About 2 million people annually report being bitten by an animal, and even more than that go unreported. Animal bites therefore represent a major public health problem, largely unrecognized by both the public and governmental officials.

Two concerns result from an animal bite: immediate tissue damage, and later infection resulting from microorganisms. A dog's mouth may carry more than 60 different species of bacteria, some of which are very dangerous to humans. Two examples of infection - tetanus and rabies - have been almost completely eradicated by medical advances but can still pose a potential problem. Seventy-five tetanus cases were reported during a recent year.Many different kinds of animals contributed to the millions of bites in the United States. Interestingly, humans account for up to 15 percent of all bites. However, dogs bite the most and account for 60 percent to 90 percent of all bites. A dog's bite can apply between 150 to 450 pounds of pressure per square inch - producing great damage. This type of force results in about 50,000 cases requiring medical attention. About 50 deaths a year are caused by dogs, with half of them related to pit bulls alone.

Especially prone to animal bites are children, the elderly and invalids, since members of these groups are sometimes unable to detect a dangerous situation. Interestingly, many of the deaths occurred when the victim was left alone with the offending dog, and the dog was a pet. Contrary to popular belief, wild or stray dogs seldom are involved in fatal attacks.

Damage mostly occurs on the hands (48-59 percent of all bites), 16-26 percent on the arms, 15 percent on the legs and 8-30 percent on the face. Facial damage presents several problems since it is susceptible to bleeding due to the closeness of blood vessels to the skin's surface. Facial disfigurement and scarring can result in emotional trauma. Complete or partial loss of an eye can also occur.

First aid

- If the wound is not bleeding heavily, wash it with soap and water. Washing should take 5 to 10 minutes. Scrubbing can traumatize tissues, so avoid it whenever possible. Allowing a wound to bleed a little helps remove bacteria left in the tissues.

- Rinse the wound thoroughly with running water.

- Control bleeding with direct pressure. If an extremity is involved and the bleeding continues, use elevation along with the direct pressure.

- Cover with a sterile dressing but do not seal the wound tightly with tape or butterfly bandages.

- Due to the danger of infection, seek medical attention for further cleaning, possible tetanus and/or rabies shots and stitches to close the wound.

- Alton Thygerson is a professor of health sciences at Brigham Young University.