Description of the targeted water supply and hygiene response strategy implemented during the cholera outbreak of 2017-2018 in Kinshasa, DRC

Abstract

Background: Rapid control of cholera outbreaks is a significant challenge in overpopulated urban areas. During late-2017, Kinshasa, the capital of the Democratic Republic of the Congo, experienced a cholera outbreak that showed potential to spread throughout the city. A novel targeted water and hygiene response strategy was implemented to quickly stem the outbreak.

Methods: We describe the first implementation of the cluster grid response strategy carried out in the community during the cholera outbreak in Kinshasa, in which response activities targeted cholera case clusters using a grid approach. Interventions focused on emergency water supply, household water treatment and safe storage, home disinfection and hygiene promotion. We also performed a preliminary community trial study to assess the temporal pattern of the outbreak before and after response interventions were implemented. Cholera surveillance databases from the Ministry of Health were analyzed to assess the spatiotemporal dynamics of the outbreak using epidemic curves and maps.

Results: From January 2017 to November 2018, a total of 1712 suspected cholera cases were reported in Kinshasa. During this period, the most affected health zones included Binza Météo, Limeté, Kokolo, Kintambo and Kingabwa. Following implementation of the response strategy, the weekly cholera case numbers in Binza Météo, Kintambo and Limeté decreased by an average of 57% after 2 weeks and 86% after 4 weeks. The total weekly case numbers throughout Kinshasa Province dropped by 71% 4 weeks after the peak of the outbreak.

Conclusion: During the 2017-2018 period, Kinshasa experienced a sharp increase in cholera case numbers. To contain the outbreak, water supply and hygiene response interventions targeted case households, nearby neighbors and public areas in case clusters using a grid approach. Following implementation of the response, the outbreak in Kinshasa was quickly brought under control. A similar approach may be adapted to quickly interrupt cholera transmission in other urban settings.

Keywords: Case cluster-targeted interventions; Cholera; Democratic Republic of the Congo; Hygiene promotion; Kinshasa; Outbreak response; Vibrio cholerae; Water supply; Water treatment.

Fig. 1

Map of study area: Kinshasa Province. DRC, Democratic Republic of the Congo

Fig. 2

Schematic diagram of the cluster grid response strategy. The case cluster is shown in green, case residences are represented by red dots, nearby neighbors (≤50 m from a case household) are represented in red squares and peripheral neighbors (> 50 m from a case household, within the case cluster) are represented in orange squares

Fig. 3

Epidemic curves of the cholera outbreak in Kinshasa and corresponding weekly precipitation levels. The epidemic curve and weekly precipitation levels cover week 15 of 2017 to week 45 of 2018. The top panel displays weekly cholera case numbers in the entire city (dashed line) as well as heavily-affected health zones, which are color-coded and ordered based on cumulative number of cholera cases during the 2017–2018 period (up to week 45, 2018) as displayed in Additional file 1. The bottom panel displays the corresponding estimated weekly precipitation levels in Kinshasa (mm)

Fig. 4

Spatial localization of all cholera cases per health zone in Kinshasa from November 2017 to March 2018. The red circles represent the number of cumulative cholera case numbers (suspected and confirmed) in each health zone during the five-month period. The only areas not represented on the map are the large health zones located in the east of Kinshasa Province, Maluku II and Maluku I, which reported seven and 21 cases, respectively, during the five-month period. Health zones, main roads, railroads and waterbodies in Kinshasa are indicated on the map. The locations of the CTCs in Binza Météo (Camp Luka) and Limeté (Pakadjuma) are also indicated. Neighboring Republic of the Congo is shown in green. Localization of Kinshasa Province (gray) and the Kinshasa map area (red square) are specified on the map of the DRC in the lower right corner

Fig. 5

Cholera epidemic curve per targeted health zone and response activity timeframe. Weekly cholera case numbers are shown on the y-axis and epidemic weeks/years are indicated on the x-axis. The start and end points of the response activities in each health zone are shown with green and red arrows, respectively