HARDSCIENCEONLYME Lyme disease prevention. Two Effective Practices?

It has long been known that ticks harbor Bartonella and that humans who have Lyme disease may also have Bartonellosis. However, the actual transmission of Bartonella from tick to host has not been demonstrated until a mouse study by Drs Reis and colleagues was published in May 2011. The study is available free on line for those interested. “This work represents the first in vivo demonstration of a Bartonella sp. transmission by ticks. It . . . corroborate[s] a prospect that ticks play a role in the natural cycles of some of the bartonellae including those pathogenic for humans. Consequently, bartonelleosis should be included in the differential diagnosis for patients exposed to tick bites.”

A new article has resurrected the old myth about disease transmission being impossible before a certain time after the tick bites. In the New Haven (CT) Register this week, Dr. David Katz writes: “Ticks need to be embedded for 24 hours or more to transmit Lyme.” This is an improvement on the usual 36-48-hour minimum we usually see, but it is still misleading. See the science and judge for yourself.

A 12-year-old thoroughbred was examined because of signs of depression, neck stiffness, and poor performance and a reluctance to raise its neck and head above a horizontal plane. The horse responded well to doxycycline treatment for 60 days and returned to normal exercise. However, 60 days after treatment was discontinued, the horse again developed a stiff neck and rapidly progressive neurologic deficits. The horse's condition deteriorated rapidly despite IV antibiotic treatment, and the horse was euthanized. Postmortem examination revealed findings consistent with a diagnosis of neuroborreliosis (leptomeningitis, lymphohistiocytic leptomeningeal vasculitis, cranial neuritis, and peripheral radiculoneuritis with Wallerian degeneration). Nervous system infection with B burgdorferi should be considered in horses with evidence of meningitis and high or equivocal serum anti-B burgdorferi antibody titers. Evaluation of immune function is recommended in adult horses evaluated because of primary bacterial meningitis.

One of the hot topics in Lyme disease is whether the bacteria that causes Lyme disease persists. There are a lot of factors that go into proving this, but one is whether there is a “plausible biological mechanism for persistence.” What this means is whether there is a mechanism in biology that might allow the bacteria to survive. Simply put, the Infectious Diseases Society of America says there isn’t and other researchers disagree. The most recent article on this subject is from Straubinger, who is best known for his research on persistence in dogs. The highlights of the study after the jump. . .

During his interview with NPR’s Terry Gross on Fresh Air, journalist Michael Specter got a key piece of information WRONG: that a tick must be attached for at least 36 hours before it can transmit infection.

Michael Kruse says he thinks people “should be looking at all of the evidence, not just the few studies that agree with an opinion that moves us emotionally.” Then he bases his argument on evidence that agrees with an opinion that moves him emotionally.