Diphtheria is a dangerous respiratory disease is caused by a potent toxin produced by certain strains of the bacterium Corynebacterium diphtheriae. Diphtheria is extremely contagious through coughing or sneezing. Risk factors include crowding, poor hygiene, and lack of immunization.

Last year in the Americas, three countries reported cases of the vaccine-preventable disease–the Dominican Republic, Haiti and Venezuela.

Western hemisphere map Public domain image/ E Pluribus Anthony
Western hemisphere map
Public domain image/ E Pluribus Anthony

According to the Pan American Health Organization (PAHO), the number of countries reporting suspected and/or confirmed diphtheria cases has risen to five–Brazil, Colombia, the Dominican Republic, Haiti, and Venezuela.

In Venezuela through Oct. 21, a total of 511 probable diphtheria cases were reported. Samples were taken from 452 of the cases (88.5%), of which 146 (32.3%) were laboratory confirmed (69 by isolation and determination of toxin production by Elek test and 38 by Polymerase Chain Reaction). The confirmed cases were reported in 17 federal entities.

According to the report provided by national authorities, from January to September 2017, vaccination coverage with Pentavalent in children under 1 year of age reached 67.8%; and 41.9% of children aged five had the booster. The vaccination coverage with tetanus toxoid was 49.2% in pregnant women and 68.3% in schoolchildren.

The Venezuela Ministry of Popular Power for Health has intensified vaccination against diphtheria as part of the national plan; a total of 9 million doses of the vaccine are available for this activity. In addition, national and local authorities are strengthening epidemiological surveillance, active search and investigation of cases, and contact tracing.

In Brazil, year-to-date, there were 39 suspected diphtheria cases reported, distributed in 13 states, 5 of which were confirmed (1 by laboratory confirmation, 1 by clinicalepidemiological criteria and 3 by clinical criteria). The vaccination status of the five confirmed cases is as follows: the laboratory confirmed case was not vaccinated; of the remaining four cases, two had a completed vaccination schedule and two were not vaccinated.

LISTEN: Diphtheria: A short history, the disease, treatment and the success of the vaccines

In Colombia, there were 14 suspected diphtheria cases reported, all of which were later discarded by laboratory testing.

In the Dominican Republic,  there were 3 confirmed diphtheria cases reported. No deaths occurred due to diphtheria.

In Haiti, a total of 120 probable diphtheria cases were reported, of which 51 were laboratory confirmed, including 7 deaths (case fatality rate of 14%). Of the confirmed cases, most (82%) were five years of age or older and 53% were female. Of the confirmed cases, 26% were vaccinated, 33% were not vaccinated, and vaccination status is unknown for 41%.