VPMD: Diphtheria
What is Diphtheria?
Diphtheria is an infectious disease that mainly affects the respiratory system and is caused by the bacterium Corynebacterium diphtheriae. When infected, the bacteria settles in the upper respiratory tract where it grows and produces toxin. This toxin leads to the characteristic symptoms of the disease. It is spread through contact with open sores and respiratory droplets, from coughing, sneezing and talking. While the incidence of Diphtheria is relatively low in the US, as a result of the current immunization program, incidence of disease is relatively elevated in other countries including Nigeria, India and Ethiopia according to the most recent WHO data.
What are the symptoms of Diphtheria?
Common symptoms of Diphtheria include fever, sore throat, enlarged neck lymph nodes, difficulty swallowing, malaise and the characteristic thick grey membrane in the nose and throat. Involvement of the skin may lead to development of pus filled lesions (pustules) and slow healing ulcers. Common complications include inflammation of the heart (myocarditis), nerve inflammation (neuritis), sepsis. respiratory failure and death. The disease course tends to be more serious in young children and older adults.
How is Diphtheria diagnosed?
Demonstration of the Corynebacterium diphtheria and toxin production through culture and genetic testing leads to confirmation of diagnosis. This testing is usually undertaken by local health departments in conjunction with the CDC. This process may take longer, so treatment is started before final results are obtained as it can significantly alter the course of the disease.
How is Diphtheria treated?
Treatment of Diphtheria entails controlling the continued growth of the bacteria and effects of the toxin. Erythromycin and Penicillin are the choice antibiotics used to treat Diphtheria. Diphtheria antitoxin (DAT) helps to neutralize the toxin and its effects in respiratory diphtheria. People whom are infected require isolation to prevent spread of illness.
While Penicillin and Erythromycin are widely available in the US, DAT is not and must be obtained from CDC.
How is Diphtheria prevented?
The Diphtheria vaccine has been recommended in the US since the mid 1900s, currently with the primary series given as DTaP (with Tetanus and Pertussis) in the first 6 months of life and boosters given in the second, fourth and eleventh year of life, then every 10 years with Td/Tdap.
Close contacts of those with Diphtheria are treated with prophylactic antibiotics, vaccination, if due, and quarantining to monitor for development of disease within 2 weeks of exposure.
Sources: CDC, Britannica, NHS and WHO