Zambia Cholera Fact Sheet

Cholera Overview

Seventh pandemic cholera was first reported in Zambia in 1977. Since 1990, large-scale outbreaks have occurred in 1990-93, 1999-2001, 2004, 2006, 2009, 2010 and 2018. The overall yearly trend shows a decrease in case numbers over time (Fig. 1).

Between 1999 and 2017, epidemiological surveillance reported 61,157 cases with 1,832 fatalities (case fatality rate (CFR) ≈ 3%)1. The majority of outbreaks were reported in the provinces of Lusaka, Luapula, Copperbelt, Northern, Central and Southern2.

The country has been affected by cross-border outbreaks primarily along the borders with the Democratic Republic of the Congo (DRC), the United Republic of Tanzania and Zimbabwe (Fig. 2).

 

Cholera Distribution

From 1999 to 2018 (up to week 22 of 2018), most cholera cases (74%) were reported by Lusaka Province, which includes the capital Lusaka. On average, outbreaks lasted for four months.2

Luapula, Copperbelt and Northern Provinces,

located at the border with DRC and around Lakes Mweru and Tanganyika, reported 18% of all cholera cases. On average, outbreaks lasted approximately two months in Copperbelt Province and up to four months in Luapula Province. Additionally, Northern Province was the most regularly affected, with ten outbreaks over the near 20-year period (Fig. 2 and Table I)2.

In the middle part of the country, Central Province accounted for 3% of the total cases and was affected seven times, mainly in the Lukanga swamp (Kapiri Moshi) and the neighboring city of Kabwe (Fig. 3 and Table I)2.

In the southern part of the country, Southern Province notified 2.5% of all cases and was affected five times. Heavily affected areas were located at the border with Zimbabwe and around the Kafue Flat swamp and Kariba Lake (Fig. 3 and Table I)2.

A marked seasonality was observed with outbreak onset at the end of the dry season (from September to October) and outbreak termination at the end of the rainy season (May). A greater number of cases was reported during the rainy season, especially in Lusaka2,4,5 (Fig. 3 and Table I).

Strategic Recommendations

High-risk areas along the borders were located in zones where cholera outbreaks spread between neighboring countries such as DRC, Tanzania and Zimbabwe (Table II). This highlights the role of the Zambian National Public Health Institute in implementing cross-border surveillance and coordinated response between countries in the sub-region.

In cholera hotspots, preparedness and response plans should be developed and implemented including: (1) strengthening early detection and rapid response including community-based surveillance and cross-border alerts; (2) establishing multisectoral and cross border coordination mechanisms; (3) building outbreak management capacity; (4) developing risk communication, social mobilization and community engagements plans with harmonized approaches and messaging (Table II – Type 1 to Type 4).

Sustainable water, sanitation, hygiene and social mobilization activities should be implemented in the 12 priority districts regularly affected by outbreaks of extended duration (Table II – Types 1 and 2). While preventive measures are implemented, oral cholera vaccine campaigns conducted in border hotspots may reduce the likelihood of large-scale cholera epidemics in Lusaka. The Type 1 and Type 2 hotspots accounted for 91% of the disease burden3. Identification of transmission foci at a finer geographical scale (ward, village) is necessary to best target at-risk populations.

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