This case reflects a typical presentation of tetanus, diagnosed based on generalized hypertonia causing painful muscle spasms, including the jaw and neck. A.N exhibited spasms triggered by various stimuli, along with lockjaw and neck extension. Neurological examination confirmed generalized hypertonia, bilateral ankle clonus, and hyperreflexia. Despite the usual pattern of spasms starting in the face, A.N's symptoms may have initiated from the back due to an initial complaint of backache. Classic tetanus features, such as lockjaw, risus sardonicus, severe muscle spasms, and opisthotonus, aligned with A.N's clinical presentation. Trismus typically appears first, followed by spasms progressing throughout the body, triggered by external stimuli, as observed in this case.
Additional potential findings not observed in A.N during the physical examination include the Spatula test, abdominal tenderness, guarding, or cranial nerve palsies, particularly the 8th cranial nerve (4). Tetanus can also manifest autonomic nervous system stimulation, such as alternating hypertension and tachycardia with hypotension and bradycardia, potentially leading to cardiac arrest. While A.N had a normal heart rate, routine blood pressure measurements were challenging.
The broomstick injury likely served as the portal of entry for the infection, posing an increased risk due to its use in a compound with potential exposure to clostridia from soil. Tetanus, caused by Clostridium tetani, a gram-positive, spore-forming, obligate anaerobic bacillus, thrives in soil, dust, or animal feces, especially in hot and wet climates rich in organic matter. Entry into the human body occurs through wounds, punctures, lacerations, or skin breaks, emphasizing the importance of wound care and prevention in high-risk environments (5)(6).
A.N’s mother was fully vaccinated for tetanus with A.N in utero and in turn, A.N had completed childhood vaccinations, but the potential risk was waning immunity at 11 years, as protection typically lasts up to 10 years post-vaccination. He missed the WHO-recommended tetanus booster for his age. Tetanus is more common in the unvaccinated neonates and children in countries lacking immunization programs (7)(8). HIV infection, a potential cause of immune incompetence, was ruled out with the negative HIV serology.
C. tetani secretes tetanospasmin and tetanolysin toxins causing muscle spasms, rigidity, autonomic instability, and tissue damage. Tetanus spores germinate in wounds, releasing tetanospasmin. This toxin inhibits glycine and GABA release, inducing muscle paralysis. Two to 14 days after inoculation, it travels to the central nervous system, inhibiting neurotransmitter release, leading to tetanic spasms.
AN's symptoms appeared 2 weeks post-injury, indicating an incubation period of approximately 14 days. However, the incubation period can range from one to 60 days, with an average of 7 to 10 days. The severity of symptoms is influenced by the distance from the point of entry to the central nervous system, with shorter incubation periods associated with more severe symptoms.
Tetanus diagnosis relies on clinical assessment; there's no specific lab test. Approximately 30% of cases show positive wound cultures. Critical clinical features include acute muscle contractures and spasms without another medical cause. Notably, not all patients recall an injury history. Antitoxin level assays, though limited, can help exclude tetanus. A serum antitoxin level of 0.01 IU/mL or higher is considered protective, aiding in ruling out tetanus. Severity of tetanus may is graded as mild, moderate, severe and very severe, classified as Grades I-IV respectively. The hallmark of grade III includes apneic spells while grade IV is characterized by autonomic dysfunction (9).
First-line treatment for tetanus includes (Human Tetanus Immunoglobulin) HTIG at 3000–6000 U to bind unbound tetanospasmin, shortening the illness and reducing severity. Early wound debridement eliminates spores, preventing further toxin release. A.N received HTIG and underwent debridement, retrieving the broomstick.
Metronidazole is the preferred antibiotic, reducing C. tetani proliferation; penicillins are avoided due to GABA antagonism. Diazepam, a benzodiazepine, was used for anxiety, sedation, and muscle relaxation. Alternating diazepam with chlorpromazine was effective. Supportive management includes high-calorie feeds, blood pressure control, and temperature regulation. Severe cases are best managed in the ICU with sedation, ventilation, and tracheostomy if needed.
AN received the first tetanus toxoid vaccine dose during recovery, as infection doesn't confer future immunity. Prognosis depends on the time from symptom onset to the first spasm; AN's 1-week interval suggested a better prognosis. Recovery is slow, with potential complications like fractures, ileus, pneumonia, pressure sores, and autonomic dysfunction. Mortality results from respiratory failure and cardiovascular collapse associated with autonomic dysfunction (10).