Objective: Parainfluenza virus (PIV) is one of the major causes of upper and lower respiratory tract diseases in children and adults. The four serotypes of the parainfluenza virus that cause infection are; PIV-1, PIV-2, PIV-3 and PIV-4. In this retrospective study, it was aimed to investigate the distribution of PIV infections according to serotypes and seasons in patients followed for respiratory tract infection.

Methods: PIV agent was studied by multiplex polymerase chain reaction (m-PCR) method in nasopharyngeal swab samples of patients who were followed up with symptoms of respiratory tract infection between September 1, 2020 and August 31, 2023 at Necmettin Erbakan University Medical Faculty Hospital.

Results: As a result of the study, any of the PIV types was detected in 434 (6.7%) of 6509 nasopharyngeal swab samples. PIV-3 was the most common agent in the distribution of subtypes with 199 (45.9%). This is followed by PIV-4 with 99 (22.6%), PIV-1 with 90 (20.7%) and PIV-2 with 47 (10.8%). It appears that the frequency of PIV-1 increases in the fall, PIV-2 and PIV-4 in the winter and spring, and PIV-3 in the summer.

Conclusion: Detection of PIV infections, which can cause seasonal epidemics, by m-PCR method will guide clinicians about the treatment and prevention process of these viral infections. Although PIV infection is seen throughout the year in our region, it has been observed that its frequency increases in the autumn months. In our study, PIV-3 was the most common PIV serotype in nasopharyngeal swab specimens that were positivated by m-PCR method.