Assessment of the prevalence of respiratory pathogens and the level of immunity to respiratory viruses in soldiers and civilian military employees in Poland.

Background: This study provides a detailed analysis of respiratory tract infections (RTIs) and immunity levels against influenza and SARS-CoV-2 among soldiers and military personnel in Poland. Owing to their unique service environments, this occupational group is at high risk. During deployments, they often face adverse physical conditions, close living quarters, and exposure to both local and endemic pathogens. It particularly increases their susceptibility to RTIs, which remain a leading cause of illness worldwide.

Methods: The study cohort included 379 participants aged between 19 and 60 years. We used polymerase chain reaction (PCR) techniques to detect 34 common respiratory pathogens and analyzed blood serum samples to assess the degree of immunity against the influenza A, B, and SARS-CoV-2 viruses. In 78.10% of the participants, at least one respiratory pathogen was detected.

Results: Human rhinovirus (HRV) was the most common (8.71%), followed by SARS-CoV-2 (4.75%) and influenza A (H1N1) sw (2.90%). Staphylococcus aureus was the most prevalent bacterial pathogen (18.47%), with significant occurrences of Haemophilus influenzae (14.24%) and Klebsiella pneumoniae (9.76%). Additionally, 52.3% of those with coinfections had combinations of bacterial and viral pathogens, highlighting the complexity of diagnosing and managing these infections. We also assessed immunity levels, which focused on antibodies specific to influenza A/B and SARS-CoV-2 viruses. For all the results obtained, statistical analyses were performed. A weak positive correlation between age and levels of anti-influenza antibodies was observed, suggesting a slight increase in antibody levels with age. A total of 81.53% of the participants had received at least one dose of the SARS-CoV-2 vaccine. A significant correlation between the number of vaccine doses and higher anti-SARS-CoV-2 IgG antibodies was observed, indicating stronger immunity with more vaccinations.

Conclusions: This study underscores the importance of specialized health monitoring and preventive measures such as vaccinations to protect military personnel from RTIs and maintain their operational readiness. The detailed analysis of pathogen prevalence and immunity levels offers valuable insights into this occupational group's health risks and needs.

Clinical trial number: Not applicable.