Diphtheria (Human)

Unique identifier / Notation

BI0051

Synonyms

Not identified.

Diphtheria is a widespread severe infectious disease caused by the bacterium Corynebacterium diphtheriae and the toxin they produce. It is a potentially life-threatening, vaccine-preventable disease that primarily affects the throat and upper airways and has the potential for epidemics (WHO, 2018).

Primary reference(s)

WHO, 2018. Immunization, Vaccines and Biologicals: Diphtheria. World Health Organization (WHO). Accessed 15 November 2019.

Additional scientific description

Transmission of Corynebacterium diphtheriae is through direct physical contact or from breathing in the aerosolised secretions from coughs or sneezes of infected individuals. The resulting respiratory illness has an acute onset and the main characteristics are sore throat, low fever and swollen glands in the neck. The diphtheria toxin causes a membrane of dead tissue to build up over the throat and tonsils, making breathing and swallowing difficult. The disease is fatal in 5–10% of cases, with a higher mortality rate in young children (WHO, 2018). Cutaneous infection can also occur, leading to absorption of the toxin and severe and occasionally fatal disease.

Laboratory criteria for diagnosis is through the isolation of C. diphtheriae from a clinical specimen, or a four-fold or greater rise in serum antibody (but only if both serum samples were obtained before the administration of diphtheria toxoid or antitoxin) (WHO, 2014).

Surveillance data can be used to monitor the incidence of disease and levels of vaccination coverage (target more than 90%) as measures of the impact of control programmes.

The World Health Organization has published recommended surveillance standards for diphtheria (WHO, 2014).

Metrics and numeric limits

In 2018, there were 16,648 reported cases of diphtheria globally, compared to 8819 in 2017 (WHO, 2019).

Key relevant UN convention / multilateral treaty

International Health Regulations (2005), 3rd ed. (WHO, 2016).

Examples of drivers, outcomes and risk management

Diphtheria remains a significant health problem in countries with poor routine vaccination coverage or pockets of unimmunised (WHO, 2017).

Vaccination against diphtheria has reduced the mortality and morbidity of diphtheria dramatically, however diphtheria is still a significant child health problem in countries with poor coverage. In countries endemic for diphtheria, the disease occurs mostly as sporadic cases or in small outbreaks. Treatment involves administering diphtheria antitoxin to neutralise the effects of the toxin, as well as antibiotics to kill the bacteria (WHO, 2018).

Control of diphtheria is based on the following three measures: primary prevention of disease by ensuring high population immunity through immunisation; secondary prevention of spread by the rapid investigation of close contacts, to ensure their proper treatment; and tertiary prevention of complications and deaths by early diagnosis and proper management (WHO, 2014).