Cholera: Assessment of Epidemiological Situation on Cholera around the World and in Russia in 2008–2017. Forecast for 2018

Abstract

The trend of morbidity reduction at an average annual rate of 1.113 % in 2017 (in comparison to 2008) continues. The tendency of intensive monthly cholera incidence growth around the world in 2017 in relation to 2015 and 2016 is established. 25 countries with 70 endemic areas and 11734 imported cases of cholera onto different continents with predominance of interstate carrying of infection in Asia were identified. In Russia in 2008, 2010, 2012 and 2014 cholera importations from India have been registered. V. cholerae O1 biovar El Tor ctxA–tcpA–, ctxA–tcpA+, V. cholerae O139 ctxA– and tcpA– and singular V. cholerae O1 biovar El tor ctxA+tcpA+ strains were isolated from surface water bodies. INDEL typing of 242 V. cholerae O1 strains, isolated from environmental objects (2014–2017), provided the data which confirmed their belonging to common cluster of V. cholerae O1 ctxA–tcpA+. Along with genetic diversity of V. cholerae O1 ctxA–tcpA–, several strains of the same or closely related genotypes in some regions were isolated every year. For the first time ever the algorithm for risk of epidemic process activation assessment in case of cholera in Russia, taking into account the various factors (conditions), their gradation and expert scores, has been developed for the prediction. The forecast for cholera at the global level and in Russia for 2018 is unfavorable.

Keywords

• cholera
• epidemiological situation
• importation
• endemic areas
• v. cholerae o1
• v. cholerae o139
• forecast