Seasonal incidence of respiratory viral infections in Telangana, India: utility of a multiplex PCR assay to bridge the knowledge gap

Abstract

Objective: The diagnosis of acute viral respiratory tract infections (RTI) is a challenge due to overlapping clinical presentations and lack of availability of robust diagnostic methods. This in turn leads to lack of data regarding incidence and seasonality of viral RTIs which could potentially help to implement efficient strategies of antimicrobial stewardship as well as vaccine administration. Here we utilise a commercial Multiplex PCR assay for the early diagnosis of acute respiratory tract infections and discuss their epidemiology. Methods: A prospective, observational study was conducted over a period of 3 years (2017–2019). Respiratory samples received from outpatients and inpatients with suspected acute RTIs from three multispeciality hospitals located in the twin cities of Hyderabad-Secunderabad were subjected to FilmArray Respiratory Panel (RP) (BioFire Diagnostics, Salt Lake City, Utah, USA). Results were tabulated and statistically analysed. Results: Of 513 samples, 261 (50.9%) were positive for one or more pathogens. The viruses detected included influenza A H1 2009 (26.0%), human rhinovirus/enterovirus (21.5%), influenza A H3N2 (17.0%), human metapneumovirus (9.4%), influenza B (6.6%), coronavirus (4.9%), parainfluenza virus (4.5%), respiratory syncytial virus (3.1%) and adenovirus (2.1%). The largest number of samples was positive during the monsoon season (43.8%). Influenza A H1 2009 peaked in the monsoon season with another, smaller peak in February. Conclusions: There is a bimodal peak of respiratory infections relative to the seasons, and vaccine administration should take place in April–May before the advent of the monsoons in this part of the country. Multiplexed PCR may be used as first line for diagnosis of viral infections so that infection control measures can be prioritised and antibiotic administration can be avoided in those who do not require it.