A total of 22 CDCCs initially responded to the invitation, with 19 ultimately taking part (fig 1). These CDCCs were spread across the borough and included a range of facilities from large day nurseries with over 90 children to a small nursery school with just 10 children.
Overall, 30% (range 10–66%) of parents approached consented for their child to take part. Of these 264 children, 30 (11%) did not have a NP swab taken. This was due to the child being absent or unwilling to have the test done on the day. All parents except two returned the questionnaire, although some questionnaires were not fully completed.
The age range of participating children was 6 months to 5 years: 69% were aged between 2 and 4 years and 20% were under 2 years, 53% were boys, 81% of the children were white and 77% of parents belonged to social class 1 or 2 (mainly professional, managerial or technical occupations).
Thirteen children were reported as having a chronic medical condition, with asthma the most common complaint, and 35 children (13%) had been hospitalised in the preceding year. Most admissions were for elective surgery or an infectious disease (measles, chicken pox, herpes simplex infection, gastroenteritis and other non‐specific viral illness or chest infection). No parent reported previous pneumococcal infection. However, two children were admitted with non‐specified pneumonia and one with non‐specified meningitis. In the preceding year 30% of children had experienced one or more ear infections.
Five children had received antibiotics on the study day, in three cases this was part of long‐term prophylaxis for urinary tract infections, and 21% had received a course of antibiotics in the previous 3 months. Only 66% of parents could remember which antibiotic had been taken, and in almost half of cases it was a β‐lactam. Five children had received a macrolide. The most common indication for antibiotic treatment was ear infection.
The majority of children attended CDCC on 4 days a week, with a mean length of stay of 6 h per day. On average children had been attending for 1 year, and age at first attendance ranged from 1 month to 3 years.
Prevalence of pneumococcal carriage
Of 234 NP swabs analysed, 120 grew pneumococcus. The overall carriage rate was 51% (95% CI 44.6% to 57.8%). Pneumococcal carriage of over 40% was seen across each of five age groups, ranging from 43% of 3–4‐year‐old children to 61% of children who were 1–2 years of age.
The number of swabs collected at each CDCC ranged from four to 22. No pneumococcal isolates were found at the smallest centre (10 children of whom four were swabbed), however between one and 14 isolates were identified at the remaining 18 CDCCs, representing a range of carriage of 25–80%.
None of the 120 pneumococcal isolates tested was resistant to penicillin (upper CL 3% using the exact method).
Of 120 (17.5%) pneumococcal isolates, 21 were resistant to erythromycin, and nine of these were also resistant to tetracycline.
Results were available for 119 of 120 pneumococcal isolates. Nineteen different serotypes were identified. The most frequently observed serotype was 6A (20/119) followed by 19F and 23F (17 each) (fig 1). In the 17 centres where more than one child carried pneumococcus, at least two and up to eight different serotypes were identified.
Sixty eight (57%) of the isolates were serotypes that are contained in the 7‐valent pneumococcal conjugate vaccine. Additionally, 20 were serotype 6A which may be cross‐covered by the vaccine, bringing potential coverage to 74%.13,14
A further 11 isolates belonged to vaccine‐associated serogroups, although there is less evidence of cross protection for these.
Sixteen (of 21) antibiotic resistant pneumococci belonged to a serotype contained in the 7‐valent conjugate vaccine, with another one belonging to serotype 6A. Thus, 81% of resistant serotypes seen would be covered by the 7‐valent conjugate vaccine. Of the other four resistant pneumococci, three were serotype 19A and one 15A.
Univariate analysis of each predictor variable in turn found no significant association between pneumococcal carriage and a range of health variables, including number of ear infections, recent history of antibiotic use, chronic medical condition or hospitalisation (table 1).
Table 1Demography and risk factors by carrier status
Ethnicity was the only variable which achieved significance on univariate analysis, and this remained significantly associated with pneumococcal carriage when the effect of all other demographic, day care and health variables were taken into consideration. The odds ratio for belonging to a non‐white ethnic group was 0.26 (95% CI 0.12 to 0.54) (adjusted OR 0.27 (95% CI 0.1 to 0.6)).