Persistence and Significance of in the Housefly, L.

Trachoma is the leading cause of infectious blindness worldwide. Ocular infection by the obligate intracellular pathogen, causes the eyelashes to turn in and scratch the cornea, leading to blindness if left untreated. The disease is most prevalent in poor, rural communities that lack the infrastructure for basic hygiene, clean water, and proper sanitation. Infection is often spread through infected clothes, contaminated hands, and face seeking flies. The goal of this research was to understand the biological role of flies in the transmission of . PCR, tissue culture, and immunofluorescence microscopy were used to determine the presence, viability, and the anatomical location of within the digestive tract of . Flies were fed with and then harvested at various time intervals after feeding. The data confirmed the presence of DNA and viable elementary bodies (EBs) in fly crops, up to 24 h postfeeding. DNA was also isolated from the upper portions of the alimentary tract of flies up to 48 h postfeeding. In addition, DNA was isolated from the regurgitation material from fly crops up to 12 h postfeeding. The viability of isolated EBs was repeatedly confirmed between 12 and 48 h and up to 7 days in crops stored at room temperature. Our data suggest that eye-seeking flies such as can ingest during regular feeding. Because does not occur in continental United States, we did not use it in any of our studies. These data also confirm, for the first time, that ingested chlamydia remains viable inside the flies for 24-48 h postfeeding. We further show that these flies can regurgitate and transmit the trachoma agent at their next feeding. We believe that these findings reveal an opportunity for efficient intervention strategies through fly vector control, especially as we near new target date for global elimination of trachoma.