Summary of the included studies.

Table 1: Summary of the included studies.

Author	Study	Results
Fleshner, et al. 1988 [1]	Case Report	A large cell lymphoma male patient, who underwent a gastrectomy and transverse colectomy, presented fever, back pain, dysphagia, trismus and opisthotonus 21 days later.
Dhalla, 2004 [2]	Literature Review	The period of incubation > 7 days and the interval between the first symptom and the first spasm > 48 hours is associated with poor outcome of postoperative tetanus. The presence of necrosis, secondary infection and foreign bodies can facilitate the growth of the organism.
Beisland, et al. 1998 [3]	Case Report	A case of severe postoperative tetanus who underwent bowel resection after strangulation of the ileum. The patient was treated on an intensive care unit and was artificially ventilated for 64 days. Sevenmonths later, shehadfully recovered.
Kasher, et al. 2007 [4]	Case Report	A patient underwent rubber band ligation of the internal hemorrhoid presented symptoms compatible with tetanus postoperative. This patient had never been immunized against tetanus.
Strypstein, et al. 2019 [5]	Case Report	The case shows a patient who presents symptoms of tetanus postoperative and evolved respiratory deterioration and acute cardiac failure. The patient of her vaccination status against tetanus and has no record of immunization against tetanus.
Furui, et al. 1999 [6]	Case report	After undergoing surgery to resect a gangrenous perforated small intestine, a man developed severe tetanus within 24 hours. The patient was diagnosed with tetanus only after opisthotonus became apparent and the standard treatment for tetanus proved to be effective.
Mori, et al. 2012 [7]	Case Report	This case presents a patient without history of toxoid tetanus immunization who developed tetanus 3 days after the resection of a gangrenous small intestine caused by obturator hernia incarceration.
Park, et al. 2019 [8]	Case Report	The postoperative tetanus has a shorter incubation period, and symptoms may appear after 24h. In this case, the symptoms resolved after a month without sequelae.
Philips 1892 [9]	Literature Review	This author describes the tetanus as a complication of ovariotomy after analyzing statistics of 64 procedures from various specialists in Europe and elsewhere.
Malins 1881 [10]	Case Report	The author describes a case of tetanus after ovariotomy, in which the patient evolved, on the 1st postoperative day, with exhaustion, staring and spasms, in addition to suffocation and chest discomfort. On the 10^th day, the patient convulsed for 30 minutes and died.
Federmannand Kotzerke, 1989 [11]	Case report	In this case, a man experienced a severe case of tetanus 12 days after having an operation for a pericaecal abscess caused by appendix perforation, requiring mechanical ventilation was required for 37 days. The patient also suffered from additional complication such as pneumonia with septicaemia, disseminated intravascular coagulopathy and renal failure.