Diphtheria in the Americas - Summary of the situation
In 2020, as of 11 November, 5 countries reported a total of 56 confirmed cases of diphtheria, including 16 deaths in the Region of the Americas: Brazil (2 confirmed cases), the Dominican Republic (3 confirmed cases, including 2 deaths), Haiti (42 confirmed cases, including 11 deaths), Peru1 (4 confirmed cases, including one death) and the Bolivarian Republic of Venezuela (5 confirmed cases, including 2 deaths).
Various factors have contributed to the occurrence of diphtheria outbreaks in the Region of the Americas, including non-compliance with vaccination coverage. Moreover, the onset of the COVID-19 pandemic has affected vaccination, among other essential health services, with a decrease in the demand for vaccination services: coverage of the first dose of the diphtheria, tetanus and pertussis vaccine (DPT1) and the third dose of the diphtheria, tetanus and pertussis vaccine (DPT3); in addition to the postponement of vaccination campaigns (Figure 1).
In 2019, the 3-dose diphtheria, tetanus, pertussis (DTP3) vaccination coverage of ≥95% had not been achieved in 24 countries/territories in the Region of the Americas, and 6 countries (Argentina, Bolivia, Brazil, Haiti, Paraguay, and Venezuela) had <80% coverage for DPT3.
The following is the epidemiological situation for diphtheria for countries where new confirmed cases or an update has been reported since the prior PAHO/WHO Epidemiological Update on Diphtheria published on 22 September 2020.
In the Dominican Republic, between EW 7 and EW 45 of 2020, a total of 3 confirmed cases of diphtheria including 2 deaths, were reported. The information about the first two cases notified in 2020 was published in the Epidemiological Update of 22 September 2020
The following is a description of the last confirmed case:
The case 3 corresponds to a pregnant 14-year-old Dominican female resident of National District who had symptom onset on 28 September 2020. The case had no travel history and no vaccination history.
All 3 cases were laboratory-confirmed, and Corynebacterium diphtheriae was isolated from all samples. The samples were sent to the international reference laboratory (Center for Disease Control and Prevention - CDC) and Elek test results are pending. No epidemiological link was identified between these cases.
The vaccination schedule in Dominican Republic includes 3 doses in children under 1 year of age, and 2 boosters, which are administered at 18 months and 4 years of age.
The country does not meet the 95% goal established in the regional immunization action plan, and 34% of the country's municipalities report coverage ≥95%.
The country has a national vaccination policy for health personnel.
In Haiti, between EW 32 of 2014 and EW 43 of 2020, there were 1,112 suspected cases 3 of diphtheria reported, including 73 deaths; of the total cases, 364 were confirmed (352 laboratory-confirmed and 12 by epidemiological link) (Table 1, Figure 2).
The number of suspected cases reported between EW 1 and EW 43 of 2020 (135 cases) is lower than the number reported during the same period in both 2018 (266 cases) and 2019 (174 cases) (Table 1). Considering the long duration that the disease has been transmitted within the country, diphtheria is considered endemic in Haiti.