Diphtheria in the Americas - Summary of the situation
In 2017, there were four countries in the Region of the Americas—Brazil, the Dominican Republic, Haiti, and the Bolivarian Republic of Venezuela—that reported confirmed diphtheria cases. As of epidemiological week (EW) 8 of 2018, four countries in the Region—Brazil, Colombia, Haiti, and Venezuela—have reported suspected and confirmed diphtheria cases.
Following is a summary of the situation in each country with reported suspected and confirmed cases in 2018.
In Brazil, in 2017 there were 40 suspected cases reported in 14 states, of which 35 were discarded and 5 have been confirmed in four states: Acre (1), Minas Gerais (2), Roraima (1 fatal case, imported from Venezuela), and São Paulo (1). Three of the 5 confirmed cases (2 in Minas Gerais and 1 in São Paulo) had received the full doses schedule. The confirmed cases range from 4 to 66 years of age (median 19 years); four are male and one female.
Additionally, in EW 2 of 2018 a suspected case was reported in the state of Bahia and is currently under investigation.
In Colombia, in EW 7 of 2018 a fatal confirmed case of diphtheria was reported in the Department of La Guajira, imported from Venezuela. The case is a 3-year-old child from Venezuela, with unknown vaccination history and onset of symptoms on 2 January. The case died on 8 January and was laboratory confirmed by culture and by RT-PCR technique as positive for Corynebacterium diftheriae without identifying biotype and positive toxin. To date, there are no secondary cases reported.
In Haiti, since the beginning of the outbreak at the end of 2014 up to EW 6 of 2018, there have been 410 probable cases of diphtheria reported, including 75 deaths.1 Reported case-fatality rates were 22.3% in 2015, 27% in 2016 and 10.7% in 2017 and 2018. During the first four epidemiological weeks of 2018, 2 to 5 probable cases per EW were reported similar to that observed during the last four weeks of 2017.
Females accounted for 57% of the total probable cases in 2015, 50% in 2016, 60% in 2017, and 47% in 2018 (up to EW 6). With respect to vaccination coverage, between 2015 and 2018 the unvaccinated cases accounted for 17% (2018) to 38% (2015) of the total cases. Children less than 10 years of age accounted for 64% of the probable cases reported between 2017 to EW 4 of 2018.
Since the beginning of the outbreak the departments reporting the highest number of probable cases are Artibonite, Centre, and Ouest.
In Venezuela, since the beginning of the outbreak in July 2016 up to EW 5 of 2018 a total of 969 probable diphtheria cases were reported (324 cases in 2016, 609 in 2017, and 36 in 2018) 726 of which were confirmed by laboratory or clinically, and 113 died (17 in 2016 and 96 in 2017); with a case fatality rate of 15.5%.
In 2016 cases were reported in five states (Anzoátegui, Bolívar, Delta Amacuro, Monagas, and Sucre), and in 2017 there were 22 states and the Capital District reporting confirmed cases. In 2018, 9 federal entities reported confirmed cases. Cases were reported in all age groups, however, the majority of cases occurred in the 5 to 39 age group, with the highest incidence rate in the group of 5 to 19 years of age.
The health authorities are intensifying epidemiological surveillance, case detection, medical care and vaccination, in addition to maintaining constant training of health personnel (based on the updated manual of standards, guidelines and procedures for the management of the disease) and health education.