Respiratory Pathogen Distribution During and After the COVID-19 Pandemic

May 20, 2026 updated by: Bekir Sami Uyanık, Hisar Intercontinental Hospital

Comparative Analysis of Respiratory Pathogens During and After the SARS-CoV-2 Pandemic: A Retrospective Multiplex PCR-Based Study

This retrospective observational study aims to evaluate changes in the prevalence and distribution of respiratory pathogens detected by multiplex respiratory polymerase chain reaction (PCR) testing during and after the SARS-CoV-2 pandemic. The study includes 537 patients presenting with respiratory infection symptoms at a tertiary care center. Patients were divided into pandemic-period and post-pandemic-period groups, and respiratory pathogen profiles were compared between the groups.

The study investigates the epidemiological impact of COVID-19-related public health measures on respiratory pathogen circulation patterns, including bacterial and viral respiratory infections. The findings may contribute to improved respiratory infection surveillance, diagnostic strategies, and post-pandemic public health preparedness.

Study Overview

Status

Completed

Conditions

Detailed Description

The COVID-19 pandemic significantly altered the epidemiology of respiratory infections worldwide. Non-pharmaceutical interventions (NPIs), including mask use, social distancing, travel restrictions, enhanced hygiene measures, and lockdown policies, were implemented primarily to reduce SARS-CoV-2 transmission. However, these interventions also affected the circulation patterns of other respiratory pathogens.

Several studies have demonstrated substantial reductions in influenza, respiratory syncytial virus (RSV), and other respiratory viral infections during periods of strict public health measures. Following the relaxation of these interventions, many regions experienced re-emergence and altered seasonal patterns of respiratory pathogens. Continuous surveillance of respiratory infections has therefore become increasingly important for both clinical management and public health preparedness.

This retrospective observational cohort study aims to evaluate changes in respiratory pathogen prevalence during and after the SARS-CoV-2 pandemic using multiplex respiratory PCR testing data obtained from patients presenting with respiratory infection symptoms at a tertiary care center. A total of 537 patients were included and categorized into pandemic-period and post-pandemic-period groups.

Demographic characteristics and multiplex PCR results were analyzed and compared between the groups. Respiratory pathogens evaluated in the study included bacterial and viral agents such as Streptococcus pneumoniae, Haemophilus influenzae, Influenza A/B, SARS-CoV-2, RSV, Rhinovirus, Bocavirus, Parainfluenza virus, Coronavirus, and Metapneumovirus.

The study aims to contribute to understanding the long-term epidemiological effects of the COVID-19 pandemic and associated public health measures on respiratory pathogen distribution. In addition, the findings may support future infection surveillance strategies, diagnostic approaches, and healthcare preparedness in post-pandemic periods.

Study Type

Observational

Enrollment (Actual)

537

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Turkey (Türkiye)
      • Istanbul, Turkey (Türkiye), 34768
        • Hisar Intercontinental Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

The study population consisted of patients presenting with respiratory infection symptoms who underwent multiplex respiratory polymerase chain reaction (PCR) testing at a tertiary care center during the pandemic and post-pandemic periods. Patients with complete demographic and laboratory data were included in the analysis.

Description

Inclusion Criteria:

  • Adults and/or pediatric patients presenting with respiratory infection symptoms
  • Patients who underwent multiplex respiratory PCR testing
  • Patients with complete demographic and laboratory records
  • Patients included during the defined pandemic or post-pandemic study periods

Exclusion Criteria:

  • Incomplete laboratory or demographic data
  • Duplicate test records from the same infection episode
  • Invalid or inconclusive PCR results
  • Patients without respiratory infection symptoms

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Pandemic Period Group
Patients presenting with respiratory infection symptoms who underwent multiplex respiratory PCR testing during the SARS-CoV-2 pandemic period.
Post-Pandemic Period Group
Patients presenting with respiratory infection symptoms who underwent multiplex respiratory PCR testing during the post-pandemic normalization period.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in the prevalence of respiratory pathogens between the pandemic and post-pandemic periods
Time Frame: Retrospectively assessed at the time of respiratory PCR testing during the study periods. Pandemic period: March 2020 - May 2023 Post-pandemic period: June 2023 - December 202
The primary outcome is the difference in detection rates of respiratory pathogens identified by multiplex respiratory PCR testing between the SARS-CoV-2 pandemic period and the post-pandemic period.
Retrospectively assessed at the time of respiratory PCR testing during the study periods. Pandemic period: March 2020 - May 2023 Post-pandemic period: June 2023 - December 202

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Hisar Intercontinental Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 1, 2021

Primary Completion (Actual)

December 30, 2024

Study Completion (Actual)

December 30, 2024

Study Registration Dates

First Submitted

May 13, 2026

First Submitted That Met QC Criteria

May 20, 2026

First Posted (Actual)

May 22, 2026

Study Record Updates

Last Update Posted (Actual)

May 22, 2026

Last Update Submitted That Met QC Criteria

May 20, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • HHI-RP-PCR-2026-001

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data (IPD) will not be shared because this retrospective study contains hospital-based patient data, and sharing such data may compromise patient confidentiality and institutional data protection policies.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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