Bird flu is bad for livestock; it's not a dire threat to most of us - yet

Getty Images

By Amy Maxmen
KFF Health News

Headlines are flying after the U.S. Department of Agriculture confirmed that the H5N1 bird flu virus has infected dairy cows around the country. Tests have detected the virus among cattle in nine states, mainly in Texas and New Mexico, and most recently in Colorado, said Nirav Shah, principal deputy director at the Centers for Disease Control and Prevention, at a May 1 event held by the Council on Foreign Relations.

A menagerie of other animals have been infected by H5N1, and at least one person in Texas. But what scientists fear most is if the virus were to spread efficiently from person to person. That hasn’t happened and might not. Shah said the CDC considers the H5N1 outbreak “a low risk to the general public at this time.”

Viruses evolve and outbreaks can shift quickly. “As with any major outbreak, this is moving at the speed of a bullet train,” Shah said. “What we’ll be talking about is a snapshot of that fast-moving train.” What he means is that what’s known about the H5N1 bird flu today will undoubtedly change.

With that in mind, KFF Health News explains what you need to know now.

Who gets the bird flu? Mainly birds. Over the past few years, however, the H5N1 bird flu virus has increasingly jumped from birds into mammals around the world. The growing list of more than 50 species includes seals, goats, skunks, cats, and wild bush dogs at a zoo in the United Kingdom. At least 24,000 sea lions died in outbreaks of H5N1 bird flu in South America last year.

What makes the current outbreak in cattle unusual is that it’s spreading rapidly from cow to cow, whereas the other cases — except for the sea-lion infections — appear limited. Researchers know this because genetic sequences of the H5N1 viruses drawn from cattle this year were nearly identical to one another.

The cattle outbreak is also concerning because the country has been caught off guard. Researchers examining the virus’s genomes suggest it originally spilled over from birds into cows late last year in Texas, and has since spread among many more cows than have been tested. “Our analyses show this has been circulating in cows for four months or so, under our noses,” said Michael Worobey, an evolutionary biologist at the University of Arizona in Tucson.

Is this the start of the next pandemic? Not yet. But it’s a thought worth considering because a bird flu pandemic would be a nightmare. More than half of people infected by older strains of H5N1 bird flu viruses from 2003 to 2016 died. Even if death rates turn out to be less severe for the H5N1 strain currently circulating in cattle, repercussions could involve loads of sick people and hospitals too overwhelmed to handle other medical emergencies.

Although at least one person has been infected with H5N1 this year, the virus can’t lead to a pandemic in its current state. To achieve that horrible status, a pathogen needs to sicken many people on multiple continents. And to do that, the H5N1 virus would need to infect a ton of people. That won’t happen through occasional spillovers of the virus from farm animals into people. Rather, the virus must acquire mutations for it to spread from person to person, like the seasonal flu, as a respiratory infection transmitted largely through the air as people cough, sneeze, and breathe. As we learned in the depths of covid-19, airborne viruses are hard to stop.

That hasn’t happened yet. However, H5N1 viruses now have plenty of chances to evolve as they replicate within thousands of cows. Like all viruses, they mutate as they replicate, and mutations that improve the virus’s survival are passed to the next generation. And because cows are mammals, the viruses could be getting better at thriving within cells that are closer to ours than birds’.

The evolution of a pandemic-ready bird flu virus could be aided by a sort of superpower possessed by many viruses. Namely, they sometimes swap their genes with other strains in a process called reassortment. In a study published in 2009, Worobey and other researchers traced the origin of the H1N1 “swine flu” pandemic to events in which different viruses causing the swine flu, bird flu, and human flu mixed and matched their genes within pigs that they were simultaneously infecting. Pigs need not be involved this time around, Worobey warned.

Will a pandemic start if a person drinks virus-contaminated milk? Not yet. Cow’s milk, as well as powdered milk and infant formula, sold in stores is considered safe because the law requires all milk sold commercially to be pasteurized. That process of heating milk at high temperatures kills bacteria, viruses, and other teeny organisms. Tests have identified fragments of H5N1 viruses in milk from grocery stores but confirm that the virus bits are dead and, therefore, harmless.

Unpasteurized “raw” milk, however, has been shown to contain living H5N1 viruses, which is why the FDA and other health authorities strongly advise people not to drink it. Doing so could cause a person to become seriously ill or worse. But even then, a pandemic is unlikely to be sparked because the virus — in its current form — does not spread efficiently from person to person, as the seasonal flu does.

What should be done? A lot! Because of a lack of surveillance, the U.S. Department of Agriculture and other agencies have allowed the H5N1 bird flu to spread under the radar in cattle. To get a handle on the situation, the USDA recently ordered all lactating dairy cattle to be tested before farmers move them to other states, and the outcomes of the tests to be reported.

But just as restricting covid tests to international travelers in early 2020 allowed the coronavirus to spread undetected, testing only cows that move across state lines would miss plenty of cases.

Such limited testing won’t reveal how the virus is spreading among cattle — information desperately needed so farmers can stop it. A leading hypothesis is that viruses are being transferred from one cow to the next through the machines used to milk them.

To boost testing, Fred Gingrich, executive director of a nonprofit organization for farm veterinarians, the American Association of Bovine Practitioners, said the government should offer funds to cattle farmers who report cases so that they have an incentive to test. Barring that, he said, reporting just adds reputational damage atop financial loss.

“Outbreaks have a significant economic impact,” Gingrich said. “Farmers lose about 20% of their milk production in an outbreak because animals quit eating, produce less milk, and some of that milk is abnormal and then can’t be sold.”

The government has made H5N1 tests free for farmers, Gingrich added, but hasn’t budgeted money for veterinarians who must sample the cows, transport samples, and file paperwork. “Tests are the least expensive part,” he said.

If testing on farms remains elusive, evolutionary virologists can still learn a lot by analyzing genomic sequences from H5N1 viruses sampled from cattle. The differences between sequences tell a story about where and when the current outbreak began, the path it travels, and whether the viruses are acquiring mutations that pose a threat to people. The research has been hampered by the USDA’s slow and incomplete posting of genetic data, Worobey said.

The government should also help poultry farmers prevent H5N1 outbreaks since those kill many birds and pose a constant threat of spillover, said Maurice Pitesky, an avian disease specialist at the University of California-Davis.

Waterfowl like ducks and geese are the usual sources of outbreaks on poultry farms, and researchers can detect their proximity using remote sensing and other technologies. By zeroing in on zones of potential spillover, farmers can target their attention. That can mean routine surveillance to detect early signs of infections in poultry, using water cannons to shoo away migrating flocks, relocating farm animals, or temporarily ushering them into barns. “We should be spending on prevention,” Pitesky said.

OK, it’s not a pandemic, but what could happen to people who get this year’s H5N1 bird flu? No one really knows. Only one person in Texas has been diagnosed with the disease this year, in April. This person worked closely with dairy cows, and had a mild case with an eye infection. The CDC found out about them because of its surveillance process.

Clinics are supposed to alert state health departments when they diagnose farmworkers with the flu, using tests that detect influenza viruses, broadly. State health departments then confirm the test, and if it’s positive, they send a person’s sample to a CDC laboratory, where it is checked for the H5N1 virus, specifically. “Thus far we have received 23,” Shah said. “All but one of those was negative.”

State health departments are also monitoring around 150 people, he said, who have spent time around cattle. They’re checking in with these farmworkers via phone calls, text messages, or in-person visits to see if they develop symptoms. And if that happens, they’ll be tested.

Another way to assess farmworkers would be to check their blood for antibodies against the H5N1 bird flu virus; a positive result would indicate they might have been unknowingly infected. But Shah said health officials are not yet doing this.

“The fact that we’re four months in and haven’t done this isn’t a good sign,” Worobey said. “I’m not super worried about a pandemic at the moment, but we should start acting like we don’t want it to happen.”

Bird-flu impact may go beyond eggs, birds; experts call for more surveillance as the virus appears able to spread among mammals

Centers for Disease Control and Prevention chart; for a larger version, click on it.

The U.S. is experiencing a record outbreak of bird flu, a virus that is currently deemed a low risk to humans, but has hiked prices of eggs and poultry. The Biden administration is weighing whether to vaccinate poultry against the disease and it appears that the virus can spread among mammals. 

"Egg prices are up 60%, which means we are paying upwards of $5-7 for a dozen eggs. That is if you can find them," reports epidemiologist Katelyn Jetelina in her newsletter titled Your Local Epidemiologist. "Why? A constellation of reasons, but there is one we can’t ignore: the avian flu is hammering poultry farmers." 

The U.S. Department of Agriculture reported in December: "As a result of recurrent outbreaks, U.S. egg inventories were 29 percent lower in the final week of December 2022 than at the beginning of the year. By the end of December, more than 43 million egg-laying hens were lost to the disease itself or to depopulation since the outbreak began in February 2022. . . . The average shelf-egg price was 267 percent higher during the week leading up to Christmas than at the beginning of the year and 210 percent higher than the same time a year earlier." 

USDA adds that egg prices are expected to decrease as flocks are replenished. 

Bird flu spread among minks at a farm in Spain. (Nature photo) 

Another concern is that that virus appears capable of spreading among mammals, including humans.  

"The virus is primarily a threat to birds," reports The New York Times' Emily Anthes, "but infections in mammals increase the odds that the virus could mutate in ways that make it more of a risk to humans, experts say."

Anthes reports that a new variant of the H5N1 virus has "taken an unusually heavy toll on wild birds and repeatedly spilled over into mammals, such as foxes, raccoons and bears, that might feed on infected birds." 

More recently, it has infected farmed minks, which scientists describe as a "new and troubling development," pointing to an outbreak in Spain where the virus appeared to spread from mink to mink and had an unusual mutation that might be a sign of adaptation to mammals, Anthes reports, adding that experts say the mink outbreak is no cause for panic, but highlights the need for more proactive surveillance.  

Michael Osterholm, director of the University of Minnesota’s Center for Infectious Diseases Research and Policy, also told Stat in April 2022 that the presence of bird flu in the U.S. calls for heightened surveillance. Jetelina reports that "from 2003-2021 there have been very few human cases worldwide: 864. But, among these cases, 456 died—a 53% mortality rate." 

Jetelina also notes that the risk of bird flu in humans is "currently very low," citing research from the Centers for Disease Control and Prevention, which tracked the health of more than 5,190 people who have been exposed to infected birds in 2022 and only one human case was reported. The Times reports "fewer than 10 known cases in people since December 2021, and there have been no documented instances of human-to-human transmission, according to the CDC."

Federal scientists are gearing up to test the first vaccines in poultry against the bird flu as a way to counter the growing oubreak, Alexander Tin reports for CBS News. The Biden administration has not yet greenlighted the use of these vaccines. Officials told Tin that one of the concerns about issuing these vaccines is that it could make it harder to export American poultry products. 

"A record 58 million birds — mostly commercially-raised poultry — have died in the outbreak so far, according to figures tallied by the USDA's Animal and Plant Health Inspection Service — either killed by the virus itself or put down in efforts to quash its transmission. Every state has detected the virus spreading among wild birds and 47 have spotted them in poultry," Tin reports.

The virus is spread from an infected bird's nasal secretions, saliva and feces. The USDA says properly prepared and cooked poultry and eggs should pose no risk to consumers. 

"Right now you don’t need to do anything, unless you’re in close contact with birds. A person’s level of risk is dependent on duration and intensity of exposure. In other words, a person with one chicken in their backyard is at much lower risk than someone at a poultry farm," Jetelina writes. 

She adds, "Those around wild birds, such as at parks, lakes, rivers, or other waterways, need to exercise caution, including wearing PPE, washing hands, and changing clothes. If you have backyard poultry, wear a mask and wash your hands. Also, monitor the health of your flock, especially if they come in contact with other wild birds."

West Nile virus report for Kentucky: four cases in humans, four in horses, and in some mosquitoes in Jefferson County

Four cases of West Nile virus have been found in Kentucky this summer: two in Hopkins County and one each in Jefferson and Fayette counties, the state Department for Public Health reported Friday. All were in adults. The number is below the annual average of 10 reported from 2012 to 2016.

All but eight states have reported cases of West Nile in people, horses, birds or mosquitoes this year, the department said. The virus is transmitted by mosquito bites. The Louisville health department recently found West Nile-infected mosquitoes in four Jefferson County ZIP codes (40204, 40205, 40206, 40208, 40212 and 40214), but there have been no other positive reports of mosquitoes with the virus in Kentucky.

“It’s common for us to find mosquitoes infected with West Nile in Louisville around this time each year. What this means is people should take the appropriate precautions, Louisville Health and Wellness Director Sarah Moyer told Darla Carter of The Courier-Journal.

The state health department says four horses have tested positive for West Nile, in Bourbon, Franklin, Hart, and Russell counties. The virus can cause severe illness in horses and certain species of birds, but does not usually affect domestic animals. There is no West Nile vaccine available for people, but several are available for horses, and owners are advised to vaccinate their horses annually.

In most human cases, infected people have no symptoms or show relatively mild symptoms, such as fever, headache, body aches, joint pains, vomiting, diarrhea, or rash. They typically recover on their own, though symptoms may last several weeks. Fewer than 1 percent will develop a serious illness such as encephalitis or meningitis. People over 50 and those with certain medical conditions, such as cancer, diabetes, hypertension, kidney disease and organ transplants, are at greater risk for serious illness if they contract West Nile.

The health department advises Kentuckians to avoid mosquitoes, particularly between dusk and dawn, when the insects are most active. It recommends these precautions:

Avoid Mosquito Bites

·        Use insect repellents when you go outdoors. Repellents containing DEET, picaridin, IR3535, and some oil of lemon eucalyptus and para-menthane-diol products provide longer-lasting protection. To optimize safety and effectiveness, repellents should be used according to the label instructions. More information about insect repellents can be found at http://www.cdc.gov/westnile/faq/repellent.html.

·        When weather permits, wear long sleeves, long pants and socks when outdoors. Mosquitoes may bite through thin clothing, so spraying clothes with repellent containing permethrin or another EPA-registered repellent will give extra protection. Don't apply repellents containing permethrin directly to skin. Do not spray repellent on the skin under your clothing.

Mosquito-Proof Your Home

·        Install or repair screens on windows and doors to keep mosquitoes outside.

·        Help reduce the number of mosquitoes around your home by emptying standing water from flowerpots, gutters, buckets, pool covers, pet water dishes, discarded tires and birdbaths on a regular basis.

More information can be found online at: https://www.cdc.gov/westnile/ or http://www.chfs.ky.gov/dph/epi/westnile.htm. 

New state public-health veterinarian appointed; her responsibility is diseases that spread from animals to humans

Dr. Kelly Giesbrect

According to the World Health Organization, nearly 75 percent of the new diseases that have affected humans over the past 10 years originated from an animal or an animal product. Kentucky has just appointed a new public health veterinarian, Dr. Kelly Giesbrecht, to help protect Kentuckians and the state's animal populations from such diseases.

“We are very pleased to have Dr. Giesbrecht join our staff at the Cabinet for Health and Family Services,” Health Secretary Vickie Yates Brown Glisson said in a news release. “Her wealth of experience in public health and veterinary science is a perfect fit for this extremely important role and will be a tremendous asset to our work to improve the public health of Kentucky.”

Among other things, Giesbrecht is tasked with identifying and evaluating diseases that are spread between animals and humans, called zoonotic diseases.

The federal Centers for Disease Control and Prevention says every year tens of thousands of Americans get sick from diseases spread between animals and people, which are caused by harmful germs like viruses, bacteria, parasites and fungi.

Zoonotics are transmitted in several ways, including direct contact with the body fluid of an infected animal; indirect contact from touching a contaminated surface; being bitten by a tick, flea or mosquito; or eating contaminated food.

Some of the more recognizable ones in the United States are Zika virus, West Nile virus, bird flu (Avian influenza), rabies, cat scratch disease, Lyme disease, E.Coli and Salmonella, though there are many more.

Giesbrecht, who will be part of the Division of Epidemiology and Health Planning in the state's Department of Public Health, will develop policies, guidelines and strategies to control zoonotic and foodborne diseases and share information as needed to health experts and the public.

Giesbrecht comes to the department with over 22 years of combined experience in veterinary medicine and public health. She has a doctorate in veterinarian medicine from the University of Florida and a masters of public health from the University of Texas. After clinical practice, she spent 11 years in the U.S. Air Force as a public health officer and most recently worked at the Northern Kentucky Health Department as a regional epidemiologist.

State health department warns about danger of getting rabies from wildlife, especially bats; says to never handle any bat

Bats in a home. Photo by Brian Carver,
Kentucky Department of Fish & Wildlife

By Melissa Patrick
Kentucky Health News

Public health officials are reminding Kentuckians about the dangers of rabies exposure from contact with infected wildlife.

“We want the public to understand that rabies is still a serious public health concern, and we need to do everything we can to prevent it,” Kelly Giesbrecht, state veterinarian with the state Department of Public Health, said in a news release. “It is extremely important that we vaccinate all dogs, cats and ferrets in order to maintain this invisible barrier between rabid wildlife and humans.”

The Lexington Herald-Leader has reported two stories about rabies in the last month. Morgan Eads reported that a bat found in a Lexington home tested positive for rabies, and Bill Estep reported that dozens of teen girls at a church camp in Harlan County were potentially exposed to rabies from bats in their cabin. One camper woke up with a bat on her, but Giesbrecht told Estep that there is no confirmation that any of the girls were bitten. Another state health official told Estep that 25 to 30 girls who were considered to be at higher risk, plus some whose parents were concerned, are being treated for the disease.

Rabies is a viral disease that is transmitted from animals to humans by the saliva of a rabid animal, usually from a bite. The virus cannot infiltrate intact skin.

State law requires all dogs, cats and ferrets to have a current rabies vaccination. The health department reports there have been no human rabies cases from exposure to a rabid dog in Kentucky since dog vaccinations became required in 1954.

In the U.S., rabies is most commonly spread by bats, raccoons, skunks, coyotes and foxes. Giesbrecht stressed that wildlife should not ever be handled or treated as pets to avoid exposure to rabies.

“Rabies is relatively rare in the U.S.,” said Giesbrecht, “but a dangerous, and often life-threatening condition, if contracted.”

The health department says bats are the most common source of rabies exposure to humans in the U.S., and a bat bite is so small, people don't always know that they have been bitten.

The department's website notes that any time a bat is found in the room of a sleeping person or in the room with an unattended child or near a mentally impaired or intoxicated person, medical advice should be sought and, if possible, the bat should be tested for rabies.

Home entryways for bats--most common source of rabies
image: Maryland Dept. of Natural Resources

Public health officials warn Kentuckians to never hold any bat. They also note that the most common ways for bats to enter homes are through chimneys, vents and openings behind shutters or under doors, siding, eaves and shingles.

The health department says the best time to seal any holes around your home that are larger than a quarter-inch by a half-inch is in the fall or winter so that any bats that might already be inside are not unintentionally trapped.

Symptoms of rabies can initially mimic the flu, including general weakness, fever and headache. A person can also have a strange sensations at the site of the bite from a rabid animal. These symptoms can progress within days to symptoms of anxiety, confusion and agitation. Further progression of the disease includes symptoms of hallucinations, insomnia and a fear of water, all of which are quickly followed by death, according to the Centers for Disease Control and Prevention. "Once a person begins to exhibit signs of the disease, survival is rare," says the CDC.

While rabies deaths in the U.S. are rare, an estimated 40,000 Americans are vaccinated against rabies every year after contact with a possible rabid animal. The CDC estimates that more than 59,000 people around the world die from rabies each year, about 95 percent of them in Asia and Africa.

If you have been bitten by an animal that you think could have rabies, wash the wound immediately with soap and water for at least 10 minutes and seek medical attention. If your physician decides you need a rabies vaccination, it should be given as soon as possible after exposure, says the CDC. All bites by mammals are required to be reported to the local health department.

Click here for more information about rabies in Kentucky.

Frankfort area has an outbreak of a new, stronger strain of dog flu; cats could also be affected; vets say pets shouldn't socialize

Hattie relaxes at East Frankfort Park Wednesday afternoon.
Her owner said she will get her canine flu vaccination soon.

(State Journal photo by Austin Horn)

Dog owners in Franklin County are being warned to keep their pets away from others' pets because a strain of canine flu has become widespread in and around Frankfort.

Dr. Denis King of the Frankfort Animal Clinic told Austin Horn of The State Journal he found the H3N2 virus capital among “some dogs that had been boarding here [that] started coughing and were running fevers.”

"With 20 to 30 other dogs boarding at the clinic exhibiting similar symptoms — which include reduced appetite, high fever, cough, runny nose and lethargy — King said that it was safe to assume that they also contracted the disease," Horn reports.

"H3N2 is relatively new in the United States, having originated in South Korea in 2006 but only finding its way to the US in 2015," Horn writes. "It is most often spread through dog shows or other events and places where dogs congregate en masse according to Dr. Cynda Crawford, a professor and leading infectious-disease researcher at the University of Florida."

Dogs with the virus "can be contagious for up to four weeks even if they are no longer showing symptoms," Horn reports. "Crawford noted that dog owners should be aware of crucial differences between H3N2 and the other strand of dog flu, H3N8, with which Americans are more familiar. The most pertinent, she noted, is that H3N2 puts dogs at a much higher risk for pneumonia, which could prove fatal. And she added that the virus has been known to affect cats as well as dogs. While Crawford advocated for a temporary pause in dog exposure to boarding areas to stem the virus’ advance, she emphasized that vaccination was the most important step a dog owner can take."

The outbreak has prompted King's clinic and other pet-care facilities in Franklin County "that deal with large numbers of dogs to make their operations more conservative," Horn reports. "Jeff Poe, co-owner of Pet Domain and Suites, said he required all animals staying at the pet hotel to be vaccinated against the new flu. At the Franklin County Humane Society, a similar approach was taken according to technician Kerry Lowary. The humane society provided all its dogs with the new vaccine."

Stanton Elementary School, closed almost three weeks because of bat infestation, is scheduled to reopen Wednesday

By Melissa Patrick
Kentucky Health News

Stanton Elementary in Powell County will reopen this week after being closed for almost three weeks because of a bat infestation, school officials said Monday.

"They are moving everything back into the building today," Arliss Crowe, secretary to the district's director of pupil personnel, told Kentucky Health News on Monday. "Students will be back in the school on Wednesday." Schools in the county were dismissed Monday and Tuesday while crews moved furniture serving students who were moved to alternate facilities.

The state Department for Public Health closed the school Nov. 14 after bats were reported frequently entering the building, county School Supt. Mike Tate told The Clay City Times. An animal-removal company found three to five bats initially and did not see any more after they began their work, he said.

The company completed its work last week and told the school system to monitor the building for a week and if no bats are sighted it "could be safe to move back in," Tate told the weekly newspaper.

Tate told the weekly newspaper that he met with state health officials Friday, Nov. 29, to determine what needed to happen next. "We want to be careful and not act too quickly," he said then. "We want to get back, but we want to make sure the school is safe." (Read more)

Increased contact with bats leads to more rabies vaccinations in N. Ky.; health officials say all encounters should be reported

Fruit bat roosting in a home

Northern Kentucky health officials are warning residents to be more wary of bats after an unusually high number of residents have made contact with bats inside their homes and have had to receive the rabies vaccine. They are asking them to report any encounter with bats to the health department.

Bats are commonly infected with rabies and have very small teeth, and so someone who wakes up with a bat in their bedroom might not realize it has bitten them, Northern Kentucky Health Department spokeswoman Emily Gresham-Werle told Brenna Kelly of The Kentucky Inquirer.

It is crucial to vaccinate against rabies after contact with a bat, if the bat cannot be captured to receive testing for rabies. "If someone is exposed to the rabies virus and not treated, the result is neurological disease and death," Kelly notes.

Each year, tens of thousands of people are successfully protected from developing rabies through vaccination after being bitten by an animal like a bat that may have rabies, says the Center for Disease Control and Prevention. "There are usually only one or two human rabies cases each year in the United States, and the most common way for people to get rabies in the United States is through contact with a bat," says the CDC. Some of these reported cases resulted from known encounters with bats.

The problem In Northern Kentucky may be due to development in the area that has caused bats to lose their natural habitat. So far this year, 13 people who were exposed to bats have decided to get the vaccine. Usually only two to three people a year in the area have to get the vaccine because of a bat, Gresham-Wherle said. "Local and state health officials speculate that the weather and loss of bat habitat have contributed to the high number," reports Kelly.

"The rabies vaccine, which is nearly 100 percent effective against the virus, involves four rabies shots and one antibody shot over a period of two weeks. The vaccine, which is given by shots in the arm, can also be expensive, with costs ranging from $2,000 to $6,000 for the series, with additional fees for doctors or emergency room visits," Gresham-Werle told Kelly.

All exposure to bats and all bites by mammals must be reported to the local health department. In some instances the animal may be captured for rabies testing so that the bitten individual will not need to be vaccinated against the deadly disease. You can't tell if an animal carries the rabies virus just by looking at it, because rabies can only be confirmed in a laboratory, warns the CDC.

UK scientists discover a clue to treating diseases like 'mad cow'

University of Kentucky scientists may be a step closer to finding a way to treat diseases related to prion proteins, including bovine spongiform encephalitis, or mad-cow disease. They've learned that plasminogen, a protein used to bust blood clots in the body, increases the speed at which prion diseases progress.

"Since prion diseases can lay undetected for decades, delaying the ability of the disease-associated prion protein to replicate by targeting the cofactor of the process could be a monumental implication for treatment," said Chongsuk Ryou, right, senior author of the study.

Prion diseases are rare, fatal diseases characterized by oddly-shaped protein molecules in the brain. Besides mad-cow, they include Creutzfeldt-Jakob disease in humans; scrapie in sheep; and chronic wasting disease in deer and elk, UK's news source UKNow reports. The study was published by the Federation of American Societies of Experimental Biology in the December issue of The FASEB Journal.

Scientists used test tube reactions to multiply disease-associated proteins, UKNow reports. The reactions were done with and without plasminogen present. "By showing how prions hijack our own clot-busting machinery, this work points to a new target for anti-prion therapy," said Dr. Gerald Weissman, editor-in-chief of the journal. (Read more)