High prevalence nasal carriage of methicillin-resistant Staphylococcus aureus among long term care facility healthcare workers in relation to patient contact

Hsin-I Shih; Chia-Ming Chang; Fan-Ching Shen; Yun-Ju Lee; Chiu Hui Wu; Hsiang-Chin Hsu; Chia-Yu Chi

doi:10.1016/j.infpip.2021.100117

High prevalence nasal carriage of methicillin-resistant Staphylococcus aureus among long term care facility healthcare workers in relation to patient contact

Infect Prev Pract. 2021 Jan 17;3(1):100117. doi: 10.1016/j.infpip.2021.100117. eCollection 2021 Mar.

Authors

Hsin-I Shih^{1

2

3}, Chia-Ming Chang^{4

5}, Fan-Ching Shen⁶, Yun-Ju Lee⁶, Chiu Hui Wu⁷, Hsiang-Chin Hsu^{1

2}, Chia-Yu Chi^{6

8

9}

Affiliations

¹ Department of Emergency Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
² School of Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
³ Department of Public Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
⁴ Division of Geriatrics, Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
⁵ Division of Geriatrics, Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan.
⁶ National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Tainan, Taiwan.
⁷ Department of Nursing, National Cheng Kung University Hospital, Taiwan.
⁸ Department of Paediatrics, National Cheng Kung University Hospital, Tainan, Taiwan.
⁹ The Doctoral Degree Program in Environmental and Occupational Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.

Abstract

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a major public health concern worldwide. Healthcare workers (HCWs) are an important source of transmission of MRSA. We conducted a prospective study to define the frequency of S. aureus nasal colonization with emphasis on the carriage of MRSA in HCWs in relation to the intensity of patient contact.

Methods: Out-of-hospital care emergency medical technicians and students, and HCWs in the emergency department, intensive care unit and a long-term care facility (LTCF) were enrolled to compare the prevalence of MRSA and methicillin-susceptible S. aureus (MSSA) nasal colonization. The MRSA isolates were further identified by their microbiological and molecular characteristics.

Findings: S. aureus was isolated from 63 of 248 HCWs (25.4%). The overall MRSA nasal carriage rate was 15/248, 6%, and the prevalence was higher in the HCWs who had worked for 5-10 years (12.8%), and among female HCWs (10.3%) than male HCWs (0.9%). LTCFs had the highest prevalence (12%). In contrast, the overall carriage of MSSA was 48/248, 19.4%, and most carriers worked for ≥5 years (52.1%). Hospital nurses had the highest rate of MSSA carriage (21.4%). Most of the MRSA isolates were SCCmec IV/ST59 or ST45 (60%), and were resistant to erythromycin and clindamycin (53%).

Conclusions: Hospital nurses have highest S. aureus nasal carriage, whereas HCWs in the LTCFs comprise a significant reservoir of MRSA colonization. The differences in the characteristics of MRSA and MSSA nasal carriage among HCWs highlights the importance on long-term nasal screening of S. aureus in healthcare facilities.

Keywords: CA-MRSA, community-associated Methicillin-resistant Staphylococcus aureus; ED, emergency department; EMTs, emergency medical technicians; Emergency medical technician; HA-MRSA, healthcare-associated Methicillin-resistant Staphylococcus aureus; HCWs, Healthcare workers; Healthcare worker; ICU, intensive care unit; LTCF, long-term care facilities; Long term care facilities; MRSA; MRSA, Methicillin-resistant Staphylococcus aureus.