Friday, 21 September 2012


Regurgitation Transmission of Borrelia burgdorferi to humans ; The Rapid pathway
as contrasted with Salivary gland transmision ( the Slow pathway)

Ticks and Tickborne Bacterial Diseases in Humans: An Emerging Infectious Threat

Ticks are currently considered to be second only to mosquitoes as vectors of human infectious diseases in the world

Clinical Infectious Diseases Year 2001 vol 32: 897-928
(an Official publication of the Infectiious Disease Society of America) link here 

An ongoing debate in the Lyme community is over how long it can take to be infected by a tick. I read an interesting post by Dr Alan MacDonald on the subject on the Lymenet Europe forum  which I share.

'Salivary gland processing of Bb is an accepted pathway to transmission of infection to the mammallian host.
The Minimal Infective Dose ( Minimal Infective number) of properly conditioned Bb
from an infected tick is not known with certainty, although estimates or outright guessing of 
Minimal tick attachment time for tranmission of infection are bandied about in the literature.

Overlooked in Tick transmission of infection to mammalian hosts is Regurgitation Transmission.

Regurgitation Transmission is a reallity which is discussed in the attachment.

In essence,the Rate of delivery of borrelia from tick to mammalian host via the salivary route
is slow. In Contrast, with regurgitation transmission, the rate of delivery of borrelia to the
mammalianhost is high.. A Huge bolus of ifectomes is delivered with a single episode of tick vomitus.

Regurgitation transmission explains cases of Erythema migrans which develop rapidly,
even those cases of EMgreater than 5cm diameter noted with the tick still attached to the center of the EM lesion.

Walter Reed's collegues solved the mystery of Yellow Fever transmission in Cuba
by "sticking out his arm" and allowing the mosquitos to feed.

If there is commentator confidence that short term attachment produces no human Bb infections
then let those experts "stick out their arm" and allow the Infected Ixodid nymphs to feed .
Food for thought...stand behind your expert stickingout your arm.'

Thank you Dr MacDonald 
There is not much humor involved with reading about patients chronically ill with this disease but a mental picture of some of the most ardent deniers of Chronic Lyme Disease standing in line 'sticking out their arms' amused me today. Of course these deniers of Chronic Lyme Disease know far more than they let on about the complexity of this disease to do anything so fool hardy, as a trawl through patent applications will soon confirm. here

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