Researchers find reason for cholera outbreak in Yemen

Between April 27, 2017 and July 1, 2018, more than one million suspected cases of cholera in two waves were reported in Yemen, which had been declared a high-level emergency by the United Nations in 2015. Humanitarian organizations implemented a robust response to cholera despite numerous challenges including famine-like conditions, active civil conflict and destroyed health infrastructure within a shrinking humanitarian space in Yemen.

Prior to the outbreak, Yemen did not have a sufficient cholera preparedness and response plan in place despite previous cholera outbreaks, endemicity of cholera in the region and active conflict, according to a new report from the Johns Hopkins Center for Humanitarian Health, which is based in the Department of International Health at the Johns Hopkins Bloomberg School of Public Health. This lack of preparedness, in addition to extreme insecurity, resulted in gaps in disease surveillance, insufficient ability to reach conflict-affected populations and social mobilization interventions, and delays in evaluating the use of the oral cholera vaccine, among other obstacles, found the researchers.

The new report, "Cholera in Yemen: a case study of epidemic preparedness and response," calls for better anticipation of and preparedness for epidemics in complex humanitarian emergencies with weakened public health systems. Recommendations include technical components, such as boosting the presence of peripheral laboratories to confirm cholera cases combined with improved surveillance in order to better monitor the outbreaks, to the humanitarian, such as improving coordination and requesting the UN to adopt a stronger stance on the protection of both health facilities as well as water and sanitation infrastructure from airstrikes.

"We largely know 'what to do' to control cholera, but context-specific practices on 'how to do it' in order to surmount challenges to coordination, logistics, insecurity, access and politics remain needed," the report states.

"The cholera response in Yemen remains extremely complicated, with no easy fixes," says Paul Spiegel, MD, MPH, director of Johns Hopkins Center for Humanitarian Health and the report's lead author. "Humanitarian access in Yemen is extremely limited, and the humanitarian community did well in a very difficult and insecure environment. Our goal was to produce meaningful recommendations for how to better prepare for future cholera outbreaks in Yemen and other emergency-prone countries, taking into account the extreme limitations of working in Yemen during an active conflict."

For their report, the authors conducted an extensive literature review of global cholera guidance and key informant interviews with practitioners, donors and technical experts involved in the response in Yemen. Among the 20 top recommendations made:

The early warning alert and response functions of disease surveillance systems should be evaluated and primed, such that the surveillance system should be able to handle outbreak detection and response of evolving magnitudes.

A small set of WASH (water, sanitation and hygiene) and health rapid-response teams should be preemptively trained and placed on standby to respond to cholera and other outbreaks, enabling the early targeting of a localized response and containment when there are few case clusters at the beginning or end of the epidemic.

Diarrhea treatment centers and oral rehydration corner networks should be mapped according to population and epidemiological needs, particularly in fragile settings.

For early control of the epidemic and throughout the outbreak, focus is needed on a strategy providing decentralized, targeted WASH responses to interrupt transmission related to confirmed and suspected cholera cases.

Planning and response between the health and WASH sectors should always be integrated. In conflict-affected and cholera-prone countries, different scenarios for oral cholera vaccination should be integrated ahead of time into national cholera preparedness plans to better prepare the Ministry of Health and its partners.

Specific to Yemen, airstrikes on health, water and sanitation infrastructure should be terminated. Besides the UN proactively sharing the locations of health and water/sanitation facilities with the Saudi-led Coalition, monitoring and documenting attacks against this infrastructure using a geo-located database system with systematic reporting should be undertaken.

"Lessons learned from the first and second waves of the cholera epidemic are already being applied in the current cholera outbreak," says Spiegel. "Areas such as coordination, decentralization of services, decisive use of oral cholera vaccine­ when appropriate, flexible funding, improved surveillance and improved integration of WASH and health services will serve as important aspects to address for future cholera control in extreme and complex environments similar to Yemen."