Wounds at risk of tetanus: unexpected level of underimmunization in a patient cohort

Abstract Background: Tetanus is an acute and potentially fatal disease caused by Clostridium tetani, an extremely resilient pathogen. This bacterium can contaminate traumatic wounds which account for approximately 5.4% of all visits to the Emergency Department. According to several surveillance programs, the incidence of clinical tetanus in Italy is tenfold higher than in other industrialised countries. In 2010, Italy accounted for 57 of the 74 confirmed cases reported within the European Union. We decided to conduct a study in the Emergency Department to assess the proportion of patients immunised against tetanus. Methods: The study analyses data from 1094 patients who presented to the Emergency Department of the Fondazione IRRCS Policlinico San Matteo between April 2016 and November 2017 with wounds potentially at risk of infection with Clostridium tetani. Results: Data showed that in Italy, the percentage of population protected against tetanus infection is unexpectedly low with 432 patients out of 506 having no significant level of antibodies against tetanus infection. In conformity with the literature, the elderly (> 60 years old) constitutes a high-risk category, with 219 (92%) unprotected individuals out of 238. Also, the patients aged 60+ showed statistically significant difference between female and male subjects.The data comparative analysis showed that younger patients lack protective immunity as well.Conclusions: This study highlights the unexpectedly low level of immunization in the sample of patients that has been taken into consideration. The low level of protection against tetanus infection is a concerning issue not only in the elderly but also in the youngest individuals. This fact could explain the higher incidence of tetanus in Italy in comparison to other European countries. Adopting a well-defined algorithm for the prevention of tetanus infection could help to avoid the excessive administration of prophylaxis, as well as to put in place the necessary preventive measures for each patient. Such a method could help to increase the percentage of the population vaccinated against tetanus infection and eventually reducing the cases of tetanus infection observed in Italy. The analysed data equally suggest the need for conducting awareness campaigns on the topic of vaccines and vaccine-preventable infections.