domingo, 23 de julio de 2017



ProMED logo    ISID logo

« prev

ProMED logo    ISID logo

Published Date: 2017-07-23 09:04:18
Subject: PRO/AH/EDR> Plague - USA (10): (AZ,TX) bubonic, prairie dogs, fleas
Archive Number: 20170723.5197563
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases

In this posting:
[1] Arizona
[2] Texas

[1] Arizona
Date: Fri 21 Jul 2017
Source: The Independent [edited]

Bubonic plague, the disease that killed millions of people in Europe in the 1300s, is thankfully, a lot more deadly to prairie dogs and other rodents than it is to people in 2017. But [sylvatic plague is] still out there.

The bacterium that causes the disease, _Yersinia pestis,_ was found in fleas collected from prairie dog burrows earlier this month [July 2017]. The burrows are located on the south side of Highway 61, on ranch land in Concho [Apache County]. The disease caused a die-off in several prairie dog colonies in the area. [MM] was the first to notice there was something wrong with the prairie dogs. "I watch prairie dogs from my porch when I drink my coffee in the morning," she said, noting that she can also see their burrows from other locations on her property.

In late June and early July [2017], MM noticed the burrows were strangely silent. No prairie dogs scurrying around in the cool of the morning, barking and calling to each other. She asked her husband, who runs cow-calf pairs at a ranch, to watch other burrows on the property. He also found some of them were silent, seemingly deserted. Knowing something was amiss, MM began calling state and local agencies, trying to get someone to check it out.

On [13 Jul 2017], Dr Joe Busch, a staff scientist with the Pathogen and Microbiome Institute at Northern Arizona University [NAU], arrived in Concho with some student assistants. MM didn't know how they had heard about the problem with prairie dogs in Concho, but she was glad to see them. MM wasn't aware that her chain of telephone calls had activated a state network that includes the Arizona Department of Health Services and the Arizona Game and Fish Department.

The network, which includes county health departments, keeps an eye on plague outbreaks in the state. Northeastern Arizona's prairie dog populations are the primary hosts for the disease in the state. "She did all the right things, she was very proactive," Busch said in a telephone interview.

Busch and his student team came to Concho to take samples of fleas from the silent burrows outside MM's home. Wearing gloves taped to their long sleeves and pants taped at the ankle, the scientists placed 4-inch square pieces of white flannel into the entrances of a number of the burrows, after breathing onto the little squares of cloth. "The carbon dioxide from their breath is what attracts the fleas." Busch said.

Why collect fleas? Fleas, and the rodents they commonly live on and feed off of, act as hosts for the biological lifecycle of the bacteria. "Plague can replicate and grow in fleas," Busch said. The infected fleas then bite the rodents they live on and infect them with plague bacteria. Prairie dogs are quite susceptible to the disease and die quickly. Since their hosts are dead and the fleas can no longer get a meal of blood from them, the insects abandon their hosts who expire deep in their burrows. They climb up and hang out near the entrance of the burrow, hoping to catch a ride and a meal on another passing animal, usually another rodent.

The team spent about 6 hours in Concho, collecting samples from different burrows. "We might get one flea from a burrow, we might get 30 fleas," he said. After the fleas jump onto the fabric, the students promptly placed it inside a zipper baggie, noting the GPS location of each burrow that was sampled.

Back in the lab at NAU, the fleas are frozen overnight to kill them, then they are mashed up and their DNA extracted from the mashed cells. The scientists look for the bacteria in the flea's DNA. 10 percent of the fleas from the sampled burrows in Concho tested positive for plague bacteria. Apache County Health Department director Chris Sexton said the county has contracted with Coconino County to visit Concho and dust the affected prairie dog burrows to kill the fleas.

This is not the 1st time a prairie dog die-off from the plague has occurred in Concho. Busch visited the area to take samples from burrows in 2012 as well.

The risk of infection for pets and humans is minimal.

Since the plague has such a deadly reputation, it can be alarming. MM said that her husband has taken precautions, wearing insect repellent, and they have also treated their dog for fleas as a preventive measure. These are all good steps to take, according to Busch, because people and pets can get the plague if they are bitten by infected fleas.

In 2017, however, the risk of infection is low and the disease is readily treated with antibiotics; drugs that were far beyond the imagination of people who suffered with the disease in the 1300s.

The US averages about 7 cases of plague in humans annually, according to the Centers for Disease Control, although the disease did cause 4 deaths in 2015. Most US cases are in Arizona and New Mexico, according to a map on the CDC website.

Sexton said the best way to protect yourself and your pets is to stay away from burrows where a die-off has occurred. If you live in proximity to these burrows, use flea preventive products on your pets and keep them confined away from burrows if they run loose. People should wear insect repellent, tight-fitting clothes and hats if they venture near burrows, or if they work, camp, or hike outdoors. Don't let pets sleep in your bed.

Plague symptoms are similar to the flu -- aches, fever, nausea, lack of energy. Symptoms usually occur within 2 to 7 days after a flea bite. People infected with the plague can also develop black, swollen boils near lymph nodes in the neck, underarms and groin -- the symptom that led to the name "Black Death." See your doctor promptly if you develop flu symptoms and you think you may have been bitten by a flea.

MM feels authorities took too long to alert people to the potential threat, so she took steps herself to notify neighbors and people in the area. "I felt like I'm sort of ground zero on this. I felt like if somebody got sick and I didn't tell people, I would feel responsible," she said.

For more information about plague and how to prevent it, see the Public Health Notice on the homepage of the Apache County website at <> or visit the CDC webpage about the plague at

[Byline: Trudy Balcom]

Communicated by:

[The state of Arizona can be located on the HealthMap/ProMED-mail interactive map at Apache County can be seen on the map at
To find Concho, go to,_Arizona. - Mod.MHJ]

[2] Texas
Date: Fri 21 Jul 2017 9:53 AM CDT
Source: Rare Houston [edited]

The same plague virus that wiped out 60 percent of the European population during the black death is now sweeping through West Texas prairie dogs. Muleshoe National Wildlife Refuge [Bailey County] released a statement confirming the plague outbreak.

As a safety measure, the refuge has closed down 2 areas in the park, including Paul's Lake. "To protect our visitors, we have voluntarily closed the area where plague has been found. It is well marked and we are asking the public to respect all signs and closures for their own safety," the park's manager Jude Smith explained in the statement. The outbreak is currently limited to 2 prairie dog populations.

While the plague can be transferred from the infected animals to humans or other animals through infected flea bites, park officials ensure the public that it is still safe to visit the open areas. If they bring pets with them to the park, they should take measures to protect their pets from fleas.

Communicated by:
ProMED-mail from HealthMap Alerts

[The state of Texas can be located on the HealthMap/ProMED-mail interactive map at Bailey County can be seen on the map at
To find Muleshoe National Wildlife Refuge, go to

One always needs stimulating field exercises to educate one's graduate students, and collecting fleas from prairie dog colonies is good, with an extra dimension of instilling sound biosecurity. I have done this with _Mycobacterium leprae_ infected armadillos, _Vibrio cholerae_ in frozen frog legs, lead content in Spanish Moss on trees next to roads and car exhaust, and a large number of others. Believe me, the students learn and remember. Plus over the years I saw a good publication rate from these student exercises. - Mod.MHJ]

See Also

Plague - USA (09): (TX) prairie dog, alert 20170704.5150405
Plague - USA (08): (NM) 20170626.5132081
Plague - USA (07): (CO) feline 20170615.5108564
Plague - USA (06): (NM) 20170606.5087671
Plague - USA (05): (CO) feline, bubonic, alert: corr 20170506.5017288
Plague - USA (05): (CO) feline, bubonic, alert 20170505.5014699
Plague - USA (04): (NM) feral cat, alert 20170419.4980169
Plague - USA (03): (NM) feline, canine 20170412.4965194
Plague - USA (02): (CO) prairie dog, alert 20170318.4910519
Plague - USA: (NM) canine 20170211.4832639

No hay comentarios: