On Friday August 10th 2001, a notification from the Saudi Red Crescent to Riyadh Regional Health affairs reported cases of an unknown disease among laborers in a company compound north of Riyadh. The Field Epidemiology Training Program (FETP) was assigned to investigate this outbreak. Twenty-three cases of chickenpox were identified, 4 were confirmed by laboratory. Investigation aimed to determine the size of the problem, possible cause of the outbreak, and develop measures to prevent similar situations in the future.
Methodology
A case control study was conducted. A case was defined as any person from this company compound with rash, fever or blisters in his body, from 13/ 07/2001 to 22/8/2001. A list of laborers names was provided by the company. Healthy laborers living at the same compound were randomly selected to be controls.
Results
A total of 23 cases were found, all were male laborers from Bangladesh. Those who did not have previous history of chickenpox had 16 times the chance to acquire the disease than those who had it before (OR=16, P-value = 0.0008), and this was the main risk factor. Both exchanging clothes between laborers and contact with diseased patients played an important role in developing chickenpox (OR= 4.5, p- value = 0,006, and OR= 3.6 p-value =0.014, respectively).
Conclusion
Absence of acquired immunity among laborer was the main reason for getting the infection. However, late isolation and low hygienic standards helped in dissemination of the disease among the closed and highly crowded population. Education of laborers on the importance of personal hygiene, and concentrating on proper isolation, should diminish the existence of the outbreak and spread of cases.