WILLMAR -- The bare feet of summer don't always mix well with barbed wire or rusty nails.
That's why local health officials say it's a good idea to have a tetanus vaccination that's up to date.
"If you can't remember when the last one was, it's probably time for you to get it," said Stacey Zondervan, director of patient services at Family Practice Medical Center.
Clostridium tetani spores live in soil, dust and manure, where they persist for months or even years. If someone sustains a cut, laceration or puncture wound outdoors, it can provide an opening for the bacteria to enter through the skin, creating a situation ripe for a tetanus infection.
Because the vaccine is part of the childhood immunization series that's required for children entering kindergarten, most youngsters are current on their tetanus shots.
There are some exceptions to this. In recent weeks, two children treated at Affiliated Community Medical Centers for laceration-type injuries hadn't been vaccinated for tetanus because their parents opted out, said Jo DeBruycker, manager of the Health Learning Center at ACMC.
More often, however, it's adults who are lagging on their tetanus booster shots. Because the boosters are recommended only once every 10 years, people tend to forget about them, DeBruycker said.
"It may be something that you don't even think about."
"Ten years passes very quickly, and we forget when the last one was," Zondervan agreed. "I think that adds to the challenge of keeping up to date."
It's common for many adults to receive a tetanus booster only if they come to the clinic or emergency room with an injury, she said. "That's usually when we were catching people."
The local medical clinics are trying to be more systematic about offering the vaccine to adults who are due -- or overdue -- for a booster.
This has been made a little easier by the introduction of a vaccine that combines a tetanus booster with boosters for diphtheria and for pertussis, or whooping cough.
"It's a good idea for any adult under 64 to have one time. If you have the opportunity, take advantage," DeBruycker said. "If you've ever had pertussis, it's a miserable cough. You also can be infecting other people."
Zondervan said the availability of the combined vaccine has "helped increase the vaccination rate, which is a good thing."
Because tetanus boosters wane over time, some people might need another booster shot if they step on a rusty nail or get snagged on a barbed wire fence -- even if it has been less than 10 years since their last tetanus booster.
"Any time you have an injury in an outdoor setting, I think it's always important to check with your health care provider to see if you should be reimmunized," Zondervan said.
Before the late 1940s, 500 to 600 cases of tetanus were reported in the United States each year. Once childhood vaccination became widespread, these numbers dropped dramatically. Since 2000, there have only been 30 or so cases reported annually, according to the U.S. Centers for Disease Control and Prevention.
Tetanus microbes contain potent neurotoxins that affect the nervous system, causing rigidity and severe, convulsive muscle spasms. The disease often is called lockjaw because of the stiffening of the jaw and neck that is one of its hallmarks.
Victims typically require intense medical care and can take months to fully recover. About one in 10 cases is fatal, most often among older patients or patients who have not been vaccinated.
"It really is a devastating disease," Zondervan said. "Just because we have not seen a case of tetanus does not mean the spores are not out there. It's that the immunization to prevent tetanus is so effective that we don't see it anymore."