Mortality Related Factors in Patients Requiring Hospitalization for Influenza Like Illness

Abstract

The knowledge about the viral etiologies causing respiratory disease in adults is limited. Viral respiratory diseases may lead deterioration in certain patient populations. The aim of this study was to determine the viral etiologies of influenza-like illness among patients requiring hospitalization and to document the risk factors for mortality. This prospective study was performed in one of the 7 centers in Turkey in the context of influenza surveillance by the Global Influenza Hospital Surveillance Network. A 35-bed Adult Emergency Service and 10-bed Acute Care Unit were screened for consequent recruitment of eligible patients daily, on weekdays only. ICD-10 codes in the electronic health records and direct patient encounters were used to screen for the following eligibility diagnoses: acute respiratory tract infection, asthma, heart failure, pneumonia, influenza, chronic obstructive lung disease, dyspnea/respiratory abnormality, respiratory symptoms, cough and fever. A total of 334 patients who were admitted with the eligible ICD-10 codes within the 24th and 48th hours were screened during the study period and of those eligible ones, 106 consented and were swabbed. Nasal or nasopharyngeal swabs were collected using Virocult (Medical Wire & Equipment, UK) and sent to the central laboratory in 1-3 days. Swabs were collected and specimens were introduced to real-time polymerase chain reaction based multiplex kits, as well as, ABI 7500 platform with CDC primers and probes. A total of 106 patients were swabbed. Hospital mortality was 12.2%. More than one fourth of the patients needed a sort of mechanical ventilation support and at least one organ failure developed in one third of the patients. One or more viral pathogens were detected in 56 (52.8%) of the swabbed patients, with influenza H3N2 being the most prevalent one. Having a lower body mass index (OR, 0.845, p=0.034) was associated with mortality. Chronic lung diseases were shown to confer a survival advantage (OR, 0.127, p=0.009). Community acquired viral respiratory infections might lead to significant compromise in adult patients. Prevention of malnutrition might result in better outcomes in patients who need acute admission. The survival advantage of those with chronic lung diseases warrants further investigation.