Factors associated with in-hospital mortality of adult tetanus patients–a multicenter study from Bangladesh

Background: Tetanus, a vaccine-preventable disease, is still occurring in the elderly population of low- and middle-income countries with a high case-fatality rate. The objective of the study was to elucidate the factors associated with in-hospital mortality of tetanus in Bangladesh. Methods: This prospective observational study, conducted in two specialized infectious disease hospitals, conveniently selected adult tetanus patients (≥18 years) for inclusion. Data were collected through a preformed structured questionnaire. Kaplan Meier survival analysis and univariate and multivariable Cox regression analysis were carried out to assess factors associated with in-hospital mortality among patients. All analysis was done using Stata (version 16) and SPSS (version 26). Results: A total of 61 tetanus cases were included, and the overall in-hospital mortality rate was 34.4% (n = 21). Patients had an average age of 46.49 ±15.65 years (SD), and the majority were male (96.7%), farmers (57.4%), and came from rural areas (93.4%). Survival analysis revealed that the probability of death was significantly higher among patients having an age of ≥ 40 years, incubation time of ≤12 days, onset time of ≤ 4 days, and having complication(s). However, on multivariable Cox regression analysis, age (adjusted hazard ratio [aHR] 4.03, 95% Confidence Interval [CI] 1.07–15.17, p = 0.039) and onset time (≤4 days) (aHR 3.33; 95% CI 1.05–10.57, p = 0.041) came as significant predictors of in-hospital mortality after adjusting for incubation period and complications. Conclusion: Older age and short onset time are the two most important determinants of in-hospital mortality of tetanus patients. Hence, these patients require enhanced emphasis and care. Author summary: The number of new cases of tetanus occurring every year decreased considerably in many countries through mass vaccination programs. However, it continues to cause deaths of many people in low- and middle-income settings. The majority of hospital-admitted adult (≥18 years) tetanus patients included in this study were male, farmer and came from rural areas. More than one-third of them died within hospital. However, one must note that these hospitals lacked intensive care facilities. Tetanus mortality after hospitalization is dependent on many factors. Our study found that patients’ older age, short incubation period (time from injury to the appearance of symptom), short onset time (interval between the first symptoms and the first spasm), and development of complications were significant contributors of in-hospital deaths. Meticulous and individualized management of adult tetanus patients with one or more of the above features is required to increase their survival. Moreover, adult males from high risk occupation could be potential targets for booster vaccination strategies to prevent incidence of tetanus in Bangladesh.