The Duration of Motility of the Spirochaetes of Yaws in a Small West Indian Fly—Hippelates Pallipes Loew

View More View Less
  • Laboratory of the Jamaica Yaws Commission
Restricted access


  1. 1.In Jamaica, Hippelates pallipes feed on yaws lesions in enormous numbers.
  2. 2.Hippelates pallipes show a marked preference for feeding on lesions on the lower extremities.
  3. 3.Hippelates pallipes will crawl underneath scabs to feed and thus frequently obtain fresh material containing living T. pertenue.
  4. 4.These flies, if fed on highly infectious lesions, will take in large numbers of spirochaetes, some of which may later be regurgitated in “vomit drops.”
  5. 5.Hippelates pallipes often feed intermittently on different persons or different ulcers.
  6. 6.Male flies feed only on very rare occasions on ulcer material.
  7. 7.Hippelates pallipes caught in an area where there are no infectious cases of yaws do not naturally contain T. pertenue or any other spirochaetes resembling this organism.
  8. 8.the technic of dissecting Hippelates flies is described.
  9. 9.The majority of the Treponema pertenue ingested by Hippelates pallipes from framboesia lesions on patients, remain actively motile for about seven hours in the oesophageal diverticulum. In the stomach, however, they loose their motility very rapidly.
  10. 10.The majority of the ingested spirochaetes are found in the oesophageal diverticulum for the first eight hours following the infecting feed, after which time they have passed over into the stomach.
  11. 11.Very few spirochaetes remain in the proboscis of the flies, and those that do lose their motility quickly.