Background

On 27th March 2019, the Hagadera Refugee Camp reported an outbreak of acute watery diarrhea. An investigation was initiated to confirm the causative organism and define the epidemiology of the outbreak to support evidence-based control measures.

Method

A suspected case was a resident of Hagadera Refugee Camp or the surrounding community with a sudden onset of acute watery diarrhea and vomiting between March 27 and September 16, 2019. A probable case was defined as a suspected case with a positive rapid test for Vibrio cholerae; a confirmed case was a probable case with a positive stool culture for V. cholerae. We conducted a systematic case finding by visiting health facilities and villages. We reviewed patient records to identify suspected cholera casepatients. We conducted a descriptive epidemiologic study, examining the distribution of the cases. We computed the attack rates by age, sex, and residence. The case fatality rate was calculated as the ratio of the total number of suspected cholera death to the total number of cholera case-patients. We conducted targeted interventions including spraying, handwashing demonstration, distribution of soaps health education and promotion.

Results

We identified 667 suspected cholera cases between March and September 2019 of these, 38% (253/667) had a positive rapid diagnostic test for V. cholerae; 6% (43) were negative and 56%(371) rapid diagnostic test (RDT) were not conducted. Out of the 94 rectal swabs for culture, 71% (64/94) were confirmed to be V. cholera O1 serotype Inaba. The epidemic curve exhibited a continuous common-source outbreak with several peaks. The mean age of the case-patients was 15-years (range: 0.2-70-years). Both males and female had an attack rate of 9/10000 respectively. The highest attack rate was in ≥30-years (14 per 10,000).

Conclusion

This was a continuous common source cholera outbreak caused by V. cholerae 01 serotype Inaba. We recommended strengthening the surveillance system improving early detection and effective response.

Keywords

Cholera; Outbreak; Kenya; Garissa; Protracted; Hagadera; Epidemiological; Descriptive.

Abbreviations

RDT: Rapid diagnostic test; WHO: World Health Organization; CTC: Cholera Treatment Centre; AWD: Acute watery diarrhea; TCBS: Citrate bile salt sucrose; CFR: Case fatality rate; OCV: Oral cholera vaccine; IRC: International Rescue Committee; UNHCR: United Nations High Commissioner for Refugees.

Objective

This cartographic and analytical study, using the social network analysis method, aims to characterize sheep mobility from breeders producing lambs in the Middle Atlas Mountains to the fattening centers, passing through livestock markets in order to describe the exchange network, to identify the main mobility hubs and to secure the production of fattening lambs by improving the efficiency of the epidemiological surveillance system for “peste des petits ruminants” (PPR) in lambs producers of the Middle Atlas in Morocco.

Design

Descriptive cross-sectional study within the framework of active epidemiological surveillance. It was carried out at a regional level, for mapping the movements of sheep and to analyze the network of exchange relating to this species by the Social Network Analysis (SNA) method in the middle atlas massif and in the zone of sheep fatteners to guide epidemiological surveillance efforts. A total of 807 breeders producing lambs, sheep fatteners and traders were surveyed, including 54 fatteners in fattening workshops (sampling fraction of 48.6%), 150 breeders and traders in livestock markets of Middle Atlas and 603 producing lamb breeders of this massif (sampling fraction at the massif level of 6.64%).

Results

The study revealed a very strong commercial relationship between middle Atlas breeders and fattening zone breeders whose longrange outflows mainly converge towards urban consumption centers. The major strategic livestock markets of the middle Atlas proved to be key points in the articulation of the flows, as was the commune gathering the fatteners. Centrality indicators were used to identify the main trade hubs that contribute to the spread of diseases and to quantify their importance in the influence of sheep movement, while network cohesion parameters have shown that network is vulnerable to the spread of epidemics.

Conclusion

The results of this survey revealed the main commercial hubs at the Middle Atlas level and at the level of the province of fatteners, which represent a great risk of spreading sheep diseases over long distances rather quickly in event of an epizootic, but also representing the ability to control the spread through the control of the movement of animals at their level.

Keywords

Ovine network; Epizotic of (Peste des Petits Ruminants); Mapping; Social network analysis; Hub; Betweenness; Degree; Strong component; Cutpoint.