Etiology, clinical characteristics, and risk factors associated with severe influenza-like illnesses in Mexican adults

Paola Del Carmen Guerra-de-Blas; Ana M Ortega-Villa; Ana A Ortiz-Hernández; Alejandra Ramírez-Venegas; Sarbelio Moreno-Espinosa; Beatriz Llamosas-Gallardo; Santiago Pérez-Patrigeon; Sally Hunsberger; Martín Magaña; Rafael Valdez-Vázquez; Laura Freimanis; Juan Francisco Galán-Herrera; M Lourdes Guerrero-Almeida; John H Powers 3rd; Guillermo M Ruiz-Palacios; John Beigel; Arturo Galindo-Fraga; Mexican Emerging Infectious Diseases Clinical Research Networka

doi:10.1016/j.ijregi.2023.01.012

Etiology, clinical characteristics, and risk factors associated with severe influenza-like illnesses in Mexican adults

IJID Reg. 2023 Feb 1:6:152-158. doi: 10.1016/j.ijregi.2023.01.012. eCollection 2023 Mar.

Authors

Paola Del Carmen Guerra-de-Blas¹, Ana M Ortega-Villa², Ana A Ortiz-Hernández³, Alejandra Ramírez-Venegas⁴, Sarbelio Moreno-Espinosa⁵, Beatriz Llamosas-Gallardo³, Santiago Pérez-Patrigeon⁶, Sally Hunsberger², Martín Magaña⁷, Rafael Valdez-Vázquez⁸, Laura Freimanis⁹, Juan Francisco Galán-Herrera^{1

10}, M Lourdes Guerrero-Almeida⁶, John H Powers 3rd¹¹, Guillermo M Ruiz-Palacios⁶, John Beigel², Arturo Galindo-Fraga⁶; Mexican Emerging Infectious Diseases Clinical Research Networka

Affiliations

¹ The Mexican Emerging Infectious Diseases Clinical Research Network (LaRed), Mexico City, Mexico.
² National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, USA.
³ Instituto Nacional de Pediatría, Mexico City, Mexico.
⁴ Instituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas", Mexico City, Mexico.
⁵ Hospital Infantil de México Federico Gómez, Instituto Nacional de Salud, Mexico City, Mexico.
⁶ Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico.
⁷ Hospital Regional Dr. Ignacio Morones Prieto, San Luis Potosí, Mexico.
⁸ Hospital General "Dr. Manuel Gea González", Mexico City, Mexico.
⁹ Westat, Rockville, Maryland, USA.
¹⁰ Instituto Politécnico Nacional, Mexico City, Mexico.
¹¹ Clinical Research Directorate, Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA.

Abstract

Objective: The aim of this study was to determine the risk factors associated with severe influenza-like illness (ILI) in Mexican adults that could be useful to clinicians when assessing patients with ILI.

Methods: Data from adult patients enrolled from 2010 through 2014 in ILI002 - a prospective hospital-based observational cohort study - were analyzed. Etiology and clinical characteristics were compared between cases of severe ILI (defined as hospitalization and/or death) and cases of non-severe ILI.

Results: Overall, 1428 (39.0%) out of a total 3664 cases of ILI were classified as severe. Adjusted analyses showed a higher risk of severe ILI associated with signs and symptoms related to lower tract infection, i.e. cough with sputum (odds ratio (OR) 2.037, 95% confidence interval (CI) 1.206-3.477; P = 0.008), dyspnea (OR 5.044, 95% CI 2.99-8.631; and shortness of breath (OR 5.24, 95% CI 3.0839.124; P < 0.001), and with increases in lactate dehydrogenase (OR 4.426, 95% CI 2.321-8.881; P < 0.001) and C-reactive protein (OR 3.618, 95% CI 2.5955.196; P < 0.001). Further, there was an increased risk of severe ILI with a longer time between symptom onset and inclusion (OR 1.108, 95% CI 1.049-1.172; P < 0.001) and with chronic steroid use (OR 14.324, 95% CI 8.059-26.216; P < 0.001).

Conclusions: Respiratory viruses can cause severe ILI. The results of this study highlight the importance of evaluating data compatible with lower tract involvement and previous use of immunosuppressants at baseline, because patients meeting these conditions may develop severe illness.

Keywords: Adults; Disease severity; Influenza; Risk factors.