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Methicillin-resistant Staphylococcus aureus (MRSA)
infections and methamphetamine use are emerging public
health problems. We conducted a case–control investiga-
tion to determine risk factors for MRSA skin and soft tissue
infections (SSTIs) in residents of a largely rural southeast-
ern community in the United States. Case-patients were
persons >12 years old who had culturable SSTIs; controls
had no SSTIs. Of 119 SSTIs identifi ed, 81 (68.1%) were
caused by MRSA. Methamphetamine use was reported in
9.9% of case-patients and 1.8% of controls. After we ad-
justed for age, sex, and race, patients with MRSA SSTIs
were more likely than controls to have recently used meth-
amphetamine (odds ratio 5.10, 95% confi dence interval
1.55–16.79). MRSA caused most SSTIs in this population.
Transmission of MRSA may be occurring among metham-
phetamine users in this community.
M
ethicillin-resistant Staphylococcus aureus (MRSA)
is a growing public health problem for urban and ru-
ral communities in the United States (1,2). Skin and soft
tissue are the most common sites of MRSA infection, com-
prising >75% of MRSA disease (3,4). Skin and soft tissue
infections (SSTIs), commonly caused by S. aureus, annu-
ally account for an estimated 11.6 million visits to hospital
outpatient departments and emergency departments in the
United States (5), and the percentage of SSTIs caused by
MRSA in urban emergency departments increased from
29% in 2001 and 2002 to 64% in 2003 and 2004 (6). Some
of the fi rst reports of MRSA were in injection drug users in
urban Detroit during the early 1980s (7,8).
Illegal methamphetamine use in the United States led
to a rising number of methamphetamine-related hospital
admissions from the early 1980s through the early 2000s
(9). In 2004, 0.2% of the national population >12 years
of age reported using methamphetamine in the previous
month; 0.6% reported using it in the previous year (10).
The prevalence of methamphetamine use has been reported
to be >5% in at-risk populations such as young men from
low-income, urban neighborhoods (11) and urban HIV-
positive men who have sex with men (12).
On August 2, 2005, the Georgia Division of Public
Health invited the Centers for Disease Control and Preven-
tion (CDC) to assist in an on-site investigation of increased
SSTIs among patients of a low-cost, fee-for-service clinic
in rural Georgia. The clinic’s nurse practitioner had noted a
history of methamphetamine use in multiple patients with
SSTIs. Methamphetamine use has been associated with
MRSA skin infections among urban HIV-positive men who
have sex with men (12), but no study has evaluated the as-
sociation of methamphetamine use and MRSA infection in
a community with a large rural population. The objectives
of this investigation were to defi ne the public health effects
and to determine risk factors, including methamphetamine
use, for MRSA SSTI among residents of a community in
the southeastern United States.
Methods
Epidemiologic Investigation
We conducted a prospectively enrolled case–control
investigation at 3 emergency departments and 3 urgent care
clinics in Georgia from September 6 through October 31,
2005. Two low-cost urgent care clinics that serve primarily
Methamphetamine Use and
Methicillin-Resistant
Staphylococcus
aureus
Skin Infections
Adam L. Cohen,* Carrie Shuler,*† Sigrid McAllister,* Gregory E. Fosheim,* Michael G. Brown,‡
Debra Abercrombie,§ Karen Anderson,* Linda K. McDougal,* Cherie Drenzek,† Katie Arnold,†
Daniel Jernigan,* and Rachel Gorwitz*
Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 13, No. 11, November 2007 1707
*Centers for Disease Control and Prevention, Atlanta, Georgia,
USA; †Georgia Division of Public Health, Atlanta, Georgia, USA;
‡Kennestone Hospital, Marietta, Georgia, USA; and §Northwest
Georgia Health District 1–1, Rome, Georgia, USA
RESEARCH
low-income populations and all emergency departments in
a 3-county area were included in an attempt to capture sites
where methamphetamine users might seek medical care for
SSTI. The third urgent care clinic was affi liated with one of
the participating hospitals but was located in a neighboring
county. According to the 2000 US Census, 43.9% of the
population of these 3 counties lives in rural areas (13).
We defi ned a case-patient as a person >12 years of age
with a laboratory culture–confi rmed SSTI who came to a
participating emergency department or clinic for treatment
during the investigation period. Clinicians at participating
institutions identifi ed patients with culturable SSTIs and
were asked to incise, drain, and culture all infected skin
and soft tissue. Patients with SSTIs that were not cultur-
able, such as simple cellulitis, were not included. Patients
whose primary language was not English were enrolled if
they could speak English fl uently enough to answer survey
questions. Patients with new or recurrent SSTI could also
be enrolled; however, we excluded patients who had previ-
ously enrolled in the investigation.
Controls were patients >12 years of age with no current
skin infection who were frequency matched by investiga-
tion site at a rate of 3 controls to 1 case-patient with MRSA
infection. Controls were excluded if they reported a current
skin infection or if infection was identifi ed on physical ex-
amination. Persons could be enrolled as control patients if
illness was minor and comparable in severity to an SSTI.
For example, patients with major trauma and critically ill
patients were excluded from control selection.
Upon seeking treatment, patients voluntarily consent-
ed to be interviewed by trained staff of the participating
healthcare facilities, local public health departments, or
CDC to identify SSTI case-patients. To ensure as much
privacy as possible, the interviews were usually conducted
in the patient’s room with no family or friends present. The
interview survey contained questions about demographics,
clinical history, and potential risk factors for SSTI. Each
patient was asked a specifi c question about methamphet-
amine use: “In the past 3 months, have you used metham-
phetamine (crystal meth or meth)?” If the patient answered
yes, 2 follow-up questions were asked: 1) “How did you
take methamphetamine?” with the choices “smoked or
inhaled,” “injected,” or “swallowed or took pills,” and 2)
“Have you shared drug equipment or rinse water with any-
one else, including a signifi cant other?” To identify health-
care exposure, patients were asked whether they had had
surgery or dialysis or if they had stayed overnight in a hos-
pital within the previous 3 months. All patients, and their
parents if the patients were <18 years of age, were given a
letter explaining the investigation and asked to give verbal
informed consent to enroll in the investigation.
We examined trends in S. aureus skin infections and
cultures at one of the main emergency departments in our
investigation by reviewing billing codes and laboratory mi-
crobiology reports from January 2004 through September
2005, the start of the case–control survey investigation.
This investigation was deemed exempt from review by the
CDC Institutional Review Board because it was part of a
public health response by CDC and the Georgia Division
of Public Health.
Laboratory Investigation
Specimens were obtained from at least 1 infection
site in all case-patients. Staff at all 3 hospital emergency
departments and the urgent care clinic affi liated with 1
of the hospitals collected cultures and performed antimi-
crobial drug susceptibility testing at their facility. Two
low-cost, urgent care clinics sent all cultures to CDC for
culture and antimicrobial drug susceptibility testing. All 6
investigation sites sent both MRSA and methicillin-sus-
ceptible S. aureus (MSSA) isolates to CDC for further
characterization.
All available isolates from methamphetamine users and
a random sample of isolates not related to methamphetamine
use from each of the 6 investigation sites were tested at CDC
for antimicrobial susceptibility by the Clinical and Labora-
tory Standards Institute broth microdilution method (14). We
tested for susceptibility to chloramphenicol, clindamycin,
daptomycin, doxycycline, erythromycin, gentamicin, levo-
fl oxacin, linezolid, oxacillin, penicillin, rifampin, tetracy-
cline, trimethoprim-sulfamethoxazole, and vancomycin. In
addition, we performed the cefoxitin disk diffusion test to
predict mecA-mediated resistance to oxacillin (14) and the
D-zone test for inducible clindamycin resistance (15). Iso-
lates were also tested by using PCR for genes encoding the
staphylococcal cassette chromosome mec (SCCmec) resis-
tance complex, Panton-Valentine leukocidin (PVL) cytotox-
in, and toxic shock syndrome toxin (16). Chromosomal DNA
was analyzed by pulsed-fi eld gel electrophoresis (PFGE) af-
ter digestion with SmaI restriction endonuclease (17). The
relatedness of PFGE patterns in different isolates was defi ned
by using Dice coeffi cients and 80% relatedness by the un-
weighted pair-group method with arithmetic averages (Ap-
plied Maths, BioNumerics, Austin, TX, USA) (18).
Statistical Methods
We conducted univariate analysis of the data to de-
scribe patient demographics and compared binary and
categorical variables with the χ
2
test; continuous variables
were compared by using the t test with unequal variances.
We evaluated risk factors for MRSA SSTIs by using condi-
tional logistic regression with stratifi cation by investigation
site. Risk estimates were adjusted for age (categorized as
<18 years, 19–34 years, 35–64 years, and >65 years), sex,
and race (categorized as white and nonwhite) because they
were potential confounding variables.
1708 Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 13, No. 11, November 2007
Methamphetamine Use and MRSA
Results
Epidemiologic Investigation
We identifi ed 119 case-patients with skin infec-
tions in the investigation. MRSA was isolated from 81
(68.1%) of the skin and soft tissue cultures, MSSA from 20
(16.8%), and bacteria other than S. aureus from 18 (15.1%)
(Table 1). Compared with controls with no skin infection,
a higher percentage of patients with MRSA SSTIs were
male (p<0.001). The proportion of patients that were male
did not differ signifi cantly between controls and patients
with either MSSA or non–S. aureus SSTIs (p = 0.67 for
MSSA, p = 0.12 for non–S. aureus) or between patients
with MRSA and MSSA SSTIs (p = 0.16).
Fifteen patients who reported recently using metham-
phetamine were identifi ed: 8 with MRSA SSTIs, 2 with
MSSA SSTIs, and 5 controls. Half (8 [53.3%]) of the meth-
amphetamine users were male. Ten percent of patients with
MRSA skin infections (8/81) reported using methamphet-
amine in the past 3 months, signifi cantly more than the 2%
of controls (5/283) who reported this behavior (p<0.001).
After adjusting for age, sex, and race, we determined that
patients with MRSA SSTI were signifi cantly more likely
to have recently used methamphetamine than were con-
trols (adjusted odds ratio [AOR] 5.10, 95% confi dence
interval [CI] 1.55–16.79) (Table 2). Of the 8 methamphet-
amine users with MRSA SSTIs, most (5 [62.5%]) smoked
or inhaled the drug. Only 1 (12.5%) injected the drug, and
1 (12.5%) took the drug orally. For 1 methamphetamine
user with MRSA SSTI, we could not determine the route
of drug administration. Of the 8 methamphetamine users
with MRSA SSTIs in our investigation, 2 (25.0%) reported
sharing drug equipment or rinse water with other persons;
we did not have information on drug-sharing behavior for 1
methamphetamine user with a MRSA SSTI.
In our study population, having had a skin infection
within the previous 3 months was the factor most strongly
associated with current MRSA skin infection (AOR 7.92,
95% CI 4.10–15.28) (Table 2). Recent sexual contact with
someone with a skin infection was also a signifi cant risk
factor for MRSA skin disease (AOR 5.42, 95% CI 1.68–
17.50), when compared with recent sexual contact with
a person without a skin infection. Frequent skin-picking
behavior was independently associated with MRSA SSTI
(AOR 2.53, 95% CI 1.22–5.23). Crowded living condi-
tions, defi ned as >1 person per bedroom, had a small but
signifi cant association with MRSA SSTI (AOR 1.78, 95%
CI 1.004–3.15).
Only 10% of MRSA case-patients had healthcare-asso-
ciated risk factors traditionally associated with MRSA in-
fection, namely, recent hospitalization, surgery, or dialysis.
Additional factors not signifi cantly associated with MRSA
SSTI in our study population included use of antimicrobial
agents in the previous 6 months, recent stays in a jail or
prison, bathing less than daily, history of diabetes or liver
disease, recent tattoo or body piercing, and participation in
contact sports in the previous 3 months. In addition, very
few or no patients were HIV positive (2 [0.5%]), homeless
(0), or recently had sex with someone of the same sex (7
[1.6%]), suggesting that none of these were signifi cant risk
factors for MRSA SSTI in this population.
The number of visits for S. aureus skin infections at
one of the main emergency departments in our investiga-
tion increased from ≈1 per 1,000 emergency department
visits to 12 per 1,000 visits over the 20 months leading up
to the investigation (Figure 1). This emergency department
accounted for 46.2% of all study participants in our inves-
tigation. Over the same period, MRSA infections increased
Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 13, No. 11, November 2007 1709
Table 1. Demographic characteristics of study participants with (case-patients) and without (controls) skin and soft tissue infections
(SSTIs)*
Patients with SSTIs
Characteristic
MRSA (N = 81), no. (%) MSSA (N = 20), no. (%) Other† (N = 18), no. (%)
Patients without SSTIs
(N = 284), no. (%)
Age, y
<18 12 (14.8) 0 2 (11.1) 18 (6.3)
19–34 30 (37.0) 13 (65.0) 8 (44.4) 102 (35.9)
35–64 35 (43.2) 6 (30.0) 7 (38.9) 135 (47.5)
>65 4 (4.9) 1 (5.0) 1 (5.6) 29 (10.2)
Male sex‡ 48 (59.3)§ 8 (40.0) 10 (55.6) 104 (36.6)
Race¶
White 73 (90.1) 18 (90.0) 16 (88.9) 244 (85.9)
Black 5 (6.2) 2 (10.0) 2 (11.1) 36 (12.7)
Other 3 (3.7) 0 0 3 (1.1)
Hispanic ethnicity# 2 (2.5) 0 0 4 (1.4)
*MRSA, methicillin-resistant Staphylococcus aureus; MSSA, methicillin-susceptible S. aureus.
†Bacteria other than S. aureus isolated from SSTI in our investigation included other Staphylococcus spp., viridans group streptococci, Group B
Streptococcus, Enterobacter cloacae, Stenotrophomonas maltophilia, and mixed flora.
‡6 records did not indicate sex (1 MRSA case, 1 MSSA case, and 4 controls).
§p<0.0001, when compared with controls.
¶For 1 control, race was not indicated.
#3 records did not indicate ethnicity (2 MRSA cases, 1 other skin infection).
RESEARCH
from 2 to 38 per month in the same emergency department.
Most emergency department S. aureus cultures for both
SSTIs and non-SSTIs were resistant to methicillin, with the
prevalence of methicillin-resistance remaining stable over
the same 20-month period (median 82%, range 50–100%).
Laboratory Investigation
MRSA (n = 32) and MSSA (n = 13) isolates tested
were commonly susceptible to clindamycin, daptomycin,
doxycycline, gentamicin, levofl oxacin, linezolid, rifampin,
tetracycline, trimethoprim-sulfamethoxazole, and vanco-
mycin (Table 3). None of the MRSA isolates and only 1
(7.7%) of the MSSA isolates had inducible clindamycin
resistance. MRSA susceptibility patterns of isolates from
methamphetamine users and nonusers were similar, except
that both MRSA isolates susceptible to erythromycin were
found in those who did not use methamphetamine. The
MSSA isolate from a methamphetamine user was suscep-
tible to all but penicillin.
We detected genes for PVL in all MRSA isolates and
5 (41.7%) MSSA isolates; however, the MSSA isolate
from a methamphetamine user did not carry the PVL locus.
All available MRSA isolates from 6 methamphetamine
users and 21 nonusers of methamphetamine had type IV
SCCmec resistance complex and were PFGE type USA300.
Most of the MRSA isolates were a single strain, PFGE type
USA300-0114 (4 [66.7%] were methamphetamine users,
15 [71.4%] were non-methamphetamine users) (Figure 2).
One third (33.3%) of MRSA isolates from methamphet-
amine users and one fi fth (19.0%) of MRSA isolates from
non-methamphetamine users were variants of USA300-
0114, such as USA300-0047.
Discussion
MRSA caused over two thirds of all skin infections in
the Georgia community we investigated, which is among
the highest reported rates of MRSA in SSTI nationwide
(16). We found that many previously known risk factors
for MRSA skin infection, such as recent skin infection and
household contact with someone with a skin infection (19),
were common in this population. However, we also identi-
fi ed a novel association between MRSA skin infections and
methamphetamine use in a community with a large rural
population. Methamphetamine use was reported in nearly
1 in 10 patients with MRSA SSTI and was more common
in patients with MRSA skin infections than in patients
without skin infections. While most community-associated
MRSA SSTI occur in persons without defi ned risk factors
(16), some settings such as prisons and military training
facilities appear to facilitate and amplify MRSA transmis-
sion (20,21). A similar amplifi cation of transmission may
be occurring among methamphetamine users in this com-
munity.
Methamphetamine use is associated with a number of
socioeconomic and behavioral risk factors that may pre-
dispose persons to MRSA SSTI. We found that MRSA
SSTI was associated with living with someone with a skin
infection, which may increase skin contact with infected
persons. Skin-picking was also associated with MRSA
SSTI. Methamphetamine use causes formication, a sensa-
1710 Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 13, No. 11, November 2007
Table 2. Risk factors for MRSA skin and soft tissue infection*
Risk factors
Case-patients,
no. (%)
Controls,
no. (%)
Crude OR (95% CI) Adjusted OR† (95% CI)
Drug use and medical history
Recent skin infection‡ 34 (42.0) 22 (7.8) 8.41 (4.54–15.59) 7.92 (4.10–15.28)
Recent methamphetamine use‡ 8 (9.9) 5 (1.8) 5.64 (1.80–17.69) 5.10 (1.55–16.79)
Antimicrobial agents within 6 months 40 (49.4) 114 (40.1) 1.43 (0.87–2.34) 1.52 (0.89–2.60)
Recent hospitalization, surgery, or dialysis‡ 8 (9.9) 27 (9.5) 1.06 (0.46–2.44) 1.24 (0.51–2.97)
Diabetes 10 (12.4) 23 (8.1) 1.61 (0.73–3.57) 2.03 (0.83–4.98)
Liver disease 1 (1.2) 9 (3.2) 0.38 (0.05–3.07) 0.59 (0.70–4.91)
Contact exposure
Household contact with someone with skin
infection
21 (25.9) 27 (9.5) 3.26 (1.72–6.17) 3.19 (1.58–6.48)
Crowding (>1 person/bedroom) 44 (54.3) 111 (39.1) 2.06 (1.22–3.45) 1.78 (1.004–3.15)§
Recent sexual contact‡ 48 (59.3) 182 (64.1) 0.85 (0.51–1.42) 0.68 (0.38–1.22)
Recent sexual contact with someone with
skin infection‡
7 (8.6) 6 (2.1) 4.28 (1.40–13.08) 5.42 (1.68–17.50)
Recent contact sports‡ 9 (11.1) 11 (3.9) 2.92 (1.17–7.31) 1.37 (0.47–4.03)
Recent jail‡ 4 (4.9) 9 (3.2) 1.46 (0.44–4.90) 1.75 (0.48–6.42)
Hygiene practices
Frequent skin picking 17 (20.1) 24 (8.5) 2.77 (1.40–5.47) 2.53 (1.22–5.23)
Bathe less than daily 5 (6.2) 31 (10.9) 0.50 (0.19–1.34) 0.56 (0.19–1.67)
*MRSA, methicillin-resistant Staphylococcus aureus; OR, odds ratio; CI, confidence interval.
†All models are adjusted for age, sex, race, and methamphetamine use, except the model for methamphetamine use, which is adjusted only for age, sex,
and race.
‡Recent = within the 3 months prior to survey.
§p = 0.048.
Methamphetamine Use and MRSA
tion of something crawling on the body or under the skin,
which can lead to skin-picking behavior, skin breakdown,
and portals of infection. Other poor hygiene habits that can
break the skin, such as fi ngernail biting, have been associ-
ated with MRSA SSTI (12). Methamphetamine use may
be associated with limited access to medical care, stays
in correctional facilities, and homelessness, all of which
have been associated with MRSA SSTI in previous studies
(20,22). However, our investigation did not fi nd these to be
signifi cant risk factors for MRSA SSTI in this population.
Methamphetamine use has been associated with HIV
(23) and sexually transmitted bacterial infections (24),
purportedly from increased unprotected sex related to the
sexually stimulating property of the drug. A study among
urban HIV-positive men who have sex with men found
that, in addition to methamphetamine use, use of other
sexually stimulating drugs such as nitrates (“poppers”) and
sildenafi l (e.g., Viagra) was associated with MRSA SSTI
(12). These previous fi ndings and the results of the current
investigation suggest that the use of methamphetamine and
other sexually stimulating drugs may increase direct skin-
to-skin sexual contact and transmission of MRSA, which
can be transmitted through sexual contact (25). We found
an increased risk for MRSA SSTI in case-patients who had
recently had sex with someone with a skin infection.
Injection of the drug may act as a method of introduc-
ing the bacteria into the skin if users fail to clean injection
sites or share drug paraphernalia and other potentially con-
taminated items (26). Injection of methamphetamine can
lead to transmission of bloodborne pathogens when injec-
tion equipment is shared, as demonstrated in an outbreak
of hepatitis B among methamphetamine users in Wyoming
(27). A recent case series of 14 patients with MRSA nec-
rotizing fasciitis found that 43% of the patients had current
or past injection drug use (28). In contrast to early reports
of MRSA in urban injection drug users, our investigation
suggested that MRSA skin infections in methamphetamine
users are not necessarily due to unclean drug injection. Few
methamphetamine users in our population injected the drug
or shared equipment; rather, the methamphetamine users in
this community commonly smoked or inhaled the drug.
The absolute number of SSTIs at 1 emergency depart-
ment in this investigation increased during the 18 months
preceding the investigation, but the percentage of MRSA
isolates was stable over that period. This increase in SSTIs
led to a concomitant increase in MRSA SSTIs, which were
more common among men, and echoes repeated reports of
MRSA SSTI outbreaks in male populations (20,29). This
sex difference was not due to increased methamphetamine
use in men in our population, since our population of sur-
Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 13, No. 11, November 2007 1711
Table 3. Antimicrobial susceptibility patterns and toxin gene presence of selected MRSA and MSSA isolates*
Antimicrobial agent or toxin MRSA isolates† (N = 32), no. (%) MSSA isolates (N = 13), no. (%)
Antimicrobial susceptibility
Chloramphenicol 32 (100.0) 10 (76.9)‡
Clindamycin 32 (100.0) 12 (92.3)
Inducible resistance (D-zone test) 0 1 (7.7)
Daptomycin 32 (100.0) 13 (100.0)
Doxycycline 32 (100.0) 13 (100.0)
Erythromycin 2 (6.5) 6 (46.2)
Gentamicin 32 (100.0) 13 (100.0)
Levofloxacin 27 (84.4) 12 (92.3)
Linezolid 32 (100.0) 13 (100.0)
Penicillin 0 2 (15.4)
Rifampin 32 (100.0) 13 (100.0)
Trimethoprim-sulfamethoxazole 32 (100.0) 13 (100.0)
Vancomycin 32 (100.0) 13 (100.0)
Toxin gene presence
Panton-Valentine leukocidin 32 (100.0) 5 (38.5)
TSST–1 0 0
*MRSA, methicillin-resistant Staphylococcus aureus; MSSA, methicillin-susceptible Staphylococcus aureus; TSST, toxic shock syndrome toxin.
†Methicillin resistance was determined by the oxacillin MIC and disk diffusion using a 30-μg cefoxitin disk (14).
‡Three (23.1%) isolates had intermediate resistance to chloramphenicol.
Figure 1. Number of Staphylococcus aureus skin infections at a
southeastern United States emergency department, January
2004–September 2005.
RESEARCH
veyed methamphetamine users was evenly divided between
the sexes. We also did not fi nd many MRSA infections in
nonwhite patients. This fi nding contrasts with previous
reports of higher incidence of MRSA SSTIs in African
Americans in urban centers compared to other races (4) and
likely refl ects the predominantly white racial distribution
(98.9%) in these 3 rural southeastern US counties (13).
The laboratory investigation found that the most com-
mon MRSA strain causing community SSTI was PFGE
type USA300-0114, a highly conserved strain that has been
implicated in multiple community outbreaks (19). The sec-
ond most common MRSA strain in this community, and
the only other strain found among methamphetamine us-
ers, was USA300-0047, which has only a 1-band difference
from USA300-0114. MRSA SSTIs in methamphetamine
users were not due to a novel or unusual strain of MRSA
but rather the most common strain of MRSA in community
settings across the United States.
Our investigation is subject to some limitations. First,
we did not identify nor do we have data on every SSTI pa-
tient who came to the participating clinics and emergency
departments for treatment; not every patient with SSTI pro-
vided specimens for culture or participated in our survey.
Second, we relied on patient report of methamphetamine use
and did not conduct drug screens for confi rmation. Third, we
excluded patients who could only speak Spanish, which may
have added to the low number of Hispanic study participants
and affected the generalizability of the results. However,
Hispanic, foreign-born, and non-English primary speakers
each comprise only 5%–10% of the population of these 3
counties (13). Fourth, we were unable to test for other physi-
ologic theories of why methamphetamine may be associated
with MRSA, which include weakening the immune system
and predisposing users to MRSA carriage by changing the
nasal environment. Fifth, we were unable to test whether
methamphetamine itself or drug paraphernalia were contam-
inated with MRSA. Lastly, transmission of MRSA in this
population may have occurred in either the community or
in the healthcare setting; for some cases, we were unable to
determine the origin of the community strains.
Our investigation has direct implications for clinicians.
Most clinicians in the participating emergency departments
and urgent care clinics did not routinely drain or culture
SSTIs. Incision and drainage is a primary therapy for SSTI,
and empiric antimicrobial drug therapy may be given in
addition to incision and drainage (30). Because of the
growing and changing resistance patterns in the commu-
nity, clinicians should consider culturing SSTI (30). In this
population, antimicrobial agents currently recommended
for treatment of MRSA (e.g., clindamycin, doxycycline,
and trimethoprim-sulfamethoxazole) would be appropri-
ate choices for empiric treatment of outpatient SSTI be-
cause of low prevalence of resistance (30.) Patients should
also be educated about the risks for transmission through
household and sexual skin-to-skin contact. Transmission of
MRSA in this community is likely due to various factors,
and some of these community strains may have been trans-
mitted through healthcare exposure.
Patients with MRSA SSTIs who seek treatment may
help clinicians identify a vulnerable population of metham-
phetamine users. Prevention measures, such as improved
hygiene and correct care for wounds, may be helpful when
directed at methamphetamine users. However, MRSA SSTIs
in methamphetamine users may also impact family and com-
munity members who do not use methamphetamine. The
same strains of MRSA were circulating among both users
and nonusers in our investigation. Public health offi cials and
clinicians should be aware of proper identifi cation, appro-
priate treatment, prevention of MRSA SSTIs, and the link
between methamphetamine use and these SSTIs.
Acknowledgments
We thank our collaborators at all the participating hospitals
and clinics, the Northwest Georgia Health District, the Georgia
Division of Public Health, and CDC. We also thank Stanley H.
Cohen for his support and thoughtful discussion of statistical anal-
ysis, and Connie Hogle for her editorial comments.
Dr Cohen is a medical epidemiologist in the Respiratory
Diseases Branch of the Division of Bacterial Diseases at CDC.
This investigation was completed when he was an Epidemic In-
telligence Service Offi cer in the Division of Healthcare Quality
Promotion. His primary research interests are the epidemiology of
antimicrobial-resistant bacteria, pediatric patient and drug safety,
and vaccine-preventable diseases.
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1712 Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 13, No. 11, November 2007
Figure 2. Dendrogram of pulsed-fi eld types for methicillin-resistant
Staphylococcus aureus (MRSA) and methicillin-susceptible S.
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Methamphetamine Use and MRSA
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Address for correspondence: Adam L. Cohen, Respiratory Diseases
Branch, Division of Bacterial Diseases, Centers for Disease Control and
Prevention, 1600 Clifton Rd NE, Mailstop C23, Atlanta, GA 30333, USA;
email: alcohen1@cdc.gov
Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 13, No. 11, November 2007 1713
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