The news media recently picked up a CDC report documenting the effects of tetanus on a 6-year-old child in Oregon whose parents declined the tetanus shot. He contracted the disease in 2017. What started out as a simple cut on the forehead from playing on the family farm turned into 57 days in the hospital and $800,000 in medical bills.

The CDC has been documenting tetanus cases since 1947. The good news is that incidence and mortality have greatly improved. Yet, tetanus still has a 10% mortality rate—even for those who receive the best medical care.

Tetanus is caused by the toxins produced by the Clostridium tetani bacteria, which causes extremely painful muscle rigidity as well as spasming. These symptoms can cause death if the muscles related to breathing become clenched. “Lockjaw” is a common term referring to the jaw clenching—preventing speaking or swallowing—that often occurs in those with tetanus.

With the assistance of modern medical treatment and equipment—including a ventilator (aka “breathing tube”)—the young boy survived. Unfortunately, survival doesn’t automatically grant future protection from another trip to the ICU caused by tetanus bacteria. Getting the tetanus shot now would protect him, but his parents rejected that option—even after witnessing the painful consequences.

Who needs a tetanus shot booster?

The CDC recommends most people, regardless of age, get a tetanus vaccination every 10 years. Anyone who is not vaccinated is susceptible to infection from tetanus; however some people might be at higher risk than others. Persons in certain occupations such as farming, firefighting, and construction are at higher risk, as well as those who enjoy hobbies such as gardening and camping. Adults over 65 are at higher risk, possibly due to more compromised immune systems and greater likelihood of not maintaining a lifetime long booster vaccination schedule. People with diabetes are also at a greater risk. In fact, according to the CDC, people with diabetes accounted for 13% of all reported cases of tetanus in the U.S. from 2009-2015 and 25% of tetanus-related deaths.

Tetanus is often contracted through a puncture wound, such as that caused by a nail or animal scratch. The bacteria gains entry through the wound and can grow rapidly in this anaerobic—oxygen-free—environment. This is why narrow wounds like pinpricks, scratches, and punctures actually pose a greater threat than larger, open wounds. In the classic “stepped on a rusty nail” example, the culprit isn’t the rust. The culprit is the soil surrounding the rusty nail, which can be home to spores of Clostridium tetani.

The good news is that with increased rates of vaccinations and lower levels of exposure of wounds to potential contamination, rates of tetanus have declined in the U.S. since 1900. But that doesn’t mean that tetanus has been eliminated as a risk. The bacteria that causes tetanus is still present in the natural environment, and there is still a risk of contracting the disease. This is why the CDC recommends children get vaccinated and adults receive a booster of the tetanus shot every 10 years.

The vast majority of people can receive a tetanus vaccination with nothing more than a day or two of soreness at the injection spot. Sometimes there can be mild redness or swelling, a slight fever/headache, or general tiredness. This also passes in a few days. However, in rare cases severe change in muscle status can occur at the site of the injection within 2-4 days. If this is the case, seek medical attention immediately. Others who should speak to their doctor before vaccination include anyone who has had a severe allergic reaction to a previous tetanus shot or any vaccines given for diphtheria or pertussis—as tetanus shots are sometimes given as Tdap, which also protects against those diseases. Anyone with an autoimmune disorder, especially Guillain-Barré syndrome, seizures, or nervous system problems should also speak to their doctor before getting a booster shot.

How vaccine literate are you? For more health literacy topics on immunization, please see our quiz on the most important vaccines for older adults.

When asked in a recent Health IQ quiz which standard vaccine included the tetanus booster shot, women were statistically significantly more likely than men to know the correct answer. This falls in line with the fact that the majority of women in families have the primary responsibility in the family for navigating healthcare for their children. Conversely, men were statistically more likely to correctly answer a question about the common methods of contracting tetanus, perhaps because men are more likely to be employed in occupations with greater risk of exposure to Clostridium tetani bacteria.