Friday, 15 January 2010


I was interested to read this research on infection times following tick attachment. We are so frequently told that the tick needs to be attached more than 24hours to pass infection on and yet there are many documented cases where people have been infected in a lesser time frame.

Sadly in reality we are not able to ask if the tick has fed prior to attaching to us and those of us with pets who could and do bring ticks indoors, may be interested in reading this article. So in reality relying on 24 hour attachment is not always sensible, particularly when about 40% of people do not get the tell tale bulls eye rash.

http://www.ncbi. pmc/articles/ PMC266148/

Accelerated transmission of Lyme disease spirochetes by partially fed vector ticks.C M Shih and A SpielmanDepartment of Tropical Public Health, Harvard School of Public Health, Boston, Massachusetts 02115.This article has been cited by other articles in PMC.AbstractTo determine how rapidly Lyme disease spirochetes (Borrelia burgdorferi) can be transmitted by partially fed vector ticks (Ixodes dammini), attached nymphs were removed from their hosts at various intervals post-attachment and subsequently permitted to re-feed to repletion on non infected mice. We confirm previous reports that ticks deposit Lyme disease spirochetes in the skin of their hosts mainly after 2 days of attachment. Those that have been removed from a host within this interval can reattach and commence feeding. Spirochete-infected nymphs that have previously been attached to a host for 1 day become infectious to other hosts within another day. Non infected nymphs acquire infection from spirochete-infected hosts within a day of attachment and become infectious to other hosts 3 to 5 days later. Virtually all ticks transmitted infection when reattaching after first feeding for 2 days. We conclude that partially fed nymphal ticks transmit spirochetal infection more rapidly than do ticks that have never been attached to a host and that infected ticks become infectious before they molt.

No comments:

Post a Comment