Nosocomial Malaria Transmissions Resolved by Genomic Analyses-A Retrospective Case Report Study in France: 2007-2021

Exposure of blood to malaria parasites can lead to infection even in the absence of the mosquito vector. During a stay in a healthcare facility, accidental inoculation of the skin with blood from a malaria patient might occur, referred to as nosocomial malaria. Between 2007 and 2021, we identified 6 autochthonous malaria cases that occurred in different French hospitals, originating from nosocomial transmission and imported malaria cases being the infection source. Four cases were observed during the coronavirus disease 2019 pandemic. The genetic relatedness between source and nosocomial infections was evaluated by genome-wide short tandem repeats (STRs) and single-nucleotide polymorphisms (SNPs). None of the patients with autochthonous malaria had travel history to an endemic area nor had been transfused. For each case, both the source and recipient patients stayed a few hours in the same ward. After diagnosis, autochthonous cases were treated with antimalarials and all recovered except 1. Genetically, each pair of matched source/nosocomial parasite infections showed