Plague, caused by Yersinia pestis, is endemic in HSR 1. Surveillance in predator species has revealed that plague remains active in the small mammal populations of the Region. Beginning in 1976, plague has been confirmed in at least 15 counties in HSR 1. Yearly plague summaries with maps may be reviewed at: www.dshs.state.tx.us/idcu/disease/plague/information/Reports/.
Anyone living near a prairie dog colony should be alert to its activity. There are several reasons for decreased activity in prairie dog towns. A decline may be noticed during colder weather, but the black-tailed prairie dog does not have a true hibernation, so there should be animals running about during warmer periods in the winter if the population is healthy. Population reductions may occur through shooting, poisons and other diseases, such as tularemia. However, in our area a decline in population has a high probability of being due to plague. People should avoid entering a prairie dog town that appears to be dying out. Anytime a plague die-off occurs, the fleas will be seeking new sources of blood. While the fleas most commonly associated with prairie dogs prefer blood sources other than humans, a desperate flea will utilize humans for a blood meal.
Pets that are allowed to roam outside may bring plague home to their human family, either as an infectious process in their bodies or by transporting infected fleas. A child in New Mexico died in June of 2009. He and his sister apparently contracted plague from fleas the dog brought home. No flea control had been applied to the dog, and it slept with the children. In June of 2012 a man and woman in Oregon contracted plague from a cat when they removed a mouse from the cat’s mouth. The man lost all of his fingers, which is not a good thing for a welder. The woman was diagnosed earlier in the disease process and recovered without the loss of any appendages.
All pets that spend time out doors should be on a good flea and tick control program to reduce risks to their health and that of their owners. While cats are most susceptible to plague, dogs may also become symptomatic. An infected dog or cat will usually develop one of two syndromes. One is infection of the lymphatic tissues in the throat region, with swelling and potential rupture of the lymph nodes. The second is pneumonia. The common methods of transmission from infected pets to humans are either through the drainage from the infected lymph nodes or through respiratory secretions expelled when the animal coughs or sneezes. Any pet which has been prowling around a prairie dog town and then exhibits either pneumonia or swollen lymph nodes in the throat area should be promptly examined by a veterinarian. Potential contact of the pet with plague or a dying prairie dog town should be mentioned to the veterinarian so proper precautions may be taken during the examination. This will also ensure plague will be one of the differential diagnoses.
There are three forms of plague in humans. Pneumonic plague is a rapid-onset infection of the lungs with typical respiratory symptoms, but with the addition of blood in the sputum. This form is easily transmitted between humans through coughing or sneezing. Septicemic plague is a generalized dissemination of the plague organism throughout the body. These two forms are highly fatal in humans if treatment is not initiated within 24 hours of onset. Humans who may have been exposed to a source of plague infection and begin to develop symptoms of pneumonia or a flu-like illness with fever, chills, and muscle aches should seek medical attention promptly, and the possibility of plague exposure should be mentioned. A wildlife biologist in the Grand Canyon area of Arizona failed to mention his profession when he sought treatment in 2008 for a respiratory infection. Plague was diagnosed at autopsy. Bubonic plague involves large, purplish and painful swollen lymph nodes in the groin or axillary (arm pit) regions, usually with the possibility of infection in the lymph nodes of the neck region. While treatment should begin promptly, the fatality rate is not quite as high as for cases of pneumonic and septicemic plague.
In June of 2008 a cluster of cases of Q fever was detected in the Panhandle. A definite source of exposure has not yet been determined. However, since the etiologic agent, Coxiella burnetii, has been found in several locations in the Panhandle, South Plains and West Texas, the detection of cases was not a great surprise. The organism is carried by ruminant livestock, with cattle being the primary reservoir. Cats also have been shown to be a potential source of infection for humans when parturition occurs. A case in 2007 in the South Plains was apparently due to exposure to hay contaminated by a parturient cat.
Cases of Q fever may be missed by physicians due to the relatively slow antibody development in humans. The majority of people who are infected will not develop detectable antibody levels until 2-4 weeks after symptoms develop. If you have a flu-like illness that does not resolve itself within a reasonable amount of time, you might ask your physician to consider Q fever. If you have a negative test for this disease early in the clinical phase of the syndrome, a retest at least 2 weeks later is advisable. This is especially important if you have been assisting cattle, sheep, goats or cats in birthing, or if you handled the afterbirth or a newborn of these species while they were still wet with birthing fluids. Since the organism is in the dried manure and dust of the region, it is possible people may become exposed to the organism during periods of high winds. Doxycycline is the drug of choice for most cases. People with damaged heart valves, artificial valves or cardiac vascular grafts are at increased risk of developing the chronic form of q fever since the organism has a preference for these areas.
A serological survey was conducted HSR 1 in 2009. Serum samples from 600 people were collected by the Coffee Memorial Blood Center during blood drives in the Panhandle. Thirty-eight of the 41 Panhandle counties had 1 or more donor included. Almost all participants (589) qualified to be included in the project. The overall prevalence rate of antibodies was 10.7%. The county level prevalence ranged from 0-50%, however, only 6 people participated in the county with the highest prevalence. The prevalence in the donor population of 7 counties ranged from 16-29%. Additional analysis continues.
West Nile Virus
West Nile virus (WNV) activity was detected in HSR 1 in 2012 after having been absent in 2011. While we continue in a drought, there were some rains in mid-August that may have been enough to support adequate mosquito activity in our Region. We recorded over 70 cases but there were more than 1800 in the state. The greatest activity was found in the Dallas-Fort Worth area. For the most recent statistics on WNV activity statewide. Please plan to take steps to reduce the risk of becoming infected with West Nile virus when the weather warms up in in 2013. Strive to eliminate mosquito breeding sites around your dwelling. Even very small amounts of water can be enough to support mosquito eggs and larvae. Having effective window screens to keep mosquitos out of homes is also critical if windows are to be opened during the vector season. The use of an effective repellent and wearing long sleeves and long pants when outside during periods of mosquito activity can help reduce risk. Information on insect repellents may be found at: http://www.cdc.gov/ncidod/dvbid/westnile/RepellentUpdates.htm
Horses, mules and donkeys all should be vaccinated against West Nile virus to protect them. In the Region we had 9 reported equine cases. The 2012 statistics for reported equine West Nile virus cases statewide in 2012 may be found at www.txwestnile.org also.
Distemper appears to still be creating some animal cases with symptoms matching those of rabies but with a negative rabies lab result. A veterinarian may pursue the issue to determine if distemper is the cause of non-rabies neurologic cases. Instructions may be sent along with a specimen asking that if the animal's brain is negative for rabies, it be forwarded to the Texas Veterinary Medical Diagnostic Laboratory (TVMDL) for distemper testing. While there is no charge for rabies testing by the DSHS laboratory, the veterinarian will be billed by TVMDL for distemper testing. Since there is no way to be certain an animal with neurological symptoms indicative of rabies is not rabid except through testing, distemper drives up the cost to local animal control agencies, the state and the owners of such pets. It also creates anxiety in anyone exposed to the animal.
As an example, in early December 2012 a dog exhibiting symptoms compatible with distemper, as well as rabies, bit an Animal Control Officer. The dog had also potentially exposed four children in the family. Due to timing of the bite late on a Wednesday and bus schedules, it was about 11:20 on the next Saturday before everyone could breathe easier when the dog was reported as rabies negative. In order to help reduce the fear associated with such a scenario, as well as to reduce the loss of pets to the disease, it is a good idea to immunize dogs against that disease at the appropriate time, and maintain the recommended schedule of boosters. By immunizing the canine population against distemper, as well as rabies, there should be fewer candidates for the laboratory procedures. This will help reduce the cost to animal control agencies, pet owners and our agency by reducing the number of animals that have to be shipped and tested, and also reduce the anxiety that occurs while a person is waiting to find out if exposure to rabies has occurred.
Quarantine facilities for the observation of biting dogs and cats are regulated by State law under the Texas Health and Safety Code Chapter 826.042. Quarantine of Animals. The Board rules for that section can be found in the Texas Codes Annotated, Chapter 169. Rabies Control and Eradication. Failure to comply with any section of TAC 169 is a Class C misdemeanor.
To see what is required for the legal quarantining of a biting dog or cat, access the law through the domain name of www.texaszoonosis.org. Select “Laws,” then “Laws/Rules,” and finally “Rabies Control and Eradication - Chapter 169, Subchapter A, – Texas Administrative Code.” Shelter standards are found in 169.26.
In May 2011, an eight year-old California girl, Precious Reynolds, joined the very sparse ranks of rabies survivors. The Milwaukee protocol, first used successfully to save Jeanna Giese, was used for this girl and it was successful. So far the protocol has not yielded a lot of success but once the symptoms have begun it is about the only choice available at present.
In 2009, a teenager in Texas survived rabies without the usual treatment protocol or the Milwaukee protocol. This was a highly unusual case and most likely occurred due to only a very small amount of rabies virus being deposited by a bat that brushed by the individual. Her story can be accessed at: www.cdc.gov/mmwr/pdf/wk/mm5907.pdf.
Other cases of this nature probably have occurred without being detected. However, it is the exception, not the rule. Jeanna Giese, “The Girl Who Survived Rabies” is a study in why rabies prophylaxis is important, along with the over 55,000 people who die annually around the world.
Rather than take chances that the innovative approach used in treating Jeanna and Precious will work, or that only a minor amount of virus was deposited, anyone bitten by a bat should retain the animal and get it tested. If it cannot be caught or tested, the person should begin the prevention protocol. When the bat bit her, Jeanna tossed it away. At home the wound was treated with hydrogen peroxide. In spite of her failure to seek proper rabies prophylaxis, she survived the disease. However, recognition of a bite and the risk of rabies, followed by prompt post-exposure prophylaxis (treatment) is certainly a less-expensive and less traumatic way to deal with rabies exposures.
If you have access to the Discovery Channel, you may want to monitor the listings to see if “The Girl Who Survived Rabies” will be shown again. Jeanna's story is inspiring, but also heartbreaking. Although she survived, she suffered some apparently permanent neurological deficits and, at last report, can no longer participate in athletics, where she once excelled. Entering “the girl who survived rabies” in a search engine will identify numerous sites devoted to her story.
Unfortunately, not everyone is as blessed as Jeanna and Precious. A 34 year-old man died from rabies in Dubai in July 2012 after having been bitten by a bat in April in California. In 2011, while Precious survived, six other people did not. A man from Wisconsin, a man from Massachusetts and a woman from South Carolina all died due to infections by bat rabies variants acquired in the US. In addition, a woman from Haiti and a man from South America apparently were infected by rabies before their arrival and death in the US due to infection by canine rabies variants unique to their home countries. In August of 2011 a man who served in the U.S. Army in Afghanistan died in New York from rabies acquired through a dog bite while overseas. This resulted in the U.S. Army establishing a better dog bite surveillance/treatment system for its members.
Deaths due to rabies will be prevented only when animal bites are recognized and reported with proper treatment provided if needed. Rabies deaths will continue to occur when animal bites are ignored by the victims or their families. The following basic advice applies to all animal bite or scratch incidents where saliva may have entered a person's body: 1) capture the animal if it is possible to do without additional exposure risk; if it cannot be captured, contact your local animal control agency for assistance; 2) wash the wound thoroughly with soap and water; 3) apply an antiseptic, such as iodine, alcohol, etc. – remember Jenna used hydrogen peroxide and almost died; 4) report the bite and seek an assessment by your physician; 5) be sure the animal, if captured or killed, is either observed in quarantine or submitted for rabies testing; and 6) contact a Zoonosis Control team member if you have any questions about the situation. Please read on for specific guidelines applying to bat exposures.
Guidelines for Bat Exposures
Bats, which migrate into our area in the spring months, predominantly April, and emigrate in August-October, are ecologically important, as well as protected by law. Because of this, colonies should not be destroyed. However, due to the ability of bats to transmit rabies, we do not advocate handling them or encouraging their habitation of a building occupied by humans. If a bat bites someone, it must be tested if it can be captured, and if found to be infected with rabies, the person who was bitten must undergo immediate post-exposure treatment in order to prevent death. If a bat is present in a room with people and a bite cannot be ruled out, testing should be done. If the bat cannot be tested negative for rabies, anyone who may have been bitten should receive treatment. Situations that warrant this consideration include anyone sleeping in a room where a bat is found or the presence of a bat in a room with children or an intoxicated or otherwise mentally impaired person.
Rabies Vaccine Supply