The oral cavity revealed as a significant reservoir of Staphylococcus aureus in an acute hospital by extensive patient, healthcare worker and environmental sampling

https://doi.org/10.1016/j.jhin.2020.03.004Get rights and content
Under a Creative Commons license
open access

SUMMARY

Background

methicillin-susceptible Staphylococcus aureus (MSSA) bloodstream infection rates have risen steadily in recent years, with a marked decline in the corresponding rates due to methicillin-resistant S. aureus (MRSA). Screening for MSSA carriage is not routinely undertaken and MRSA screening is not universal, thus the extent of S. aureus colonization pressure in nosocomial settings is unknown.

Methods

We conducted a prospective, observational study of patients and healthcare workers (HCWs) across nine inpatient wards in a tertiary referral hospital over a two-year period. Participants were screened for MSSA and MRSA using nasal swabs and oral rinses. Environmental surfaces and air were also tested for S. aureus using contact plates and active air sampling.

Findings

We enrolled 388 patients and 326 HCWs; and took 758 contact plate samples from surfaces and 428 air samples. MSSA was recovered from 24% of patients, 31.3% of HCWs, 16% of air samples and 7.9% of surface samples. MRSA was recovered from 6.4% of patients, 3.7% of HCWs, 2.5% of air samples and 2.2% of surface samples. Inclusion of the oral cavity in addition to the anterior nares in the sampling regimen identified 30 patients and 36 HCWs who exhibited exclusive oral colonization.

Conclusions

The oral cavity comprises a significant nosocomial reservoir for S. aureus that is currently under-appreciated. Oral screening should be considered both in terms of the colonization pressure in a healthcare facility, and on an individual patient level, especially in patients where decolonization attempts have repeatedly failed and in those undergoing high-risk procedures.

Keywords

Staphylococcus aureus
MRSA
MSSA
Oral colonization
Nasal colonization

Cited by (0)