Author(s): Anna Minta, Fiona Havers, Rania Tohme

Infectious Agent

The causative agent of tetanus is Clostridium tetani, a spore-forming, anaerobic, gram-positive bacterium. Ubiquitous in the environment, spores of C. tetani germinate into toxin-producing bacteria when they enter the body under specific conditions.

Transmission

Tetanus is transmitted via direct contamination of open wounds and non-intact skin. Non-neonatal tetanus typically is acquired when spores enter certain wounds, including wounds contaminated with dirt, animal or human excreta or saliva, or necrotic tissue. Burns, crush injuries, and deep punctures are also at increased risk for tetanus infection. Even wounds without visible contamination can become infected with tetanus spores; tetanus transmission has been associated with abortion, dental infection, injection drug use, otitis media, pregnancy, and surgery. Neonatal tetanus is typically acquired when spores contaminate the umbilical cord due to unhygienic delivery practices. Direct person-to-person transmission does not occur.

Epidemiology

Tetanus is distributed worldwide. It is more common in rural and agricultural regions; areas where contact with soil or animal excreta is likely; warm and moist environments; and areas where immunization against tetanus is inadequate. Because the spores exist in the environment, tetanus cannot be eradicated. In 2020, over 11,750 tetanus cases across the globe were reported to the World Health Organization / United Nations Children’s Fund, of which 2,230 occurred in neonates. Most tetanus cases were reported from countries in Africa and Southeast Asia.

Maternal and neonatal tetanus elimination, defined as <1 neonatal tetanus case per 1,000 live births per year in every district in a country, has not been achieved in Afghanistan, Angola, Central African Republic, Guinea, Mali, Nigeria, Pakistan, Papua New Guinea, Somalia, Sudan, South Sudan, or Yemen. Any traveler not up to date with tetanus vaccination is at risk of acquiring tetanus infection. Because hygienic obstetric care might not be available, travelers (especially pregnant travelers) going to countries that have not eliminated maternal and neonatal tetanus might be at increased risk for morbidity and mortality from tetanus infection; in addition, proper wound management and tetanus immune globulin (TIG) are less likely to be available in these settings.

Tetanus can affect any age group. The risk for injuries after natural disasters is high; therefore, humanitarian aid workers should be up to date on tetanus vaccination before travel. The number of US travelers who acquire tetanus infection abroad is unknown; surveillance might be limited because travelers with injuries are unlikely to seek care at a travel clinic when they return from their trip. Injuries are common among travelers, however, and any tetanus-prone wound is a risk, so ensure that all travelers are properly vaccinated.

Clinical Presentation

The incubation period is on average 10 days (range 3–21 days). The duration of the incubation period is inversely related to the severity of symptoms, and shorter incubation periods are associated with injuries closer to the central nervous system. Tetanus is classified as generalized, localized, and cephalic. Generalized tetanus, which occurs in >80% of cases, is characterized by lockjaw, generalized spasms, risus sardonicus, and opisthotonus. Symptoms of localized tetanus include muscle spasms confined to the injury site. Cephalic tetanus is characterized by a head or face wound and flaccid cranial nerve palsies. Progression from localized and cephalic tetanus to generalized tetanus can occur. Neonatal tetanus occurs in newborns who have contaminated umbilical stumps and whose mothers are unimmunized or inadequately immunized. Neonatal tetanus can lead to long-term sequelae, including behavioral, intellectual, and neurologic abnormalities. Severe tetanus can lead to respiratory failure and death. Case-fatality ratios for generalized tetanus vary between 25% and 100% and can only be reduced to 10%–20% where modern intensive care is available. The case-fatality ratio is <1% for localized tetanus.

Diagnosis

Diagnosis is based on clinical findings with epidemiologic support; no confirmatory laboratory tests are available. Tetanus is a nationally notifiable disease in the United States.

Treatment

The goals of treatment are to inactivate circulating toxin by immediately administering tetanus immune globulin (TIG); eliminate the bacteria with aggressive wound care and debridement to stop further toxin formation; provide supportive care; and provide antibiotic treatment for 7–10 days. Metronidazole is the most appropriate antibiotic; parenteral penicillin G is an alternative treatment. Patients with tetanus must be hospitalized in a quiet, dim room to minimize spasms. Additional supportive care measures include agents to control muscle spasm and autonomic dysfunction, and respiratory support. Patients should be vaccinated and receive TIG as described below. Additional information about diagnosis and treatment can be found at the Centers for Disease Control and Prevention (CDC) Tetanus website.

Prevention

Vaccine

Indications for Use

Tetanus disease does not result in immunity. Vaccination is the only prevention against tetanus. Because immunity after vaccination wanes over time, lifelong vaccination with tetanus toxoid–containing vaccine (TTCV) is necessary to attain and sustain immunity against tetanus. All travelers should be up to date with vaccination before departure.

Children

DTaP (diphtheria-tetanus-acellular pertussis) and DT (diphtheria-tetanus) are indicated for children <7 years, while Tdap (tetanus-diphtheria-acellular pertussis) and Td (tetanus-diphtheria) are indicated for children ≥10 years. Infants and children should receive 5 doses of DTaP at 2, 4, 6, and 15–18 months, and at 4–6 years; adolescents should receive 1 dose of Tdap at 11–12 years of age. Children ≥7 years old can receive Tdap for catch-up vaccination.

Adults

Adults should receive TTCV booster doses every 10 years. Adults who have never received Tdap should receive Tdap; otherwise, clinicians can administer either Td or Tdap. Previously unvaccinated pregnant people should receive 2 doses of TTCV during their pregnancy. Pregnant people also should be properly vaccinated to prevent infant pertussis, irrespective of their vaccination history, by receiving Tdap during every pregnancy at 27–36 weeks’ gestation, preferably earlier in this period. See the CDC Immunization Schedules website for routine and catch-up vaccination schedules and minimum intervals between TTCV doses.

Adverse Reactions & Safety

TTCV are safe. The most common adverse reactions are fatigue, headache, and injection site pain.

Contraindications & Precautions

A severe allergic reaction (e.g., anaphylaxis) to a previous dose or a component of the vaccine is a contraindication for any TTCV (DTaP, DT, Tdap, or Td). For DTaP or Tdap, encephalopathy without an identifiable cause occurring within ≤7 days of a previous dose of DTP, DTaP, or Tdap is a contraindication to vaccine administration. Encephalopathy is a contraindication for the pertussis component of the vaccines; therefore, people with this contraindication should receive either DT in place of DTaP or Td in place of Tdap, to ensure protection against diphtheria and tetanus.

Precautions for all TTCV include Guillain-Barré syndrome ≤6 weeks after a previous dose of TTCV, history of Arthus-type hypersensitivity after a previous dose of tetanus or diphtheria toxoid–containing vaccine (in which case, vaccination should be deferred until ≥10 years after the last TTCV), and moderate or severe acute illness with or without fever.

Due to the pertussis component of these vaccines, an additional precaution for DTaP and Tdap is a progressive or neurologic disorder, in which case vaccination should be deferred. Please see Liang et al. for additional information about when TTCV can be given.

Wound Management

Patients with wounds should be evaluated for risk for tetanus infection based on the type of wound and TTCV status, and clinicians should provide prophylaxis accordingly (see Table 5-05). Complete information on tetanus prophylaxis and the use of TIG when indicated for wound management is available from Liang et al.

CDC websites: Tetanus, Pinkbook: Tetanus