Tétanos

Incubación: 3–21 días (media: 7–10 días). Incubación corta = peor pronóstico.

Tétanos generalizado (forma más frecuente):

• Trismo — imposibilidad de abrir la boca (signo cardinal)

• Risa sardónica — contractura facial característica

• Opistótonos — hiperextensión dorsal por espasmo de músculos dorsales

• Laringoespasmo doloroso — riesgo de asfixia

• Disautonomía: taquicardia, hipertensión, hipersudoración

Tétanos neonatal: Puerta de entrada umbilical — trismo, dificultad de succión; mortalidad 70–100 % sin tratamiento

The risk of tetanus is determined primarily by vaccination status and the nature of wound exposure. Unlike most infectious diseases, tetanus has no person-to-person transmission component.

Risk factors for acquiring tetanus:

• Incomplete or absent vaccination: The single most important risk factor. In high-income countries, tetanus occurs almost exclusively in unvaccinated or under-vaccinated individuals (elderly who missed childhood vaccines, immigrants from countries with low coverage, individuals who declined vaccination).

• Wound characteristics: Puncture wounds (especially from nails, thorns, or splinters), crush injuries, wounds contaminated with soil or manure, burns, frostbite, avulsions, and compound fractures create anaerobic conditions favorable for spore germination. However, tetanus can follow minor injuries — in ~20% of cases, no wound is identified.

• Injection drug use: Particularly subcutaneous injection ("skin popping") of contaminated drugs. Wound botulism should be co-considered.

• Neonatal risk: Unclean delivery practices (cutting the umbilical cord with non-sterile instruments, applying traditional substances to the umbilical stump) in infants of unimmunized mothers.

• Surgical and procedural risk: Post-surgical tetanus (rare) following gastrointestinal surgery, dental procedures, or intramuscular injections with contaminated needles.

Risk factors for severe disease and poor outcomes:

• Age: Case-fatality rate increases sharply in neonates and in adults aged >60 years. In the elderly, both incomplete immunity and reduced physiological reserve contribute.

• Short incubation period: Incubation <7 days (and especially <48 hours between the first symptom and the first spasm — the "onset time") predicts more severe disease.

• Delayed treatment: Access to ICU care with mechanical ventilation and autonomic management is the major determinant of survival in severe cases. Resource-limited settings have CFR 50–70% vs. 10–20% in well-equipped ICUs.

• Wound proximity to CNS: Cephalic tetanus (head wounds, otitis media) may progress rapidly.

• Portal of entry: Neonatal tetanus (umbilical route) and post-abortive tetanus carry particularly high mortality.

Populations at elevated risk in high-income countries:

• Elderly (waning immunity, often >30 years since last booster)

• Agricultural workers and gardeners

• Injection drug users

• Immigrants and refugees from low-coverage countries

• Parada respiratoria por laringoespasmo (principal causa de muerte)

• Disautonomía: arritmias cardíacas, hipertensión lábil

• Rabdomiólisis por espasmos prolongados

• Neumonía nosocomial (ventilación prolongada)

• Letalidad global: 10–20 % en países industrializados, hasta 50 % en otros