Cholera Factsheet Malawi
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CHOLERA FACTSHEET MALAWI Figure 1. Annual number of cases and case fatality rate in Malawi, CHOLERA OVERVIEW 1990 – 20171 Seventh pandemic cholera was first reported in Malawi in 1973. Since 1990, large-scale outbreaks were reported in 1990-1991, 1993, 1999, and 2002. The yearly trend shows that epidemics have decreased in magnitude since 2002 (Fig. 1).1 Between 2001 and 2018, epidemiological surveillance reported 42,397 cases with 473 fatalities (case fatality rate ≈ 1.1%). The majority of suspected cases were reported in Southern Region (57%), where the districts that reported the greatest number of cases were Blantyre, Machinga, Chikwawa. More recently, the most affected districts from 2014 to 2018 were Machinga (23%), Karonga (17%) and Chikwawa (14%).2 The country has been affected by cross-border outbreaks, especially along the southern border with Mozambique and likely along the border with Tanzania albeit to a lesser degree (Fig. 2).3 Figure 2. Cumulative cholera incidence by district in Malawi, 2001- CHOLERA DISTRIBUTION 20182 From 2001 to 2018, Lilongwe District reported the highest proportion of cholera cases (27.8%). Lilongwe was affected by 11 outbreaks over the 18-year period, although the large majority of cases were reported from 2002 to 2009 (Fig. 4, Table I).2 Blantyre District reported 16.4% of all cases, which were primarily reported between 2001 and 2012. Blantyre also reported 11 outbreaks over the study period (Fig. 4, Table I).2 In the Lake Chilwa area, Machinga, Zomba and Phalombe accounted for a combined 13.9% of all cholera cases, where affected populations often involved fishing communities living on islands or floating homes on the lake. Since 2010, Lake Chilwa districts have accounted for 34.5% of all cases (Fig. 4, Table I).2,3 In the Shire River floodplain, Chikwawa and Nsanje reported a combined 13.1% of all cases. Since 2010, this percentage has increased to 31.5%. Chikwawa was also the most often affected district with 14 outbreaks from 2001 to 2018 (Fig. 4, Table I).2 In Northern Region, Karonga District reported 4.5% of all cases, which represents the highest proportion among districts along Lake Malawi (Fig. 4, Table I).2 Cholera case numbers in Malawi tended to increase between December and April following the rainy season (Fig. 3).2,4 Table I. Epidemiological parameters of cholera outbreaks in primarily affected districts in Malawi, 2001-20182 [1] Figure 3. Monthly cholera case numbers and precipitation levels in (%) atality DISTRICT 2,4 f e Malawi, 2015 – 2018 cases at (No. (No. of Cases / r deaths % of %total of outbreaks) Recurrence Case Lilongwe 11,789 / 18 27.8 0.2 11 Blantyre 6,959 / 126 16.4 1.8 11 Machinga 4,243 / 59 10 1.4 9 Chikwawa 3,860 / 61 9.1 1.6 14 Balaka 2,831 / 0 6.7 0.0 8 Kasungu 2,432 / 0 5.7 0.0 4 Karonga 1,904 / 45 4.5 2.4 9 Nsanje 1,696 / 22 4 1.3 9 Mangochi 1,384 / 33 3.3 2.4 8 Zomba 1,187 / 15 2.8 1.3 6 Note: [1] Total cases = 42,397 and deaths = 473, from 2001 to 2018 (week 27). CHOLERA FACTSHEET MALAWI Figure 4. Priority cholera foci in Malawi by district, 2001-20182 PRIORITY CHOLERA FOCI Location of cholera foci (Table II, Fig. 4): • Urban districts of Lilongwe and Blantyre • Lake Chilwa districts – Machinga, Zomba and Phalombe, including fishing communities temporarily living on islands or floating homes on Lake Chilwa • Shire River floodplain and districts bordering Mozambique – Chikwawa and Nsanje • Lake Malawi districts –Karonga, Nkhata Bay and Salima • Cross-border district with Tanzania - Karonga • Balaka District – crossroad between Zomba and Lilongwe (via road) as well as Blantyre and Salima (via rail) STRATEGIC RECOMMENDATIONS High-risk areas along national borders were located in zones where cholera outbreaks spread between neighboring countries, including Mozambique and to a lesser degree Tanzania (Table II, Fig. 4). This highlights the importance of cross-border surveillance and coordinated response between countries in the region, especially in Southern Region and Karonga District. In priority cholera foci, 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) targeted pre- positioning of supplies and (5) developing risk communication, social mobilization and community engagement plans with harmonized approaches and messaging (Table II – Type 1 - Type 3). In hard-to-reach areas, early rehydration (e.g., community 3,5,6 oral rehydration points) should be enhanced to reduce the CFR. Risk factors • Limited access to safe water - 63% of rural populations and 87% Sustainable water, sanitation, hygiene and social mobilization of urban population have access to at least basic drinking water activities should be implemented in the six priority districts sources regularly affected by cholera outbreaks, especially fishing • Limited access to sanitation facilities - 43% of rural populations communities of Lake Chilwa, residents of the Shire River and 49% of urban populations have access to at least basic floodplain, overpopulated urban areas, and cross-border districts sanitation with high population flux to and from Mozambique and Tanzania • Living in floodplain areas in Chikwawa and Nsanje Districts (Table II – Types 1-2). The Type 1 and Type 2 priority areas • Frequent travel to Mozambique during a cholera outbreak in accounted for 71.8% of the disease burden.2 Identification of provinces across the border transmission foci at a finer scale within the priority counties is • Obtaining drinking water from Lake Chilwa • Performing open defecation (approximately 7% of rural necessary to best target at-risk communities. populations) Table II. Summary of priority cholera foci classification in Malawi, 2001-20182 Attack rate Priority Recurrence Case fatality Cross-border Region District % of total cases (median per 10,000 area type (No. of outbreaks) rate (%) area inhabitants) SOUTHERN CHIKWAWA 9.1 14 3.7 1.6 Yes SOUTHERN BLANTYRE 16.4 11 5.3 1.8 No Type 1 NORTHERN KARONGA 4.5 9 4.3 2.4 Yes SOUTHERN MACHINGA 10 9 5.1 1.4 Yes CENTRAL LILONGWE 27.8 11 1.9 0.2 Yes Type 2 SOUTHERN NSANJE 4 9 2.8 1.3 Yes SOUTHERN BALAKA 6.7 8 1.2 0 No NORTHERN NKHATA BAY 1 7 2.0 2.7 No Type 3 SOUTHERN ZOMBA 2.8 6 3.3 1.3 No CENTRAL SALIMA 1.7 5 1.6 1.4 No SOUTHERN PHALOMBE 1.1 4 1.3 1.9 Yes Note: Type 1: Highest-priority area with outbreaks of high frequency (≥9 outbreaks) and high median incidence rate; Type 2: High-priority area with outbreaks of high frequency and moderate median incidence rate; Type 3: Medium-priority area with outbreaks of moderate frequency (4-8 outbreaks) and moderate median incidence rate. References[10:50:24] jessica dunoyer: and a long duration (>40th percentile) Authors 1. Global Health Atlas. WHO (http://apps.who.int/globalatlas). Moore S. PhD, Dunoyer J. MSc, Kagoli M. MD, Chimwaza W. PhD, Khambira M. MSc, 2. Ministry of Health Malawi, epidemiological surveillance data (2001–2018). Valingot C. MSc, Piarroux M. MD PhD, Piarroux R. MD PhD, Sudre B. MD PhD. 3. Moore et al., Epidemiological study of cholera hotspots and epidemiological basins in East and Southern Africa. In-depth report on cholera epidemiology in Malawi (2018), UNICEF. Acknowledgements 4. Precipitation data, Famine Early Warning Systems Network (http://www.fews.net). Ameda M.I. and Tabbal G. (UNICEF ESARO) 5. Msyamboza KP, et al. Cholera outbreaks in Malawi in 1998-2012: social and cultural Senbete M. (UNICEF Malawi) challenges in prevention and control. J Infect Dev Ctries. 2014;8(8):720–6. 6. Joint Water Supply and Sanitation Monitoring Programme, WHO, UNICEF, 2015 .