Residents in the Concho Valley area off of Highway 61 noticed hundreds of prairies dogs had died in a short span of time. Prairie dogs are considered sentinel animals to the fact that plague is in the area. Officials with Arizona Game and Fish were notified by an alert resident and further contact was made with health officials from Apache and Coconino counties, the state health department, as well as experts at Northern Arizona University. NAU is home to the Microbial Genetics and Genomics Center and has been a key player in testing for plague for the past 10 years. The lab sent a team to the area to trap fleas in the prairie dog holes that had recent die-offs. The team’s first visit was on August 27 and results from the lab testing showed positive for plague.
On September 14, the El Paso County Public Health’s lab tested a wild rabbit found on the northeast side of Colorado Springs and confirmed the animal had plague. Investigators say the area where the rabbit was found is East of Powers Boulevard near the St. Francis Medical Center/Hospital. According to a statement released Friday, Public Health infectious disease experts conducted an investigation to determine potential human exposures and to assess the general area for additional plague concerns. The people exposed have been identified and have been given antibiotics to prevent plague from developing. “Plague health alert” flyers will be provided to residents and signs will be posted in the general area to raise the level of awareness and ask people to take precautions to prevent plague. Public Health will continue to monitor plague activity in the area and maintain the signage as appropriate. Plague is a bacterial disease transmitted to humans by the bite of an infected flea. In humans, the symptoms are high fever, chills, headache, extreme fatigue and tender or swollen lymph glands. Public Health advises residents who experience these symptoms to contact their physician. El Paso County’s last reported human case occurred in 1991. The public shouldn’t attempt to catch, feed, handle or exterminate prairie dogs or any type of squirrel, chipmunk, rabbit or other wild animal. Also, keep your dogs on leashes and cats inside and do not allow them to chase wild animals. If you live in the affected area, it is especially important to keep cats indoors, because they are more vulnerable to plague than dogs. Residents within the affected area should also clear property of trash, lumber piles, and other areas where animals my live or hide. Talk with your veterinarian about treating your pets for fleas. Plague is endemic in El Paso County and precautions to prevent plague should always be taken. Additional information on plague can be found at the link below.
Plague was first introduced into the United States in 1900, by rat–infested steamships that had sailed from affected areas, mostly from Asia. Epidemics occurred in these port cities. The last urban plague epidemic in the United States occurred in Los Angeles from 1924 through 1925. Plague then spread from urban rats to rural rodent species, and became entrenched in many areas of the western United States. Since that time, plague has occurred as scattered cases in rural areas. Most human cases in the United States occur in two regions:
Northern New Mexico, northern Arizona, and southern Colorado
California, southern Oregon, and far western Nevada
Between 1900 and 2010, 999 confirmed or probable human plague cases occurred in the United States. Over 80% of United States plague cases have been the bubonic form. In recent decades, an average of seven human plague cases have been reported each year (range: 1–17 cases per year) . Plague has occurred in people of all ages (infants up to age 96), though 50% of cases occur in people ages 12–45. It occurs in both men and women, though historically is slightly more common among men, probably because of increased outdoor activities that put them at higher risk.
In the pre–antibiotic era (1900–1941), mortality among those infected with plague in the United States was 66%. Since antibiotics for plague have been available, overall mortality for the years 1942–2010 decreased to 16%. In recent decades (1990–2010), mortality decreased further, to 11%. Mortality is still significant despite availability of effective antibiotics, though it is lower for bubonic plague cases (13%) than for septicemic (28%) or pneumonic (36%) plague cases. Plague occurs in all months of the year, though most cases occur in warmer months, when fleas and rodents are more active.
Plague cases in the United States, 1900–2010. In 1907, an outbreak of plague followed in the aftermath of the San Francisco earthquake. Since the mid–20th century, plague in the United States has typically occurred in the rural West.
This bar graph shows the number of plague cases by year, but can be interpreted in two separate time frames. From 1900 to 1942, plague occurred in mostly urban areas, particularly in port cities. The disease was sporadic in nature--characterized by epidemics, followed by years without cases. Since 1942, the number of plague cases has become more uniform in nature, with cases occurring nearly every year and with fewer large outbreaks. Since 1942, plague has primarily occurred in rural and suburban areas, and over time, has begun to resemble that of a low level endemic disease.