Cholera Epidemic - Lusaka, Zambia, October 2017-May 2018.

On October 6, 2017, an outbreak of cholera was declared in Zambia after laboratory confirmation of Vibrio cholerae O1, biotype El Tor, serotype Ogawa, from stool specimens from two patients with acute watery diarrhea. The two patients had gone to a clinic in Lusaka, the capital city, on October 4. Cholera cases increased rapidly, from several hundred cases in early December 2017 to approximately 2,000 by early January 2018 (Figure). In collaboration with partners, the Zambia Ministry of Health (MoH) launched a multifaceted public health response that included increased chlorination of the Lusaka municipal water supply, provision of emergency water supplies, water quality monitoring and testing, enhanced surveillance, epidemiologic investigations, a cholera vaccination campaign, aggressive case management and health care worker training, and laboratory testing of clinical samples. In late December 2017, a number of water-related preventive actions were initiated, including increasing chlorine levels throughout the city's water distribution system and placing emergency tanks of chlorinated water in the most affected neighborhoods; cholera cases declined sharply in January 2018. During January 10-February 14, 2018, approximately 2 million doses of oral cholera vaccine were administered to Lusaka residents aged ≥1 year. However, in mid-March, heavy flooding and widespread water shortages occurred, leading to a resurgence of cholera. As of May 12, 2018, the outbreak had affected seven of the 10 provinces in Zambia, with 5,905 suspected cases and a case fatality rate (CFR) of 1.9%. Among the suspected cases, 5,414 (91.7%), including 98 deaths (CFR = 1.8%), occurred in Lusaka residents.

Characteristics of cases and deaths arising from SARS-CoV-2 infection in Zambia: March 2020 to April 2021.

Introduction: since March 2020, Zambia has been experiencing a SARS-CoV-2 epidemic. Little data has been reported on cases and deaths arising from COVID-19 in Africa. We described the demographic characteristics of these cases and deaths in Zambia. Methods: we analyzed data on all persons testing positive for SARS-CoV-2 from 18th March 2020 to 25th April 2021 in Zambia. COVID-19 cases were identified through port-of-entry surveillance, contact-tracing, health-care-worker testing, health-facility-based and community-based screening and community-death screening. All diagnoses were confirmed using real-time-polymerase-chain-reaction and rapid-antigen-test-kits of nasopharyngeal specimens. We analyzed age, sex, and date-of-reporting according to whether the cases or deaths occurred during the first wave (1st July to 15th September 2020) or the second wave (15th December 2020 to 10th April 2021). We computed Mann-Whitney-U-test to compare medians of continuous variables and chi-square tests to compare differences between proportions using R. Results: a total 1,246 (1.36%) deaths were recorded among 91,378 confirmed cases during March 2020-April 2021 in Zambia. Persons who died were older than those who did not (median age 50 years versus 32.0 years, p< 0.001). Although only 4.7% of cases were among persons aged >60 years, most deaths (31.6%) occurred in this age group (p<0.001). More deaths (83.5%) occurred in the community than in health facilities (p<0.001). Conclusion: during the SARS-CoV-2 epidemic in Zambia, most deaths occurred in the community, indicating potential gaps in public health messaging about COVID-19. Improving health-seeking behaviors for COVID-19 through public messaging campaigns and engaging key community stakeholders in Zambia might reduce avoidable mortality. As the group most impacted by COVID-19 mortality, older persons might need enhanced outreach and linkage to care.