!DIPHTHERIA DIPHTHERIA, a contagious disease characterised by the formation of a false membrane on the back of the throat. Its infection 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.