RT Journal Article SR Electronic T1 Seroprevalence of community-acquired atypical bacterial pneumonia among adult COVID-19 patients from a single center in Al Madinah Al Munawarah, Saudi Arabia JF Saudi Medical Journal JO Saudi Med J FD Prince Sultan Military Medical City SP 1000 OP 1006 DO 10.15537/smj.2022.43.9.20220379 VO 43 IS 9 A1 Sari T. Alhoufie A1 Nadir A. Ibrahim A1 Naif H. Alsharif A1 Khalid O. Alfarouk A1 Hatim M. Makhdoom A1 Khaled R. Aljabri A1 Sayed H. Saeed A1 Adnan A. Khoumaeys A1 Yahya A. Almutawif A1 Mustafa A. Najim A1 Hamza M. Ali A1 Alanoud A. Aljifri A1 Ali M. Kheyami A1 Areej A. Alhazmi YR 2022 UL http://smj.org.sa/content/43/9/1000.abstract AB Objectives: To investigate the seroprevalence of the community-acquired bacterial that causes atypical pneumonia among confirmed severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) patients.Methods: In this cohort study, we retrospectively investigated the seroprevalence of Chlamydia pneumoniae, Mycoplasma pneumoniae, and Legionella pneumophila among randomly selected 189 confirmed COVID-19 patients at their time of hospital presentation via commercial immunoglobulin M (IgM) antibodies against these bacteria. We also carried out quantitative measurements of procalcitonin in patients’ serum.Results: The seropositivity for L. pneumophila was 12.6%, with significant distribution among patientsolder than 50 years (χ2 test, p=0.009), while those of M. pneumoniae was 6.3% and C. pneumoniae was 2.1%, indicating an overall co-infection rate of 21% among COVID-19 patients. No significant difference (χ2 test, p=0.628) in the distribution of bacterial co-infections existed between male and female patients. Procalcitonin positivity was confirmed amongst 5% of co-infected patients.Conclusion: Our study documented the seroprevalence of community-acquired bacteria co-infection among COVID-19 patients. In this study, procalcitonin was an inconclusive biomarker for non-severe bacterial co-infections among COVID-19 patients. Consideration and proper detection of community-acquired bacterial co-infection may minimize misdiagnosis during the current pandemic and positively reflect disease management and prognosis.