Temporal patterns of respiratory pathogen detection in southern Türkiye: a retrospective multiplex PCR study with pre- and post-earthquake comparisons

Abstract

Respiratory pathogen epidemiology in southern Türkiye was evaluated during a period marked by post-pandemic changes and earthquake-related population movement. This study assessed temporal trends and pathogen distribution among patients tested using a multiplex respiratory panel from 2021 to 2024. This retrospective cross-sectional study included patients with suspected acute respiratory tract infection who underwent multiplex real-time PCR after testing negative for SARS-CoV-2. Positivity was compared using chi-square or Fisher’s exact tests. Multivariable logistic regression models included age group, sex, season, clinical setting, year of sampling, and PCR platform. Separate sensitivity models adjusted for age group, sex, season, and clinical setting evaluated pre- and post-earthquake differences using the entire dataset, restricting the post-earthquake period to the first 12 months, and restricting analyses to samples tested only with the Bio-Speedy platform. Among 3,586 patients, 62.4% were children and 52.6% had at least one pathogen detected. The most frequently detected pathogens were S. pneumoniae (36.7%), H. influenzae (8.2%), rhinovirus (6.1%), human bocavirus (2.8%), and influenza A (2.8%). Positivity was higher in children than in adults (64.5% vs. 33.0%; p < 0.001) and peaked in autumn and winter. Overall positivity declined from 57.5% in 2021 to 34.8% in 2023 and increased to 60.7% in 2024. Although overall positivity was similar before and after the earthquakes (52.5% vs. 52.7%), unadjusted comparisons showed an increase in bacterial positivity from 34.2% to 44.9% and a decrease in viral positivity from 31.2% to 19.8%. Compared with 2021, the adjusted odds of bacterial detection were higher in 2024 (aOR, 5.50; 95% CI, 3.51–8.63). The increases in bacterial and S. pneumoniae detection observed across the entire post-earthquake period were not reproduced during the first 12 months after the earthquakes or when analyses were restricted to the Bio-Speedy platform. Respiratory pathogen detection showed substantial temporal variation. Differences between the pre- and post-earthquake periods varied according to the time window and analytic subset examined and do not support attributing these differences specifically to the earthquakes. Multiplex PCR-based surveillance may be valuable for monitoring respiratory pathogen dynamics during periods of epidemiological disruption.