Hantavirus Pulmonary Syndrome (HPS)
Hantavirus Pulmonary Syndrome (HPS) is a condition in humans caused by viruses carried by certain rodent species. The primary virus involved in Health Service Region 1 (HSR 1) is called Sin Nombre virus (in Spanish that means “without a name”). It was given that name because the people living where it was first found in the Four Corners area of the US did not want their area associated with a deadly virus (Strauss, Ellen G.; Strauss, James H. (2002). Viruses and human disease. Boston: Academic Press. p. 161. ISBN0-12-673050-4).
The main reservoir species in HSR 1 is the deer mouse (Peromyscus maniculatus), but the white footed mouse (Peromyscus leucopus) also carries the virus in our part of the state. After almost seven years without a confirmed case of HPS in HSR 1, there were four in 2014, two males and two females that all survived. Three were in Panhandle Counties and one was in a South Plains County. In June 2015 a male was diagnosed with the disease and survived. This brings our case total for the Region to 23 of the 45 confirmed cases in the state (51%). The Regional case fatality rate (CFR) for this disease has decreased to 35%.
HPS can be prevented by employing self-protection strategies to prevent rodent incursion and when cleaning up areas contaminated by mouse droppings and urine. Homes should be sealed to prevent rodent entry. Some type of sealing material should be used where pipes, electrical/phone/cable lines enter or leave a structure. Wood piles, shrubs, other vegetation and garbage should be kept clear of the house. Any debris that could serve as a breeding/nesting site for mice needs to be eliminated. Appropriate rodent poison/traps can help reduce rodent populations. Barns or storage buildings pose a greater challenge, but steps may also be taken in those structures to reduce rodent populations. Poisons and traps can help, as can outdoor cats. If cats are utilized, it would be best that they be vaccinated against rabies, at a minimum, and are neutered. Storing animal feed in rodent proof containers with lids will deprive rodents of a main food source.
Cleaning of contaminated areas should begin with airing out the space to reduce virus concentrations in the air. If the surfaces that are contaminated will not be harmed by bleach, that is an inexpensive approach. Spray the area with a 10% (1 part bleach: 9 parts water) solution and allow it to sit undisturbed for 30 minutes. Spray again and then clean up the debris while it is damp so dust will not be generated. If bleach is not an option, a commercial viricide labeled for hantaviruses should be used instead.
If there is a risk of generating dust, eye protection, such as goggles, and respiratory protection via a well-fitting face mask with an N-95 or HEPA filtration rating are recommended. Rubber/vinyl gloves are also recommended to protect hands, especially if there are any open wounds or cuts on them.
Anyone who develops a respiratory syndrome and/or an influenza–like illness within days to weeks of encountering rodent contaminated areas should see a physician. Potential exposure to rodent droppings must be shared with the physician in order to aid in the diagnosis and proper treatment if HPS is developing.
Plague, caused by the bacterium 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 in activity 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, septicemic and bubonic. 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 (a bubo) 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 giving birth also have been shown to be a potential source of infection for humans. 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 in 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 donors included. Six-hundred samples were collected and 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
At the end of 2014, the preliminary data showed the presence of West Nile virus (WNV) in 80 Texas counties in 2014, compared to 103 counties in 2013. Some had only positive mosquito pools, while others only had equine cases or human cases. Some counties had a combination of the different species. Only Harris County reported infected birds, but very few jurisdictions test birds anymore. The affected counties were 31% of the total in Texas. The last report for the year, ending with week 52 (December 26), a total of 379 symptomatic human infections had been recorded statewide with 126 being fever cases and 253 being neurologic. Viremic blood donors totaled 59 and there were 25 equine cases detected, down from 69 in 2013.
In HSR 1 54% (22) of the counties had activity. There were 36 fever cases and 38 neurologic cases reported. HSR 1 led the state in the incident rate (IR) for West Nile virus disease based on cases/100,000 population with a rate of 8.7 compared to the statewide IR of 1.4. HSR 6/5S was second with an IR of 2.8. For the 13 counties that had five or more cases, HSR 1 had four, including the top three (Castro: 59.5; Randall: 13.9; Potter: 7.9). The rains in 2014 apparently helped increase the WNV infected mosquito population since our IR increased from 6.78/100,000 in 2013. In addition to the symptomatic cases, we had 12 asymptomatic blood donors in the Region.
The continuing rains in 2015 have kept us close to the same rate of case reporting as last year and we are now in the annual time frame when WNV activity typically increases. New human cases are becoming more common and these statistics along with the current bird, equine and mosquito activity in the state can be found at www.txwestnile.org.
As long as mosquitos are active, people should continue to practice the 4 Ds:
1. Use an approved insect repellent every time you go outside. Approved repellents are those that contain DEET, picaridin or oil of lemon eucalyptus. Follow the instructions on the label.
2. Regularly drain standing water, including water that collects in empty cans, tires, buckets, clogged rain gutters and saucers under potted plants. Mosquitoes breed in stagnant water.
3. Wear long sleeves and pants at dawn and dusk when mosquitoes are most active.
4. Use air conditioning or make sure there are screens on all doors and windows to keep mosquitoes from entering the home.
The first point is usually the simplest, but most often neglected method of self-protection. The Centers for Disease Control (CDC) has information on insect repellents at: http://www.cdc.gov/westnile/faq/repellent.html
Distemper in dogs is not a zoonosis but it can cause animal cases with symptoms mimicking those of rabies. 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 schedule of boosters recommended by your veterinarian. 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.
If you are quarantining bite dogs and cats at your shelter without first having been inspected by the Texas Department of State Health Services and receiving an official certificate of inspection, you are in violation of the Texas Health and Safety Code, Chapter 826.042. Quarantine of Animals. The Board rules for that section can be found in the Texas Annotated Codes, Chapter 169. Rabies Control and Eradication, which provides the state requirements for an approved facility. You can find the information through the following link: “Rabies Control and Eradication - Chapter 169, Subchapter A.
Failure to comply with any section of TAC 169.26 is a Class C misdemeanor. If your community is currently quarantining bite dogs/cats without the facility being officially approved for the function, please contact our office so appropriate steps may be taken to establish the approved status.
Local Rabies Control Authority
Section 826.017 of the Texas Health and Safety Code, Title 10, Health and Safety of Animals, Chapter 826, Rabies required each county commissioners court and municipality in Texas to appoint a Local Rabies Control Authority (LRCA). Many of our communities and counties are either lacking in this capacity or the appointments are out of date. Please review your entity’s status to determine if an LRCA has been appointed, and if so, if the appointment is current. The LRCA is an important function in a community. Anytime there is a rabies issue, by law the LRCA has the final say in what transpires. If a bite incident occurs, the LRCA is responsible for gathering the facts surrounding the incident and deciding if an animal needs to be euthanized immediately, as in the case of a severe mauling or face wounds, or just quarantined for the 10-day observation period. Our staff is available for consultation but the LRCA is the person “on the ground” and closer to the situation. As such, that individual should be in the best position to make the final decision. Therefore, the LRCA should be someone who is interested in the issue of rabies control as well as competent to assess the facts of a situation. For more information on the appointment of an LRCA, please click on this link: Chapter 826. Rabies Control Act (PDF). Please contact Tonya Finch (email@example.com; 806-477-1104) if you have any questions about this topic.
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.
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, or other mammal capable of transmitting rabies, 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.
Sadly, 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.
In May, 2013 a kidney recipient from a North Carolina Air Force recruit died from the raccoon variant of rabies. The donor had apparently become infected in 2011 and died without rabies being recognized. The extremely long incubation in immune-suppressed individuals is unusual. The other three recipients were given the standard rabies prophylaxis as a precaution. This is the second documented solid-organ transplant rabies-associated incident in the US and the third in the world. In 2004 three people died from a bat variant of rabies after receiving solid organs in Texas from an Arkansas donor. A fourth person received an arterial graft and also succumbed to rabies. In late 2004, a woman who had visited India died in Germany. Multiple recipients died due to receiving her transplanted tissues.
Also, in May, 2013, an illegal immigrant from Guatemala died in Texas from a vampire-bat variant of rabies. This man had been transported and housed with many other illegal immigrants before dying. The Immigration agencies are working with foreign governments to locate and notify the people who may have been exposed to that case.
A middle-aged Missouri man died in 2014. His exposure was apparently from bats found in the home.
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, betadine, 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 killed (do not damage the brain), 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, many of 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 young children or an intoxicated or otherwise mentally impaired person.
Rabies Vaccine Supply
We are now able to maintain an adequate supply of rabies biologics in the region for treatment of possible rabies exposures. While we are not able to provide the pre-exposure vaccine, we encourage people in high-risk occupations for rabies exposure to be immunized using the three-vaccination pre-exposure immunization series. The full protocol for post-exposure treatment is now costing approximately $3321 for a person weighing 180 pounds. The pre-exposure series, plus two post-exposure booster vaccinations if exposed, is much less extensive.
Regardless of a person’s immunization status, it is still important that if someone is bitten, every effort be made to secure the animal for observation or testing. If this is possible, the person probably will not need to receive the biologics, which is a benefit due to the cost of rabies biologics. If you are a veterinarian, employee of a veterinary clinic, or an animal control officer, please give serious consideration to receiving the pre-exposure series. In April, 2009 a rabid horse resulted in the exposure of 7 people. Two had been immunized and paid a lot less than those who had never been vaccinated. In September 2011 five people were exposed to a rabid horse and only one had previously been vaccinated. To order the product for the pre-exposure series of 3 injections, please contact your physician. If you have been immunized in the past with a tissue-culture vaccine, it is recommended that you have your antibody titer checked periodically to see when a booster is needed. A listing of the labs that conduct the human antibody tests may be found at: www.dshs.state.tx.us/idcu/disease/rabies/information/treatment/people/Labs/
Animal Rabies Statistics for HSR 1 for 2008-2013:
HSR 1 was blessed with an ultra-low level of rabies activity in 2013. Only six cases (1 bat – Donley Co.; 2 bats – Gray Co.; 2 skunks - Lubbock Co.; and 1 bat - Randall Co.) were confirmed. That trend continued in 2014 with only three cases, 1 horse in Randall Co. and 2 bats in Donley Co. The only year in the past 18 years that our total has been lower was in 1996 when only two cases were recorded, and one of those was a feedlot animal imported from HSR 9/10 and infected with the Texas fox variant of rabies. Regrettably, in 2015 a hotspot has developed in Ochiltree County with an active skunk population. Eleven skunks have so far tested positive for the disease, exposing a number of dogs and cats. Wheeler County has also had one positive skunk.
Please keep reminding the public to maintain rabies vaccinations in pets and certain livestock. The multi-year drought and the relatively high rabies incidence in 2011 probably reduced the skunk population to the levels that were inhibiting skunk-to-skunk transmission. However, rabies is still present and on the rise again. The recent rains are aiding a resurgence of the the skunk population as more food sources are available in their normal environment. Always keep in mind that the skunk seeking food and water at your house may be the unwitting transmitter of the disease to your pets, cow, horse, you, etc. The relatively high number of rabid bats in 2013 serves as a reminder that they are also in our environment and caution must be taken when there are bats occupying the same space as humans or pets.
Statewide rabies data may be found at: www.dshs.state.tx.us/idcu/disease/rabies/cases/statistics/query/
Maps of cases state-wide may be seen at: http://www.dshs.state.tx.us/idcu/disease/rabies/maps/
If you are a veterinarian, employee of a veterinary clinic, or an animal control officer, and have not received the pre-exposure series, please give it some serious thought.
If you have comments or suggestions please contact us.