A case of tetanus infection in an adult with a protective tetanus antibody level

Tetanus is a bacterial infection caused by Clostridium tetani and most commonly presents as trismus or other muscle spasms. Despite the development of the tetanus toxoid vaccine, tetanus infection has not been eradicated. Additionally, while there are hypothesized protective levels of tetanus antibody, tetanus infection may still occur in properly vaccinated individuals. We report the case of a 31-year-old male that presented to the emergency department (ED) with a 2-day history of neck and jaw pain. He reports puncturing his hand with a rusty nail 10 days prior. His reported vaccination history was that he received his last booster vaccination 13 years prior to presentation. In the ED, tetanus vaccine, tetanus immune globulin, and metronidazole were administered. His symptoms improved over the next 2 days and resolved at day 6. Despite his presentation of tetanus infection and rule out of other causes for his symptoms, his tetanus antibody level was reported at 8.4 U/ mL, which is considered to be protective. A tetanus antibody level that is adequate for protective immunity should not preclude a patient from treatment of tetanus infection. This case demonstrates that a thorough history, physical exam, and rule out of other causes should guide treatment when there is concern for a tetanus infection.