Objective(s). To determine the relationship between blood groups & Rh factor with rate of infection to cholera in Barn.
Material & Methods: Relationship between cholera and blood groups in 74 patients, who were clinically
and para-clinically proved to be infected with Ogawa  during  the  cholera   epidemic   in   1997,  was determined. A total of 74 healthy individuals with similar socio-economical, sex and age were selected as controls.
Results: The mean age of male and female was 11.3 ± 4.7 and 14.5 ± 5.2 year, respectively.  Prevalence
of blood groups for A, B, 0 and AB in patient group was 14.9, 21.6,  62.6 and 1.3 percent,  respectively, while it was 32.4, 33.7, 29.7 and 4.2 percent in control group. The result showed that the blood group O was the highest risk groups among the others (Odds ratio = 3.8, 95%CI=l.85 • 8.19). Also this investigation showed that individuals with Rh" were 2.3 times more susceptible to disease than those with Rh+ (Odds ratio= 2.3, 95%CI= 0.78 · 6.61).
Conclusion: It is recommended that any prophylactic measures should be directed against those more than 10 years of age with blood group O in endemic and epidemic areas.