The Impact of Influenza and Tuberculosis Interaction on Mortality Among Individuals Aged ≥15 Years Hospitalized With Severe Respiratory Illness in South Africa, 2010-2016.

Sibongile Walaza,Nazir Ismail,Andries Dreyer,Claire Von Mollendorf,Neil A Martinson,Florette K Treurnicht,Nicole Wolter,Anne Von Gottberg,Ebrahim Variava,Halima Dawood,Jocelyn Moyes,Sumayya Haffejee,Meredith Mcmorrow,Stefano Tempia,Marietje Venter,Cheryl Cohen,Orienka Hellferscee

doi:10.1093/ofid/ofz020

Abstract

BackgroundData on the prevalence and impact of influenza–tuberculosis coinfection on clinical outcomes from high–HIV and –tuberculosis burden settings are limited. We explored the impact of influenza and tuberculosis coinfection on mortality among hospitalized adults with lower respiratory tract infection (LRTI).MethodsWe enrolled patients aged ≥15 years admitted with physician-diagnosed LRTI or suspected tuberculosis at 2 hospitals in South Africa from 2010 to 2016. Combined nasopharyngeal and oropharyngeal swabs were tested for influenza and 8 other respiratory viruses. Tuberculosis testing of sputum included smear microscopy, culture, and/or Xpert MTB/Rif.ResultsAmong 6228 enrolled individuals, 4253 (68%) were tested for both influenza and tuberculosis. Of these, the detection rate was 6% (239/4253) for influenza, 26% (1092/4253) for tuberculosis, and 77% (3113/4053) for HIV. One percent (42/4253) tested positive for both influenza and tuberculosis. On multivariable analysis, among tuberculosis-positive patients, factors independently associated with death were age group ≥65 years compared with 15–24 years (adjusted odds ratio [aOR], 3.6; 95% confidence interval [CI], 1.2–11.0) and influenza coinfection (aOR, 2.3; 95% CI, 1.02–5.2). Among influenza-positive patients, laboratory-confirmed tuberculosis was associated with an increased risk of death (aOR, 4.5; 95% CI, 1.5–13.3). Coinfection with other respiratory viruses was not associated with increased mortality in patients positive for tuberculosis (OR, 0.7; 95% CI, 0.4–1.1) or influenza (OR, 1.6; 95% CI, 0.4–5.6).ConclusionsTuberculosis coinfection is associated with increased mortality in individuals with influenza, and influenza coinfection is associated with increased mortality in individuals with tuberculosis. These data may inform prioritization of influenza vaccines or antivirals for tuberculosis patients and inform tuberculosis testing guidelines for patients with influenza.

Highlights

Data on the prevalence and impact of influenza–tuberculosis coinfection on clinical outcomes from high–human immunodeficiency virus (HIV) and –tuberculosis burden settings are limited
Among tuberculosis-positive patients, factors independently associated with death were age group ≥65 years compared with 15–24 years and influenza coinfection
Coinfection with other respiratory viruses was not associated with increased mortality in patients positive for tuberculosis (OR, 0.7; 95% confidence interval (CI), 0.4–1.1) or influenza (OR, 1.6; 95% CI, 0.4–5.6)

Summary

Methods

We enrolled patients aged ≥15 years admitted with physician-diagnosed LRTI or suspected tuberculosis at 2 hospitals in South Africa from 2010 to 2016. Combined nasopharyngeal and oropharyngeal swabs were tested for influenza and 8 other respiratory viruses. Tuberculosis testing of sputum included smear microscopy, culture, and/or Xpert MTB/Rif. We conducted prospective hospital-based sentinel surveillance for severe respiratory illness (SRI) at 2 hospitals in 2 provinces, Edendale Hospital in the KwaZulu-Natal Province and Tshepong Hospital in the North West Province, from June 2010 through May 2016. A case of SRI was defined as admission with physician-diagnosed lower respiratory tract infection (LRTI), including suspected tuberculosis of any duration. Patients aged ≥15 years from the hospital catchment area were included in our analysis

Results

Discussion

Conclusion