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Abstract

We appreciate the interest in our recent publication.1Hsiao C.H. Chuang C.C. Tan H.Y. et al.Methicillin-resistant Staphylococcus aureus ocular infection: A 10-year hospital-based study.Ophthalmology. 2012; 119: 522-527Abstract Full Text Full Text PDF PubMed Scopus (55) Google Scholar Sun et al conducted similar work with nearly the same study design and study interval to examine the characteristics of methicillin-resistant Staphylococus aureus (MRSA) ocular infections in a tertiary-care Australian institution, but the results were different. In our study, the high rate of MRSA and the increasing rate of community-associated (CA) MRSA in S. aureus ocular infections paralleled the trends of systemic MRSA infections in our hospital and country.2Huang Y.C. Chen C.J. Community-associated meticillin-resistant Staphylococcus aureus in children in Taiwan, 2000s.Int J Antimicrob Agents. 2011; 38: 2-8Abstract Full Text Full Text PDF PubMed Scopus (86) Google Scholar Two hundred five (74.8%) and 69 (25.2%) of 274 patients with ocular MRSA infection were cultured in the outpatient and inpatient settings, respectively. Of 406 outpatients and 113 inpatients, marginally significantly more inpatients than outpatients had MRSA (P = 0.047, Chi-square test). However, when we categorized the patients as healthcare-associated and community-associated,3Naimi T.S. LeDell K.H. Como-Sabetti K. et al.Comparison of community- and health care-associated methicillin-resistant Staphylococcus aureus infection.JAMA. 2003; 290: 2976-2984Crossref PubMed Scopus (1494) Google Scholar 93 of 274 patients (33.9%) with MRSA ocular infections and 60 of 245 patients (24.5%) with methicillin sensitive S. aureus ocular infections had healthcare exposure; MRSA infections were significantly more common among the patients with healthcare exposure (P = 0.024, Chi-square test). MRSA was associated with the following ocular diseases, in descending order: keratitis (36.1%), lid disorder (24.5%), conjunctivitis (20.1%), lacrimal system disorder (10.6%), wound infection (3.6%), endophthalmitis (3.3%), and others (1.8%) in our study. By comparison, patients with CA-MRSA infections presented with lid and lacrimal system disorders significantly more often than those with healthcare associated (HA)-MRSA infections, and CA-MRSA caused less vision-threatening disorders (i.e., keratitis, orbital cellulitis, or endophthalmitis) than HA-MRSA, so we concluded CA-MRSA mostly caused milder diseases. Sun et al reported their CA-MRSA cases involved more complicated diagnoses of dacryocystitis, endophthalmitis, and periorbital abscess. The case number was too small to draw a reliable conclusion, and dacrocystitis and periorbital abscess could be classified as lacrimal system disorder and lid disorder, respectively. The antibiotic resistance/susceptibility patterns of CA-MRSA isolates from ocular and other infections in Taiwan were different from those in the USA3Naimi T.S. LeDell K.H. Como-Sabetti K. et al.Comparison of community- and health care-associated methicillin-resistant Staphylococcus aureus infection.JAMA. 2003; 290: 2976-2984Crossref PubMed Scopus (1494) Google Scholar, 4Skiest D.J. Brown K. Cooper T.W. et al.Prospective comparison of methicillin-susceptible and methicillin-resistant community-associated Staphylococcus aureus infections in hospitalized patients.J Infect. 2007; 54: 427-434Abstract Full Text Full Text PDF PubMed Scopus (89) Google Scholar and Australia. Similar to HA-MRSA isolates, CA-MRSA clinical isolates were also resistant to multiple antibiotics, including clindamycin (>90%), erythromycin (>90%), and chloramphenicol (57%–65%), but were less resistant to gentamicin (21%–34%).2Huang Y.C. Chen C.J. Community-associated meticillin-resistant Staphylococcus aureus in children in Taiwan, 2000s.Int J Antimicrob Agents. 2011; 38: 2-8Abstract Full Text Full Text PDF PubMed Scopus (86) Google Scholar Sun et al found CA-MRSA was more susceptible than HA-MRSA to ciprofloxacin, which agrees with Blomquist's5Blomquist P.H. Methicillin-resistant Staphylococcus aureus infections of the eye and orbit (an American Ophthalmological Society thesis).Trans Am Ophthalmol Soc. 2006; 104: 322-345PubMed Google Scholar and our own results. Since fluoroquinolones are the most popular empiric therapy in ocular infections, the data may be useful clinically in selecting antibiotics for CA-MRSA ocular infections. Infectious diseases may differ by region in epidemiologic patterns, spectrum and severity of disease, and profiles of antibiotic susceptibility. We agree with Sun et al that the different results in these 2 studies are most likely due to global differences in the prevalence and resistance of MRSA and country-specific differences in healthcare structure. Ophthalmologists should be aware of the local epidemiological variations of MRSA. Methicillin-Resistant Staphylococus aureusOphthalmologyVol. 119Issue 8PreviewWe read with great interest the study by Hsiao et al1 describing the characteristics of methicillin-resistant Staphylococcus aureus (MRSA) ocular infections over a 10-year period within a Taiwanese institution. We performed a similar study to examine these characteristics within a tertiary-care Australian institution. Although there have been increasing reports of MRSA ophthalmic infections within the literature, there is little data from Australia, which is particularly important given the geographical differences in MRSA resistance. Full-Text PDF