I can remember as a kid being chased by my older brother through our neighbor's garden and cutting my leg on a rusty nail. At the time, I figured I was doomed to get tetanus, which my brother thought would be just great. (So much for concerned brothers.) I rushed inside to clean the cut, and soon after my mom whisked me off to the pediatrician to get a tetanus booster.
It turns out I had little to worry about — there is little connection between rusty objects and the risk of tetanus. This myth has probably survived for several reasons:
- Tetanus is rare in the U.S. Most people here have no actual experience with this disease. (Tetanus is a much bigger problem in other parts of the world, especially in developing countries. According to the World Health Organization, there are an estimated 213,000 deaths worldwide due to tetanus.)
- This myth is close to the truth. Wounds contaminated with soil (although not specifically rust) may lead to tetanus.
- The end result — washing out a wound thoroughly and updating one's tetanus vaccinations — is an appropriate way to reduce the risk of tetanus or other infections.
What Is Tetanus?
Tetanus is a neurological disease caused by a toxin produced by the bacterium Clostridium tetani. This microorganism lives in the soil and may set up an infection in a wound that is dirty, especially if the wound is not properly cleaned soon after injury. In cases of tetanus, exposure to C. tetani leads to mild muscle spasms within five to 15 days. Problems speaking and swallowing may soon follow because of muscle spasms in the face, jaw and neck. This condition is frequently called lockjaw. In severe cases, breathing and abdominal muscles become rigid, a situation that may be life-threatening.
Fortunately, tetanus is preventable by vaccination. Children should receive four injections beginning at age 2 months to 15 months, followed by booster injections between the ages of 4 and 6, another booster between ages 11 and 12, and then every 10 years throughout adulthood. For deep or dirty wounds, a booster is suggested if the previous one was more than five years ago (in case immunity has waned).
People with a contaminated wound who have never had the primary series of vaccinations should be vaccinated. In addition, an antibody to tetanus (called tetanus immune globulin, or TIG) should be provided by injection. In this way, there's short-term protection while awaiting adequate response to the vaccine series. Most of the 30 to 40 cases of tetanus reported in the United States each year are among people who have never been vaccinated.
It is a good idea to get a booster — if you are due for one — before an injury occurs. If you have an unfortunate encounter with a dirty nail, clean the wound well and determine when you last received a tetanus booster.
Getting the booster is not an emergency. It takes days to weeks to take effect, so getting the booster a day or so after you are wounded is acceptably safe. Watch the site for redness, pain or drainage, which could signal an infection. But don't be overly concerned about tetanus — chances that a well-tended wound will lead to tetanus in a previously vaccinated person are vanishingly small.
And finally, the best approach is to try to avoid injuries in the first place — for example, wear protective pads over the elbows and knees while rollerblading. Or, as my neighbor put it, "watch where you're going!"
Robert H. Shmerling, M.D. is associate physician at Beth Israel Deaconess Medical Center and associate professor at Harvard Medical School. He has been a practicing rheumatologist for over 20 years at Beth Israel Deaconess Medical Center. He is an active teacher in the Internal Medicine Residency Program, serving as the Robinson Firm Chief. He is also a teacher in the Rheumatology Fellowship Program.