Mad Cow Disease
Relapsing Fever and Asthma
Eating infected chicken
Doctors leave bacteria on computer keyboards
Spirochetes may "love the brain to death"
NEWS ARTICLE from The Associated Press, 5-9-01, By STEVE BAILEY, Associated Press Writer
``FOALS, FETUSES MYSTERIOUSLY DYING
LEXINGTON -- Scientists are trying to figure out why pregnant Kentucky mares are losing foals at a staggering rate this spring in a mystery that has sent fear through the state's $1.2 billion thoroughbred horse industry.
"It's got a lot of people spooked, no doubt about it," said Steve Johnson, president of the Kentucky Thoroughbred Farm Managers Club. "I've talked to a lot of farm owners who aren't going to sleep very much until they find out what is going on with their mares."
So far, most tests for toxins or viruses have come back negative. Kentucky's famous bluegrass may even be a factor, and some horse owners are sending their mares out of the state until the mystery is solved.
The number of unexplained stillborn foals and spontaneously aborted pregnancies is nearly seven times normal in central Kentucky this spring.
Between April 28 through Monday, the University of Kentucky Livestock Disease Diagnostic Center received 318 miscarried fetuses or stillborn foals for testing. It received just 46 during the same period last year ...
Claiborne Farm manager Gus Koch said one of his mares gave had a stillborn foal last week. Over the weekend, he discovered that 10 more mares, which were early in their pregnancies, had aborted their fetuses. "I've never seen anything like this. Statewide and industry-wide, it could be devastating," he said. ...
A team of more than two dozen scientists, veterinarians and farm managers has concluded that the deaths are probably related.
"So many farms having problems over such a narrow period of time indicates that there is a common source," said David Powell, a disease researcher with the University of Kentucky's Gluck Equine Research Center.
But Powell said the problem is not believed to be spread from one horse to another, unlike the outbreak of foot-and-mouth disease in Europe.
One theory is that Kentucky's warm, dry spring followed by several hard freezes allowed a fungus or toxin to develop in grasses eaten by horses . Powell and others are telling farms to mow frequently and limit horses' time in pastures.
Other possible theories involve bacteria or chemicals ... ''
NEWS ARTICLE from The Associated Press, 5-11-01, By STEVE BAILEY, Associated Press Writer
``Kentucky farms seek answers in foals' mysterious deaths
LEXINGTON, Ky. (AP) -- Scientists have named the illness that is killing foals and causing mares to lose fetuses, but still can't definitively explain the syndrome that is devastating Kentucky horse farms.
More than 1,000 farm managers, breeders and veterinarians gathered Thursday to hear scientists and equine officials offer the latest information on Mare Reproductive Loss Syndrome.
The researchers acknowledged that the illness may not be limited to Kentucky's horse farms. Participants mentioned similar cases in Illinois, Ohio and Pennsylvania.
"According to our most recent information, this syndrome may be occurring on a smaller scale in states north of Kentucky," said Dr. David Powell, equine epidemiologist at the University of Kentucky's Gluck Equine Research Center.
Dr. Grant Frazer, a reproductive specialist at Ohio State University's veterinary school, said he had reports of dying foals in Gallia, Morgan and Highland counties in southern Ohio. Dr. Pam Pintchuk, a Geauga County veterinarian, said she was aware of more than 10 deaths in her northeast Ohio area ... ''
NEWS ARTICLE from The Plain Dealer, 5-11-01, By BILL SLOAT and JOHN HORTON
``Mystery disease menaces horse farms
LEXINGTON, Ky. - A mysterious disease sweeping through the Bluegrass country's horse farms and killing unborn foals may have crossed into Ohio ...
Since the end of April, University of Kentucky livestock researchers have gotten 382 stillborn and aborted animals for autopsy. That is more than 700 percent above normal, said Lenn Harrison, director of veterinary pathology at the University of Kentucky.
Harrison said yesterday that the deaths and spontaneous abortions have defied explanation.
The mares themselves are not becoming ill even though they are losing their foals.
The Kentucky researchers, who acknowledge they are baffled by the outbreak threatening the state's $1.7 billion-a-year horse industry at the height of the foaling season, have come up with a name for the unexplained malady: "mare reproductive loss syndrome."
Harrison, during a briefing for hundreds of the state's horse breeders yesterday at Keeneland race track, said many of the aborted fetuses are full of streptococcus bacteria.
"The bacteria are probably playing an important role in the syndrome we are seeing," he said. "It may not be the initiating agent, but they are there."
He said the horses have tested negative for viruses ...
Tom Riddle, a veterinarian with the Rood & Riddle Equine Hospital near Lexington, told the Kentucky horse breeders that the amniotic fluid surrounding the fetuses is bloody and clouded, containing a "snowstorm" of toxic material ...
Plant pathologist Jimmy Henning, of the University of Kentucky, told the breeders that initial theories blaming the deaths on fescue, a type of grass that grows in pastures, may be incorrect ...
He said researchers are looking into whether a fungus may have bloomed on the tips of the bluegrass as it emerged this spring.
Henning said another possibility is that cyanide may have been produced by white clover plants.
He said climate changes may be affecting the clover plants. "They can release cyanide during stress. That includes drought," he said.
The Ohio Valley, which includes Kentucky and southern Ohio, has been experiencing higher than normal temperatures and below-average rainfall so far this year.
Another possibility, Henning said, is that toxic molds are flourishing in dry weather because the bacteria that normally prey on the molds can't survive in hot, dry conditions.
"The pastures look like August rather than early May," said Henning ...
Randy James, the Ohio State University Extension agent for Geauga County, said a meeting is being arranged to discuss the local foal deaths, which are still being studied. The suspicion, however, has centered on fescue in last year's hay harvest creating high levels of toxicity, he said.
James said last year's rain-delayed hay harvest allowed the fescue growing among the other grasses to form seeds, which are more toxic ... ''
E-mail: firstname.lastname@example.org. email@example.com
Ann N Y Acad Sci 1988; 539: 235-43 BORRELIA BURGDORFERI INFECTION IN WISCONSIN HORSES AND COWS. Burgess EC
``Blood samples from Wisconsin horses and cows suspected of having clinical disease due to Borrelia burgdorferi infection were submitted by veterinary practitioners.
All serum, milk, colostrum, and synovial samples were tested for B. burgdorferi antibodies by immunofluorescence. Whole blood, milk, colostrum, and synovial fluid samples were cultured for B. burgdorferi.
Records were kept on the clinical signs of antibody-positive animals, date of sample, and location of the animal by county ...
For both cows and horses October and May were the two peak months for the number of antibody-positive samples.
The most frequent clinical signs in antibody-positive horses and cows were lameness and swollen joints, but many also had stiffness, laminitis, ABORTIONS, and fevers.
Not all antibody positive animals showed clinical signs. These findings show that B. burgdorferi infection occurs in horses and cows and can cause clinical illness in some but not all animals.
Infection in cows and horses occurs most frequently 1 month after the emergence of adult I. dammini [ticks].
Because spirochetes could be isolated from blood, synovial fluid, colostrum, and urine, these animals could be important in providing an infected blood meal for ticks and bringing B. burgdorferi in direct contact with humans. ''
Journal of Spirochetal and Tick-Borne Diseases 1998; 5(4):54-62 EVIDENCE FOR IN UTERO TRANSMISSION OF BORRELIA BURGDORFERI FROM NATURALLY INFECTED COWS; Leibstein MM, Khan MI, Bushmich SL
Excerpts from the abstract:
``Five of 15 adult cows were spirochetemic at parturition; 4 of the calves from these cows were also spirochetemic at birth (PCR). Spirochetes were cultured from the placentas in 2 of 10 cows and from the uterine fluid in 1 of 8 cows.
Borrelia burgdorferi DNA was detected in the colostrum in 4 of 12 cows. Three of 15 calves were STILLBORN; Borrelia burgdorferi DNA was detected by PCR in 3 of 3 and spirochetes cultured from 2 of 3 stillborn calves.
Fetal tissues from which Borrelia burgdorferi DNA was detected include blood, spleen, bladder, kidney, synovial fluid and tissue, heart, cerebrum, and aqueous humor.
Borrelia burgdorferi was cultured from the spleen of one stillborn calf and the kidney of another.
Detection of Borrelia burgdorferi DNA from the tissues of STILLBORN calves, as well as spirochetemia in neonatal liveborn and stillborn calves, gives evidence for in utero transmission of Borrelia burgdorferi in naturally infected dairy cattle. ''
NEWS ARTICLE from The Associated Press, 6-7-01
``Horses still being affected by heart problems, blindness
LEXINGTON, Ky. (AP) -- A veterinary internist said he is still seeing numerous cases of horses with inflamed hearts at his Lexington clinic, while the loss of foals and fetuses has started to ease.
Dr. Doug Byars of Hagyard-Davidson-McGee Associates expects to see two or three cases of pericarditis, an inflammation of the sac around the heart, in an entire year. But just last week, five new cases were admitted to the clinic, he said. In the last month his practice has seen 10 times the number of pericarditis cases it normally sees in a year.
Since the mysterious Mare Reproductive Loss Syndrome surfaced a month ago, hundreds of mares have spontaneously aborted and others have given birth to dead or extremely sick foals in Kentucky, Ohio, Pennsylvania and Illinois. At the same time, horses of all ages have had a host of serious health problems, from blindness to pericarditis.
Byars said it may be that sick horses keep coming in while the fetal losses have subsided because fetuses are more sensitive and were affected faster, or because some cases of pericarditis haven't been diagnosed until recently.
The illnesses also raise the worrisome possibility that a toxin still lurks in the environment.
A total of 55 pericarditis cases have been treated at Byars' clinic and at another large Lexington clinic, Rood & Riddle Equine Hospital, since April 26. The most recent was a broodmare admitted Friday.
Only half the horses with the heart problem are recovering, Byars said. At least 12 have died from the ailment, judging from the number brought in to the University of Kentucky's diagnostic lab, he said.
It's not known whether horses that recover will be able to race or whether their heart function will be permanently impaired, Byars said. It's very rare in any species to see this kind of pericarditis, accompanied by excess fluid, he said.
A total of 40 horses have gone blind in one eye, said Dr. Nathan Slovis, an internist at Hagyard-Davidson-McGee.
No one knows if there is a single cause for the reproductive losses and the health problems, or if they are two or more separate problems.
"You would think they are linked because all of these things leaped upon us in tremendous numbers very abruptly," Byars said.
In Ohio, a draft horse stallion died recently of pericarditis and another horse is being treated for it at Ohio State University's equine hospital, said Dr. Steve Reed, a veterinary internist.
He said the stallion was from a farm near Lancaster, a suburb of Columbus. All 12 of the mares on that farm had stillborn foals, leading Reed to believe there's a common culprit ... ''
NEWS ARTICLE from The Associated Press, 6-9-01
``Heart ailment mysteriously striking horses
COLUMBUS, Ohio (AP) -- A rare and deadly heart inflammation has been reported in three Ohio horses. Two of the three died and the third was released Friday in improved but guarded condition from the Ohio State University veterinary medical center.
The condition, known as pericarditis, is an inflammation in the sac that surrounds the heart. It results in a buildup of fluid and constriction of the heart muscle.
Veterinarians in Ohio and Kentucky suspect it may result from the same environmental toxins that have caused more than 1,000 foals to be born dead or near death since March.
At least two of the three Ohio cases came from farms that experienced multiple foal deaths this spring.
Autopsies conducted at the Ohio Department of Agriculture laboratories in Reynoldsburg found pericarditis in a mare and a stallion who had died at separate farms in Logan ...
More than 1,200 foal deaths were reported to the University of Kentucky between March and mid-May, the end of the foaling season.
The suspected source of the toxin is the eastern tent caterpillar, which feeds on wild cherry trees in spring, possibly excreting cyanide or mycotoxins into the grass ... ''
[Is anyone looking for diseases transmitted by the deer tick?]
NEWS ARTICLE from THE PLAIN DEALER, 5-6-01, By JOHN S. LONG
``Nation isn't doing enough to detect mad cow disease, CWRU experts say.
Two research scientists at Case Western Reserve University say the U.S. government is not testing enough cattle to detect the presence of mad cow disease.
Compounding the problem are weaknesses in the government's ability to regulate and track animals and their feed:
Hundreds of feed mills do not have measures in place to prevent mingling of feed approved for cattle with banned animal feed, which includes the processed meat and bones of dead animals.
The U.S. government has failed to track some banned European feed and cattle that have entered the United States.
"If you don't look, you won't find," said Dr. Pierluigi Gambetti, a neuropathologist at CWRU who called the amount of cattle testing done in the United States insignificant. "Unless we test more, we will never know if we have it here. If they can do it in Europe, one would think they could do it here."
Gambetti heads the National Prion Disease Pathology Surveillance Center at CWRU, which the federal government set up to monitor a human variation of the disease.
Dr. Man-Sun Sy, an immunologist at CWRU, agreed. "Even if it were here," Sy said, "they will not find it at the current rate of testing." Sy is part of a team of the world's top disease prevention scientists developing a test that will allow cattle to be checked without being killed. The test, which is in preliminary development, would provide more information than current tests.
Mad cow, also known as bovine spongiform encephalopathy, is a disease in which abnormal protein material (scientifically called a prion protein) attacks the central nervous system of an animal and eats away at the brain.
It is always fatal. No cases of mad cow disease have been found in the United States, though it now has been confirmed in 31 other countries.
Humans can contract a number of mad cow-type diseases. One is transmitted by eating mad-cow-infected beef. It's called Variant-Creutzfeld-Jakob disease.
Another, Creutzfeld-Jakob disease, is transmitted genetically or develops for reasons that scientists can't determine.
A third, chronic wasting disease, comes from eating infected elk and deer. There have been a number of cases of this in the United States and Canada ...
Dr. Linda Detwiler, a senior staff veterinarian with the federal government, ... confirmed that quarantined sheep in Vermont were infected with either mad cow or scrapie, a variation of the disease found in sheep. The sheep were euthanized and tested at a federal laboratory in Iowa in March ...
Detwiler is an Ohio State University Veterinary School graduate who began her career in Northeast Ohio. She works for the U.S. Department of Agriculture's Animal and Plant Health Inspection Service and heads the USDA's cattle testing program ...
About 100 cases of Variant-Creutzfeld-Jakob Disease have been discovered, 97 of them in England, and the remainder in France and Ireland.
Because of the disease's long incubation period - five to 20 years - scientists estimate that during that period another 140,000 cases of the human variant will occur in Great Britain ...
From 1990 through 2000, the United States tested fewer than 12,000 cattle for mad cow disease, and none tested positive for it. In the same period, the EU, including the United Kingdom, tested 270,000 cattle.
Every week since late last year, the EU has tested between 120,000 and 140,000 cattle for the disease.
CWRU's Gambetti acknowledges that the situation in Europe is different than it is here, but he still points to actions there that should prompt the United States to increase its testing for mad cow disease.
Last year, officials in Italy and Germany assured the public there was no mad cow disease in their countries, according to Gambetti, who added that they spoke before testing enough to know.
The Swiss thought the amount of testing throughout Europe was too low, so they began intensive testing. Their results showed that the number of infected cattle was far larger than previous tests indicated. This led the EU to mandate increased testing five months ago throughout Europe.
"Germany and Italy immediately found cases," said Gambetti. "Italy tested 50,000 to 60,000 and found 12, about one in every 5,000 - and that's not a small number ...
"Most of our testing is limited to downer cows," admitted Detwiler, referring to cattle that show signs of an impaired central nervous system. ''
More on Mad Cow Disease
NEWS ARTICLE from REUTERS, 4-26-01
``NEW BORRELIA SPECIES IDENTIFIED IN DEER TICKS
A previously unrecognized Borrelia species has been found in deer ticks, making it the fifth transmissible agent linked to the insect responsible for transmitting Lyme disease.
WESTPORT, CT (Reuters Health) Apr 26 - A previously unrecognized Borrelia species has been found in deer ticks, making it the fifth transmissible agent linked to the insect responsible for transmitting Lyme disease.
Dr. Durland Fish and colleagues, from the Yale School of Medicine in New Haven, Connecticut, found the organism during a routine experiment investigating transmissible agents in a tick/rodent model.
The researchers observed the organism in tick nymphs that fed upon mice that were not infected with Borrelia burgdorferi, the Lyme disease-causing spirochete.
The findings by Dr. Fish's team are published in the Spring  inaugural issue of Vector Borne and Zoonotic Diseases.
The unnamed organism resembles the tick-borne spirochete Borrelia miyamotoi, found in Japan. "We sequenced a portion of the DNA to determine what it was and it turned out to be a spirochete that is related to relapsing fever spirochetes rather than the Lyme disease spirochete," Dr. Fish noted in a statement released by Yale.
"It is not yet known if the bacteria can infect humans, but we do know that all the other organisms that this tick transmits to mice can also infect people," Dr. Fish pointed out.
Approximately 2% of the ticks tested in Rhode Island; Lyme, Connecticut; Westchester County, New York; and northern New Jersey harbored the newly identified organism, Dr. Fish noted.
It was previously thought that Borrelia burgdorferi was the only spirochete carried by the tick, but the new findings indicate that up to 20% of infected ticks may carry the newly identified organism ... ''
NEWS ARTICLE from REUTERS, 5-8-01
``ASSOCIATION BETWEEN CHRONIC ASTHMA, CHRONIC INFECTION DELINEATED
A substantial number of patients with chronic stable asthma have Mycoplasma species, Chlamydia species, or both in their airways, researchers have found.
WESTPORT, CT (Reuters Health) May 08 - A substantial number of patients with chronic stable asthma have Mycoplasma species, Chlamydia species, or both in their airways, researchers have found.
Dr. Richard J. Martin, of the National Jewish Medical and Research Center, Denver, Colorado, and colleagues note that chronic infection may play a role in the pathophysiology of asthma.
They used PCR, culture and serology for Mycoplasma species, Chlamydia species, and viruses from the nasopharynx, lung and blood to compare 55 patients with chronic stable asthma with 11 control subjects.
The team reports that 25 of the asthmatic patients had positive results for a Mycoplasma species pathogen, compared with only one control subject.
Seven of the asthmatic subjects tested positive for a Chlamydia species, and one of them had positive results for both C. pneumoniae and M. pneumoniae.
No controls were positive for Chlamydia species. These pathogens were mostly found on lung biopsy specimens or in bronchoalveolar lavage (BAL) fluid.
"For the 55 asthmatic subjects, 31 (56.4%) had positive results for either Mycoplasma species, Chlamydia species, or both," the investigators report in the April issue of the Journal of Allergy and Clinical Immunology ... ''
J Allergy Clin Immunol 2001;107:595-601.
FEATURE ARTICLE from THE COLUMBUS DISPATCH, 5-27-01, By Steve Rissing
``Biology: Warning labels on meat once were unnecessary
My grandmother would spin in her grave if she knew the government requires safe-handling instructions on packages of meat in stores.
She would slow down, however, if she knew we are fighting bacteria unlike any she ever encountered. Then again, if she knew we'd created them . . . well, there's no rest for ancestors these days ...
In addition to all the bacteria that caused food poisoning then, a potent new one exists now. Campylobacter, found on most raw chicken, causes more food poisoning than any other agent, afflicting 2 million Americans per year.
It wasn't a problem until 1995, when the U.S. Food and Drug Administration permitted the addition of a new class of antibiotics to the drinking water of chickens to kill the bacterium E. coli (lethal to the birds).
Then came antibiotic-resistant versions of Campylobacter, a second bacterium found in chickens that is not lethal to them but is potentially so to humans.
People who ate undercooked chicken or foods exposed to raw chicken, and who thus contracted Campylobacter, didn't respond to standard antibiotic drugs -- because those drugs were the same ones given to the birds ...
When the [Campylobacter] inevitably found its way into humans, we were (and are) defenseless.
This is as classic and predictable a case of natural selection as one can find: Create an environment favoring certain traits of organisms (such as antibiotic resistance), and those traits will occur and spread.
Back in Mom's and Grandma's days (or even my high-school days), food safety was the mainstay of the now nearly extinct home-economics course.
But a current high-school or college- freshman knowledge of biology should have predicted the inevitable outcome of providing such antibiotics to chickens. It obviously didn't and doesn't ... ''
Steve Rissing is a professor in the Department of Evolution, Ecology and Organismal Biology at Ohio State University directs the university's Introductory Biology Program. ''
NEWS ARTICLE from HealthScoutNews, 5-23-01, By Fran Berger
``Antibiotic Resistance Takes Form on the Farm
Drug-resistant genes traced from animals to groundwater
One reason antibiotics are losing the power to fight human diseases may be found down on the farm, says a new study.
Researchers at the University of Illinois at Urbana-Champaign have traced antibiotic-resistant genes from pig farms to groundwater, suggesting that resistance is being built up through the food chain.
The discovery raises concerns because antibiotics are widely used to fatten livestock and prevent disease in the animals in the United States.
"The genes are found in bacteria, and the tetracycline-resistant genes in the bacteria travel into the groundwater, where the horizontal transfer of the genes occur," says lead study author Rustam I. Aminov, a microbiologist and visiting professor of animal science.
"The resistant genes get into the ground and drinking water and will find their way into the guts of people, animals and wildlife, passing on the resistance in a continuous gene cycle," he says.
The research team analyzed water samples from lagoons, wells and groundwater on and near two Illinois pig farms, and through a DNA amplification technique, identified the trail taken by the resistant genes.
The amplification process, called a polymerase chain reaction (PCR), rapidly duplicates DNA, allowing experts to identify a gene's unique fingerprint.
"These [antibiotic resistant] genes were found to be predominant in the gastrointestinal tracts of pigs and steers" and suggested the flow of the genes to the water came directly from the animals, say researchers ...
Aminov says the process by which antibiotic resistance may be passed along "is really poorly understood." In another investigation, he says researchers are looking at the disposal of livestock waste products, which may be returned to the ground in forms of manure.
From there, antibiotic resistance may transfer to corn or soybeans, as either livestock feed or consumer product, says Aminov.
He says antibiotics to make farm animals bigger has been banned in Sweden since the l980s, and the European Union is currently phasing out the practice.
Aminov says 21 antibiotics now are "administered to swine for growth promotion or prophylaxis, and we studied only one class of the gene. He says the problem is of particular concern in rural areas where people use untreated well water, which they assume is very clean.
"There is a race for profit because agricultural [work] is so low profit, and many depend on antibiotics to survive," but using antibiotics to fatten animals or prevent disease may make the drugs useless in fighting human disease, he says.
"We have to preserve antibiotics for other purposes," says Aminov.
The study is published in the 4-01 issue of Applied and Environmental Microbiology. ''
NEWS ARTICLE from REUTERS, 5-25-01
``Drug-Resistant Bacteria Found in US Meat
ORLANDO, FL -- A preliminary survey of beef and poultry sold in US supermarkets, conducted by the US Food and Drug Administration (FDA), has found relatively high levels of antibiotic-resistant bacteria, according to a report presented here on Tuesday at the 101st annual meeting of the American Society for Microbiology.
In the study, researchers analyzed Enterococcus strains in meat bought at several Washington, DC-area supermarkets. The investigators found "fairly substantial amounts of resistance to a number of drugs" in the bacteria, FDA microbiologist Dr. David Wagner told conference participants.
Enterococci were found in 67% of the chicken samples, 34% of the turkey samples and 66% of the beef samples.
The researchers tested for resistance to 29 different types of antibiotics, including 6 commonly used in animal feed ... ''
From The Plain Dealer, 6-26-01, By SANDRA G. BOODMAN
[Doctors, nurses leave bacteria on computer keyboards]
``The proliferation of computers in medical settings has meant not just technological innovation but a new and unlikely source of potentially lethal infections: keyboards used by doctors and nurses who don't wash their hands.
That's what a team of infectious-disease specialists at the Tripler Army Medical Center in Honolulu discovered when they cultured 10 computer keyboards in the intensive-care unit eight times over two months. About 25 percent of the samples harbored the bacteria hospital officials fear most: multidrug-resistant staphylococcus aureus.
This type of bacterium, which was once easily vanquished by penicillin, is responsible for about 95 percent of hospital-acquired infections nationwide, according to the federal Centers for Disease Control and Prevention. It can spread rapidly, particularly among patients with weakened immune systems, and is increasingly resistant to powerful antibiotics including vancomycin, a drug reserved for the most serious infections.
DNA tests revealed that the same strain of drug-resistant staph was found in two patients during the test period. In addition to staphylococcus aureus, researchers detected enterococcus on ICU keyboards; enterococcus can cause life-threatening gastrointestinal infections ...
While it's not clear how the keyboards became colonized by bacteria, the most likely explanation, officials said, lies in the failure of doctors and nurses to wash their hands between patients. Studies have found that compliance with hand-washing requirements, particularly among physicians, is as low as 14 percent.''
101st General Meeting of the American Society for Microbiology, [ASM], May 20-24, 2001, Orlando, Florida; Press Release of 7-8-01.
Spirochetes may "love the brain to death" (Session 179)
By Dr. Diego Cadavid, Medical School of The University of Medicine and Dentistry of New Jersey (UMDNJ) in Newark, with funding to Dr. Cadavid from the Foundation of UMDNJ and the Hispanic Center of Excellence at UMDNJ.
UMDNJ-New Jersey Medical School
``Chronic infection of the brain is a prominent feature of spirochetal infections. These include syphilis, caused by Treponema pallidum; Relapsing Fever, caused by different Borrelia species worldwide; and Lyme disease, caused by Borrelia burgdorferi in Europe and North America.
The word "spirochete" comes from the characteristic spiral morphology of these bacteria under the microscope. Lyme disease and relapsing fever are transmitted to humans by ticks in endemic areas, while syphilis is sexually transmitted.
As early as 1822, dementia was recognized as a prominent complication of syphilis. Soon it became apparent that multiple other neurological complications can occur.Examination of the brain revealed the presence of spirochetes, in cases of dementia 20 to 30 years after the initial infection.
As with Treponema pallidum in syphilis, chronic brain infection is also prominent with the relapsing fever spirochetes. During relapsing fever, patients have recurrent periods of fever separated by periods of well being. The fever is caused by the presence of large numbers of spirochetes in the blood.
Studies in relapsing fever showed that, like in syphilis, the brain could remain infected with spirochetes for years after the infection disappears from the blood.
In the earlier 1980's, Lyme disease was identified as a previously unrecognized spirochetal infection with prominent neurological manifestations. These include headache and stiff neck from meningitis, back pain and weakness from radiculitis, paralysis of the face, and problems with attention and concentration.
Lyme disease is today the most common vector-borne disease in North America and Europe, with an estimated 5-40% of cases developing neurological complications.
Although spirochetal infections are readily treatable with antibiotics, severe and permanent neurological damage can occur if they go undiagnosed or if the treatment is inadequate or delayed.
Our laboratory is investigating the mechanisms responsible for neurological complications during spirochetal infections. Studies with Treponema pallidum and Lyme disease spirochetes are limited because of the paucity of animal models featuring neurological infection.
In contrast, several animal models of Relapsing fever show prominent neurological infection. The majority of our research has been done in laboratory mice infected with a strain of relapsing fever spirochetes from South Western United States.
The data indicates that not all spirochetes are equally capable of entering into the brain. The antibody response to the infection is critical for elimination of infection from the brain.
The localization of spirochetes in the brain is mainly in the membranes covering it, known as the leptomeninges. Spirochetes are also found in the brain tissue itself, although in much lower numbers.Infection of the inner ear results in prominent vertigo.
Different serotypes vary in their ability to infect the brain. The main route of entry into the brain appears to be the blood-brain barrier. However, alternative routes of entry may be used.
Spirochetal entry into the brain results in infiltration of the brain tissue by large numbers of inflammatory cells, known as microglia, and increased statement of inflammatory molecules, like Interleukin 6. We are currently investigating whether chronic inflammation could result in damage to brain cells and in neurological disease.
Using monkeys infected with Lyme disease spirochetes, we confirmed that the localization of spirochetes in the brain is leptomeningeal. In this monkey model of Lyme disease, the number of spirochetes in the brain is very low compared with peripheral tissues like the heart or skeletal muscle, even in immunosuppressed animals. About 10% of infected monkeys examined 4-24 months after infection show evidence of inflammation in the brain, which is mild ... ''
For more information on any presentation at the 101st General Meeting contact Jim Sliwa, ASM Communications at firstname.lastname@example.org.