Assessment of contact tracing for COVID-19 among people experiencing homelessness, Salt Lake County Health Department, March-May 2020.

PURPOSE: Contact tracing is intended to reduce the spread of coronavirus disease 2019 (COVID-19), but it is difficult to conduct among people who live in congregate settings, including people experiencing homelessness (PEH). This analysis compares person-based contact tracing among two populations in Salt Lake County, Utah, from March-May 2020. METHODS: All laboratory-confirmed positive cases among PEH (n = 169) and documented in Utah's surveillance system were included in this analysis. The general population comparison group (n = 163) were systematically selected from all laboratory-confirmed cases identified during the same period. RESULTS: Ninety-three PEH cases (55%) were interviewed compared to 163 (100%) cases among the general population (P < .0001). PEH were more likely to be lost to follow-up at end of isolation (14.2%) versus the general population (0%; P-value < .0001) and provided fewer contacts per case (0.3) than the general population (4.7) (P-value < .0001). Contacts of PEH were more often unreachable (13.0% vs. 7.1%; P-value < .0001). CONCLUSIONS: These findings suggest that contact tracing among PEH should include a location-based approach, along with a person-based approach when resources allow, due to challenges in identifying, locating, and reaching cases among PEH and their contacts through person-based contact tracing efforts alone.

Human Rabies - Utah, 2018.

On November 3, 2018, the Utah Department of Health (UDOH) was notified of a suspected human rabies case in a man aged 55 years. The patient's symptoms had begun 18 days earlier, and he was hospitalized for 15 days before rabies was suspected. As his symptoms worsened, he received supportive care, but he died on November 4. On November 7, a diagnosis of rabies was confirmed by CDC. This was the first documented rabies death in a Utah resident since 1944. This report summarizes the patient's clinical course and the subsequent public health investigation, which determined that the patient had handled several bats in the weeks preceding symptom onset. Public health agencies, in partnership with affected health care facilities, identified and assessed the risk to potentially exposed persons, facilitated receipt of postexposure prophylaxis (PEP), and provided education to health care providers and the community about the risk for rabies associated with bats. Human rabies is rare and almost always fatal. The findings from this investigation highlight the importance of early recognition of rabies, improved public awareness of rabies in bats, and the use of innovative tools after mass rabies exposure events to ensure rapid and recommended risk assessment and provision of PEP.

Hepatitis A Virus Outbreaks Associated with Drug Use and Homelessness - California, Kentucky, Michigan, and Utah, 2017.

During 2017, CDC received 1,521 reports of acute hepatitis A virus (HAV) infections from California, Kentucky, Michigan, and Utah; the majority of infections were among persons reporting injection or noninjection drug use or homelessness. Investigations conducted by local and state health departments indicated that direct person-to-person transmission of HAV infections was occurring, differing from other recent, large HAV outbreaks attributed to consumption of contaminated commercial food products. Outbreaks with direct HAV transmission among persons reporting drug use or homelessness signals a shift in HAV infection epidemiology in the United States, and vaccination of these populations at high risk can prevent future outbreaks.

Outbreak of E. coli O157:H7 Infections Associated with Exposure to Animal Manure in a Rural Community - Arizona and Utah, June-July 2017.

On June 26, 2017, a hospital in southern Utah notified the Utah Department of Health of Shiga toxin-producing Escherichia coli (STEC) O157:H7 infections in two children from a small community on the Arizona-Utah border. Both children developed hemolytic uremic syndrome, characterized by hemolytic anemia, acute kidney failure, and thrombocytopenia and died within a few days of illness onset. Over the next few days, several more STEC-associated illnesses were reported in residents of the community. A joint investigation by local and state health agencies from Arizona and Utah and CDC was initiated to identify the outbreak source and prevent additional cases; a total of 12 cases were identified, including the two children who died. Investigators initially explored multiple potential sources of illness; epidemiologic and environmental information revealed cow manure contact as the likely initial cause of the outbreak, which was followed by subsequent person-to-person transmission. One of the outbreak strains was isolated from bull and horse manure collected from a yard near a community household with two ill children. Local health agencies made recommendations to the public related to both animal contact and hand hygiene to reduce the risk for STEC transmission. Animal or animal manure contact should be considered a potential source of STEC O157:H7 during outbreaks in communities where ruminants are kept near the home.

Bias with respect to socioeconomic status: A closer look at zip code matching in a pneumococcal vaccine effectiveness study.

In 2010, 13-valent pneumococcal conjugate vaccine (PCV13) was introduced in the US for prevention of invasive pneumococcal disease in children. Individual-level socioeconomic status (SES) is a potential confounder of the estimated effectiveness of PCV13 and is often controlled for in observational studies using zip code as a proxy. We assessed the utility of zip code matching for control of SES in a post-licensure evaluation of the effectiveness of PCV13 (calculated as [1-matched odds ratio]*100). We used a directed acyclic graph to identify subsets of confounders and collected SES variables from birth certificates, geo-coding, a parent interview, and follow-up with medical providers. Cases tended to be more affluent than eligible controls (for example, 48.3% of cases had private insurance vs. 44.6% of eligible controls), but less affluent than enrolled controls (52.9% of whom had private insurance). Control of confounding subsets, however, did not result in a meaningful change in estimated vaccine effectiveness (original estimate: 85.1%, 95% CI 74.8-91.9%; adjusted estimate: 82.5%, 95% CI 65.6-91.1%). In the context of a post-licensure vaccine effectiveness study, zip code appears to be an adequate, though not perfect, proxy for individual SES.

Effectiveness of 13-valent pneumococcal conjugate vaccine for prevention of invasive pneumococcal disease in children in the USA: a matched case-control study.

BACKGROUND: In 2010, 13-valent pneumococcal conjugate vaccine (PCV13) was licensed and recommended in the USA for prevention of invasive pneumococcal disease in children. Licensure was based on immunogenicity data comparing PCV13 with the earlier seven-valent formulation. Because clinical endpoints were not assessed for the new antigens, we did a postlicensure matched case-control study to assess vaccine effectiveness. METHODS: Cases in children aged 2-59 months were identified through active surveillance in 13 sites. Controls were identified via birth registries and matched to cases by age and postal (zip) code. The primary objective was the vaccine effectiveness of at least one dose against the 13 serotypes included in PCV13. Secondary objectives included vaccine effectiveness against all-cause invasive pneumococcal disease, against antibiotic non-susceptible invasive pneumococcal disease, and among children with and without underlying conditions. Vaccine effectiveness was calculated as (1 - matched odds ratio) × 100%. FINDINGS: We enrolled 722 children with invasive pneumococcal disease and 2991 controls; PCV13 serotype cases (217 [30%]) included most commonly serotypes 19A (128 [18%]), 7F (32 [4%]), and 3 (43 [6%]). Vaccine effectiveness against PCV13 serotypes was 86·0% (95% CI 75·5 to 92·3), driven by serotypes 19A and 7F, for which vaccine effectiveness was 85·6% (95% CI 70·6 to 93·5) and 96·5% (82·7 to 100), respectively. We also identified statistically significant effectiveness against serotype 3 (79·5%, 95% CI 30·3 to 94·8) and against antibiotic non-susceptible invasive pneumococcal disease (65·6%, 44·9 to 78·7). Vaccine effectiveness against all-cause invasive pneumococcal disease was 60·2% (95% CI 46·8 to 70·3). Vaccine effectiveness was similar among children with (81·4%, 95% CI 45·4 to 93·6) and without (85·8%, 74·9 to 91·9) underlying conditions. INTERPRETATION: PCV13 appears highly effective against invasive pneumococcal disease among children in the USA in the context of routine and catch-up schedules, although some new vaccine antigens could not be assessed. PCV13 immunisation provides a robust strategy for combating pneumococcal antimicrobial resistance. FUNDING: Centers for Disease Control and Prevention.