Intensive care. A boy with diphtheria under intensive care. Diphtheria is an acute infection, usually of the throat, caused by the bacillus, Corynebacterium diphtheriae. It is contracted by contact with a carrier or by air-bourne infection. The bacillus causes an area of mucous membrane to swell, which may obstruct breathing. It also secretes a toxin which may cause kidney failure, heart failure, or local paralysis. Treatment is with penicillin and an antitoxin. A tracheostomy may be necessary to alleviate breathing difficulty. Diphtheria is still a hazard in some developing countries where immunization is not practised. Photographed in a Vietnam hospital.