Relationship between Distinct African Cholera Epidemics Revealed via MLVA Haplotyping of 337 Vibrio cholerae Isolates

Sandra Moore (1, 2) , Berthe Miwanda (3) , Adodo Yao Sadji (4) , Hélène Thefenne (5) , Fakhri Jeddi (1, 2) , Stanislas Rebaudet (1, 2) , Hilde de Boeck (6) , Bawimodom Bidjada (4) , Jean-Jacques Depina (6) , Didier Bompangue (7, 3, 8) , Aaron Aruna Abedi (9) , Lamine Koivogui (10) , Sakoba Keita (11) , Eric Garnotel (5) , Pierre-Denis Plisnier (12) , Raymond Ruimy (13) , Nicholas Thomson (14, 15) , Jean-Jacques Muyembe (3, 8) , Renaud Piarroux (1, 2)

1 IP-TPT - Infections Parasitaires : Transmission, Physiopathologie et Thérapeutiques
2 Departement de Parasitologie et Mycologie
3 INRB - Institut National de Recherche Biomédicale [Kinshasa]
4 Department of Bacteriology
5 Hôpital d'Instruction des Armées Laveran
6 Department of Clinical Sciences
7 LCE - Laboratoire Chrono-environnement (UMR 6249)
8 Department of Microbiology
9 Ministry of Health
10 Institut National de Santé Publique
11 Division Prévention et Lutte contre la Maladie
12 RMCA - Royal Museum for Central Africa [Tervuren]
13 Clinical Research Department
14 LSHTM - London School of Hygiene and Tropical Medicine
15 The Wellcome Trust Sanger Institute [Cambridge]

Background Since cholera appeared in Africa during the 1970s, cases have been reported on the continent every year. In Sub-Saharan Africa, cholera outbreaks primarily cluster at certain hot-spots including the African Great Lakes Region and West Africa. Methodology/Principal Findings In this study, we applied MLVA (Multi-Locus Variable Number Tandem Repeat Analysis) typing of 337 Vibrio cholerae isolates from recent cholera epidemics in the Democratic Republic of the Congo (DRC), Zambia, Guinea and Togo. We aimed to assess the relationship between outbreaks. Applying this method, we identified 89 unique MLVA haplotypes across our isolate collection. MLVA typing revealed the short-term divergence and microevolution of these Vibrio cholerae populations to provide insight into the dynamics of cholera outbreaks in each country. Our analyses also revealed strong geographical clustering. Isolates from the African Great Lakes Region (DRC and Zambia) formed a closely related group, while West African isolates (Togo and Guinea) constituted a separate cluster. At a country-level scale our analyses revealed several distinct MLVA groups, most notably DRC 2011/2012, DRC 2009, Zambia 2012 and Guinea 2012. We also found that certain MLVA types collected in the DRC persisted in the country for several years, occasionally giving rise to expansive epidemics. Finally, we found that the six environmental isolates in our panel were unrelated to the epidemic isolates. Conclusions/Significance To effectively combat the disease, it is critical to understand the mechanisms of cholera emergence and diffusion in a region-specific manner. Overall, these findings demonstrate the relationship between distinct epidemics in West Africa and the African Great Lakes Region. This study also highlights the importance of monitoring and analyzing Vibrio cholerae isolates.

Mots clés: MULTILOCUS VARIABLE-NUMBER; TANDEM-REPEAT ANALYSIS; ENVIRONMENTAL DETERMINANTS; TRANSMISSION; OUTBREAKS; STRAINS

Domaines: Santé publique et épidémiologie

Sandra Moore, Berthe Miwanda, Adodo Yao Sadji, Hélène Thefenne, Fakhri Jeddi, et al.. Relationship between Distinct African Cholera Epidemics Revealed via MLVA Haplotyping of 337 Vibrio cholerae Isolates. PLoS Neglected Tropical Diseases, 2015. ⟨hal-01207192⟩