Influenza-like illness in a community surrounding a school-based outbreak of 2009 pandemic influenza A (H1N1) virus-Chicago, Illinois, 2009.

In April 2009, following the first school closure due to 2009 pandemic influenza A (H1N1) (pH1N1) in Chicago, Illinois, area hospitals were inundated with patients presenting with influenza-like illness (ILI). The extent of disease spread into the surrounding community was unclear. We performed a household survey to estimate the ILI attack rate among community residents and compared reported ILI with confirmed pH1N1 cases and ILI surveillance data (ie, hospital ILI visits, influenza testing, and school absenteeism). The estimated ILI attack rate was 4.6% (95% confidence interval, 2.8%-7.4%), with cases distributed throughout the 5-week study period. In contrast, 36 (84%) of 43 confirmed pH1N1 cases were identified the week of the school closure. Trends in surveillance data peaked during the same week and rapidly decreased to near baseline. Public awareness and health care practices impact standard ILI surveillance data. Community-based surveys are a valuable tool to help assess the burden of ILI in a community.

Leveraging community concerns regarding meningococcal disease to address racial and socioeconomic disparities in immunization coverage.

Following the death of 2 adolescents due to serogroup C invasive meningococcal disease (SCIMD) in April 2008, the Chicago Department of Public Health (CDPH) observed a high level of concern in 2 Chicago communities inferred to have low meningococcal vaccine (MCV) coverage rates. In response, CDPH promptly mobilized additional resources, administering 5,343 doses of MCV in 40 schools over 2 weeks and immunizing 44% of enrolled students aged 11 to 18 years. The number of eligible students vaccinated per school ranged from 9 to 466 (median, 112) and the proportion of age-eligible students receiving the vaccine ranged from 5% to 87% (median, 52%). The attributes of the SCIMD activity did not meet the definition of a community-based outbreak, but presented an opportunity to promptly intensify existing mechanisms for meningococcal vaccination of adolescents in the affected neighborhoods and overcome traditional barriers to vaccination.

Effect of a school-entry vaccination requirement on racial and ethnic disparities in hepatitis B immunization coverage levels among public school students.

OBJECTIVE: We evaluated the overall effect of Illinois' school-entry mandate on hepatitis B vaccination coverage levels and racial/ethnic differences in vaccination coverage before and after the mandate. METHODS: In 1997, the Illinois Department of Public Health mandated hepatitis B vaccination before entry into 5th grade. We conducted a retrospective cohort study of 6 consecutive Chicago public schools' 12th-grade classes; 4 entered 5th grade before the mandate (premandate cohorts) and 2 afterward (postmandate cohorts). We used Chicago public schools' vaccination database and calculated annual coverage levels for 2nd through 12th grades; the cohorts entered 12th grade during 2000-2005. We compared hepatitis B vaccination coverage levels according to race/ethnicity and coverage levels for the premandate and postmandate cohorts. RESULTS: We evaluated 106 541 students. The postmandate cohort had significantly higher hepatitis B vaccination coverage levels than the premandate cohort at 5th-grade (38.2% vs 4.3%) and 9th-grade (85.0% vs 37.4%) entry. For 9th-grade students, compared with white students, black students were less likely to have received hepatitis B vaccination before the mandate; this disparity decreased for the first postmandate cohort. For Hispanic students, the disparity was less pronounced and also decreased after the mandate. By 9th grade in the postmandate cohorts, coverage levels for all racial/ethnic groups exceeded 80%. CONCLUSIONS: There was a dramatic decrease in the disparity of hepatitis B vaccination coverage between white and black or Hispanic students. School-entry requirements effectively increased hepatitis B vaccination coverage levels regardless of race or ethnicity and should be considered for other recently recommended adolescent vaccines.