Fig 1.
Map of Kenya showing selected Rift Valley Fever (RVF) high-risk counties in grey.
A high-risk county was based on ecological and climatic factors associated with previous RVF outbreaks in Kenya, as defined by Munyua et al. [19]. The high-risk counties were selected for participation in the enhanced surveillance for RVF.
Fig 2.
Illustration of RVF surveillance system conducted in Kenya between November 2015 and February 2016.
CDVS = County Director of Veterinary Services, RVF = Rift Valley Fever, SCVO = Sub-County Veterinary Officers.
Fig 3.
Weekly number of abortions, bleeding, and death syndrome reports (top graph) and number of total reports (bottom graph) submitted to the Rift Valley Fever Alert Centre in Kenya, November 16, 2015 –February 29, 2016.
The total number of reports includes both syndromic and healthy reports.
Table 1.
Number of livestock species observed with abortion, bleeding, or death*.
Fig 4.
Time-series plots of the weekly reporting for each syndrome by whether flooding and/or mosquito swarms were observed by farmers in their area.
Fig 5.
Scatterplot and linear prediction of the correlation between the reporting of any syndrome (abortion, bleeding, or death) and observing flooding and mosquito swarms.
These variables showed high correlation, based on Pearson’s correlation coefficient (r > 0.87, p<0.001).
Fig 6.
Geographic distribution of the number of Rift Valley Fever suspect and probable herds in Kenya between November 16, 2015 and February 29, 2016.
A suspected RVF herd was defined as a livestock herd reporting abortion in an area experiencing heavy rainfall and flooding. A probable RVF herd was defined as a suspect RVF case that also reported deaths in young livestock and/or hemorrhagic signs.
Fig 7.
Mean monthly actual rainfall (light shaded bars and left x-axis) recorded in the participating counties and number of suspect and probable Rift Valley Fever (RVF) herds (dark shaded bars and right x-axis) reported in Kenya, November 2015 –February 2016.
Table 2.
Rift Valley Fever IgG ELISA test results by species and county of origin, November 2015 to February 2016, Kenya.