Tetanus, also known as lockjaw, is a serious illness caused by a bacterial toxin that affects the nervous system and causes muscles to tighten, notably in the jaw and neck. The disease does not spread from person to person. Tetanus occurs worldwide but is most common in hot, damp climates with soil rich in organic matter. The illness occurs most frequently in agricultural regions where livestock are raised. Tetanus can be fatal in up to 50% of cases if left untreated. However, with proper wound care, early diagnosis, and treatment with the tetanus vaccine and medications, the risk of death from tetanus can be reduced to less than 10%.
What Causes Tetanus?
Tetanus is caused by a toxin produced by the Clostridium tetani bacterium. Spores from this bacterium are commonly found in soil, dust, and animal feces. The spores enter the body through broken skin, usually through injuries contaminated with dirt, puncture wounds, burn wounds, or wounds resulting from surgery. Deep puncture wounds and wounds containing foreign bodies like splinters provide low oxygen environments where the spores can germinate and multiply.
Once in the body, C. tetani produces a neurotoxin called tetanospasmin that affects motor neurons controlling muscle contractions. The toxin causes painful muscle contractions, particularly in the jaw (lockjaw) and neck, which is why tetanus is often called lockjaw. As the illness progresses, other muscles, like those in the arms, legs, and abdomen, can also be affected, leading to stiffness and spasms.
Risk Factors for Tetanus
While anyone can get tetanus if exposed to the C. tetani toxin, certain factors increase risk:
- Lack of vaccination – Being unvaccinated or under-vaccinated against tetanus puts an individual at highest risk.
- Puncture wounds – Deep puncture wounds, animal bites, needles, nails, and splinters provide an anaerobic environment for spores to multiply.
- Contaminated wounds – Wounds exposed to soil, dirt, saliva, or feces are more likely to contain C. tetani spores.
- Burns – Severe burns provide ideal conditions for bacterial growth.
- Injecting drugs – Injecting drugs with contaminated needles or other equipment can introduce spores.
- Surgery – Surgery can expose wounds to spores during the operation or recovery.
- Diabetes – Having diabetes increases susceptibility to infection.
- HIV/AIDS – HIV/AIDS and other conditions that weaken the immune system increase risk.
- Elderly age – Older adults have an increased risk of contracting tetanus.
- Newborns – Babies that are born to unvaccinated mothers are prone to neonatal tetanus.
Signs and Symptoms
The incubation period of tetanus ranges from 3-21 days following exposure. On average, symptoms appear after about 8 days. Common signs and symptoms include:
- Lockjaw – Tight, painful spasms of the jaw muscles (masseter muscle) are usually the first sign of tetanus.
- Facial spasms – Muscle spasms may occur on one or both sides of the face.
- Neck stiffness – Tight neck muscles cause stiffness and head tilting.
- Difficulty swallowing – Dysphagia occurs as throat muscles contract.
- Stiffness of abdominal muscles – Muscle rigidity spreads to the abdomen.
- Painful body spasms – Sudden, severe muscle spasms occur throughout the body.
- Breathing difficulty – Spasms of the diaphragm and larynx muscles can cause breathing problems.
- High blood pressure and rapid heart rate – Autonomic instability may develop.
- Fever and sweating
- Excess saliva
- Loss of bladder control
If left untreated, tetanus symptoms get progressively worse. Muscle spasms can become intense and last for minutes. Spasms may be triggered by stimulation such as touch, noise, or other sensory input. Prolonged contractions can cause bone fractures and muscle tears. Tetanus can lead to breathing difficulty, blood clots, pneumonia, and heart failure.
Tetanus is diagnosed based on the characteristic clinical symptoms, particularly lockjaw. There is no lab test that confirms tetanus infection. However, a doctor may order tests to rule out other possible causes of stiffness and muscle spasms like meningitis, strychnine poisoning, dystonia, and seizure disorders. Tests may include:
- Blood tests
- CT scan
- Lumbar puncture
The doctor will also examine the location of any wounds as spores are likely to have entered through a break in the skin. Information about the patient’s vaccination status will also be useful for diagnosis.
There is no cure for tetanus. Treatment focuses on managing symptoms and complications until the effects of the toxin resolve.
- Medications – Antitoxins neutralize unbound tetanus toxin. Antibiotics like metronidazole kill C. tetani bacteria. Muscle relaxants treat spasms. Other drugs help control blood pressure and heart rate.
- Wound care – Prompt wound cleaning removes bacteria and foreign material. Tetanus immunoglobulin injected around the wound helps neutralize remaining toxin locally.
- Ventilatory support – Breathing machines may be required if spasms affect the diaphragm and chest muscles.
- IV fluids and nutrition – Fluids and liquid nutrition are given intravenously since jaw spasms prevent swallowing.
- Medically-induced coma – For severe muscle spasms, a temporary medically-induced coma with drugs like benzodiazepines and neuromuscular blockers may be used until acute symptoms are controlled.
With intensive medical care, most patients with tetanus recover within 4-6 weeks. But recovery can take months and include prolonged rehabilitation to regain strength and mobility.
Vaccination is the most effective way to prevent tetanus infection. Thanks to widespread immunization, tetanus is now rare in the United States, with just 30-50 cases reported annually. The tetanus vaccine is recommended for:
- Children as part of routine childhood immunizations
- Pregnant women to protect newborns who cannot be vaccinated immediately
- Adults as a tetanus booster shot every 10 years
- People with wounds prone to tetanus if more than 5 years has elapsed since the last vaccine
- Unvaccinated or inadequately vaccinated people with a risk of tetanus exposure
The tetanus vaccine can be given alone (Td) or in combination with other vaccines like diphtheria and pertussis (Tdap). Vaccination provides long-lasting immunity against the tetanus toxin.
Global Tetanus Burden
Tetanus remains a significant public health problem worldwide, especially in developing nations with limited access to vaccinations. An estimated 34,000 newborns died from neonatal tetanus in 2015. Global tetanus deaths have declined by 90% in recent decades due to increased immunization coverage. But 21 countries still have high rates of maternal and neonatal tetanus, mainly in Africa and Asia. Efforts to improve tetanus vaccination rates globally could prevent hundreds of thousands of future deaths.
|Estimated Tetanus Deaths (2015)
Tetanus acquired by newborns due to lack of maternal vaccination and unhygienic birthing practices accounts for the vast majority of tetanus deaths globally. Neonatal tetanus is most prevalent in settings with limited access to skilled birth attendants and proper cord care. The WHO estimates nearly 60,000 babies died from neonatal tetanus in 2018 based on reported cases, but the true number is likely higher due to inadequate surveillance in many countries. Sub-Saharan Africa and Southern Asia bear nearly 90% of neonatal tetanus cases.
Is Tetanus Fatal?
Historically, tetanus was often fatal. Before modern intensive care, up to 80-90% of tetanus patients died from complications like respiratory failure, hypertension, hypotension, heart failure, pulmonary embolism, pneumonia, and sepsis. Even with the best available care today, the overall tetanus mortality rate remains high at 10-50%:
- Neonatal tetanus – Fatality rate is up to 100% without hospital treatment. With hospital care, mortality is still 50-90%.
- Generalized tetanus – 20-50% of cases are fatal.
- Local tetanus – Around 10% mortality rate.
Prognosis is better for mild cases diagnosed and treated early. Factors that increase risk of death include:
- Shorter incubation period
- Faster onset of symptoms
- Dysphagia and aspiration pneumonia
- Respiratory dysfunction
- Hypertension / hypotension
- Age over 60 years
With proper wound care, early antitoxin administration, antibiotic therapy, supportive critical care, and vaccination, tetanus no longer has to be the fatal disease it once was. But tetanus can still kill if left untreated. Immunization remains the best defense against this vaccine-preventable disease. Ongoing global vaccination efforts are critical to eliminate tetanus maternal-neonatal tetanus worldwide.
Tetanus remains a potentially fatal bacterial infection in the modern era, although widespread vaccination has dramatically reduced deaths in developed countries. Globally, tetanus still kills tens of thousands of newborns and adults annually, mostly in underdeveloped regions with limited access to vaccines and medical care. While intensive care, antitoxins, and antibiotics have lowered the case fatality rate of tetanus significantly compared to historically, tetanus mortality remains high at 10-50% depending on the type, location, and resources available for treatment. However, with proper wound management, early diagnosis, vaccination, and medication, tetanus can often be treated effectively. Global vaccination efforts provide hope that one day tetanus can become a preventable disease worldwide.