Tularemia Outbreak at an International Airport, 2006Diseases in Nature Transmissible to ManJune 12, 2007J L Alexander, TDSHS Zoonosis Division

R Gilliland, USDA Wildlife ManagementD Duke, COA Environmental HealthM McGee, COA Animal ControlJM Richardson, COA Public HealthTA West, COA Emergency ManagementJR Pierce Jr, Amarillo Bi-City-County Health District

20 dead jackrabbits found along this 0.6 mi section of road

Identifying the zoonotic outbreak 05/16/06: An employee of the USDA Wildlife

Management observed a large number of dead jack rabbits on airport property.

05/17/06: The Regional Zoonosis Control veterinarian collected blood specimens and ticks from dead animals

05/18/06: CDC laboratory identified Francisella tularensis as the etiologic agent involved in the deaths

Public Health Response 05/18/06 - Closure of property; notification of

airport officials; suspension of mowing 05/19/06:

Notification of adjacent property owners and FBI Public Health Advisory to area physicians and

veterinarians Texas Health Alert Advisory Press release

Warning public of tularemia in rabbits near airport Not to handle rabbits Use insect repellant Signs and sxs of tularemia

Environmental Health and Animal Control Response 05/22/06

Begin applying tick/flea pesticides to grass Rabbit reduction program begins

05/23/06 – 05/30/06 Additional specimens submitted Broadened insecticide program

Tularemia positive specimens from airport property, 2006 Jackrabbit (Lepus californicus)

Coyote (Canis latrans)

Skunk (Mephitis mephitis)

Ticks (Haemaplysalis leporipalustris)

(Dermacentor variabilis)

Follow-up response 06/01/06 – PROMED post Next week - several calls from citizens about

dead rabbits; multiple media inquires 06/22/06 – second wide-area application of

tick and flea powder to airport property By 06/23/06 – 1300 rabbits eliminated;

subsequent tests of animals (including prairie dogs) all negative; intense reduction program closed

09/07/06 – repeat testing of rabbits negative 01/01/07 – maintenance program initiated

Tularemia - Affected Mammals

Sylvilagus floridanus, “Eastern Cottontail”

Lepus californicus, “Black-tailed Jackrabbit”Prairie Dogs

These animals are more likely to be affected through the terrestrial cycle of F. tularensis ssp. tularensis (Type A)

Tularemia - Affected Mammals

Beaver

Muskrat Vole

These animals tend to be affected through the water-borne cycle of F. tularensis ssp. holarctica (Type B)

Tularemia - Affected Arthropods

Ticks, mosquitoes, the deer fly and other biting arthropods serve as vectors for F. tularensis in its transmission to humans and animals.

Tularemia - Transmission to Humans

• Insect bite by tick, mosquito or deer fly.

• Skin contact with infected animal products, most notably rabbits, hares, and rodents.

• Ingestion of contaminated food or water.

• Inhalation of live bacteria by aerosolization of infected material.

Wildlife Strikes at Airports Reported wildlife strikes have more than

quadrupled from 2,066 in 1990 to 9,017 in 2005.

Over this time period, 172 people were injured, 9 died, and $233 million were lost as a result of incidents with wildlife.

Strikes increasing due to more flights, increased wildlife populations, more wildlife near airports, and more reports from pilots

Sources: FAA National Wildlife Strike Database; Mutzabaugh, Ben. “Today in the Sky.” USA Today. 28 February 2007

Wildlife Strikes at Airports

United States Total Wildlife Strikes

0

2,000

4,000

6,000

8,000

10,000

1990 1993 1996 1999 2002 2005

Year

Str

ike

s

Note: 2007 data includes up to 2/28/07 Total Strikes: 88,198

Source: FAA National Wildlife Strike Database

Wildlife Strikes at Airports

Source: Wildlife Hazard Management at Airports: A Manual for Airport Personnel

Source: Wildlife Hazard Management at Airports: A Manual for Airport Personnel

Coyotes and Airports

Chino, CA -- “Coyotes on Runways: Animals Endanger Airplane Landings” In four separate instances in

April 2007, pilots reported spotting coyotes on the runways.

One pilot aborted his landing and did a go-around.

Chicago – “Coyotes Slinking Around O’Hare Cause Problems” Two pilots were waved-off from

their landings at O’Hare in February 2007.

Coyotes and Airports

In October 2005 a 19-passenger Beechcraft hit a coyote on takeoff, causing the nose gear to collapse and the plane to be declared as a total loss.

In October 1994 a small plane struck a coyote. The nose gear collapsed and the propeller hit the

runway. Resulted in major damage to the engine and

crankshaft.

Sources: Mutzabaugh, Ben. “Today in the Sky.” USA Today. 28 February 2007; Wildlife Hazard Management at Airports: A Manual for Airport Personnel

Coyotes and Airports - Potential Consequences

The presence of a coyote on the runway can be disastrous for a pilot whose natural instinct is to swerve, resulting in a wing going too low and the plane crashing or in the eruption of a fire.

An animal on a runway could be sucked into an engine or hurled through a windshield.

If the strike occurs at the critical phase of landing, a coyote could be smashed by the main gear, causing major damage and possibly changing the path of the aircraft.

Coyote Strikes at Airports

Coyote Strikes by Year

0

10

20

30

40

1990 1992 1994 1996 1998 2000 2002 2004 2006

Year

Str

ike

s

United States

Note: 2007 data includes up to 2/28/07 Total Strikes: 303

Source: FAA National Wildlife Strike Database

Coyote Strikes at Texas Airports

Texas Coyote Strikes

0

2

4

6

8

2004 2005 2006 2007

Year

Strik

es

Note: 2007 data includes up to 2/28/07 Total Strikes: 12

Source: FAA National Wildlife Strike Database

Texas Coyote Strikes

Dates: January 1990 – February 2007

Number of Strikes: 26

Source: FAA National Wildlife Strike Database

Title 14, Code of Federal Regulations, Part 139.337 If an aircraft carrier experiences a multiple wildlife

strike or substantial damage from striking wildlife, a Wildlife Hazard Assessment is triggered.

Species-specific population management Food and prey management Vegetation, water, and building management

Wildlife Hazard Control Measures Repel Capture Kill

Wildlife Hazard Management at Airports: A Manual for Airport Personnel

Federal law does not protect terrestrial mammals, reptiles, or other wildlife taxa (e.g. deer, coyotes).

A shooting program may be used to remove specific problem animals or to kill one or more to reinforce repellent techniques.

Lethal neck snare traps can also be used on coyotes.

Source: Wildlife Hazard Management at Airports: A Manual for Airport Personnel

Rabbit & Coyote Population Dynamics A rule-based rabbit-coyote biological model predicts

that with the elimination of coyotes, the rabbit population will increase.

Source: Ledgard, Henry. “An Introduction to VSE: The Visual Software Environment.”

Rabbit & Coyote Population Dynamics Short-term removal effort of coyotes had no effect

on the population of other species, including cottontail rabbits.

Long-term removal efforts (>9 months) caused increases in jackrabbit population. A 2-year removal program in Texas resulted in a 320%

increase in jackrabbit population density. A study in Utah which used interaction models that

mimicked field observations showed that decreased coyote population densities result in increases in jackrabbit abundance.

Source: Henke, Scott. Effects of Coyote Control on Their Prey: A Review. Coyotes in the Southwest: A Compendium of Our Knowledge. San Angelo, TX. 13-14 December 1995.

Rabbit and Coyote Reduced numbers of coyotes as evidenced by fewer

scat counts resulted in increased numbers of rabbits, especially when coyote scat counts are zero or near zero.

Stapp P. Small Mammal Studies. Shortgrass Steppe Long-term Ecological Research. 2005. http://sgs.cnr.colostate.edu/

Amarillo airport zoonotic events In 2004, a natural increase in the rabbit

population began, which attracted coyotes. In 2004 a rabbit was "ingested" by a

commercial airplane engine during landing justifying the population reduction program.

A coyote and rabbit control program was initiated in May 2004

By the end of 2004, approx 15 coyotes and 301 jackrabbits had been removed

Amarillo airport zoonotic events In August 2005 the rabbit population at the

airport began to increase, this time without any natural predation.

In 2005, 513 rabbits were removed. The rabbit population continued to increase

until the tularemia die-off in May, 2006. Over 3500 rabbits have been removed since

the initiation of this program 3 years ago.

Acknowledgements

Thomas Gerald, TTUHSC Research Associate Contributors from the field

Rick Gilliland, USDA Wildlife Management Deree Duke, COA Environmental Health Mike McGee, COA Animal Control J Matthew Richardson, COA Public Health Theresa West, COA Emergency Management

Fellow Investigator Dr. James Alexander, TDSHS