Amoebiasis is caused by a parasite known as Entamoeba histolytica that infects the bowel. Amoebiasis can be spread by: drinking contaminated water, eating contaminated raw vegetables and fruit. The vaccine for diphtheria is given in a single shot (along with vaccines for pertussis and tetanus) and is called DTP. The DTP vaccine is administered in a series at 2, 4, and 6 months of age, and then again at around 1 and 4 years of age. Cholera is an infectious disease that causes severe watery diarrhoea, which can lead to dehydration and even death if untreated. It is caused by eating food or drinking water contaminated with a bacterium called Vibrio cholerae and is treated by using oral rehydration therapy. Syphilis is a sexually transmitted infection caused by the spirochete bacterium Treponema pallidum subspecies pallidum.