MRSA, Samoa | CDC EID

EID Journal Home > Volume 17, Number 6–June 2011

Volume 17, Number 6–June 2011
Research
Methicillin-Resistant Staphylococcus aureus, Samoa, 2007–2008
James Alesana-Slater, Stephen R. Ritchie, Helen Heffernan, Tracy Camp, Alice Richardson, Peter Herbison, and Pauline Norris
Author affiliations: University of Otago, Dunedin, New Zealand (J. Alesana-Slater, P. Herbison, P. Norris); University of Auckland, Auckland, New Zealand (S.R. Ritchie); Institute of Environmental Science and Research Limited, Wellington, New Zealand (H. Heffernan, A. Richardson); and Auckland City Hospital, Auckland (T. Camp)

Suggested citation for this article

Abstract
Little is known about the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in most Pacific Island nations. Relatively high rates of MRSA have been reported in Polynesian people living outside the Pacific Islands. To determine the prevalence and characteristics of MRSA, we assessed wound swabs from 399 persons with skin and soft tissue infection living in Samoa. MRSA was isolated from 9% of study participants; 34 of the 196 S. aureus isolates were MRSA. Five MRSA genotypes were identified; the 3 most common were USA300, the Queensland clone, and a sequence type 1 MRSA strain that shares < 85% homology with the sequence type 1 MRSA strain common in the region (WA MRSA-1). The Southwest Pacific MRSA clone was identified but accounted for only 12% of MRSA isolates. The high prevalence of MRSA in Samoa provides impetus for initiatives to improve antimicrobial drug resistance surveillance, infection control, and antimicrobial drug use in Pacific Island nations.

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) have become a global health concern during the past 2–3 decades. The epidemiology of MRSA has demonstrated marked geographic variation in the prevalence and genotypes of MRSA (1,2), and recent reports from many parts of the world indicate that the prevalence and diversity of MRSA continue to increase (3,4). Studies of the global epidemiology frequently have not included MRSA obtained from persons living in developing nations. The prevalence and genetic variation of MRSA infection in most Pacific Island nations remain unknown. The only study of MRSA in the Pacific was conducted after a report in 2004 of an increased incidence of MRSA infection in Polynesian people in Hawaii (5). This study showed that most MRSA infections in Hawaii were caused by the USA300 MRSA strain (6).

Relatively high rates of MRSA infection have been reported in Polynesian people living outside the Pacific Islands region, including in Alaska, Australia, and New Zealand, and have been attributed to infection with the Southwest Pacific clone of MRSA (sequence type [ST] 30 SCCmec type IV, also referred to as Western Samoan phage pattern [WSPP] MRSA or the Oceania strain) (7–10). The Southwest Pacific clone of community-associated MRSA was identified in New Zealand in 1992 (11). The first isolate and many subsequent isolates of this strain were from persons in New Zealand who had some association with Samoa. The Southwest Pacific MRSA clone has now spread as far as Europe and South America (4,12). This MRSA strain has been postulated to have arisen from a pandemic penicillin-resistant S. aureus strain, known as phage type 80/81, that caused serious hospital- and community-acquired infections during the 1950s (13).

full-text:
MRSA, Samoa | CDC EID


Suggested Citation for this Article
Alesana-Slater J, Ritchie SR, Heffernan H, Camp T, Richardson A, Herbison P, et al. Methicillin-resistant Staphylococcus aureus, Samoa, 2007–2008. Emerg Infect Dis [serial on the Internet]. 2011 Jun [date cited]. http://www.cdc.gov/EID/content/17/6/1023.htm


DOI: 10.3201/eid1706.101083


Comments to the Authors
Please use the form below to submit correspondence to the authors or contact them at the following address:

Stephen R. Ritchie, Department of Molecular Medicine and Pathology, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand; email: s.ritchie@auckland.ac.nz