Transcript Slide 1

Carriage Rates of Methicillin-Resistant Staphylococcus aureus (MRSA) Among College Students
Ryan Kitzinger, Leigh Nelson, Chad Sethman, Ph.D.
ABSTRACT
RESULTS
38% (1.6)
3% (5.1)
*Roommate does not play a varsity sport
62
39% (1.6)
3% (3.9)
*= Moderately Active
77
31% (1.2)
13% (3.6)
Do not play an intramural sport
33
42% (1.8)
3% (3.5)
50
30% (1.2)
22% (2.9)
Hand-washing frequency after exercise = about half the time
Figure 1. Growth of S. aureus on MSA
*
**
S.aureus
carriage
47%
%MRSA
20%
27%
27%
10%
5%
10%
3%
0%
Nursing
• S. aureus is a common cause of infections ranging from mild skin infections to severe,
invasive infections.
28
43% (1.8)
4% (2.8)
Frequency of cleaning cuts/abrasions = about half the time
57
28% (1.5)
5% (2.2)
= Moderate concern about spread of infection
106
35% (1.4)
7% (2.1)
Shower Immediately after exercise
74
36% (1.3)
8% (1.1)
Roommate/family member diagnosed with a MRSA infection
11
45% (1.8)
9% (1.1)
Worked/volunteered at a hospital last two years
46
22% (2.1)
9% (1.0)
Hand-washing frequency before eating = about half the time
69
32% (1.1)
9% (1.0)
Football
Percent MRSA/Total S.aureus Isolates
**
60%
*
50%
40%
• Mannitol salt agar (MSA) was used to differentiate S. aureus from other nasal flora
based on a yellowing of the medium indicating mannitol fermentation (fig. 1)
• Growth on MSA supplemented with methicillin was used to indicate methicillin
resistance
25%
13%
9%
56%
MRSA/S.aureus
50%
40%
% S.aureus
30%
% MRSA
20%
10%
0
Yes
No
Figure 6. Prevalence of S. aureus and MRSA
carriage in hospital workers/volunteers.
70%
1 to 2
3 to 5
6 to 7
8 to 10
11+
Figure 7. Prevalence of MRSA carriage in groups
representing increasing time spent in nursing
clinicals.
Carriage Rates by Gender
*
60%
*p-value = .024
50%
40%
S.aureus carriage
67%
30%
20%
36%
MRSA/MSSA
*
29%
14%
0%
Men
20%
Women
Figure 8. Prevalence of S. aureus and MRSA carriage in
male students versus female students.
**
*
10%
Carriages Rates by Number of Clinicals
0%
64%
30%
6%
0%
Nursing
Football
Control
Figure 3. Prevalence of MRSA among S. aureus
isolates in various student groups.
You would rate your overall activity level as:
45%
16%
12%
p-value = .029
10%
8%
6%
How many hours do you spend per week in the
University's Atheletic Facilities?
CONCLUSIONS
13%
MRSA
4%
2%
4%
0%
35%
30%
25%
% S.aureus
% MRSA
20%
15%
> Moderately Active
Figure 4. Prevalence of MRSA carriage in two
groups defined by activity level.
This
• Neither hospital work nor clinical exposure appear to be correlated with MRSA
carriage risk in this study. More detailed investigation will be required to elucidate this
correlation.
10%
5%
ACKNOWLEDGEMENTS
0%
≤ Moderately Active
• Increased activity levels appear to reduce the risk for MRSA carriage.
phenomenon will have to be investigated in more detail.
• Use of athletic/fitness facilities may be correlated with S. aureus carriage but the risk
for MRSA carriage is not evident.
40%
14%
Carriage by Percentage
METHODS
30%
60%
• Football Players are at an increased risk for S.aureus carriage, however rates of
MRSA carriage were much lower than controls.
Percentage of MRSA Carriage
 This research aims to address risk factors for MRSA carriage among groups of
college students, and also assess public health awareness of MRSA
5%
0%
%MRSA
10%
Control
Figure 2. S. aureus and MRSA carriage
rates for individual student groups.
* p-value = .030
** p-value = .016
• Methicillin resistance, facilitated by the MecA gene, can complicate treatment and
prolong disease and recovery
• Previous research has also shown that healthcare workers have one of the highest
rates of MRSA
25%
20%
15%
10%
S.aureus
carriage
Carriage by Percentage
35%
10%
Roommate play an intramural sport
70%
40%
15%
25% (2.8)
**p-value = .033
**
*
25%
50% (2.1)
30%
Table 1. Survey questions used in this study. Percent of S. aureus
and MRSA-colonized individuals as a correlate of survey answers.
Questions are arranged according to odds ratio from highest to lowest.
* indicates p <0.05.
45%
30%
4
* p-value = .053
Group Breakdown
50%
Diagnosed with a MRSA infection
Carriage Percentage
*Do not play a varsity sport for the University
• S. aureus can be harmlessly carried as normal flora primarily in the anterior nares.
• Previous research has suggested persons engaged in contact sports have an
increased risk for MRSA carriage
Have you worked/volunteered at a hospital at any
point in the last two years?
35%
MRSA
71
Percentage of S.aureus testing MRSA positive
BACKGROUND
S.Aureus
Percentage Carriage (Odds Ratio)
Percentage of Whole
Previous studies have suggested that individuals who engage in contact sports are at
an increased risk for the transmission of MRSA. This increase is thought to come from
the physical contact and increased risk for skin abrasion, as well as the sharing of
improperly sanitized athletic equipment and facilities. Prior research has also
suggested that there is a significant rise in risk in MRSA contraction among healthcare
workers due to the frequent exposure to disease which is associated with the
profession. Based on these findings, it was hypothesized that college students
engaging in these activities (contact sports and nursing clinicals) would have the
highest risk of S. aureus and MRSA contact, and would thus demonstrate a higher
prevalence of S.aureus and MRSA carriage. Nasal swabs of student participants were
screened for the presence of S. aureus, which was characterized by its resistance to
methicillin. Each subject also completed a brief questionnaire, with special attention
given to the identification of potential risk factors and assessment of public health
awareness. Our data reveals that football players are more likely to carry S. aureus, but
the prevalence of MRSA in this group is significantly lower than the control group. We
also show that carriage rates among nursing students were comparable to a control
population with 26.9 percent S. aureus carriage rate and 10.5 percent MRSA carriage
rate.
Total Subjects
Questions
* = p-value < .05
Carriage by Percentage
Discovered in 1881 by Dr. Alexander Ogston, M.D., Staphylococcus aureus is a GramPositive cocci that has since emerged as one of the most medically significant
pathogens. Recent studies suggest S.aureus has reached epidemic levels, and now
asymptomatically colonizes approximately 30% of the population at any given time.
S.aureus has also developed into one of the most common resistant pathogens, with
greater than 50% of all community-acquired S.aureus infections being caused by a
MRSA strain in some populations.
0
1 to 3
4 to 6
7 to 9
10+
Figure 5. Prevalence of MRSA carriage in groups
representing increasing time spent utilizing
athletic/fitness facilities.
We would like to thank Dr. Chad Sethman for his advice throughout the course of this
study, Dr. James Bush for his assistance in data analysis and the Waynesburg
University Center for Research and Economic Development for their financial support.