I keep reading that there is a four week "herx cycle" that is noticeable with antibiotic treatment for Lyme (and even some alternative treatments, too).

Yet the info. I have on Bb replication rates says that Bb replicates once every 7 - 22 hours (which is considered a low rate for a bacteria etc.)

If the replication rate is once per 7 - 22 hours, why do people herx significantly every four weeks? anyone know?

THANKS!

A "herx," as it was originally meant, referred to the immediate die-off that occurred in response to the introduction of antbiotics (killing many bugs at once, releasing cytokines which in turn leads to inflammation and the noted symptoms). The reaction generally included a fever, increase in white blood cells, and other symptoms as described in the literature, and was time-limited. Indeed, some people with Bb infections do have such a herx reaction.

In addition to this classic J-H reaction, evidently some people have some cyclical flare in their symptoms (and the timing of that flare is quite variable from person to person) and the colloquial term used is "herx" which clouds the issue to some degree. The nature of the cyclical flare that SOME people have and the underlying etiology have not even begun to be elucidated.

The working hypothesis by some patients (and their doctors) is that this is some type of "herx." However, given the replication duration of the bug and the fact that all bugs do not replicate begining and ending at the same time, this hypothesis is likely incorrect. However, the question remains as to the cause of the cyclical flare in symptoms (regardless of the duration of the cycle) that some Bb infected patients experience.

quote:

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"As the spirochete has a very long generation time (12 to 24 hours in vitro and possibly much longer in living systems)...."

and "Several days after the onset of appropriate antibiotic therapy, symptoms often flare due to lysis of the spirochetes with release of increased amount of antigenic material and possibly bacterial toxins. This is referred to as a Jarish Herxheimer-like reaction. Because it takes 48 to 72 hours of therapy to initiate bacterial killing, the Herxheimer reaction is therefore delayed. This is unlike syphilis, in which these reactions can occur within hours.

It has been observed that symptoms will flare in cycles every four weeks. It is thought that this reflects the organism's cell cycle, with the growth phase occurring once per month (intermittent growth is common in Borrelia species). As antibiotics will only kill bacteria during their growth phase, therapy is designed to bracket at least one whole generation cycle. This is why the minimum treatment duration should be at least four weeks. If the antibiotics are working, over time these flares will lessen in severity and duration. The very occurrence of ongoing monthly cycles indicates that living organisms are still present and that antibiotics should be continued.

With treatment, these monthly symptom flares are exaggerated and presumably represent recurrent Herxheimer-like reactions as Bb enters its vulnerable growth phase then are lysed. For unknown reasons, the worst occurs at the fourth week of treatment. Observation suggest that the more severe this reaction, the higher the germ load, and the more ill the patient.

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So, it seems Dr. B is implying that the four week flares really are "Herxheimer-like" reactions... but what's the difference between a "growth phase" and actual replication, which is measured in hours not weeks?

What are these guys doing every four weeks that makes them more vulnerable to abx if not replicating?

Any ideas?