By Eduardo Gonzales, MD
Is it true that I can get tetanus if I stepped on a rusty nail but not if the nail is clean? Can you give us some info on tetanus and the tetanus vaccine?
—lorna_ty@gmail.com
When you get punctured by a nail and you have not had a tetanus shot during the last five years, you are at risk of developing tetanus, whether or not the nail is rusty or clean. Most people think tetanus is caused by stepping on a rusty nail, but the truth is, bacteria that cause tetanus can enter the body by a nail puncture regardless of whether the nail is rusty or clean. The bacteria can likewise infect us by a variety of other means, such as a pinprick, scratch or bite from an animal, splinter, burn, dental caries, gunshot or stabbing wound, and tattooing using a contaminated needle.
The nature of tetanus bacteria
Tetanus is an infection that is caused by Clostridium tetani, a bacterium whose spores or seeds are present in soil that has been contaminated by human or animal feces, which means soil in practically all places. It is not dangerous when it gets on our skin surface because it can only germinate and thrive in an oxygen-deprived setting, and especially if surrounded by dead tissue. This is why deep wounds, even small ones, and burn injuries are particularly fertile grounds for the tetanus bacteria.
When introduced into a wound, the spores germinate and the bacteria propagate, producing a toxin (poison) that attacks the nervous system.
Tetanus is no joke
The mortality rate from tetanus is a high 40 percent if untreated, but even with the best treatment, 10 percent of patients still die. The usual initial symptom of the disease, which occurs five days to 15 weeks (or an average of eight to 12 days) after the injury, is slight pain or a tingling sensation at the site of the wound, followed by spasms of the muscles around that area. Afterward, there is stiffness of the jaw muscles (lockjaw), neck rigidity, difficulty in swallowing, and painful spasms of the facial, abdominal, and back muscles. But sometimes, there are no manifestations at the site of bacterial entry, in which case the initial manifestation of the disease consists of a lockjaw and neck muscle rigidity. At any rate, convulsive seizures occur as late manifestations of the disease. Note that fever is not a typical manifestation of tetanus, but when present, it is generally low-grade.
In case of a puncture, burn, or similar injury
Clean the wound with soap and water. If it is a puncture wound or if it is dirty or the result of an animal or human bite and you hadn’t had a tetanus vaccine booster shot in the last five years, see a doctor because you need to receive a shot of the vaccine. The shot has to be administered within 48 hours of the injury. If the wound was caused by a cat or a dog, you may have to be given active and passive rabies immunizations, too.
The tetanus vaccine
The most effective way to prevent tetanus is by active immunization with a tetanus toxoid vaccine. In children, primary immunization with tetanus is usually given simultaneously with the diptheria and pertussis (whooping cough) vaccines via the DTaP vaccine. The primary immunization consists of three doses given at ages two, four, and six months. This is followed by a fifth dose at 15 to18 months of age, a sixth dose at four to six years, and booster doses consisting of Tdap at 11 to 12 years, and of Td (tetanus and diphtheria vaccine) every 10 years thereafter.
Adults who are without any active immunization against tetanus should have primary immunization consisting of three doses. The preferred vaccine for adults is the Tdap vaccine, which prevents not only tetanus but also diphtheria and pertussis. To complete the primary three-dose schedule, a minimum interval of four weeks should be observed between the first and second doses, and six calendar months between the second and third doses. For continuous immunity, a booster dose of the Td vaccine has to be administered every 10 years after the primary series has been completed.
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