Hospital Infection Prevention-Case suggests spread of MRSA in day care

Preschooler likely acquired bug from classmate

A 2-year-old boy likely acquired methicillin-resistant Staphylococcus aureus (MRSA) in a day-care center after exposure to a child with community-acquired MRSA, investigators report.¹ Highlights of the investigation are summarized as follows:

• The authors used a point prevalence survey and questionnaire in a Toronto, Ontario, child-care center to try to determine colonization rates after a diagnosis of community-acquired MRSA disease in a previously well 2½-year-old attendee. Of 201 children, 164 (81.6%) underwent screening with parental consent.

• A 2-year-old classroom contact with chronic dermatitis had MRSA detected on perianal swab. In addition, the seven-year-old sibling of the classroom contact was positive for MRSA. Three adult household contacts of the index case and the parents of the day care contact case were negative. The isolates of the three children were identical and not related to any of the common strains circulating in regional health care institutions.

• These MRSA isolates also had the same antibiotic susceptibility pattern: resistant to penicillin, methicillin, cephalothin, and amoxicillin; and susceptible to erythromycin, tetracycline, clindamycin, trimethoprim or sulfamethoxazole, vancomycin, chloramphenicol, and gentamicin.

• The MRSA-positive classroom contact had a history of chronic skin disease and eczema during the preceding six months, and was described by child care center staff as having hives and two episodes of scarlet fever. The direction of the transmission in the center was unclear. The source of the MRSA in the classmate with dermatitis also could have been any one of a variety of his ambulatory care providers, his sister, or the index case. Dermatitis in the classroom contact actually preceded the acute ear disease in the index case by about three months, raising the possibility that the index case was actually a secondary case.

• Of the 164 children in the entire day care center, the rate of MRSA recovery (including the index case) was 1.2% (2/164). The classroom attack rate was 17% (2/12). None of 38 staff members screened were colonized. In addition, 40 children (24.4%) were colonized with methicillin-sensitive S. aureus.

• While it is not possible to determine if failure to exclude the child with dermatitis was of importance, the recommendation that such children be excluded should be reiterated. When a child is identified with MRSA in a child-care center, at a minimum, parents ought to be informed of the pathogen's presence, the authors concluded. In the event that a child becomes ill, the physician can obtain appropriate cultures earlier than usual, avoiding protracted use of ineffective antibiotics, they noted. Infection with MRSA should be suspected in disease unresponsive to standard antibiotic therapy.

Reference

1. Shahin R, Johnson IL, Jamieson F, et al. Methicillin-resistant Staphylococcus aureus carriage in a child care center following a case of disease. Arch Pediatr Adolesc Med 1999; 153:864-868.