ARTICLE | doi:10.20944/preprints202207.0149.v1
Subject: Medicine & Pharmacology, Pathology & Pathobiology Keywords: clinical S.aureus; skin carriage; geriatric-MRSA pneumonia; endogenous-S.aureus
Online: 11 July 2022 (04:33:22 CEST)
The changing epidemiology of Staphylococcus aureus has created several gaps in its population structure and emergence of strains. Two global shifts in the aftermath of the past methicil-lin-resistant S. aureus (MRSA) pandemic are: a rise in healthcare-associated infections and evolu-tion of cutaneous and soft tissue infections with high morbidities and mortalities. Furthermore, bitter lessons from COVID-19 showed S. aureus necrotizing-pneumonia and skin conditions ag-gravating Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) and Monkeypox manifestations. Limited data and paucity of high-quality evidence exist for many key clinical questions. Using clinical microbiology, molecular characterization, hospital data on age and in-fection sites, and antibiograms, we have investigated S. aureus infection patterns. We showed that age-specific distribution in both intensive care unit (ICU) and non-ICU revealed highest infection rates (94.7%) in senior-patients >50 years; most were MRSA (81.99%). However, specific distribu-tions of geriatric MRSA and MSSA rates were 46.5% and 4.6% in ICU and 35.48% and 8.065% in non-ICU, respectively. Intriguingly, age groups 0-20 years showed uniquely similar MRSA pat-terns in ICU and non-ICU patients (13.9%, 9.7%, respectively) and MSSA in ICU (11.6%). In age groups 20-50 years, MRSA were 2-fold in non-ICU (35%) than ICU (18.6%). Interestingly, highly significant association was found between infection-site and age-groups (P-value .000). Skin in-fections remained higher in all ages; pediatrics 32.14%, adults 56%, and seniors 25% while res-piratory infections were lower in pediatrics (14.3%) and adult 17%), and highest in seniors (38%). Blood and “other” sites in pediatrics recorded (28.6%; 25%, respectively), slightly lower in adults (18.6%; 8.6%) and seniors (14%); 22.8%), respectively. Further, significant association existed between infection-site and MRSA (Chi-Square Test, P-value .002). The common cutaneous infec-tions across all age-groups and the significant association of MRSA to geriatric-respiratory infec-tions have a high potential for skin-carriage as reservoir for endogenous infection. The similar frequencies of both lineages in youth in all settings imply MSSA-carriage as potential evolutionary origins for MRSA. These findings have important clinical implications for strategic planning in patient management and S. aureus control particularly in age-specific infections and vigilance for potential viral coinfections.