Epidemiological and Diagnostic Aspects of Cholera Epidemics in Eastern Democratic Republic of Congo between January 2011 and June 2022

Introduction: Nearly 4 million cases of cholera are reported each year worldwide, including 189,000 (5 to 14%) in the Democratic Republic of Congo (DRC). The eastern provinces, known as “hot spots”, report more than half of these cases. Objective: Describe the epidemiological and diagnostic aspects of cholera in eastern DRC. Methods: This is a cross-sectional, retro-prospective descriptive and analytical study of Vibrio cholerae (Vc) O1 isolates collected at the North Kivu provincial public health laboratory (AMI LABO) from January 1, 2011 to June 30, 2022. Results: A total of 4,709 out of 17,443 suspected cholera cases have been confirmed, representing a prevalence of 26.99%. Only 4382 isolates fulfilled the inclusion criteria. The majority of samples (72.46%, n = 3175) came from the province of North Kivu. Half of the patients (51.5%, n = 2258) were male with a median age of 11 years [IQR: 4-25]. Children under 14 accounted for 57.8% of cases (2535/4382). Of the 3 serotypes isolated, the serovar Inaba was the majority (57.6%, n = 2522). Over 90% of 83 Vc Hikojima strains and 98.9% of 1777 Vc Ogawa strains were isolated between 2019 and 2022, making them emerging strains in the region. Very high levels of resistance were found to ampicillin (74.7%), nalidixic acid (83.8%), erythromycin (73.6%), chloramphenicol (68.8%) and Sulfamethoxazole/ Trimethoprim (82%). On the other hand, quinolones (except nalidixic acid), macrolides (except erythromycin) and cyclins remained relatively sensitive. Conclusion: Cholera remains a real public health problem in eastern DRC. Hence the importance of strengthening epidemiological surveillance, improving hygiene conditions and access to drinking water.