Seventh Pandemic Vibrio cholerae O1 Sublineages, Central African Republic

Abstract

Four cholera outbreaks were reported in the Central African Republic during 1997-2016. We show that the outbreak isolates were Vibrio cholerae O1 serotype Inaba from 3 seventh pandemic El Tor sublineages originating from West Africa (sublineages T7 and T9) or the African Great Lakes Region (T10).

Keywords: Central African Republic; Vibrio cholerae O1; bacteria; cholera; enteric infections; food safety; foodborne infections; genomics; outbreak; waterborne infections.

Figure 1

Geographic location of cholera cases during the 4 outbreaks reported in the Central African Republic, 1997–2016. Inset shows the location of Central African Republic in the continent of Africa. Numbers correspond to outbreaks during 1) June–October 1997; 2) June–August 1997; 3) September–October 2011; and 4) July–December 2016. Arrows show movement of outbreaks corresponding to colors for each outbreak

Figure 2

Phylogenomics of the Vibrio cholerae O1 El Tor isolates from CAR, 1997–2016. A) Maximum-likelihood phylogeny for 1,215 7PET genomic sequences. A6 was used as an outgroup. The last 9 sublineages introduced into Africa (T5–T13) are indicated. On inner ring, color scale denotes geographic locations of the V. cholerae isolates. On outer ring, brown denotes isolates from CAR. Tree branches containing isolates from CAR are shown in red. Scale bar indicates substitutions per variable site. B) Locations on the African continent in which T7, T9, and T10 V. cholerae O1 serotype Inaba isolates were detected before their identification in CAR. CAR, Central African Republic.