Cross-Border Cholera Outbreaks in Sub-Saharan Africa, the Mystery behind the Silent Illness: What Needs to Be Done?

<div><p>Introduction</p><p>Cross-border cholera outbreaks are a major public health problem in Sub-Saharan Africa contributing to the high annual reported cholera cases and deaths. These outbreaks affect all categories of people and are challenging to prevent and control. This article describes lessons learnt during the cross-border cholera outbreak control in Eastern and Southern Africa sub-regions using the case of Uganda-DRC and Malawi-Mozambique borders and makes recommendations for future outbreak prevention and control.</p><p>Materials and Methods</p><p>We reviewed weekly surveillance data, outbreak response reports and documented experiences on the management of the most recent cross-border cholera outbreaks in Eastern and Southern Africa sub-regions, namely in Uganda and Malawi respectively. Uganda-Democratic Republic of Congo and Malawi-Mozambique borders were selected because the countries sharing these borders reported high cholera disease burden to WHO.</p><p>Results</p><p>A total of 603 cross-border cholera cases with 5 deaths were recorded in Malawi and Uganda in 2015. Uganda recorded 118 cases with 2 deaths and CFR of 1.7%. The under-fives and school going children were the most affected age groups contributing 24.2% and 36.4% of all patients seen along Malawi-Mozambique and Uganda-DRC borders, respectively. These outbreaks lasted for over 3 months and spread to new areas leading to 60 cases with 3 deaths, CRF of 5%, and 102 cases 0 deaths in Malawi and Uganda, respectively. Factors contributing to these outbreaks were: poor sanitation and hygiene, use of contaminated water, floods and rampant cross-border movements. The outbreak control efforts mainly involved unilateral measures implemented by only one of the affected countries.</p><p>Conclusions</p><p>Cross-border cholera outbreaks contribute to the high annual reported cholera burden in Sub-Saharan Africa yet they remain silent, marginalized and poorly identified by cholera actors (governments and international agencies). The under-fives and the school going children were the most affected age groups. To successfully prevent and control these outbreaks, guidelines and strategies should be reviewed to assign clear roles and responsibilities to cholera actors on collaboration, prevention, detection, monitoring and control of these epidemics.</p></div

Reported cross-border cholera cases in Malawi and Uganda in 2015.

<p>Reported cross-border cholera cases in Malawi and Uganda in 2015.</p

The distribution of cholera cases by country of origin and sex.

<p>The distribution of cholera cases by country of origin and sex.</p

Annual number of cholera cases and deaths reported in Uganda 1997–2010.

<p>There was a major outbreak in 1998 and a fluctuating, but persistent burden of cholera in the years since the outbreak.</p

Age breakdown of cholera cases from non-random sample of cholera outbreaks, 2002–2010.

<p>The percentage distribution of cholera cases in Uganda is similar to the overall age distribution of the population.</p

Laboratory results of the cross-border cholera cases seen in Uganda and Malawi in 2015.

<p>Laboratory results of the cross-border cholera cases seen in Uganda and Malawi in 2015.</p

Risk factors for the cross-border cholera outbreaks, interventions implemented and challenges experienced during response in Uganda and Malawi, 2015.

<p>Risk factors for the cross-border cholera outbreaks, interventions implemented and challenges experienced during response in Uganda and Malawi, 2015.</p

Cross-Border Cholera Outbreaks in Sub-Saharan Africa, the Mystery behind the Silent Illness: What Needs to Be Done? - Fig 2

<p>The map of Malawi (2a) and Uganda (2b) showing the location of the cholera affected districts and the distribution of the cholera cases in the study area.</p

Epidemic curves of cholera outbreaks in Uganda, 2002–2010.

<p>The epidemic curves from a convenience sample of fifteen outbreaks shows both large and small outbreak have occurred during the period 2002–2010. There is considerable variation in the duration of outbreaks with longer outbreaks in districts with higher average annual incidence rates.</p

Map of reported cholera incidence by district, hospitalized cases, 2005–10.

<p>The estimated incidence by district varies considerably in Uganda with a distinct pattern of low-incidence versus high incidence districts.</p