Survival of persons with hantavirus infection diagnosed in Paraná State, Brazil

Abstract: Hantavirus infection is an emerging disease with public health impact. Since the signs and symptoms are nonspecific and easily confused with those of other diseases, the prognosis could be improved by knowledge of the factors potentially contributing to the outcome. The study aimed to identify the factors associated with survival time in persons with hantavirus infection. This was a study of confirmed cases of hantavirus infection from January 1992 to June 2016 in Paraná State, Brazil. Each case presented two possible competitive outcomes: death or cure. Survival analysis used a competitive risks model and outcome probabilities estimated by the Aalen-Johansen estimator. The measure of association was the hazards ratio (HR) with 95% confidence interval (95%CI). Of the 280 individuals with hantavirus infection, 107 (38.21%) evolved to death, 161 (57.5%) to cure, and 12 (4.29%) were censored. The final survival model consisted of the use of mechanical ventilation for death (HR = 2.86; 95%CI: 1.76-4.64; p = 0.00002), hemorrhagic signs for death (HR = 2.86; 95%CI: 1.69-4.84; p = 0.00009) and for cure (HR = 0.66; 95%CI: 0.45-0.95; p = 0.03), headache for cure (HR = 1.99; 95%CI: 1.12-3.54; p = 0.02), and age under 20 years for cure (HR = 1.73; 95%CI: 1.05-2.84; p = 0.03). Hemorrhagic signs and use of mechanical ventilation are factors associated with the severity of cases and do not allow sufficient time to reverse the outcome. However, these signs of severity corroborate the argument of the importance of timely suspicion, allowing adequate clinical management to reduce case-fatality.