A Case of Concomitant Plasmodium falciparum Malaria and Bacillus cereus Bacteremia in a Returning Traveler From Tanzania

Malaria has been associated with bacterial co-infections, but the importance of bacterial co-infections in uncomplicated malaria is poorly described. We report a unique case of a 27-year-old female with concomitant Plasmodium falciparum and Bacillus cereus bacteremia who acquired those infections while traveling in Tanzania but became ill only after returning to the United States. Blood parasites screen revealed Plasmodium falciparum and blood cultures obtained at presentation showed Bacillus cereus. Even after completing treatment for malaria, she continued to have abdominal pain and watery diarrhea, which improved only after IV vancomycin. Bacillus cereus bacteremia cases are reported in travelers and immigrants returning from countries where malaria transmission occurs, mainly from sub-Saharan Africa but co-infection with Plasmodium falciparum and Bacillus cereus has not been described in the literature yet. In this case, malaria symptoms resolved after targeted treatment was initiated but persistent diarrhea improved only after appropriate therapy against Bacillus cereus. Persistent watery diarrhea and dehydration in patients with malaria should raise concerns about Bacillus cereus co-infection.