Cholera in Zimbabwe, 2018–2019: How the Outbreak Was Contained

Suspected and confirmed cholera cases in Zimbabwe by date of illness, September 2018–March 2019, with the two rounds of oral cholera vaccination in Harare marked. CDC.

The outbreak

• The alarm: on September 5–6, 2018, 52 patients in Harare were hospitalized with suspected cholera, an acute bacterial infection causing watery diarrhea. Rapid tests found Vibrio cholerae O1, and on September 6 Zimbabwe's Ministry of Health and Child Care (MOHCC) declared an outbreak.
• The toll: from the first cases on September 4, 2018, to March 12, 2019, 10,730 cases and 69 deaths (0.64%) were reported from nine of Zimbabwe's 10 provinces.
• The strain: the National Microbiology Reference Laboratory confirmed V. cholerae O1, serotype Ogawa; antimicrobial susceptibility testing was confirmed at South Africa's National Institute for Communicable Diseases.

The response

MOHCC led the response with the City of Harare, the World Health Organization and many local and international partners, coordinated through its Inter-Agency Coordinating Committee on Health.

• Surveillance: enhanced surveillance and reporting nationwide; CDC gave extra surveillance training to frontline staff in Harare, and about 200 health workers took Integrated Disease Surveillance and Response training — a strategy adopted by the WHO African Region in 1998 — in a training-of-trainers effort backed by MOHCC, WHO and Africa CDC.
• Treatment: cholera treatment centers were set up with Médecins Sans Frontières, with on-site case-management training.
• Laboratories: partners supplied equipment and training to strengthen national and regional lab capacity.
• Water and sanitation: within 1 week of the declaration, MOHCC's National Coordination Unit, supported by UNICEF, began community-wide WASH work — household water treatment products and water-quality monitoring. From late October, as cases fell, city and nongovernmental teams investigated cases, taught hygiene, gave soap and water treatment to patients' households and their neighbors, and chlorinated priority water points.
• Vaccination: a two-dose oral cholera vaccine campaign in Harare began October 3, 2018:

The last case was reported on March 12, 2019.

In context

Zimbabwe's first cholera case was in 1972, and outbreaks have come almost yearly recently. Its largest — among the largest ever in Africa — was in 2008–2009: 98,592 cases and 4,288 deaths (4.3%). WHO says that with proper treatment, fatality should stay below 1%; in 2018–2019 it was 0.64%, counting deaths in communities and health facilities.

Lessons

• Declare early: the timely declaration was crucial to mobilizing resources.
• Prevent: better water, sanitation and hygiene, community engagement and vaccination reduce cholera's toll.
• Work together: an effective response covers every pillar — WASH, surveillance, laboratory testing, social mobilization, case management and vaccination.
• Train locally: building local capacity is vital to global health security.

Sources

Based on "Notes from the Field: Cholera Outbreak — Zimbabwe, September 2018–March 2019," by Alison Winstead and colleagues from CDC, Zimbabwe's Ministry of Health and Child Care, the City of Harare, the National Microbiology Reference Laboratory and WHO, MMWR, Centers for Disease Control and Prevention, citing Chimusoro and others (2018) and WHO's Global Task Force on Cholera Control (2017). MMWR material is in the public domain.