Impact of the ABO and Rh Blood Groups on Malaria Incidence, Recurrence, and Severity Among a Moroccan Military Contingent in the Central African Republic

Malaria is a persistent and serious threat to military personnel deployed in endemic regions like the Central African Republic (CAR). While we know our blood type can sometimes influence how our bodies react to malaria, the full picture isn't always clear. We conducted an eight-month study (October 2024 - May 2025) with 749 Moroccan soldiers to investigate if their ABO and Rh blood groups played a role in their risk of contracting malaria, how often they got it, or if they developed severe forms. It's important to know that these soldiers were diligently following a weekly mefloquine chemoprophylaxis regimen and consistently using physical protective measures like insect repellents and bed nets. During the study, 156 soldiers (20.8%) experienced at least one malaria episode, with a striking 89% of these cases caused by <i>Plasmodium falciparum</i>, the most dangerous species. Only eight soldiers (1.1% overall) developed severe malaria. Despite <i>P. falciparum'</i>s strong presence (where blood group O is often reported to offer protection), our statistical analysis found no significant association between a soldier's ABO or Rh blood group and the incidence of malaria, its recurrence or disease severity. These findings are quite insightful. They suggest that, even when facing the predominant and severe <i>P. falciparum</i> strain, rigorous malaria prevention strategies used in this military setting, including effective chemoprophylaxis and consistent physical protection, likely overshadow any inherent genetic influences from blood groups. In environments with strong preventive measures, individual blood type appears to play a less dominant role in determining who gets sick or how severely. Our study reinforces the critical importance of robust and consistently applied malaria prevention programs for protecting military personnel in high-risk zones.