title: Mechanical transmission of Cryptosporidium parvum oocysts by flies.
abstract: Long term field studies and laboratory experiments demonstrated that synanthropic filth flies can mechanically transmit infectious oocysts of Cryptosporidium parvum, an anthropozoonotic protozoan parasite which significantly contributes to the mortality of immunocompromised or immunosuppressed people. C. parvum oocysts are acquired from unhygienic sources, and can pass trough fly gastrointestinal track without alteration of their infectivity and can be subsequently deposited on visited surfaces. Transmission of the oocysts by adult flies occurs via: (1) mechanical dislodgement from the exoskeleton; (2) fecal deposition; and (3) regurgitation, i.e., vomits. Filth flies can cause human or animal cryptosporidiosis via deposition of infectious oocysts on the visited foodstuf, and the biology and ecology of synanthropic filth flies indicate that their potential for mechanical transmission of C. parvum is high.
authors.affiliation: Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205, USA. tgraczyk@jhsph.edu
authors.forename: Thaddeus K
authors.initials: TK
authors.lastname: Graczyk
authors.forename: Barbara H
authors.initials: BH
authors.lastname: Grimes
authors.forename: Ronald
authors.initials: R
authors.lastname: Knight
authors.forename: Beata
authors.initials: B
authors.lastname: Szostakowska
authors.forename: Wiesława
authors.initials: W
authors.lastname: Kruminis-Lozowska
authors.forename: Maria
authors.initials: M
authors.lastname: Racewicz
authors.forename: Leena
authors.initials: L
authors.lastname: Tamang
authors.forename: Alexandre J
authors.initials: AJ
authors.lastname: Dasilva
authors.forename: Przemysław
authors.initials: P
authors.lastname: Myjak
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000469:parasitology / Q000635:transmission*; D003457:Cryptosporidiosis / Q000469:parasitology / Q000635:transmission / Q000662:veterinary*; D016785:Cryptosporidium parvum / Q000302:isolation & purification*; D004175:Diptera / Q000469:parasitology*; D005243:Feces / Q000469:parasitology*; D006790:Host-Parasite Interactions; D006801:Humans; D007303:Insect Vectors / Q000469:parasitology; D008297:Male; D033661:Oocysts / Q000302:isolation & purification*