Role of surveillance data in detecting malaria outbreaks in an epidemic-prone region in Kenya: findings from an investigation of a suspected outbreak in Nandi County

The increase in malaria cases in Nandi County displayed a seasonal pattern that coincided with either the long or short rainy seasons, the investigation did not reveal an active outbreak at the time of the inquiry. Sub-county hospitals in Tinderet and Aldai sub-counties had malaria cases exceeding both the alert and action thresholds at specific times during the year under review, suggesting a potential occurrence of unidentified outbreaks, while several other facilities had an increase of cases reaching alert thresholds, indicating upsurges. In healthcare settings, we noted there were problems with data quality. We advised routine data review, analysis, and feedback; mentorships for data analysis and on the job and support supervision; mentorships for malaria diagnosis; and installation of laboratory quality assurance.