Measles Outbreak Associated with a Migrant Shelter - Chicago, Illinois, February-May 2024.

Measles, a highly contagious respiratory virus with the potential to cause severe complications, hospitalization, and death, was declared eliminated from the United States in 2000; however, with ongoing global transmission, infections in the United States still occur. On March 7, 2024, the Chicago Department of Public Health (CDPH) confirmed a case of measles in a male aged 1 year residing in a temporary shelter for migrants in Chicago. Given the congregate nature of the setting, high transmissibility of measles, and low measles vaccination coverage among shelter residents, measles virus had the potential to spread rapidly among approximately 2,100 presumed exposed shelter residents. CDPH immediately instituted outbreak investigation and response activities in collaboration with state and local health departments, health care facilities, city agencies, and shelters. On March 8, CDPH implemented active case-finding and coordinated a mass vaccination campaign at the affected shelter (shelter A), including vaccinating 882 residents and verifying previous vaccination for 784 residents over 3 days. These activities resulted in 93% measles vaccination coverage (defined as receipt of ≥1 recorded measles vaccine dose) by March 11. By May 13, a total of 57 confirmed measles cases associated with residing in or having contact with persons from shelter A had been reported. Most cases (41; 72%) were among persons who did not have documentation of measles vaccination and were considered unvaccinated. In addition, 16 cases of measles occurred among persons who had received ≥1 measles vaccine dose ≥21 days before first known exposure. This outbreak underscores the need to ensure high vaccination coverage among communities residing in congregate settings.

Community-Based Testing for SARS-CoV-2 - Chicago, Illinois, May-November 2020.

On May 13, 2020, Chicago established a free community-based testing (CBT) initiative for SARS-CoV-2, the virus that causes COVID-19, using reverse transcription-polymerase chain reaction (RT-PCR). The initiative focused on demographic groups and geographic areas that were underrepresented in testing by clinical providers and had experienced high COVID-19 incidence, including Hispanic persons and those who have been economically marginalized. To assess the CBT initiative, the Chicago Department of Public Health (CDPH) compared demographic characteristics, economic marginalization, and test positivity between persons tested at CBT sites and persons tested in all other testing settings in Chicago. During May 13-November 14, a total of 253,904 SARS-CoV-2 RT-PCR tests were conducted at CBT sites. Compared with those tested in all other testing settings in Chicago, persons tested at CBT sites were more likely to live in areas that are economically marginalized (38.6% versus 32.0%; p<0.001) and to be Hispanic (50.9% versus 20.7%; p<0.001). The cumulative percentage of positive test results at the CBT sites was higher than that at all other testing settings (11.1% versus 7.1%; p<0.001). These results demonstrate the ability of public health departments to establish community-based testing initiatives that reach communities with less access to testing in other settings and that experience disproportionately higher incidences of COVID-19.

Challenges with hepatitis B vaccination of high risk adults - A pilot program.

BACKGROUND: Acute hepatitis B virus (HBV) infections in the United States occur predominantly among persons aged 30-59 years. The Centers for Disease Control and Prevention (CDC) recommends vaccination of adults at increased risk for HBV infection. Completing the hepatitis B (HepB) vaccine dose-series is critical for optimal immune response. OBJECTIVES: CDC funded 14 health departments (awardees) from 2012 to 2015 to implement a pilot HepB vaccination program for high-risk adults. We evaluated the pilot program to assess vaccine utilization; vaccine dose-series completion, including by vaccination location type; and implementation challenges. METHODS: Awardees collaborated with sites providing health care to persons at increased risk for HBV infection. Awardees collected information on doses administered, vaccine dose-series completion, and challenges completing and tracking vaccinations, including use of immunization information systems (IIS). Data were reported by each awardee in aggregate to CDC. RESULTS: Six of 14 awardees administered 47,911 doses and were able to report patient-level dose-series completion. Among persons who received dose 1, 40.4% received dose 2, and 22.3% received dose 3. Local health department clinics had the highest 3-dose-series completion, 60.6% (531/876), followed by federally qualified health centers at 38.0% (923/2432). While sexually transmitted diseases (STD) clinics administered the most doses in total (17,173 [35.8% of 47,911 doses]), 3-dose-series completion was low (17.1%). The 14 awardees reported challenges regarding completing and tracking dose-series, including reaching high-risk adults for follow-up and inconsistencies in use of IIS or other tracking systems across sites. CONCLUSIONS: Dose-series completion was low in all settings, but lowest where patients may be less likely to return for follow-up (e.g., STD clinics). Routinely assessing HepB vaccination needs of high-risk adults, including through use of IIS where available, may facilitate HepB vaccine dose-series completion.

Successful Use of Interventions in Combination to Improve Human Papillomavirus Vaccination Coverage Rates Among Adolescents-Chicago, 2013 to 2015.

In 2013, National Immunization Survey-Teen data indicated that >40% of female adolescents had not initiated the human papillomavirus (HPV) vaccine series and >60% had not completed the series, documenting vaccination rates much lower than those for other vaccines recommended for adolescents. The Chicago Department of Public Health (CDPH) was 1 of 22 jurisdictions nationwide to receive a Prevention and Public Health Fund award through the Centers for Disease Control and Prevention to improve HPV vaccination rates among adolescents. The CDPH implemented 5 interventions targeting the public, clinicians and their staff, and diverse immunization and cancer prevention stakeholders. Compared with 2013 jurisdiction-specific HPV vaccination rates among all adolescents, Chicago's HPV vaccination rates were increased significantly in 2014 and 2015. This article details the methods and results of Chicago's successful interventions, the particular strengths as well as barriers encountered, and future steps necessary for sustaining improvement.