ABSTRACT
On the last week of May of 2018, a community-based syndromic surveillance system detected mass abortions and deaths of young livestock in northeastern Kenya. Two weeks later, Rift Valley fever (RVF) was confirmed in humans presenting with febrile illness and hemorrhagic syndrome in the same region. A joint animal and human response team carried out an investigation to characterize the outbreak and identify drivers of disease transmission. Here, we describe the outbreak investigation and findings. A total of 106 human cases were identified in the months of May and June 2018: 92% (98) and 8% (8) of these cases occurring in the northern and western regions of Kenya, respectively. Seventy-six (72%) were probable cases, and 30 (28%) were laboratory confirmed by ELISA and/or PCR. Among the confirmed cases, the median age was 27.5 years (interquartile range = 20), and 60% (18) were males. Overall, the case fatality rate was 7% (n = 8). The majority of the confirmed cases, 19 (63%), reported contact with livestock during slaughter and consumption of meat from sick animals. All confirmed cases had fever, 40% (12) presented with hemorrhagic syndrome, and 23% (7) presented with jaundice. Forty-three livestock herds with at least one suspect and/or confirmed animal case were identified. Death of young animals was reported in 93% (40) and abortions in 84% (36) of livestock herds. The outbreak is indicative of the emergence potential of RVF in traditionally high- and low-risk areas and the risk posed by zoonosis to livestock keepers.
Subject(s)
Disease Outbreaks , Meat/virology , Rift Valley Fever/epidemiology , Adolescent , Adult , Animals , Female , Hemorrhage , Humans , Kenya/epidemiology , Livestock , Male , Middle Aged , Rift Valley Fever/virology , Sentinel Surveillance , Young Adult , ZoonosesABSTRACT
To describe the epidemiology and clinical course of patients hospitalized with pandemic (H1N1) 2009 in Kenya, we reviewed medical records of 49 such patients hospitalized during July-November 2009. The median age (7 years) was lower than that in industrialized countries. More patients had HIV than the general Kenyan population.
Subject(s)
Hospitalization/statistics & numerical data , Influenza A Virus, H1N1 Subtype , Influenza, Human/epidemiology , Pandemics , Adolescent , Adult , Child , Child, Preschool , Female , Humans , Infant , Influenza, Human/mortality , Influenza, Human/virology , Kenya/epidemiology , Length of Stay , Male , Middle Aged , Sentinel Surveillance , Young AdultABSTRACT
In January 2007, an outbreak of Rift Valley fever (RVF) was detected among humans in northern Tanzania districts. By the end of the outbreak in June, 2007, 511 suspect RVF cases had been recorded from 10 of the 21 regions of Tanzania, with laboratory confirmation of 186 cases and another 123 probable cases. All confirmed RVF cases were located in the north-central and southern regions of the country, with an eventual fatality rate of 28.2% (N = 144). All suspected cases had fever; 89% had encephalopathy, 10% hemorrhage, and 3% retinopathy. A total of 169 (55%) of the 309 confirmed or probable cases were also positive for malaria as detected by peripheral blood smear. In a cohort of 20 RVF cases with known outcome that were also positive for human immunodeficiency virus, 15 (75%) died. Contact with sick animals and animal products, including blood, meat, and milk, were identified as major risk factors of acquiring RVF.
Subject(s)
Disease Outbreaks , Rift Valley Fever/epidemiology , Rift Valley Fever/physiopathology , Rift Valley fever virus , Adolescent , Adult , Aged , Aged, 80 and over , Animals , Child , Female , Hemorrhage/epidemiology , Humans , Liver/pathology , Liver/virology , Male , Middle Aged , RNA, Viral/analysis , RNA, Viral/isolation & purification , Retinal Diseases/epidemiology , Rift Valley Fever/mortality , Rift Valley Fever/virology , Rift Valley fever virus/genetics , Rift Valley fever virus/isolation & purification , Risk Factors , Tanzania/epidemiology , Young AdultABSTRACT
OBJECTIVE: To evaluate the prevalence of Rift Valley fever virus (RVFV) antibodies in livestock and presence of competent mosquito vectors of RVFV during an interepizootic period (IEP) in Kenya. ANIMALS: 208 sheep and 84 goats ranging in age from 4 months to 15 years, from 2 breeding herds. PROCEDURES: Blood specimens were collected from the sheep and goats during the 1999-2006 IEP in Rift Valley Province, and serum was harvested. Serum specimens were tested for IgG and IgM antibodies against RVFV by use of an ELISA. In addition, 7,134 mosquitoes were trapped in Naivasha, Nairobi, and Northeastern Province, and speciation was performed. RESULTS: No animals were seropositive for IgM against RVFV. Of the animals born after the 1997-1998 epizootic, 18% (34/188) of sheep were seropositive for IgG against RVFV, compared with 3% (2/75) of goats. Seventy percent (8,144/11,678) of the mosquitoes collected were of the Culex subgenera; 18% (2,102/11,678) were Aedes spp. CONCLUSIONS AND CLINICAL RELEVANCE: Detection of IgG in the sera of sheep and goats born after the 1997-1998 epizootic and before the 2006 epizootic indicated that virus activity existed during the IEP. Detection of Aedes mosquitoes, which are competent vectors of RVFV, suggested that a cryptic vector-to-vertebrate cycle may exist during IEPs.
