No 42/43 - 2022

Methicillin-resistant Staphylococcus aureus (MRSA) 2021

2021 recorded a total of 2,714 new MRSA cases, Figure 1, which was a 6% reduction compared with 2020 (2,883), EPI-NEWS no. 25-26/2021. The continued COVID-19-induced travel restrictions, limitations on social contacts and reduced number of healthcare contacts produced a decline for the second year running.

For a detailed epidemiological description of the 2021 incidence, please see the 2021 annual MRSA report.

In 2021, a total of 30 outbreaks were registered at hospitals, nursing homes and other institutions, comprising a total of 109 MRSA cases. Five of the outbreaks occurred in neonatal departments, comprising a total of 42 cases. Additionally, seven outbreaks occurred at other hospital departments (a total of 16 patients), and 13 outbreaks were recorded in nursing homes or associated with home care (30 cases).

The number of livestock MRSA CC398 cases comprised 35% (n = 959) of the total number of cases, which is in line with the shares recorded in the three preceding years. 2021 saw 101 persons with no livestock contact who became infected with livestock MRSA CC398 (95 persons in 2020 and 86 persons in 2019). This is a small increase, but spreading of livestock MRSA CC398 in the general population does not seem to follow an increasing trend despite the fact that more persons with livestock contact have tested positive over the years.

In 2021, a total of six cases of bacteraemia with livestock MRSA CC398 were observed. Two patients died in the 30 days following their sampling date. A total of 558 patients died due to Staphylococcus aureus bacteraemia primarily caused by methicillin-sensitive S. aureus.

In 254 (9%) cases, MRSA had been acquired abroad, which is considerably lower than before COVID-19 and the ensuing travel restrictions.

Furthermore, a minor decline was seen in community-acquired MRSA compared with 2020, which may also be explained by reference to restrictions on personal contact.

(A. Petersen, A.R. Larsen, Bacteria, Fungi and Parasites, T. Urth, Department of Infectious Disease Epidemiology and Prevention)
26 October 2022