Pneumococcal conjunctivitis at an elementary school — Maine, September 20-December 6, 2002

Morbidity and Mortality Weekly Report, Jan 31, 2003

On October 18, 2002, the nurse at an elementary school in Westbrook, Maine, notified the Maine Bureau of Health (MBOH) of an increase in the number of students with conjunctivitis. During September 23-October 18, a total of 31 students in kindergarten and in first and second grades either were reported by parents to the nurse as having conjunctivitis or had conjunctivitis diagnosed by the nurse at school. Conjunctival swab cultures from five (38%) of the 13 students who were tested initially grew Streptococcus pneumoniae. This report documents additional cases in the community and summarizes preliminary results of the investigation of this outbreak, which indicated that the outbreak was caused by the same nontypeable strain of pneumococcus that caused an outbreak of conjunctivitis among college students in New Hampshire during January--March 2002 (1). This is the first time that this strain has been reported as the cause of a conjunctivitis outbreak among schoolchildren. Health-care providers and public heal th officials should be aware that nontypeable S. pneumoniae can cause outbreaks of conjunctivitis in school-age children and college students; outbreaks should be reported to state health departments and CDC.

School nurses and child care center managers were asked to report to MBOH any children or staff member who had onset of conjunctivitis during September 20-December 6. Reported episodes of conjunctivitis were considered culture-confirmed if S. pneumoniae was isolated from eye secretions. A questionnaire to identify children and family members with conjunctivitis was sent home with all children attending the index elementary school. Among 361 students, 101 (28%) (median age: 6 years; range: 5-8 years) had at least one episode of conjunctivitis, and 11 (55%) of 20 students tested had an episode of culture-confirmed pneumococcal conjunctivitis (Figure). The attack rate was highest among first-grade students (51 [38%] of 136), followed by morning kindergarten (20 [29%] of 70), second-grade (28 [26%] of 108), and afternoon kindergarten students (two [4%] of 47). Among school staff; three (13%) of 23 classroom teachers and three (15%) of 20 other staff members had conjunctivitis during the study period. Of 709 fami ly members who did not attend the school, 37 (5%) (median age: 4 years; range: <1-42 years) reported conjunctivitis; 28 (76%) of the 37 were household contacts of students who were ill previously. Of 221 household contacts of students with conjunctivitis, 28 (13%) reported having conjunctivitis with onset after the student's illness.

A second questionnaire was distributed to all students in selected classrooms. Among 65 students with conjunctivitis who responded, the symptoms reported most commonly were red eyes (55 [85%]); itchy, painful, or burning eyes (45 [69%]); crusty eyes in the morning (42 [65%]); grey or yellow discharge from eyes (42[65%]); and swelling of the eyelids (30 [46%]). Redness in both eyes was reported for 35 (64%) of the 55 students who had red eyes. The median duration of symptoms was 3 days (range: 1-14 days). Of the 65 students, 53 (82%) missed school during their illness, with a median absence from school of 2 days (range: 1-7 days). Symptoms of systemic pneumococcal infections were not identified in any of the students or contacts.

School nurses and child care staff in the community reported an additional 77 students who had conjunctivitis with onset during September 20-December 2, including 53 (4%) of 1,313 students, ranging from kindergarten through grade 12 at four schools, and 24 (9%) of 271 children attending three community child care centers. Among the 53 students with conjunctivitis at other schools, 10 (19%) had a family member at the index school, and seven (29%) of 24 ill child care attendees had a sibling at the index school.

Of 20 conjunctival specimens collected from students at the index school and 15 collected from students at other schools, 11 (55%) and five (33%), respectively, grew S. pneumoniae. All seven isolates that were tested for antimicrobial susceptibility were resistant to erythromycin but susceptible to penicillin and third-generation cephalosporins. Nine isolates were sent to CDC for serotyping; eight could not be typed by using CDC antisera, and one isolate from a conjunctival swab collected from an index school student was serotype 38. Nontypeable isolates, but not the serotype 38 isolate, produced identical electrophoretic patterns by pulsed field gel electrophoresis to pneumococcal isolates from an outbreak of conjunctivitis on a college campus in New Hampshire during January--March 2002 (1). Viral cell cultures of specimens from 30 students were negative for adenovirus (i.e., no cytopathic effect in cell culture was identified after 10 days' incubation).

To prevent transmission at the school, students and teachers were encouraged to wash hands frequently with soap and water and to clean and limit the sharing of objects in the classroom. In addition, symptomatic children were excluded from school. Implementing prevention measures in this setting was difficult. Teachers reported that increased hand washing at school was disruptive to classes, and excluding symptomatic students from school placed a burden on parents. One student from the index school was reported as having conjunctivitis during Thanksgiving recess (November 25-29), and no children were reported with conjunctivitis after the recess. Five students at other schools were reported to have had conjunctivitis after the recess. Surveillance for additional cases of conjunctivitis at area schools is continuing.