Respiratory infections

SPEAKER: In this step, we will show you how antibiotics are overused for respiratory infections. We will also bring you an update in the laboratory diagnosis of respiratory infections.

Fever and respiratory infections are amongst the most common reasons why people seek care. Most respiratory infections are caused by viruses for which antibiotics are not effective. Therefore, presumptive treatment of respiratory infections with broad spectrum antibiotics has contributed to the emergence of antibiotic resistance. In the US, approximately 40 million people are given antibiotics each year for respiratory issues. A study by Shapiro et al. found that of those 40 million only 13 million really needed antibiotics to treat their bacterial infections. Therefore, simple rapid diagnostic tests that can be used to distinguish between bacteria and viral infections would be very useful to guide the appropriate use of antibiotics.

There are three types of tests that can be used for the laboratory diagnosis of respiratory infections. Increasingly, there are more molecular panel type tests that can be used to detect the DNA or RNA of pathogens most commonly associated with respiratory infections. These panels can include viruses such as adenovirus, human metapneumovirus, human rhinovirues or enteroviruses, influenza A or B, para influenza types one to four, respiratory syncytial virus, and bacterial pathogens such as Bordetella pertussis and Bordetella parapertussis, chlamydia, pneumoniae, and mycoplasma pneumoniae. Some essays have been adapted now for the diagnosis of SARS coronavirus 2, the cause of COVID. The time to result for these assays is anywhere from 36 minutes to four hours.

There are also many rapid antigen tests that have been developed to detect viral proteins for the diagnosis of COVID and flu. These can give results within 15 minutes. There are also rapid tests for host biomarkers, such as the c-reactive protein and procalcitonin. These assays can be used to distinguish routine bacterial and viral infections. These are increasingly used as a rapid triage in emergency units to know whether to prescribe antibiotics or not.