7 March 2012
- Diphtheria is an infectious disease that spreads from person to person by respiratory droplets from the throat through coughing and sneezing.
- The disease normally breaks out 2 to 5 days after infection.
- Diphtheria usually affects the tonsils, pharynx, larynx and occasionally the skin.
- Symptoms range from a moderately sore throat to toxic life-threatening diphtheria of the larynx or of the lower and upper respiratory tracts.
- Diphtheria is often complicated by diphtheric myocarditis (toxic damage to heart muscles) and neuritis (toxic damage to peripheral nerves).
- The disease can be fatal. Between 5% and 10% of diphtheria patients die, even if properly treated. Untreated, the disease claims even more lives.
- Untreated patients are infectious for 2 to 3 weeks.
- Diphtheria vaccines are based on diphtheria toxoid, a modified bacterial toxin that induces protective antitoxin.
- Three doses are delivered during infancy, starting as early as 6 weeks of age, and are given at least 4 weeks apart.
- Diphtheria toxoid combined with tetanus and pertussis vaccines (DTP) has been part of the WHO Expanded Programme on Immunization (EPI) since its inception in 1974.
- Following the primary immunization series, the average duration of protection is about 10 years.
- Protective immunity may be boosted through exposure to circulating strains of toxigenic C. diphtheriae.
- Where natural boosting does not occur, booster doses of diphtheria toxoid beyond infancy and early school age are required to maintain protective immunity.
- Treatment consists of immediate administration of diphtheria antitoxin and antibiotics.
- Antibiotic treatment usually renders patients non-infectious within 24 hours.
- Unless immunized, children and adults may repeatedly be infected with the disease.
How can an epidemic be controlled?
- The most effective method is mass immunization of the entire population.
- Those individuals who are in close contact with a sick person should be identified and treated immediately with antibiotics.
- The disease should be diagnosed early and proper case management procedures (i.e.immediate treatment and hospitalization) should be followed in order to prevent complications and death.
- Diphtheria is still a significant child health problem in countries with poor EPI coverage.
- In 2010, a total of 4,187 cases were reported. 5,000 deaths had been estimated in 2004.
- The occurrence of diphtheria reflects inadequate coverage of the national childhood immunization programme. Therefore, obstacles to optimal vaccine delivery must be identified and forceful measures taken to improve immunization coverage.
- Where EPI coverage is high and natural boosting low, as in most industrialized countries, a large proportion of the adult population is gradually rendered susceptible to diphtheria as a result of waning immunity.
- Diphtheria remains endemic in developing countries with low vaccination coverage.