Nolwenn Conan , Renate Sinke, Annick Lenglet, Florien Oudenaarden, Mary Jo Frawley, Tammam Aloudat, Begench Djumageldyev, Silvia de WeerdtMédecins Sans Frontières (MSF), Amsterdam, Netherlands;

BACKGROUND

CONCLUSIONS and RECOMMENDATIONS

Oral cholera vaccine mass-vaccination campaign in a closed setting, Maban County refugee camps, South Sudan, December-February, 2013.

December 2012 - February 2013: preventative mass vaccination with oralcholera vaccine (OCV) in Maban county (Map 1); Four camps targeted: Jamam, Batil, Gendrassa (MSF-OCA) and Doro (MSF-OCB); See Map. Two doses vaccination, 14 days apart; Target population: host and refugee population, ≥1 year of age;

Objective: To describe the campaign experience, the vaccinationcoverage achieved and lessons learnt by MSF-OCA.

METHODS

RESULTS

Prior to the campaign: Social mobilisation and intensive health messaging on cholera and general hygiene by 200-300 trained community-health workers; The coverage objective was 85% with two doses.

Campaign implementation was semi-mobile: Each camp had four to nine fixed vaccination sites (with one-two teams per site) for at least the three first days; Then, non-vaccinated individuals actively identified through mop-up searches; All acutely sick persons were excluded from vaccination.Vaccination coverage estimates: Two two-staged randomised cluster surveys in Jamam and Gendrassa/Batil based on vaccination-card and verbal history.

From 27/12/2012 to 02/02/2013 146,962 doses of OCV administered in two rounds; Each round lasted a mean of five days; Vaccination coverage estimates by camp and stratified from age and gender are shown in Figure 1 and 2; 143 perons reported one or more adverse events after vaccination (Figure 3) ; Main challenges identified in this mass vaccination campaign:

1. Ensuring double dose vaccination in all individuals: explaining needs for two doses, mobile catch up especially during second round;

2. Maintaining a stable cold chain as the OCV is freeze sensitive and several freezers mal-functioned during the campaign;

3. Working in a community with an ongoing hepatitis E outbreak: high number of acutely sick persons, and ensuring no confusion about the type of vaccine being administered;

4. Working with a mobile host community: high turnover and movement.

First time that OCV was used as a pre-emptive measure for cholera prevention in closed settings by MSF; High coverage in the target population shows that the mixed-strategies employed were successful in this context and probably for the future; Importance to involve community team leaders to allow a good adherence of the population; Surveillance for suspected cholera in Maban county has been strengthened in order to monitor the overall efficacy of the OCV and detect any suspected outbreaks of cholera early.

Map: Refugee camps, Maban County, South SudanFigure 1: Vaccination coverage rates for OCV, Maban County, South Sudan, January-February 2013. NB: oral history includes vaccination card history

Figure 2: Vaccination coverage rates for OCV by age group, Maban County, South Sudan, January-February 2013.

Figure 3: Majority of reported adverse events, OCV mass vaccination, Maban County, South Sudan, December 2012-February 2013.

Jamam (CI95%) Batil and Gendrassa

(CI95%)

Overall coverage for two doses oral history 91.4 % (89.2- 93.7) 93.4% (92.1-94.6)

Received at least one dose oral history 98.5% (97.5- 99.2) 98.8% (98.3-99.2)

Coverage by gender two doses oral history:

Male

Female

91.1% (88.8- 93.3)

91.8% (89.1- 94.4)

91.5% (89.8- 93.3)

95.0% (93.8- 96.2)

Acknowledgement: Map by L. Dupuis, MSF, 2013