Relationship Between the Prevalence of Blood Groups and Severity of Leptospirosis: A Case-Control Study

INTRODUCTION: The correlation between the prevalence and severity of leptospirosis with blood groups has not been investigated so far, but several studies have been conducted to link the infectious diseases with blood groups. The aim of this study was to investigate the prevalence of blood type in patients with leptospirosis and its association with disease severity. METHODS: This is a case-control study performed on hospitalized patients with the diagnosis of leptospirosis in Mazandaran province, Iran, in 2018. The control group was selected from among the families of patients. Blood groups (ABO and Rh) and severity of the disease were assessed. Data were analyzed by SPSS 22. RESULTS: A total of 300 people (150 in the case and 150 in the control) enrolled in the study. The mean age was 44.35 ± 15.39 years and 81.3% were men. The highest frequency of blood type in both groups was O+, A+, and B+, respectively. There was a statistically significant difference in the frequency of blood groups (P = .037). Comparison between severity of disease and blood types (ABO, Rh) showed no significant difference (P > .05). CONCLUSIONS: According to our study, O+ was the most common among patients with leptospirosis. The frequency of O in patients was significantly higher than in the control group, but there was no significant relationship between leptospirosis and Rh. The prevalence of this blood type was higher in people with a severe form of the disease. Finally, there is no statistically significant difference between the severity of the disease and ABO and Rh.