As of 19^th April 2020, COVID-19 (Coronavirus Disease 2019) or SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) has 23,29,651 reported cases globally. Out of these 23,29,651 cases, 1,60,721 patients have died while 5,95,433 have recovered. In the absence of a preventative vaccine and a proper treatment protocol, this virus is being actively monitored for mutations and coinfections with other respiratory pathogens.

Based on initial reports from Wuhan, China, SARS-CoV-2 has low rates of coinfections with other respiratory pathogens. Epidemiologists however note how that couldn’t be true as patients infected with other pathogens are also getting infected with SARS-CoV-2. To test this further, the Centers for Disease Control and Prevention (CDC) included testing for other respiratory pathogens in their list of recommendations. In the absence of expansive rapid testing, evidence of other infections could help with evaluating patients who are susceptible to COVID-19. This CDC report shows the co-infection rates between SARS-CoV-2 and other respiratory pathogens in just Northern California.

This approach to testing gathered steam from 3^rd March 2020 and continued all the way up to 25^th March 2020. Real-time Reverse Transcriptase–Polymerase Chain Reaction tests for SARS-CoV-2 and other respiratory pathogens on nasopharyngeal swabs of symptomatic patients who presented with a cough, fever, and dyspnea were analyzed. Multiple specimens from multiple cites were processed simultaneously. Patients afflicted with non–SARS-CoV-2 respiratory pathogens such as influenza A/B, respiratory syncytial virus, non–SARS-CoV-2 Coronaviridae, adenovirus, parainfluenza 1-4, human metapneumovirus, rhinovirus/enterovirus, Chlamydia pneumoniae, and Mycoplasma pneumoniae were also tested at selected sites.

Each sample that tested positive for the SARS-CoV-2 virus was stratified by each non–SARS-CoV-2 pathogen infection status. Using χ tests with continuity correction (significance threshold, P < .05), the differences in proportions of SARS-CoV-2 pathogens and non-SARS-CoV-2 pathogens were assessed. Using 2-sided t tests, the mean ages of all patients in all the subgroups were compared. Then the data was analyzed in R version 3.6.0 (R Foundation for Statistical Computing). The main aim of this metanalysis was to come up with a better diagnostic test.

Out of the 1217 specimens tested for SARS-CoV-2 and other respiratory pathogens, from 1206 unique patients; 116 of the 1217 specimens (9.5%) tested positive for SARS-CoV-2 and 318 (26.1%) tested positive for 1 or more non–SARS-CoV-2 pathogens. 

116 specimens that tested positive for SARS-CoV-2, 24 (20.7%) were found to be positive for 1 or more additional non-SARS-CoV-2 pathogens, compared with 294 of the 1101 specimens (26.7%) that tested negative for SARS-CoV-2. That’s a difference of 6.0% (95% CI, –2.3% to 14.3%).

Out of the non-SARS-CoV-2 pathogens, rhinovirus/enterovirus (6.9%), respiratory syncytial virus (5.2%), and non–SARS-CoV-2 Coronaviridae (4.3%) showed up repeatedly.

As you can see, data showed how the difference in rates of non–SARS-CoV-2 pathogens and positive/negative SARS-CoV-2 pathogens were statistically significant at P < 0.05.

There were 318 specimens which tested positive for 1 or more non–SARS-CoV-2 pathogens. Out of these 318 samples, 24 (7.5%) tested positive for SARS-CoV-2.

There were 899 specimens which tested negative for other pathogens. Out of these 899 samples, 92 (10.2%) tested positive for SARS-CoV-2. That’s a difference of 2.7% (95% CI, –1.0% to 6.4%).

As far the demographics go, patients infected with co-infections had a mean age of 46.9 years while patients infected with SARS-CoV-2 had a mean age of 51.1 years. That’s a 4.2 years difference (95% CI, –4.8 to 13.2).

You can distinctly see how those infected with other respiratory pathogens are more susceptible to being co-infected by SARS-CoV-2. Also, the presence of a non–SARS-CoV-2 pathogen is not going to safeguard a patient from a SARS-CoV-2 infection.

The study was conducted in one region of a few country. Apparently, the SARS-CoV-2 virus is mutating in certain regions. This makes the spatiotemporal variation in viral epidemiology of the virus and any specific co-infection patterns region specific.

We can however conclude that routine testing for non–SARS-CoV-2 respiratory pathogens during the ongoing COVID-19 pandemic will provide clinical benefits moving forward.