Wednesday 21 March 2012

PROPHYLACTIC TREATMENT WAS TOTALLY INEFFECTIVE WHEN DELIVERED 2 DAYS (48HRS) AFTER TICK REMOVAL

Since 2001 the Infectious Diseases Society of America (IDSA) has been recommending preventive treatment of a single dose of doxycyline for tickbites under certain narrow conditions:- The IDSA recommends preventive treatment with antibiotics only in people who meet ALL of the following criteria:
 - Attached tick identified as an adult or nymphal I. scapularis (deer) tick
- Tick is estimated to have been attached for ≥36 hours (based upon how engorged the tick appears or the amount of time since outdoor exposure)
- Antibiotic treatment can begin within 72 hours of tick removal
- The local rate of tick infection with B. burgdorferi is ≥20 percent (known to occur in parts of New England, parts of the mid-Atlantic states, and parts of Minnesota and Wisconsin)
- The person can take doxycycline (eg, the person is not pregnant or breastfeeding or a child <8 years of age)

Piesman et al. have just published a new article concluding that if the treatment is given as little as 24 hours after the bite, only 47% of the mice were cured. 

Piesman also concludes that "Prophylactic treatment was totally ineffective when delivered ≥2days (48hrs) after tick removal."

The IDSA recommends treating if * Tick is estimated to have been attached for ≥36 hours (based upon how engorged the tick appears or the amount of time since outdoor exposure) * Antibiotic treatment can begin within 72 hours of tick removal

 IDSA recommends "If the person meets ALL of the above criteria, the recommended doseof doxycycline is a single dose of 200 mg for adults and 4 mg/kg, up to a maximum doseof 200 mg, in children ≥ 8 years"

In 2004 Zeidner et al. noted that the "sustained release" doxy was curative, but regular doxy only 43% effective. [Antimicrob Agents Chemother. 2004Jul;48(7):2697-9. Sustained-release formulation of *doxycycline* hyclate for prophylaxis of tick bite infection in a murine model of Lyme borreliosis.]

In 2008 Dolan et al. reported on the success of 14 days of exposure to antibiotic bait formulations.. Am J Trop Med Hyg. link  2008 May;78(5):803-5. A doxycycline hyclate rodent bait formulation for prophylaxis and treatment of tick-transmitted Borrelia burgdorferi.

Dolan MC link ,
Zeidner NS link ,
Gabitzsch E link ,
Dietrich G link ,
Borchert JN link ,
Poché RM  link;,
Piesman J link
Abstract
The prophylacticand curative potential of doxycycline hyclate formulated in a rodent bait at concentrations of 250 and 500 mg/Kg was evaluated in a murine model of Lyme borreliosis. Both bait formulations preventedtick-transmitted Borrelia burgdorferi infection in 100% of C3H/HeJ mice (N = 16), as well as cured acute, established infection in mice (N = 8) exposed to bait for 14 days. Spirochete infection was cleared in 88.9% to 100% of infected nymphs feeding on mice fed 250 and 500 mg/Kg antibiotic bait formulations, respectively. These data provide evidence for exploring alternative techniques to prevent transmission of Lyme disease spirochetes.

This month Peisman and Hoigaard note that "prophylactic treatment was totally ineffective when delivered ≥2days after tickremoval." [2 days = 48 hrs] Ticks Tick Borne Dis. link  2012 Mar 13. [Epub ahead of print]

 Protective value of prophylactic antibiotic treatment of tick bite for Lyme disease prevention: An animal model. 
 Piesman J link , 
 Hojgaard A link

Abstract 
Clinical studies have demonstrated that prophylactic antibiotic treatment of tick bites by Ixodes scapularis in Lyme disease hyperendemic regions in the northeastern United States can be effective in preventing infection with Borrelia burgdorferi sensu stricto, the Lyme disease spirochete. A large clinical trial in Westchester County, NY (USA), demonstrated that treatment of tick bite with 200mg of oral doxycyclinewas 87% effective in preventing Lyme disease in tick-bite victims (Nadelman, R.B., Nowakowski, J., Fish, D., Falco, R.C., Freeman, K., McKenna, D., Welch, P., Marcus, R., Agúero-Rosenfeld, M.E., Dennis, D.T., Wormser, G.P., 2001. Prophylaxis with single-dose doxycyclinefor the prevention of Lyme disease after an Ixodes scapularis tick bite. N. Engl. J. Med. 345, 79-84.). Although this excellent clinical trial provided much needed information, the authors enrolled subjects if the tick bite occurred within 3days of their clinical visit, but did not analyze the data based on the exact time between tick removal and delivery of prophylaxis. An animal model allows for controlled experiments designed to determine the point in time after tick bite when delivery of oral antibiotics would be too late to prevent infection with B. burgdorferi. Accordingly, we developed a tick-bite prophylaxis model in mice that gave a level of prophylactic protection similar to what had been observed in clinical trials and then varied the time post tick bite of antibiotic delivery. We found that two treatments of doxycycline delivered by oral gavage to mice on the day of removal of a single potentially infectious nymphal I. scapularis protected 74% of test mice compared to controls. When treatment was delayed until 24h after tick removal, only 47% of mice were protected; prophylactic treatment was totally ineffective when delivered ≥2days after tick removal. Although the dynamics of antibiotic treatment in mice may differ from humans, and translation of animal studies to patient management must be approached with caution, we believe our results emphasize the point that antibiotic prophylactic treatment of tick biteto prevent Lyme disease is more likely to be efficacious if delivered promptly after potentially infectious ticks are removed from patients. There is only a very narrow window for prophylactic treatment to be effective post tick removal. 

In the past 11 years, the misinformation has spread widely on the internet. Your mission, should you choose to accept it, is to seek out sites displaying the inaccurate information and ask them to correct it. Let's see if we can turn this around before another 11 years goes by. You will be saving lives.

Thanks to Phyllis Mervine  Lyme Disease.org  for this information



5 comments:

  1. You just heard about this? Oh man, I am totally pissed off about this.

    Sorry. Just couldn't contain myself over this because this is part of why I suffer from chronic Lyme disease.

    I wrote about this here:
    http://campother.blogspot.com/2012/03/one-pill-of-doxycycline-is-not-enough.html

    Apparently the Russians have been giving people 5-10 days of doxycycline as prophylaxis and in a number of places test the tick for pathogens using PCR.

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  2. Sounds like the Russians are half a step ahead but my neighbor failed 2 weeks antibiotics given following HPA/IDSA guidelines. I hear that there is much more awareness of Lyme Disease in Scandinavian countries and places in Germany and much better early treatment but still no acceptance of Chronic Lyme.

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  3. I don't know what the Russians know that we don't - at least not entirely. I've been trying to do research on their research, but accessing the full text of their own papers is not easily done even on their databases - and even then, almost everything is written in Russian and has to be run through a translation app which does not always get things quite right.

    I do know they are more aggressive early on in treating someone with an embedded tick. And in general, I get the impression their medical societies and doctors believe Borrelia can be latent for a while; that one can be asymptomatic in early infection and later on turn out to have full blown, late stage Lyme disease.

    But they are not sure how to deal with those of us with chronic Lyme disease as whole, either, based on what I've read so far. There are a number of doctors who think Lyme Borrelia can be intracellular and persist, and patients can have relapsing-remitting symptoms just as in relapsing fever - only drawn out over a different periodicity. Then there are a number of doctors who think Lyme Borrelia can lead to an autoimmune condition. And then there are some who, like me, believe some combination of persistent infection and immune dysregulation leads to ongoing symptoms. (Obviously, Russian research providing evidence for this is something I am looking for.)

    I would be happy if someone from Russia responded to my survey for Russians who have had Lyme disease or currently have it now. I'd really like to know what their experiences have been and not just go by what I've read on the internet, including their forums. But in the 5 days that post has been published, no one has responded yet. No clue why, because I know a number of Russians visit and read the blog.

    I agree that there is more awareness of Lyme disease in the countries/regions of Europe you mention. I think that the two most well-known forums I know of are in Norway, Germany, and Poland. But even then, you're right - there is little to no acceptance of chronic Lyme disease as a real condition in these places.

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  4. I know there is someone on Eurolyme who lives in Russia and has struggled to get appropriate treatment for his son.I have e mailed him and will let you know if he has anything to add.
    I understand the meeting in Canada was well received but awaiting the official report which I think will be published on Canlyme shortly. Certainly the line up of speakers was impressive, Fallon, Barthold Luft and Felix Sperling Entomologist- can't remember the rest of the presenters.

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  5. Joanne,

    Thanks for letting me know about your contact in Russia. It would be useful to know the circumstances around his son's Lyme disease and how the medical system there has (or in this case, has not) responded to him.

    It's one thing to do the research I do online and see what the doctors are telling patients in forums and also what they state on medical education sites - and perhaps another when it comes to people's actual experiences. So this is why I wrote up my survey and hoped someone would answer it. Could you perhaps ask your contact in Russia to fill it out, and if he knows anyone else who is in similar situation to go there? I would appreciate it a lot. We hear so little about the treatment of Lyme disease in certain countries and I was thinking not all of them have equally followed IDSA guidelines.

    I look forward to hearing more about the meeting in Canada. I agree that those are great speakers and wished I could have been present to hear them speak and ask them questions.

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