Influenza co-infection associated with severity and mortality in
COVID-19 patients
Abstract
Background In COVID-19 patients, undetected co-infections may have
severe clinical implications associated with increased hospitalization,
varied treatment approaches and mortality. Therefore, we investigated
the implications of viral and bacterial co-infection on COVID-19
clinical outcomes. Methods Nasopharyngeal samples were obtained from 48
COVID-19 patients (29% ICU and 71% non-ICU) and screened for the
presence of 24 respiratory pathogens using six multiplex PCR panels.
Results We found evidence of co-infection in 34 COVID-19 patients
(71%). Influenza A H1N1 (n=17), Chlamydia pneumoniae (n=13) and human
adenovirus (n=10) were the most commonly detected pathogens. Viral
co-infection was associated with increased ICU admission (r=0.1) and
higher mortality (OR 1.78, CI=0.38-8.28) compared to bacterial
co-infections (OR 0.44, CI=0.08-2.45). Two thirds of COVID-19 critically
ill patients who died, had a co-infection; and Influenza A H1N1 was the
only pathogen for which a direct relationship with mortality was seen
(r=0.2). Amongst comorbidities, co-infection in patients with diabetes
was associated with a significantly higher mortality (p=0.02). We also
found that Troponin T was strongly related (p=0.001) with ICU admission
and could be used as a predictor of COVID-19 severity. Conclusions The
similarity in clinical presentation for both COVID-19 and Influenza
makes it difficult to assess their impact on ICU admission and
mortality. Our study highlights the importance of screening for
co-infecting viruses in COVID-19 patients, given the high prevalence of
Influenza viruses. The detection of co-infections in COVID-19 cases
shows the importance of flu vaccination and warrants its increased
coverage to reduce the hospitalization and associated mortality.