3 |
| Epizootic (national) | 1955 | Kenya | Nakuru, Trans Nzoia, Uasin Gishu and Laikipia districts of Rift Valley Province; Thika, Nyeri and Maragwa districts of Central Province; Nairobi Metropolitan district of Nairobi Province | Unknown | None | None | 6 |
| Epizootic (national) | 1960–1961 | Kenya | Nakuru, Trans Nzoia, Uasin Gishu, Laikipia, Narok, Kajiado, and West Pokot districts of Rift Valley Province; Thika, Nyeri, Maragwa and Kiambu districts of Central Province; Nairobi Metropolitan district of Nairobi Province; Garissa, Wajir, and Mandera districts of Northeastern Province; Isiolo, Marsabit, Machakos, and Makueni districts of Eastern Province; Kwale, Kilifi, and Tana River districts of Coast Province | Unknown | None | None | 6 |
| Epizootic (national) | 1964 | Kenya | Nakuru, Trans Nzoia, Uasin Gishu, Laikipia, Narok, Kajiado and West Pokot districts of Rift Valley Province; Thika, Nyeri, Maragwa and Kiambu districts of Central Province; Nairobi Metropolitan district of Nairobi Province; Garissa, Wajir and Mandera districts of Northeastern Province; Isiolo, Marsabit, Machakos and Makueni districts of Eastern Province; Kwale, Kilifi and Tana River districts of Coast Province | Unknown | None | None | 6 |
| Epizootic (localized) | 1965 | Kenya | 2 of the previously affected districts (not specified) | Unknown | None | None | 6 |
| Epizootic (national) | 1967–1968 | Kenya | 12 of the previously affected districts (not specified) | Virus isolation and serology | None | None | 6, 12 |
| Epizootic (localized) | 1969 | Kenya | 2 of the previously affected districts (not specified) | Unknown | None | None | 6 |
| Epizootic (national) | 1970–1971 | Kenya | 3 of the previously affected districts (not specified) | Unknown | None | None | 6 |
| Epizootic/epidemic | 1973, 1976 | Sudan | Nile, Khartoum, Kassala, El Gezira, Sennar and White Nile districts in Northern Province | Virus isolation | Unknown | 2 (0) | 13 |
| Epizootic (national) | 1977–1978 | Kenya | 11 of the above districts (not specified) | Unknown | None | None | 6 |
| Epizootic | 1977–1978 | Tanzania | Northern part | Unknown | Unknown | None | 14 |
| Epizootic | 1979 | Madagascar | Antananarivo | Unknown | None | None | 12 |
| Epizootic (national) | 1981 | Kenya | 8 of the previously affected districts (not specified) | Unknown | None | None | 6 |
| Epizootic (national) | 1983 | Kenya | 9 of the previously affected districts (not specified) | Unknown | None | None | 6 |
| Epizootic (localized) | 1985–1986 | Kenya | 1 of the previously affected districts (not specified) | Unknown | None | None | 6 |
| Epizootic (localized) | 1987–1988 | Kenya | 1 of the previously affected districts (not specified) | Unknown | None | None | 6 |
| Epizootic (national) | 1988–1989 | Tanzania | Northern part | Unknown | Unknown | None | 14 |
| Epizootic (national) | 1989–1991 | Kenya | 9 of the previously affected districts (not specified) | Virus isolation and serology | None | None | 12 |
| Epizootic | 1990–1991 | Madagascar | Antananarivo | Unknown | None | None | 15 |
| Epizootic/epidemic (national) | 1997–1998 | Kenya, Somalia and Tanzania | 22 of the 27 previously affected districts (not specified) | Virus isolation, RT-PCR and serology | 89 000 | 0 (478) | 3, 5, 16, 17 |
| Epizootic (localized) | 1999 | Kenya | 1 of the previously affected districts (not specified) | Unknown | None | None | 6 |
| Epizootic (localized) | 2002 | Kenya | 1 of the previously affected districts (not specified) | Unknown | None | None | 6 |
| Epizootic/epidemic (national) | 2006–2007 | Kenya | Previously affected districts and Baringo, Samburu, Kirinyaga, Murang'a, Taita-Taveta, Lamu, Malindi, Kitui, Meru (Central and north), Mwingi, Moyale, Embu, and Mbeere districts | Virus isolation, RT-PCR and Serology | 75 000 | 700 (158), CFR=22.6% | 18, 19, 20 |
| Epizootic/epidemic (national) | 2006–2007 | Somalia | Lower Juba Gedo Hiran, Middle Juba, Middle Shabelle, Lower Shabelle regions. | Unknown | 30 000 | 114 (51), CFR=45% | 20 |
| Epizootic/epidemic (national) | 2006–2007 | Tanzania | Arusha, Dares Salaam, Dodoma, Iringa, Manyara, Morogoro, Mwanza, Pwani, Singida, Tanga regions. | Unknown | 40 000 | 309 (144), CFR=46.6% | 20 |
| Epizootic/epidemic (national) | 2007–2008 | Sudan | White Nile, Sennar, El-Gazira, Sennar (near White Nile and Blue Nile Rivers) River Nile, Khartounm and Kassala States | Serology | 75 000 | 747 (230), CRF=30.8% | 21, 22 |
| Epizootic/epidemic (national) | 2008 | Madagascar | Alaotra Mangoro, Analamanga, Itasy, Vakinakaratra and Anosy Regions. | Unknown | Unknown | 476 (19), CFR=4.1% | 23 |
| Epizootic/epidemic | 2010 | Sudan | El Gezira State | Unknown | Unknown | Unknown | 24 |
Abbreviation: case fatality rate, CFR.
a
CFR was calculated only with confirmed cases.