To the Editor—Methicillin-resistant Staphylococcus aureus (MRSA) represents a major problem for public health systems with resistance to methicillin and other antibiotics with high prevalence in hospital and community settings. Remarkably, in the United States the estimated number of deaths due to MRSA infections exceeds that due to human immunodeficiency virus (HIV)/ AIDS.Reference Klevens, Morrison and Nadle ¹ MRSA colonization plays a key role in the epidemiology and pathogenesis of staphylococcal infections in HIV-infected patients. Recently, Zervou and colleaguesReference Zervou, Zacharioudakis, Ziakas, Rich and Mylonakis ² conducted a meta-analysis and showed that individuals with HIV infection are frequently colonized with MRSA. The overall estimated prevalence was 6.9% (95% CI, 4.8%–9.3%) and varied between geographic regions, from 1.0% in Europe to 8.8% in North America. The pooled prevalence rate was 5.8% (95% CI, 2.8%–9.8%) in the Asian HIV-infected population.Reference Zervou, Zacharioudakis, Ziakas, Rich and Mylonakis ² Information about MRSA colonization amongst HIV-infected populations may be useful for implementation of effective strategies to prevent staphylococcal infections.

The prevalence of AIDS cases in mainland China has grown steadily in the period of 2004 to 2013, with a 10-fold increase.Reference Xu, Yang and Liu ³ Unfortunately, the study by Zervou et alReference Zervou, Zacharioudakis, Ziakas, Rich and Mylonakis ² did not provide prevalence data specifically about MRSA colonization rates among HIV-infected individuals in China.

Currently, strains of MRSA are the most prevalent nosocomial pathogen in China, and several reports have shown that this is an increasing trend.Reference Qu, Cui and Guo ^{4 ,} Reference Xiao, Wang and Li ⁵ One surveillance study performed in China showed that 63% of S. aureus isolates were MRSA, including 77% of nosocomial isolates and 43% of community isolates.Reference Xiao, Wang and Li ⁵ Dissemination of virulent MRSA clones among healthy persons in China may contribute to the presence of clinically significant MRSA infections in some locales,Reference Du, Chen and Ding ⁶ but few studies have described the epidemiology and prevalence of MRSA colonization in healthy Chinese individuals. Most studies have been conducted in inpatients, especially in intensive care units.Reference Li, Zhuang, Lin, Xi and Yao ⁷ Only 3 published studiesReference Qu, Cui and Guo ^{4 ,} Reference Du, Chen and Ding ^{6 ,} Reference Ma, Sun and Wang ⁸ were found when we searched for the prevalence of MRSA colonization among healthy Chinese individuals using both English and Chinese databases (Table 1). We found that in mainland China the prevalence of MRSA colonization among healthy persons was higher than in other countries, including the United StatesReference Gorwitz, Kruszon-Moran and McAllister ⁹ and European countries.Reference den Heijer, van Bijnen and Paget ¹⁰ Such high MRSA colonization rates pose a significant challenge for MRSA prevention programs in China.

TABLE 1 Characteristics and Results of Studies That Investigated Methicillin-Resistant Staphylococcus aureus (MRSA) Colonization Among Healthy Chinese Individuals

Although there is no study investigating the prevalence of MRSA colonization in Chinese HIV-infected populations thus far, it seems reasonable to speculate that the prevalence will be high. There is a clearly a critical need to characterize the epidemiology of MRSA colonization/infection more fully in mainland China so that effective prevention programs can be implemented.