Identification of MRSA in the Pre-Admission Clinic
in Patients Scheduled for Lower Limb Arthroplasty
Hunain Aslam1, Werdah Zafar2, Mahad Amjad1*, Muhammad Umer Ahmed1 and Mustafa Pervez2
1Ziauddin University Ziauddin Medical College Karachi, Pakistan
2MS Trainee Orthopedics Ziauddin University Hospital Karachi, Pakistan
Submission: June 27, 2019;Published: July 30, 2019
*Corresponding author: Mahad Amjad, Ziauddin University Ziauddin Medical College Karachi, Pakistan House No F-8,1/6, Tipu Sultan Road KDA scheme, Pakistan
How to cite this article: Hunain Aslam, Werdah Zafar, Mahad Amjad, Muhammad Umer Ahmed, Mustafa Pervez. Identification of MRSA in the Pre-
002 Admission Clinic in Patients Scheduled for Lower Limb Arthroplasty. JOJ Orthoped Ortho Surg. 2018; 2(3): 555586. DOI: 10.19080/JOJOOS.2019.02.555586
Since the introduction of superior surgical techniques for lower limb arthroplasty including total knee replacement (TKR) and total hip replacement (THR) surgeries, many patients have benefitted from the advanced surgical techniques of Prosthetic Joint Replacement. However, with the increase in number of surgeries performed there is an increasing risk of arthroplasty revision  due to Peri-Prosthesis Joint Infection (PJI) and surgical site infection (SSI).
SSI are one of the most common causes of nosocomial infection and complicate up to 10% operations . Among the pathogens coagulase negative staphylococcus is most prevalent organism which causes SSI in orthopedic surgeries . Staphylococcus Aureus (SA) is the most commonly cultured bacteria from SSI  and preoperative nasal colonisation of SA is one of the most common risk factors for SSI [5,6]. Out of all the people presenting for elective surgery approximately 28% have SA colonisation and out of which 1.8% have methicillin resistant Staphylococcus Aureus (MRSA) .
Over the past decade there has been an increase in MRSA, a subpopulation of the bacterium with unique resistance and virulence characteristics. Furthermore, there is an economic burden related to SSI following orthopedic surgery, with MRSA-associated SSI leading to longer Hospital stays and increased hospital costs. However, some controversy does exist about the effectiveness of screening and eradication programme before surgical admission in order to reduce the risk of SSI .
The aim of this study was to identify the MRSA-colonized patients in the pre-admission clinic, followed by their treatment and follow up these patients for superficial and deep post-operative infection with MRSA.
We included the cohort of patients assessed in pre-assessment clinic awaiting lower limb arthroplasty from January
2010 to December 2012. Data collected included resident status, age, gender, and the results of nasal swab for MRSA and treatment carried out. The subset of patients with initial positive MRSA swabs were treated using standard protocols and were subsequently followed up for any superficial and deep infection in the post-operative period. The protocol used for treatment, followed the national infection guidelines and consisted of Bactroban nasal ointment three times a day for five days. Three negative swabs were necessary before declaring the patient MRSA free. The Patients with positive nasal swabs were stratified and were followed over time post operatively to look for post of MRSA wound infection.
A Cohort of 396 patients were screened for MRSA of
which 271 patients were total hip and 125 were for total knee
arthroplasty. 8 patients were detected to have positive nasal
swab MRSA at the time of their assessment in the preadmission
clinic. None of the patients developed SSI with MRSA. All the
patient presented to us were from home (Figures 1 & 2).
Methicillin was licensed in England in the treatment of
penicillin-resistant S. aureus infections in 1959. Just as bacterial
evolution allowed microbes to develop resistance to penicillin,
strains of S. aureus evolved to become resistant to methicillin.
The first MRSA isolates were reported in 1961 in a British study
followed by similar detections in western Europe and Australia
between 1961 to 1967 . MRSA, possesses the mecA gene
and the penicillin bindingprotein PBP2a, making it resistant to
methicillin and oxacillin. 
Our study data shows consistent result with approximately
2% patient having MRSA colonisation. At any given point SA
colonizes 25-30% population  and carriers are at higher risk
of infection after invasive surgical procedure. Most commonly
colonized sites are Anterior nasal nares however other sites
that can be colonized are rectum, throat, groin and axillae. In
orthopedic patients the anterior nares are frequently colonized
and approximately 25-30% with methicillin sensitive S. Aureus
(MSSA) [9,10] and 2-6% with MRSA . There’s is a fourfold
increase in risk of SSI in patients with MRSA positive colonisation
compared to MSSA . MRSA colonisation is more common
in certain population such as elderly, immunocompromised,
patient on dialysis and patients who are frequently hospitalized.
According to a study male population is at increased risk of
colonisation and among all the ethnicities, Caucasian males were
at the highest risk . Male Patients with BMI > 30 and history
of asthma have also been associated with increased risk of both
MRSA and MSSA colonisation .
Orthopedic surgeries are advancing every day with
increasing number or procedures done, it is estimated that
annually 436,736 THR, 680,839 TKR and 413,171 spinal fusion
procedures are performed . With an increase in surgeries
performed the risk of revision surgeries due to PJI and SSI also
increasing. It is estimated that orthopedic surgery SSI account
for 38,000 complications, out of which 0.7%-4.1% due to
spinal fusion infection rate, 0.67%-2.4% from Hip replacement
infection rate and 0.68%-1.6% from knee replacement infection
rate . With such a high number of orthopedic SSI that not only
increases morbidity and mortality but also increases the length
of hospital stay and cost. MRSA has become the primary cause
of health care–associated infections throughout Europe, Asia,
Australia, and The United States. Incidentally Ireland has one of
the highest nosocomial MRSA colonisation rates in the European
Community . With such a high number of orthopedic SSI,primary focus should be on to prevent the number of infections
rather than to treat it by revision surgeries. As revision surgeries
are done in 2 stages, first by removing the implant and second
surgery to re implant the prosthesis, this not only increases the
cost but also increases patient morbidity and mortality
Prevention of SSI by screening for nasal MRSA colonisation
pre-operatively and treating it significantly reduces the rate of
SSI in orthopedic patients. Pre-operative screening is not only
cost effective but overall reduces the rate of re hospitalization
and increase patient morbidity and mortality. Since 1999, Ireland
has participated in the European Antimicrobial Resistance
Surveillance System (EARSS), which shows that MRSA levels vary
throughout Europe. A significant contribution was made by the
Strategy for the Control of Antimicrobial Resistance in Ireland
(SARI), to stabilize the increase in MRSA cases, an initiative
focusing on surveillance of antimicrobial resistance . The
chief measures to control MRSA are proper hand hygiene,
restricted use of antibiotics and the detection and appropriate
isolation of infected colonised patients.
As per our study, the frequency of MRSA infection post
primary lower limb arthroplasty was found to be 0%. The result
shows that, MRSA screening in PAC is an important adjuvant to
the MRSA reduction protocol in patients undergoing lower limb
arthroplasty. However, a positive correlation was failed to be
established. The question now arises as to if its MRSA screening
could be safely excluded from the pre-operative care of patients
or not. Further assessment is however needed in this regard to
establish a definitive outcome.