Medical professionals universally appreciate seeing smiles on patients, yet one particular expression—risus sardonicus, also termed the sardonic grin or devil's smile—is dreaded as it signals tetanus infection.
Increasing Cases Despite Past Success
Following years of effective control, tetanus is showing signs of resurgence in the United States. This trend is linked to reduced immunization coverage and heightened exposure risks from climate-induced natural disasters.
Historical data shows 601 tetanus cases reported in 1948 when the vaccine was first combined with diphtheria and pertussis. Recent annual figures had stabilized between 15 and 28 cases. However, 2024 recorded 32 cases, and this year has already seen at least 37 confirmed infections—the highest in over ten years.
Vaccination Decline and Vulnerability
An investigation by NBC News and Stanford University reveals significant drops in kindergarten tetanus vaccination. In states with data since 2019, over 75% of U.S. counties and jurisdictions report declining rates for the DTaP vaccine series, which begins at two months of age.
Although tetanus does not spread person-to-person, lower vaccination levels increase individual susceptibility. Doctors express concern even about minor increases in this severe infection, commonly called lockjaw.
Symptoms and Medical Impact
Symptoms, emerging between three to 21 days after exposure, include muscle spasms that impair breathing. The infection causes jaw clenching, creating a forced smile appearance, and painful arching of back muscles.
"It looks terrible," stated Dr. Mobeen Rathore, chief of pediatric infectious diseases and immunology at the University of Florida College of Medicine-Jacksonville.
Tetanus bacteria thrive in soil and manure, entering through puncture wounds. Treatment is prolonged and expensive. A CDC report cited an unvaccinated 6-year-old Oregon boy who incurred nearly $1 million in medical bills after contracting tetanus in 2019.
Rathore contrasted vaccine costs with intensive care expenses: "It's not even pennies to dollars; it's pennies to hundreds of thousands of dollars. It's very expensive."
Clinical Experiences and Global Context
This year, Rathore treated a 9-year-old unvaccinated Florida patient with muscle spasms, recalling tetanus wards from his training where patients required dark, silent isolation. "The slightest noise would cause many of these patients to go into spasm," he noted.
Spasms, also triggered by light (photophobia), are intensely painful and can constrict airway muscles. The child required sedation, intubation, antibodies, and vaccination, hospitalized for 37 days.
Dr. Matthew Davis, enterprise physician-in-chief at Nemours Children’s Health, emphasized that "it wasn't until we had widespread vaccination that we saw a decline in cases of tetanus and thereby a reduction in the risk of mortality from it."
John Johnson, a vaccination adviser with Doctors Without Borders, works in countries like the Democratic Republic of the Congo, where 540 tetanus cases occurred last year. He remarked, "It's one of those things that's so stupidly easy to prevent. If you see one case of tetanus in the U.S., it's a shame. There's no reason we should be seeing this disease anymore."
Adult Cases and Booster Awareness
After childhood immunization, adults need booster doses every decade, though many are unaware. Nikki Arellano, 42, hadn't received a shot since 2010 when a minor leg cut from a metal arch led to tetanus last month. Jaw pain progressed to lockjaw.
"My jaw was completely locked shut," said Arellano from Reno, Nevada. Emergency treatments failed to open it. Diagnosed with tetanus, she received IV antibiotics. Pump alarms triggered muscle contractions. Spasms spread from her arms to full body, causing severe back arching. Swallowing difficulties raised airway concerns. "It was very scary," she recalled, hospitalized nearly a week and still recovering.
Climate Change and Disaster Risks
Natural disasters like hurricanes, floods, and tornadoes elevate tetanus risks as people encounter injuries from debris. Kristie Ebi, a University of Washington epidemiologist, explained, "As the Earth warms, there's already a documented increase in the frequency, intensity and duration of many extreme weather and climate events. And as there are more flooding events, then fewer vaccinations for diseases like tetanus means that people would be at greater risk."
States with high disaster risks, including Florida, Texas, and Kansas, show notable vaccination declines. Florida, with extensive weather damage, saw kindergarten DTaP rates fall from 94.1% in 2016-17 to 88.8% in 2024-25. Broward County, highly hurricane-prone, had an 82.2% rate in 2024-25.
In Texas, 85% of counties reported declining kindergarten DTaP rates since 2019. Kansas, averaging 81 tornadoes yearly, had Ford County—with the state's most tornadoes—at 83.98% vaccination in 2024-25.
A Kansas case report described a 16-year-old unvaccinated boy with a foot puncture wound initially treated with burdock leaves and bread mold. Worsening spasms and swallowing issues led to hospitalization. He required 40 days of intensive care, developed pneumonia and bedsores, and needed rehabilitation. He received tetanus vaccination during treatment, but his family declined other vaccines upon discharge.
Rathore fears a "post-vaccination era," lamenting, "It is unfortunate that the children are going to suffer."
