An assessment of the response to Cholera outbreak in Lusaka district, Zambia - October 2023 - February 2024

Introduction: On 18 October 2023, the Zambia's Ministry of Health declared an outbreak of cholera in the capital city of Lusaka. Cholera outbreaks pose a significant threat due to their potential to spread rapidly. Examining the effectiveness of the response measures, can identify areas for improvement and enhance preparedness for future outbreaks. We assessed the response activities implemented during the 2023-2024 cholera outbreak in Lusaka district. Methods: We retrospectively reviewed case report, cluster reports and epidemiological data from cholera treatment centres (CTCs) and electronic integrated disease surveillance and response (eIDSR) platform. We extracted data on age, sex, area of residence and date of onset of illness and characterised the outbreak by person, time and place. To assess the gaps in detection and response timelines, we deployed the 7-1-7 framework; a tool adopted to evaluate the effectiveness of public health emergence response. We administered the WHO's cholera response assessment tool to identify major strengths and weaknesses focusing on five thematic areas: response coordination, surveillance and laboratory confirmation, case management, control of the environment, and control of the spread in the community. Results: Of 13,830 cases reported, majority were males (57.0%) and those aged ≥ 15 years (66.4%) were the most affected. More community deaths (62.6%) were reported than facility deaths. Majority of cases (64.6%) were clustered around two constituencies; overall case fatality rate of 3.7%. The index case was detected on 14 October 2023 at local health facility. The specific time from epidemic alert to confirmation was undefined. The epidemic was notified within 24 hours while the duration between detection and initial response exceeded 13 days. During the early stages of response, there were deficiencies in coordination and capacity to investigate and identify the source of infection at local level. Multisectoral response activities implemented included: water, sanitation and hygiene interventions, and community-based case management. Conclusion: Our study identified essential strengths during cholera outbreak response in Lusaka district. Timely notification and activation of multisectoral emergence preparedness and response committee, necessitated prompt implemented response activities. Strengthening local-level epidemiological capacity to respond and coordinate epidemics is crucial for ensuring effective initial responses to outbreaks in Lusaka district.