(b) : Diphtheria is caused by Corynebacterium diphtheriae (bacteria) usually affecting children upto five years of age. It may start as sore throat, chills with mild fever, sometimes vomiting and headache. Throat and/or tonsils show a grey membrane which may spread down and cause hoarseness and difficulty in breathing. Nose may be affected giving rise to a blood-tinged nasal discharge from one nostril. If the disease is not treated early and properly the toxin produced by the bacteria affects the heart and the nervous system, and proves fatal. The germs are present in the discharges from the nose and throat of patients and also of healthy people who act as the "carriers". The patients and the carriers spread the disease through acts like kissing, talking, coughing and sneezing. Incubation period is of 2 - 5 days. The patient should be kept in a well-ventilated room if there is no isolation hospital in the town. The most important preventive measure-against this disease is that all babies should be immunised within the first six weeks of birth using DPT vaccine.