Cholera in Gaza in 1981: epidemiological characteristics of an outbreak

An outbreak of cholera involving 161 culture-positive cases of biotype El-Tor Serotype Ogawa occurred in the Gaza Strip in the summer and autumn of 1981. The signs and symptoms of the disease were mild to moderate in two thirds of the cases. In many of them the disease was so mild that the patients did not realize they had cholera. Another outstanding feature of the disease was the high percentage of family clustering. From constant monitoring of water, sewage, and vegetables we were unable to show that they played any part in the transmission. A case control study which specifically investigated these items showed no differences between cases and controls. Epidemiological investigation indicated that the disease was probably introduced into the area by a visitor from Jordan, where an epidemic was in progress. The first spread followed a wedding party and seems to have been caused by ingestion of contaminated soft drinks. Subsequent spread was probably caused mainly by carriers who were either asymptomatic or very mild cases. The actual transmission seems to have occurred from person to person, by food contamination, or by both. The authors believe, therefore, that the transmission of El-Tor cholera has many features in common with other bacterial diseases that are transmitted by the faecal-oral route.