Khamis Mushait Military Hospital informed us that Vibrio cholerae non-O1 non-O139 had been isolated from the stool of 10 patients with diarrhea over a six-month period. The cases were among soldiers or their families in Khamis Mushait and Ahad Rofaydah in Asir Region. The source of infection was not identified. Our objectives were to determine the dimensions of the problem, enforce the surveillance system for diarrhea, define the source of infection and recommend appropriate control measures.
Methodology
We reviewed the records of the national program for diarrheal diseases in primary health care centers in Asir. Appropriate changes were made in the surveillance system to improve reporting. We interviewed 9 cases and 21 controls. Water samples were taken from wells for chlorine level and cultured for Vibrio.
Results
Thirty-two cases of Vibrio cholerae non-O1 non-O139 were discovered in the period Jan. 29-Sept. 18, 1994. Other organisms were isolated. Mean age was 30.9 years. Thirty cases (94%) were Saudi; 26 cases (81%) were males. Cases were limited to residents in Ahad Rofaydah (18 cases, 56.3%) and Khamis Mushait (14 cases, 43.7%). In these two cities water was mainly transported to the houses in tankers from desalinated water stations or surface wells. None of the 753 wells' water samples were chlorinated, and V. cholerae non-O1 non-O139 was isolated from 131 wells (17%). The case-control study showed that infection was significantly associated with green rocket (odds ratio [OR] undefined, 95% confidence interval [CI] undefined, p-value=0.01) and green onion (OR=10, 95% CI 1.02-128.04, p-value=0.02).
Conclusion
The infection was restricted to the areas near Bisha Valley, where surface wells are concentrated, particularly Khamis Mushait and Ahad Rofaydah. The surface wells are infiltrated by sewage water poured in the Bisha Valley. Farmers use the well water for irrigation, and vegetables were the source of infection. Water chlorination was recommended, and piped water and a sewage system are under development.