Diphtheria
Diphtheria is an infection caused by the bacterium Corynebacterium diphtheriae.[1] Most infections are asymptomatic or have a mild clinical course, but in some outbreaks more than 10% of those diagnosed with the disease may die.[2] Signs and symptoms may vary from mild to severe[2] and usually start two to five days after exposure.[1] Symptoms often come on fairly gradually, beginning with a sore throat and fever.[2] In severe cases, a grey or white patch develops in the throat.[1][2] This can block the airway and create a barking cough as in croup.[2] The neck may swell in part due to enlarged lymph nodes.[1] A form of diphtheria which involves the skin, eyes or genitals also exists.[1][2] Complications may include myocarditis, inflammation of nerves, kidney problems, and bleeding problems due to low levels of platelets.[1] Myocarditis may result in an abnormal heart rate and inflammation of the nerves may result in paralysis.[1]
| Diphtheria | |
|---|---|
 | |
| Diphtheria can cause a swollen neck, sometimes referred to as a bull neck.[1] | |
| Specialty | Infectious disease |
| Symptoms | Sore throat, fever, barking cough[2] |
| Complications | Myocarditis, Peripheral neuropathy, Proteinuria |
| Usual onset | 2–5 days post-exposure[1] |
| Causes | Corynebacterium diphtheriae (spread by direct contact and through the air)[1] |
| Diagnostic method | Examination of throat, culture[2] |
| Prevention | Diphtheria vaccine[1] |
| Treatment | Antibiotics, tracheostomy[1] |
| Prognosis | 5–10% risk of death |
| Frequency | 4,500 (reported 2015)[3] |
| Deaths | 2,100 (2015)[4] |
Diphtheria is usually spread between people by direct contact or through the air.[1][5] It may also be spread by contaminated objects.[1] Some people carry the bacterium without having symptoms, but can still spread the disease to others.[1] The three main types of C. diphtheriae cause different severities of disease.[1] The symptoms are due to a toxin produced by the bacterium.[2] Diagnosis can often be made based on the appearance of the throat with confirmation by microbiological culture.[2] Previous infection may not protect against infection.[2]
A diphtheria vaccine is effective for prevention and available in a number of formulations.[1] Three or four doses, given along with tetanus vaccine and pertussis vaccine, are recommended during childhood.[1] Further doses of diphtheria–tetanus vaccine are recommended every ten years.[1] Protection can be verified by measuring the antitoxin level in the blood.[1] Diphtheria can be prevented in those exposed as well as treated with the antibiotics erythromycin or benzylpenicillin.[1] A tracheotomy is sometimes needed to open the airway in severe cases.[2]
In 2015, 4,500 cases were officially reported worldwide, down from nearly 100,000 in 1980.[3] About a million cases a year are believed to have occurred before the 1980s.[2] Diphtheria currently occurs most often in sub-Saharan Africa, India, and Indonesia.[2][6] In 2015, it resulted in 2,100 deaths, down from 8,000 deaths in 1990.[4][7] In areas where it is still common, children are most affected.[2] It is rare in the developed world due to widespread vaccination but can re-emerge if vaccination rates decrease.[2][8] In the United States, 57 cases were reported between 1980 and 2004.[1] Death occurs in 5% to 10% of those diagnosed.[1] The disease was first described in the 5th century BC by Hippocrates.[1] The bacterium was identified in 1882 by Edwin Klebs.[1]