Spreading Menace: Fire Ants on the Move.

Be alert for the latest cause of nursing home "horror stories"

It sounds like something out of a horror film--a bedridden nursing home resident is attacked in the middle of the night by a swarm of vicious ants. The resident, unable to cry out or move, is stung hundreds of times. Each sting feels like a hot piercing needle. The resident dies days later from complications of the attack.

Unfortunately, this isn't an episode of The X-Files. There are at least 10 known cases of severe imported-fire-ant attacks on long-term care facility (LTCF) residents. Deaths of LTCF residents in Florida and Mississippi have turned national attention on what once seemed like isolated events. According to the United States Department of Agriculture (USDA), the incidence of fire ant attacks on individuals within healthcare facilities is rising.

The amount of territory infested by fire ants is also on the increase. Once a problem isolated to a handful of states in the Southeast, they are spreading north and west. LTCFs that ignore the potential risk do so at their residents' peril.

A Dangerous Import Spreading Coast to Coast

In the 1930s, a red fire ant queen arrived in Mobile, Alabama, with the cargo of a South American freighter. Since then, her descendants have expanded their home territory by about 5% annually. This year, 15 million additional acres will be infested. Decades of eradication and control efforts have essentially failed. Harvard entomologist Edward Wilson once called the war against fire ants "the Vietnam of the insect world."

Black and red fire ants now infest more than 310 million acres in Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia and Puerto Rico. Colonies have also been discovered in New Mexico, California, Arizona, Oregon and Washington. Migration up the West Coast appears inevitable.

Fire ants might venture even farther north if they become more cold-tolerant. Recent research has found that they can reproduce if the average minimum temperature is higher than 0[degrees]F. They've already shown signs of evolutionary adaptability. Multiple-queen colonies are now the predominant type in Texas. This adaptation makes it harder to eradicate a colony.

Always Ready to Attack

Fire ants are unusually aggressive. In some infested areas, they sting nearly 60% of the human population each year, causing millions of dollars in medical expenses. Although less than 1% of the population is allergic to fire ant stings, most people will experience unpleasant stinging sensations and welts. Those who are allergic can go into anaphylactic shock. There are 80 known deaths from outdoor fire ant stings.

A mature colony consists of 200,000 to 400,000 workers. Its queen produces up to 800 new workers per day. The colony's earthen mound is typically 3 to 36 inches high, but in some soil types there will be no visible mound. If the mound is disturbed, thousands of ants will rush to its defense, stinging a person or animal hundreds of times.

Disturbing a mound isn't the only way people get stung. Fire ants excavate foraging tunnels 50 to 100 feet long that are used to collect food for the colony. Worker ants travel through these tunnels, emerge from the opening and search for food. Once food is found, the workers return to the mound, laying a pheromone trail for others to follow. Unfortunately, sometimes the trail leads to a resident's bed.

Healthcare Facilities at Risk

Fire ants usually build their mounds outdoors, sometimes in debris on the flat roofs of buildings. They only need a tiny crack to enter a building. When they forage, residents' rooms are an attractive destination because of several easy food sources:

* Debris from the meals eaten in bed

* Soiled linen, intravenous tubes and needles

* Body oil build-up on chairs and beds that are not cleaned frequently

It's crucial to take the presence of fire ants in or around an LTCF very seriously. Professional treatment to eliminate them should begin immediately. All immobile individuals should be considered at risk for fire ant attacks and carefully supervised as long as the ants are present, according to the USDA's Agricultural Research Service.

Ignoring the presence of fire ants can be costly. A Texas nursing home was fined $275,000 per day for 55 days for failing to eradicate fire ants after a severe attack on a resident. The resident's family has also sued the facility.

Put a Plan in Place

Coordinate your facility's indoor/outdoor pest control activities for maximum effectiveness. Fire ants will quickly shift their colonies indoors during very hot, dry weather and heavy rain. If you contract with a pest control operator (PCO), make sure your service specifically covers fire ant control. A PCO or a dedicated, trained staff member should conduct at least weekly fire ant inspections both outside and inside the facility.

Outdoor control is your first line of defense. A control program that includes the broadcast applications of baits on infested lawns is a sound policy. Baits act slowly, however, taking anywhere from a week to three months depending on the chemical used. They are designed to get into the colony's food supply to kill the well-protected queen. They will not work quickly enough to treat an indoor infestation.

Another preventive measure is thorough sanitation. Residents' rooms must be thoroughly cleaned to eliminate food sources from bedside tables, clothing drawers and other storage areas. In addition, residents who are incapable of turning should be "direct turned" frequently so ants don't go unnoticed.

If you spot fire ants inside, contact your PCO to arrange immediate extermination. If possible, collect a specimen using a cotton swab or tweezers and keep it in a vial of alcohol. The specimen can help your PCO diagnose the problem and design the most effective treatment.

Coming Soon

By their very nature, fire ants are difficult to control. This persistent pest challenges even facilities with strong Integrated Pest Management (IPM) programs in place. Reinfestation is common. If you live in an area where fire ants are endemic, you must remain vigilant to protect your residents.

If you live in an area without fire ants, just wait. They're coming your way.

Zia Siddiqi, PhD, a board-certified entomologist with nearly 30 years of international experience, has designed innovative urban, industrial and agricultural pest control programs. He serves as quality assurance director for Orkin Exterminating Company's Commercial Division, Atlanta.