How often does SARS-CoV-2 infect along with other viruses?

The diagnosis of coronavirus disease 2019 (COVID-19) is normally made by either a reverse transcriptase polymerase chain reaction (RT-PCR) test or a lateral flow device test. Many countries provide lateral drainage devices free of charge or subsidize the cost of them.

In addition, tests are required by several governments to travel abroad. However, these data only provide information on infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Researchers at the Universidad de São Francisco have explored data from COVID-19 patients tested in hospitals or clinics who are also looking for evidence of other illnesses. The presence of these diseases could make a big difference in some prognosis. Their work is published in the journal Diagnostic microbiology and infectious diseases.

To study: Frequency of respiratory pathogens other than SARS-CoV-2 detected in COVID-19 tests. Image Credit: Magic Images / Shutterstock.com

About the study

The researchers obtained data from a shared COVID-19 database created by the Sao Paulo Research Foundation, which allows information to be shared between five health services in Sao Paulo. They grouped people together by sex and age group.

SARS-CoV-2 infection was confirmed by RT-PCR, while several other infections were also detected at the same time, including influenza A viruses (-H1N1 and other subtypes), the virus influenza B, human respiratory syncytial virus (HRSV), human Parainfluenza virus. Virus type I (HPIV-1), II (HPIV-2), III (HPIV-3), IV (HPIV-4), rhinovirus / enterovirus (RV / EV), adenovirus (ADV), human metapneumovirus (hMPV) , Human Coronavirus (HCoV) -229E, HCoV-HKU1, HCoV-NL63 and HCoV-OC43.

The researchers also looked for four bacterial species and tried to detect yeast in the urine. Using Pearson’s chi-square test or Fisher’s exact test, researchers assessed differences in the proportions of respiratory infections between different groups, while associations between variables were analyzed using ‘an odds ratio.

In total, the researchers gathered data from 73,897 people, of whom around 17,000 tested positive for SARS-CoV-2. In addition, 8.44% of people were tested for at least one other microorganism.

The individuals were between 25 and 61 years old and were split roughly equally between men and women. There were 850 tests performed for Influenza A virus, 728 for Influenza B virus, 780 for Influenza A-H1N1 virus, 778 for M. pneumoniae, 775 for HSRV, 3,768 for C. pneumoniae, 767 for RV / EV, 766 for ADVs, B. pertussis, HCoV-229E, HCoV-HKU1, HCoV-NL63, HCoV-OC43, HPIV-1, -2, -3, -4 and hMPV, 304 for yeasts in urine and 935 for S. pyogenes.

The most frequently detected viral group, which was observed in 594 individuals, was RV / EV. Influenza B has been observed in 199 people, while influenza A-H1N1 and other influenza A subtypes have been detected in 115 and 105 people, respectively.

For bacteria, the most commonly identified species was S. pyogenes, which was observed in 121 people, 8 of whom were also positive for COVID-19. C. pneumoniae has been observed in 20 people, all negative for COVID-19.

M. pneumoniae was seen in 10 people, two of whom were positive for COVID-19. B. whooping cough was positive in four people, one of whom had COVID-19. Only 17 individuals had the presence of yeast in their urine; however, this has been linked to testing positive for COVID-19.

Typically, most people who tested negative for COVID-19 tested positive for a different microorganism, the vast majority of which were between 25 and 60 years old. However, it was also by far the largest age group.

A total of 150 cases of detection of another microorganism, alongside COVID-19, have been connected. One of them tested positive for a total of 16 microorganisms, although the researchers recommend caution about this finding and suggest it could be a database error.

These cases are too varied to be considered individually; however, most people who tested positive for another respiratory virus tested negative for SARS-CoV-2, and nine viruses were associated with a lower risk of contracting the disease. Scientists have suggested that this could be due to immune activation or competition between viruses for cell receptors.

More than 1,300 cases of COVID-19, as well as another virus, have been detected, RV / EV being the most common. Researchers show that yeast in urine is associated with a positive test for COVID-19, which could be due to immune dysfunction caused by the disease that allows fungal infections to grow more easily.

Conclusion

The researchers stress that their results are currently exploratory; however, this information could prove to be extremely useful upon further investigation. It could be invaluable for healthcare providers to know what other respiratory viruses and bacterial infections are likely to be dangerous for patients with COVID-19 and therefore could help optimize the treatment of such patients.