Again the title is not borne out by the text of the article, what is
says is that viable bacteria linger in the joints.

Lingering Bacteria Don't Indicate Chronic Lyme Disease

ScienceDaily (Apr. 3, 2008) -- The bacteria that cause Lyme disease,
the most common tick-borne illness in the United States, can linger in
mouse tissues long after a full round of antibiotic treatment is
completed, report researchers from the University of California,
Davis.

The scientists caution that the discovery does not suggest the
presence of chronic disease, nor does it support extended use of
antibiotics to treat Lyme disease in humans. Their findings are
reported in the March issue of the journal Antimicrobial Agents and
Chemotherapy.

However, they say, the results of this study do set the stage for
controlled laboratory research investigating potential therapies for
persistent Lyme disease infections.

"Lyme disease is a tough nut to crack. The bacterium Borrelia
burgdorferi has evolved to evade the body's immune system so it's not
surprising that it can also evade antibiotics," said Stephen Barthold,
lead researcher on the study. Barthold is director of the UC Davis
Center for Comparative Medicine, a cooperative research center in the
schools of Medicine and Veterinary Medicine that investigates animal
models of human disease.

"It's important to note that the numbers of residual bacteria
identified in this study were very low and there was no evidence that
they were causing inflammation," Barthold said. "Their presence
shouldn't be misconstrued as a sign of chronic disease."

Lyme disease background

Borrelia burgdorferi, the corkscrew-shaped bacterium that causes Lyme
disease, is transmitted to humans and animals through bites from
infected deer ticks. In the United States, Lyme disease is most
prevalent in the Northeastern and Great Lakes states, and is present
to a lesser extent in Northern California. Other high-risk Lyme
disease areas are scattered throughout the nation, usually in shady,
moist deciduous forests where the carrier ticks and their wildlife
hosts flourish.

Symptoms of Lyme disease are highly variable and may include fever,
headache, fatigue and a skin rash. If the infection is not treated, it
can spread to the joints, heart and nervous system.

Usually, Lyme disease can be successfully treated with about four
weeks of antibiotics. Treatment is most successful during the early
stages of infection. A few patients, particularly those treated during
late infection, may experience persistent or recurring symptoms after
the antibiotic treatment is finished, in which case a second round of
antibiotics may be prescribed.

According to the U.S. Centers for Disease Control and Prevention,
antibiotic treatment above and beyond one repeat round has not been
shown to be beneficial and has been linked to serious complications,
including death.

Controversy

Many of those involved with Lyme disease -- including patients,
doctors, researchers and health insurance companies -- are divided
over how to treat the ailment when it persists beyond a second round
of antibiotics. Some patients with persistent or recurrent Lyme
disease symptoms report experiencing fatigue, joint pain, extreme
headaches, facial paralysis and memory loss. Much of the controversy
revolves around debate over whether symptoms reflect continued
infection after treatment.

There has been minimal scientific evidence to support the claim that
infection with the Lyme disease bacterium can persist in a chronic
state following antibiotic treatment. As a result, treatment
guidelines recommend against prescribing long-term antibiotics for
persistent Lyme disease symptoms. Many physicians and health insurance
companies refuse to prescribe or pay for extended antibiotic
treatments.

Davis study

Barthold and colleagues studied antibiotic treatments for Borrelia
burgdorferi infection in laboratory mice.

One group of mice was treated for one month with the antibiotic
ceftriaxone, beginning during the first three weeks of infection. A
second group received the same antibiotic for one month, but beginning
at four months after infection, representing a chronic infection. A
third group, serving as the control, received only saline for one
month, rather than the antibiotic.

When the antibiotic treatments were completed, DNA analysis showed
that small numbers of the Lyme disease-causing bacteria remained in
the tissues of the antibiotic-treated mice. Ticks allowed to feed on
these infected mice were also able to acquire and transmit the
infectious bacteria. Curiously, despite the apparent viability of the
bacteria, they could not be detected by standard laboratory cultures.

The findings support the theory that the bacteria remain viable and
that some bacteria evade antibiotic treatment by taking refuge in
collagen-rich tissues, skin, ligaments and tendons.

"Our theory is that these remaining bacteria are in a metabolically
dormant, non-dividing state," Barthold said. "This would explain why
we were unable to culture them.

"In future studies we need to look at the long-term fate of these
bacteria," he said. "They seem to be non-dividing. If so, are they
permanently crippled by the antibiotics and eventually would die out,
or would they grow back over the long term and cause a recurrence of
the disease?"

While the residual bacteria do not appear to cause disease, they may
contribute to the persistence of Lyme disease symptoms, the
researchers suggested.

"This may explain why some Lyme disease patients recover slowly
following antibiotic treatment, exhibiting what has been termed "post-
Lyme disease syndrome," Barthold said.

The existence of a small number of sequestered bacteria should not
come as a surprise, he added, noting that with disease-causing agents
like herpes virus and the bacteria that cause tuberculosis and
syphilis, it is not unusual for the infectious organisms to persist at
levels that do not actually cause symptoms.

"This is just part of our world of microbes," Barthold said.
"Antibiotics are designed to kill large numbers of bacteria -- to
knock them down to the point that the body's immune system can get
control of the infection."

Bacteria have evolved the means to survive antibiotics in the natural
world, he noted. Furthermore, if disease-causing organisms such as
Borrelia have evolved the means to escape clearance by the immune
system, it is not surprising that the bacteria that survive antibiotic
treatment would not be eliminated.

In the case of Lyme disease, the research findings do not suggest that
continued use of antibiotics would succeed in getting rid of the
lingering bacteria.

"I suspect that if the initial round of antibiotics hasn't eliminated
them, it's not likely that a longer regimen of antibiotics would be
any more successful," Barthold said. "It's more likely that a
completely different class of antibiotics would be needed to
accomplish that. This laboratory mouse model will allow us to address
those possibilities."

Funding for this study was provided by a U.S. Public Health Service
grant from the National Institute of Allergy and Infectious Diseases.