Outbreak of Gram Positive Bacterial Keratitis Associated with Epidemic Keratoconjunctivitis in Neonates and Infants Joo Hoon Kim 1, Mee Kum Kim 1, Joo Youn Oh 1, Ki Cheol Jang 1, Won Ryang Wee 1, Jin Hak Lee 2 Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea 1 Department of Ophthalmology, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, Korea 2 *All authors in this study declare no financial interest.

 The outbreak of Epidemic Keratoconjunctivitis(EKC)  In a community, yearly  In a health care unit (HCU), not uncommon Neonatal intensive care unit (workers, patients) Nursing home There is only 1 case of bacterial keratitis after EKC Alcaligenes Xylosoxidans (gram-negative rod) Oh et al. Korean J Ophthalmol Sep;19(3)  The outbreak of EKC in NICU at SNUH in 2007

Purpose  To report the clinical characteristics of bacterial keratitis associated with outbreak of EKC  To evaluate the risk factors for the development of bacterial keratitis in eyes with EKC Design  Retrospective case-control study with hospital based case series Participants  108 patients (45 adults and 63 children) diagnosed as EKC in a tertiary eye-care center from July 2007 to August 2007  9 out of 108 patients who were treated with bacterial keratitis after an episode of EKC

Methods (1) Clinical aspects of bacterial keratitis after EKC Demographic data: sex, age at infection, HCU-association Microbiological profile, onset of keratitis after EKC, corneal findings and classification Treatment outcome (2) Risk factors assessment for bacterial keratitis Definition –Bacterial keratitis: Any Infective corneal lesion with bacterial corneal cultures (+) or conjunctival bacterial swap culture (+) –EKC: Clinical signs (follicular hypertrophy, exudative membrane, lacrimal swelling, mucoid discharge, redness and no other identified cause of conjunctivitis) and if possible, (+) result of Adenovirus Immunofluoresence assay (IFA) or culture Risk factors (statistical analysis) –Use of steroid at early EKC period (Fisher’s test) –Interval of F/U at early EKC period (Mann-Whitney test) –MRSA colonization in conjunctiva and other part of body (Fisher’s test) –Gestational age (Mann-Whitney test) –Body Weight at infection (Mann-Whitney test) –Duration of hospitalization (Mann-Whitney test)

Result  Epidemiology of EKC, Bacterial keratitis and Microbiological Features The incidence of bacterial keratitis (Table 1) Most bacterial keratitis(88%): neonates and infants Significantly higher in HCU-based inpatients or children compared with population-based patients or adults Causative organism of bacterial keratitis (Table 2) Methicilline resistant Staphylococcus aureus(MRSA) Most frequently found (7 cases) Coinfected with Staphylococcus epidermidis and Pseudomonas aeruginosa (1 case) Streptococcus pyogenes (1case)

 Principle treatment of keratitis  Initial Tx at EKC  Topical ecolicin with or without topical steroid  Initial Tx at Keratitis  Discontinuation of steroid  Systemic antibiotics: IV Vancomycin, Amikin  Local treatment  3.1 % Vancomycin sol. q 1hr, 2% Amikin sol. q 1hr  Change according to the reported sensitivity test  If unresponsive to treatment 5% T-vanco ointment 6/d, 0.5% moxifloxacin sol. q 2hr Surgical treatment : 1 case (due to impending perforation) (Fig 1E) Amniotic membrane transplantation (Fig 1F, G, H)  Onset of ketatitis after EKC (Table 2)  Mean: 8.8 days (3-12days)  Treatment

 Clinical manifestation of bacterial keratitis and Outcome of treatment (Table 2)  Shallow infiltrations with epithelial defect (n=2) (Fig.1A)  Mean healing time: 9±5.6 days (range: 5-13 days)  Corneal sequels after 3 mo: (-)  Stromal infiltrates underlying epithelial defects (n=7) (Fig.1B, C)  Mean healing time: 25.6±16.7 days (range: days)  Corneal sequels after 3 mo  Diffuse stromal new vessle: 83.3%(5/6)  Corneal opacity: 67.7%(4/6) (Fig 1D)  Though bacterial keratitis had been resolved in all of the patients, 44.4% (4/9) of bacterial keratitis patients have been requiring corneal transplantation due to dense central opacity (3 months follow-up)

 Risk factors assessment for bacterial keratitis Incidence of bacterial keratitis Significantly higher in HCU stayed patients and children (especially in neonate and infants) (Table 1) Using topical steroid in early EKC Not significantly different in HCU-based (30%:16/54) and population-based (46%:25/54) EKC patients (p=0.07, χ 2 test) In the HCU stayed children Factors significantly higher in bacterial keratitis group Culture positive rate of MRSA in conjunctiva (Table 3) Incidence of using topical steroid in early EKC period (Table 3) Longer interval of follow-up examinations in early EKC period (Table 4) Factors with no difference between bacterial keratitis and EKC group (Table 4) (+) Results for either adenoviral IFA or culture MRSA colonization of other parts of body Gestational age Duration of hospitalization

Infants including neonates show high tendency of MRSA keratitis accompanied with EKC, especially in HCU stayed inpatients MRSA colonization in conjunctiva, use of topical steroid and longer interval of follow-up for EKC can be a risk factor in development of MRSA keratitis Conclusion

Discussion  Why bacterial keratitis after EKC in neonate and young infant? Weak physical barrier in the premature 1 epidermal barrier: mature around the 32 nd or 34 th week of gestation Weak mucosal membrane immunity 2 lower the sIgA in preterm infants at the age of 3 to 8 postnatal months Weak innate and specific immunity to pathogen 2 Unable to complain Highly susceptible of infection EKC destruction of corneal integrity & Compromised surface

 Why MRSA keratitis in health care unit?  MRSA infection 3 12%: community-associated, 85%: health care-associated  MRSA nares colonization 4 MRSA colonization in nares: 25% of MRSA infection rate compared with 2.0% of the uncolonized  MRSA ocular surface colonization and nasal carriage 5 Conjunctival MRSA (+) : Anterior nares of MRSA 78% Conjunctival MRSA (-) : Anterior nares of MRSA 11%  SNUH NICU %:neonates became colonized for MRSA in nasal/ inguinal cultures The mean time to acquire MRSA colonization was 17.1 days (1-471days) Compromised surface with EKC may elicit MRSA keratitis!! Risk factor: MRSA colonization, Topical steroid use, Long interval of F/U

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