Health Risks From Rodent Work

Editor’s Note: This article was reprinted with permission from Pinto & Associates.

Rodents pose some health and safety hazards to technicians doing rodent control. You face health risks by picking up fleas, ticks, lice, or mites from rodents, from rodent bites and scratches, and by getting diseases carried by rodents. It's up to you to determine the level of risk that you face when doing a rodent job and to take the appropriate precautions to protect yourself.

How to Protect Yourself From Rodent Ectoparasites: These ectoparasites include fleas, ticks, mites, and lice. Some rodent ectoparasites also feed on people, some can transmit disease to pets, wildlife, and people. Lyme disease is the most common vector-borne disease and occurs throughout the U.S. Two examples: (1) Lyme is spread by the bite of the black-legged tick. The tick larvae and nymphs can pick up the disease when they feed on the white-footed mouse, People can get the disease from the bite of any tick stage. Black-legged ticks and their mouse and deer hosts are most common along edge habitats-woods bordered by an open grassy area. (2) Plague is an infectious disease spread by the bite of an infected rodent flea, or by handling an infected animal. Plague in the U.S. is mostly in ground squirrels and their fleas and occurs in certain western states.

(1) When controlling a heavy rodent infestation, consider spraying the area with an insecticide/acaricide to eliminate parasitic insects, ticks, and mites so that they do not attack you or infest other people after the rodents have been eliminated.

(2) If working in Lyme disease or plague areas, use insect repellents, wear protective clothing and gloves when handling trapped animals, and stay away from wild animal nests where fleas or ticks may be waiting. After, check your body and clothes for fleas and ticks.

How to Protect Yourself From Rodent Bites and Scratches: Rodents, and in particular rats, have long incisor teeth and can give a nasty bite. They are aggressive when cornered or handled, and will try to bite and scratch. Sometimes a trapped or poisoned rodent appears dead but isn't. Bites or scratches from wild rodents can transmit diseases such as rat-bite fever, and cause other infections including tetanus.

(1) When rodents have to be handled, wear heavy animal-handling gloves (not your regular work gloves) that rodents cannot bite through.

(2) Know the best way to handle a live rat. Pick it up by grasping the whole body--palm over back and side with forefinger behind the head, and your thumb and second finger extending the rodent's forelimbs so that they may be controlled. Use your other hand to grasp the tail to keep the rat stretched out. Mice are usually caught and lifted by the tail, about two-thirds of the way up from the base.

(3) If bitten or scratched, wash the wound with soap and water. Clean the bite by allowing it to bleed. See a physician.

How to Protect Yourself From Rodent-Transmitted Diseases: From plague to typhus to hantavirus, rodents are associated with about 60 different diseases worldwide, and an increasing number of such diseases are posing risks to technicians in the U.S. The most dangerous of these is hantavirus due to its high fatality rate, even with treatment. Hantavirus is spread by inhaling airborne particles that are stirred up from deer mouse droppings. It is very rare and is more of a problem in certain western states. The greatest risk scenario is if you are doing a "clean-out" of a heavy infestation of deer mice in a rural outbuilding in an area with a significant number of past hantavirus cases.

(1) To avoid generating airborne particles when cleaning up or otherwise disturbing large accumulations of rodent droppings, wet down the area first.

(2) When you judge that there is a risk of hantavirus, wear coveralls, work shoes or boots, and gloves, either disposable or cleanable. If working in a confined space, wear goggles.

(3) Wear a respirator equipped with an N-100 or other 100 level cartridge.

(4) Dispose of rodent carcasses, nests, and droppings by inverting a plastic bag over your hand, picking up the item, then pulling the bag over the item. Add enough household disinfectant to the carcass or nest to wet it, then seal the bag for disposal.

The authors are well-known industry consultants and co-owners of Pinto & Associates.