Myiasis in humans: Case reports in Northeastern Brazil including multispecies co-infestation by Sarcophagidae

Myiasis is a parasitosis characterized by an infestation of living vertebrates (humans and other animals) by Diptera larvae, whose occurrence and etiological identification are still neglected by health professionals. Here we analyzed the human myiasis cases registered from 2010 to 2018 in health care units in the municipality of Natal, Northeast region of Brazil. Specifically, we aimed to: I) analyze the medical records of cases documented from 2010 to 2017; II) list the patients predisposing factors; and III) monitor the recent cases diagnosed in health units between August 2017 and March 2018 and report the taxonomic identity of the infesting species. Our data revealed that myiases mainly affect the elderly and individuals with predisposing medical conditions (e.g. senility, filariasis). Regarding the new cases, larvae of Calliphoridae (C. hominivorax (Coquerel, 1858)) and Sarcophagidae [Sarcophaga (Liopygia) ruficornis (Fabricius, 1794), Peckia (Sarcodexia) lambens (Wiedemann, 1830), and Helicobia morionella (Aldrich, 1930)] were identified. Furthermore, this was the first report of a co-infestation with three Sarcophagidae species and also the presence of H. morionella in a human wound. These results reinforce that myiasis is an underreported parasitosis, which may underestimate the ability of previously unreported fly species to feed on living human tissues in the Neotropical Region.