Early Estimates of Bivalent mRNA Booster Dose Vaccine Effectiveness in Preventing Symptomatic SARS-CoV-2 Infection Attributable to Omicron BA.5- and XBB/XBB.1.5-Related Sublineages Among Immunocompetent Adults - Increasing Community Access to Testing Program, United States, December 2022-January 2023.

The SARS-CoV-2 Omicron sublineage XBB was first detected in the United States in August 2022.* XBB together with a sublineage, XBB.1.5, accounted for >50% of sequenced lineages in the Northeast by December 31, 2022, and 52% of sequenced lineages nationwide as of January 21, 2023. COVID-19 vaccine effectiveness (VE) can vary by SARS-CoV-2 variant; reduced VE has been observed against some variants, although this is dependent on the health outcome of interest. The goal of the U.S. COVID-19 vaccination program is to prevent severe disease, including hospitalization and death (1); however, VE against symptomatic infection can provide useful insight into vaccine protection against emerging variants in advance of VE estimates against more severe disease. Data from the Increasing Community Access to Testing (ICATT) national pharmacy program for SARS-CoV-2 testing were analyzed to estimate VE of updated (bivalent) mRNA COVID-19 vaccines against symptomatic infection caused by BA.5-related and XBB/XBB.1.5-related sublineages among immunocompetent adults during December 1, 2022­January 13, 2023. Reduction or failure of spike gene (S-gene) amplification (SGTF) in real-time reverse transcription­polymerase chain reaction (RT-PCR) was used as a proxy indicator of infection with likely BA.5-related sublineages and S-gene target presence (SGTP) of infection with likely XBB/XBB.1.5-related sublineages (2). Among 29,175 nucleic acid amplification tests (NAATs) with SGTF or SGTP results available from adults who had previously received 2­4 monovalent COVID-19 vaccine doses, the relative VE of a bivalent booster dose given 2­3 months earlier compared with no bivalent booster in persons aged 18­49 years was 52% against symptomatic BA.5 infection and 48% against symptomatic XBB/XBB.1.5 infection. As new SARS-CoV-2 variants emerge, continued vaccine effectiveness monitoring is important. Bivalent vaccines appear to provide additional protection against symptomatic BA.5-related sublineage and XBB/XBB.1.5-related sublineage infections in persons who had previously received 2, 3, or 4 monovalent vaccine doses. All persons should stay up to date with recommended COVID-19 vaccines, including receiving a bivalent booster dose when they are eligible.

Preliminary Estimates of Effectiveness of Monovalent mRNA Vaccines in Preventing Symptomatic SARS-CoV-2 Infection Among Children Aged 3-5 Years - Increasing Community Access to Testing Program, United States, July 2022-February 2023.

On June 18, 2022, the Advisory Committee on Immunization Practices (ACIP) issued interim recommendations for use of the 2-dose monovalent Moderna COVID-19 vaccine as a primary series for children aged 6 months-5 years* and the 3-dose monovalent Pfizer-BioNTech COVID-19 vaccine as a primary series for children aged 6 months-4 years,† based on safety, immunobridging, and limited efficacy data from clinical trials (1-3). Monovalent mRNA vaccine effectiveness (VE) against symptomatic SARS-CoV-2 infection was evaluated using the Increasing Community Access to Testing (ICATT) program, which provides SARS-CoV-2 testing to persons aged ≥3 years at pharmacy and community-based testing sites nationwide§ (4,5). Among children aged 3-5 years with one or more COVID-19-like illness symptoms¶ for whom a nucleic acid amplification test (NAAT) was performed during August 1, 2022-February 5, 2023, VE of 2 monovalent Moderna doses (complete primary series) against symptomatic infection was 60% (95% CI = 49% to 68%) 2 weeks-2 months after receipt of the second dose and 36% (95% CI = 15% to 52%) 3-4 months after receipt of the second dose. Among symptomatic children aged 3-4 years with NAATs performed during September 19, 2022-February 5, 2023, VE of 3 monovalent Pfizer-BioNTech doses (complete primary series) against symptomatic infection was 31% (95% CI = 7% to 49%) 2 weeks-4 months after receipt of the third dose; statistical power was not sufficient to estimate VE stratified by time since receipt of the third dose. Complete monovalent Moderna and Pfizer-BioNTech primary series vaccination provides protection for children aged 3-5 and 3-4 years, respectively, against symptomatic infection for at least the first 4 months after vaccination. CDC expanded recommendations for use of updated bivalent vaccines to children aged ≥6 months on December 9, 2022 (6), which might provide increased protection against currently circulating SARS-CoV-2 variants (7,8). Children should stay up to date with recommended COVID-19 vaccines, including completing the primary series; those who are eligible should receive a bivalent vaccine dose.

Rising Incidence of Legionnaires' Disease and Associated Epidemiologic Patterns, United States, 1992-2018.

Reported Legionnaires' disease (LD) cases began increasing in the United States in 2003 after relatively stable numbers for >10 years; reasons for the rise are unclear. We compared epidemiologic patterns associated with cases reported to the Centers for Disease Control and Prevention before and during the rise. The age-standardized average incidence was 0.48 cases/100,000 population during 1992-2002 compared with 2.71 cases/100,000 in 2018. Reported LD incidence increased in nearly every demographic, but increases tended to be larger in demographic groups with higher incidence. During both periods, the largest number of cases occurred among White persons, but the highest incidence was in Black or African American persons. Incidence and increases in incidence were generally largest in the East North Central, Middle Atlantic, and New England divisions. Seasonality was more pronounced during 2003-2018, especially in the Northeast and Midwest. Rising incidence was most notably associated with increasing racial disparities, geographic focus, and seasonality.

Effectiveness of Bivalent mRNA Vaccines in Preventing Symptomatic SARS-CoV-2 Infection - Increasing Community Access to Testing Program, United States, September-November 2022.

On September 1, 2022, bivalent COVID-19 mRNA vaccines, composed of components from the SARS-CoV-2 ancestral and Omicron BA.4/BA.5 strains, were recommended by the Advisory Committee on Immunization Practices (ACIP) to address reduced effectiveness of COVID-19 monovalent vaccines during SARS-CoV-2 Omicron variant predominance (1). Initial recommendations included persons aged ≥12 years (Pfizer-BioNTech) and ≥18 years (Moderna) who had completed at least a primary series of any Food and Drug Administration-authorized or -approved monovalent vaccine ≥2 months earlier (1). On October 12, 2022, the recommendation was expanded to include children aged 5-11 years. At the time of recommendation, immunogenicity data were available from clinical trials of bivalent vaccines composed of ancestral and Omicron BA.1 strains; however, no clinical efficacy data were available. In this study, effectiveness of the bivalent (Omicron BA.4/BA.5-containing) booster formulation against symptomatic SARS-CoV-2 infection was examined using data from the Increasing Community Access to Testing (ICATT) national SARS-CoV-2 testing program.* During September 14-November 11, 2022, a total of 360,626 nucleic acid amplification tests (NAATs) performed at 9,995 retail pharmacies for adults aged ≥18 years, who reported symptoms consistent with COVID-19 at the time of testing and no immunocompromising conditions, were included in the analysis. Relative vaccine effectiveness (rVE) of a bivalent booster dose compared with that of ≥2 monovalent vaccine doses among persons for whom 2-3 months and ≥8 months had elapsed since last monovalent dose was 30% and 56% among persons aged 18-49 years, 31% and 48% among persons aged 50-64 years, and 28% and 43% among persons aged ≥65 years, respectively. Bivalent mRNA booster doses provide additional protection against symptomatic SARS-CoV-2 in immunocompetent persons who previously received monovalent vaccine only, with relative benefits increasing with time since receipt of the most recent monovalent vaccine dose. Staying up to date with COVID-19 vaccination, including getting a bivalent booster dose when eligible, is critical to maximizing protection against COVID-19 (1).

Effectiveness of a COVID-19 Additional Primary or Booster Vaccine Dose in Preventing SARS-CoV-2 Infection Among Nursing Home Residents During Widespread Circulation of the Omicron Variant - United States, February 14-March 27, 2022.

Nursing home residents have experienced disproportionally high levels of COVID-19-associated morbidity and mortality and were prioritized for early COVID-19 vaccination (1). Following reported declines in vaccine-induced immunity after primary series vaccination, defined as receipt of 2 primary doses of an mRNA vaccine (BNT162b2 [Pfizer-BioNTech] or mRNA-1273 [Moderna]) or 1 primary dose of Ad26.COV2 (Johnson & Johnson [Janssen]) vaccine (2), CDC recommended that all persons aged ≥12 years receive a COVID-19 booster vaccine dose.* Moderately to severely immunocompromised persons, a group that includes many nursing home residents, are also recommended to receive an additional primary COVID-19 vaccine dose.† Data on vaccine effectiveness (VE) of an additional primary or booster dose against infection with SARS-CoV-2 (the virus that causes COVID-19) among nursing home residents are limited, especially against the highly transmissible B.1.1.529 and BA.2 (Omicron) variants. Weekly COVID-19 surveillance and vaccination coverage data among nursing home residents, reported by skilled nursing facilities (SNFs) to CDC's National Healthcare Safety Network (NHSN)§ during February 14-March 27, 2022, when the Omicron variant accounted for >99% of sequenced isolates, were analyzed to estimate relative VE against infection for any COVID-19 additional primary or booster dose compared with primary series vaccination. After adjusting for calendar week and variability across SNFs, relative VE of a COVID-19 additional primary or booster dose was 46.9% (95% CI = 44.8%-48.9%). These findings indicate that among nursing home residents, COVID-19 additional primary or booster doses provide greater protection against Omicron variant infection than does primary series vaccination alone. All immunocompromised nursing home residents should receive an additional primary dose, and all nursing home residents should receive a booster dose, when eligible, to protect against COVID-19. Efforts to keep nursing home residents up to date with vaccination should be implemented in conjunction with other COVID-19 prevention strategies, including testing and vaccination of nursing home staff members and visitors.

Association of Prior BNT162b2 COVID-19 Vaccination With Symptomatic SARS-CoV-2 Infection in Children and Adolescents During Omicron Predominance.

Importance: Efficacy of 2 doses of the BNT162b2 COVID-19 vaccine (Pfizer-BioNTech) against COVID-19 was high in pediatric trials conducted before the SARS-CoV-2 Omicron variant emerged. Among adults, estimated vaccine effectiveness (VE) of 2 BNT162b2 doses against symptomatic Omicron infection was reduced compared with prior variants, waned rapidly, and increased with a booster. Objective: To evaluate the association of symptomatic infection with prior vaccination with BNT162b2 to estimate VE among children and adolescents during Omicron variant predominance. Design, Setting, and Participants: A test-negative, case-control analysis was conducted using data from 6897 pharmacy-based, drive-through SARS-CoV-2 testing sites across the US from a single pharmacy chain in the Increasing Community Access to Testing platform. This analysis included 74 208 tests from children 5 to 11 years of age and 47 744 tests from adolescents 12 to 15 years of age with COVID-19-like illness who underwent SARS-CoV-2 nucleic acid amplification testing from December 26, 2021, to February 21, 2022. Exposures: Two BNT162b2 doses 2 weeks or more before SARS-CoV-2 testing vs no vaccination for children; 2 or 3 doses 2 weeks or more before testing vs no vaccination for adolescents (who are recommended to receive a booster dose). Main Outcomes and Measures: Symptomatic infection. The adjusted odds ratio (OR) for the association of prior vaccination and symptomatic SARS-CoV-2 infection was used to estimate VE: VE = (1 - OR) × 100%. Results: A total of 30 999 test-positive cases and 43 209 test-negative controls were included from children 5 to 11 years of age, as well as 22 273 test-positive cases and 25 471 test-negative controls from adolescents 12 to 15 years of age. The median age among those with included tests was 10 years (IQR, 7-13); 61 189 (50.2%) were female, 75 758 (70.1%) were White, and 29 034 (25.7%) were Hispanic/Latino. At 2 to 4 weeks after dose 2, among children, the adjusted OR was 0.40 (95% CI, 0.35-0.45; estimated VE, 60.1% [95% CI, 54.7%-64.8%]) and among adolescents, the OR was 0.40 (95% CI, 0.29-0.56; estimated VE, 59.5% [95% CI, 44.3%-70.6%]). During month 2 after dose 2, among children, the OR was 0.71 (95% CI, 0.67-0.76; estimated VE, 28.9% [95% CI, 24.5%-33.1%]) and among adolescents, the OR was 0.83 (95% CI, 0.76-0.92; estimated VE, 16.6% [95% CI, 8.1%-24.3%]). Among adolescents, the booster dose OR 2 to 6.5 weeks after the dose was 0.29 (95% CI, 0.24-0.35; estimated VE, 71.1% [95% CI, 65.5%-75.7%]). Conclusions and Relevance: Among children and adolescents, estimated VE for 2 doses of BNT162b2 against symptomatic infection was modest and decreased rapidly. Among adolescents, the estimated effectiveness increased after a booster dose.

Association Between 3 Doses of mRNA COVID-19 Vaccine and Symptomatic Infection Caused by the SARS-CoV-2 Omicron and Delta Variants.

Importance: Assessing COVID-19 vaccine performance against the rapidly spreading SARS-CoV-2 Omicron variant is critical to inform public health guidance. Objective: To estimate the association between receipt of 3 doses of Pfizer-BioNTech BNT162b2 or Moderna mRNA-1273 vaccine and symptomatic SARS-CoV-2 infection, stratified by variant (Omicron and Delta). Design, Setting, and Participants: A test-negative case-control analysis among adults 18 years or older with COVID-like illness tested December 10, 2021, through January 1, 2022, by a national pharmacy-based testing program (4666 COVID-19 testing sites across 49 US states). Exposures: Three doses of mRNA COVID-19 vaccine (third dose ≥14 days before test and ≥6 months after second dose) vs unvaccinated and vs 2 doses 6 months or more before test (ie, eligible for a booster dose). Main Outcomes and Measures: Association between symptomatic SARS-CoV-2 infection (stratified by Omicron or Delta variants defined using S-gene target failure) and vaccination (3 doses vs unvaccinated and 3 doses vs 2 doses). Associations were measured with multivariable multinomial regression. Among cases, a secondary outcome was median cycle threshold values (inversely proportional to the amount of target nucleic acid present) for 3 viral genes, stratified by variant and vaccination status. Results: Overall, 23 391 cases (13 098 Omicron; 10 293 Delta) and 46 764 controls were included (mean age, 40.3 [SD, 15.6] years; 42 050 [60.1%] women). Prior receipt of 3 mRNA vaccine doses was reported for 18.6% (n = 2441) of Omicron cases, 6.6% (n = 679) of Delta cases, and 39.7% (n = 18 587) of controls; prior receipt of 2 mRNA vaccine doses was reported for 55.3% (n = 7245), 44.4% (n = 4570), and 41.6% (n = 19 456), respectively; and being unvaccinated was reported for 26.0% (n = 3412), 49.0% (n = 5044), and 18.6% (n = 8721), respectively. The adjusted odds ratio for 3 doses vs unvaccinated was 0.33 (95% CI, 0.31-0.35) for Omicron and 0.065 (95% CI, 0.059-0.071) for Delta; for 3 vaccine doses vs 2 doses the adjusted odds ratio was 0.34 (95% CI, 0.32-0.36) for Omicron and 0.16 (95% CI, 0.14-0.17) for Delta. Median cycle threshold values were significantly higher in cases with 3 doses vs 2 doses for both Omicron and Delta (Omicron N gene: 19.35 vs 18.52; Omicron ORF1ab gene: 19.25 vs 18.40; Delta N gene: 19.07 vs 17.52; Delta ORF1ab gene: 18.70 vs 17.28; Delta S gene: 23.62 vs 20.24). Conclusions and Relevance: Among individuals seeking testing for COVID-like illness in the US in December 2021, receipt of 3 doses of mRNA COVID-19 vaccine (compared with unvaccinated and with receipt of 2 doses) was less likely among cases with symptomatic SARS-CoV-2 infection compared with test-negative controls. These findings suggest that receipt of 3 doses of mRNA vaccine, relative to being unvaccinated and to receipt of 2 doses, was associated with protection against both the Omicron and Delta variants, although the higher odds ratios for Omicron suggest less protection for Omicron than for Delta.

Association of COVID-19 Vaccination With Symptomatic SARS-CoV-2 Infection by Time Since Vaccination and Delta Variant Predominance.

IMPORTANCE: Monitoring COVID-19 vaccine performance over time since vaccination and against emerging variants informs control measures and vaccine policies. OBJECTIVE: To estimate the associations between symptomatic SARS-CoV-2 infection and receipt of BNT162b2, mRNA-1273, and Ad26.COV2.S by day since vaccination before and during Delta variant predominance (pre-Delta period: March 13-May 29, 2021; Delta period: July 18-October 17, 2021). DESIGN, SETTING, AND PARTICIPANTS: Test-negative, case-control design with data from 6884 US COVID-19 testing sites in the pharmacy-based Increasing Community Access to Testing platform. This study included 1 634 271 laboratory-based SARS-CoV-2 nucleic acid amplification tests (NAATs) from adults 20 years and older and 180 112 NAATs from adolescents 12 to 19 years old with COVID-19-like illness from March 13 to October 17, 2021. EXPOSURES: COVID-19 vaccination (1 Ad26.COV2.S dose or 2 mRNA doses) 14 or more days prior. MAIN OUTCOMES AND MEASURES: Association between symptomatic infection and prior vaccination measured using the odds ratio (OR) from spline-based multivariable logistic regression. RESULTS: The analysis included 390 762 test-positive cases (21.5%) and 1 423 621 test-negative controls (78.5%) (59.9% were 20-44 years old; 9.9% were 12-19 years old; 58.9% were female; 71.8% were White). Among adults 20 years and older, the BNT162b2 mean OR for days 14 to 60 after a second dose (initial OR) was lower during the pre-Delta period (0.10 [95% CI, 0.09-0.11]) than during the Delta period (0.16 [95% CI, 0.16-0.17]) and increased with time since vaccination (per-month change in OR, pre-Delta: 0.04 [95% CI, 0.02-0.05]; Delta: 0.03 [95% CI, 0.02-0.03]). The initial mRNA-1273 OR was 0.05 (95% CI, 0.04-0.05) during the pre-Delta period, 0.10 (95% CI, 0.10-0.11) during the Delta period, and increased with time (per-month change in OR, pre-Delta: 0.02 [95% CI, 0.005-0.03]; Delta: 0.03 [95% CI, 0.03-0.04]). The Ad26.COV2.S initial OR was 0.42 (95% CI, 0.37-0.47) during the pre-Delta period and 0.62 (95% CI, 0.58-0.65) during the Delta period and did not significantly increase with time since vaccination. Among adolescents, the BNT162b2 initial OR during the Delta period was 0.06 (95% CI, 0.05-0.06) among 12- to 15-year-olds, increasing by 0.02 (95% CI, 0.01-0.03) per month, and 0.10 (95% CI, 0.09-0.11) among 16- to 19-year-olds, increasing by 0.04 (95% CI, 0.03-0.06) per month. CONCLUSIONS AND RELEVANCE: Among adults, the OR for the association between symptomatic SARS-CoV-2 infection and COVID-19 vaccination (as an estimate of vaccine effectiveness) was higher during Delta variant predominance, suggesting lower protection. For mRNA vaccination, the steady increase in OR by month since vaccination was consistent with attenuation of estimated effectiveness over time; attenuation related to time was greater than that related to variant.

Typhoid Fever in the US Pediatric Population, 1999-2015: Opportunities for Improvement.

BACKGROUND: Typhoid fever in the United States is acquired primarily through international travel by unvaccinated travelers. There is currently no typhoid vaccine licensed in the United States for use in children <2 years. METHODS: We reviewed Salmonella enterica serotype Typhi infections reported to the Centers for Disease Control and Prevention (CDC) and antimicrobial-resistance data on Typhi isolates in CDC's National Antimicrobial Resistance Monitoring System from 1999 through 2015. RESULTS: 5131 cases of typhoid fever were diagnosed and 5004 Typhi isolates tested for antimicrobial susceptibility. Among 1992 pediatric typhoid fever patients, 1616 (81%) had traveled internationally within 30 days of illness onset, 1544 (81%) of 1906 were hospitalized (median duration, 6 days; range, 0-50), and none died. Forty percent (799) were <6 years old; 12% were <2 years old. Based on age and travel destination, 1435 (83%) of 1722 pediatric patients were vaccine-eligible; only 68 (5%) of 1361 were known to be vaccinated. Of 2003 isolates tested for antimicrobial susceptibility, 1216 (61%) were fluoroquinolone-nonsusceptible, of which 272 (22%) were also resistant to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole (multidrug-resistant [MDR]). All were susceptible to ceftriaxone and azithromycin. MDR and fluoroquinolone-nonsusceptible isolates were more common in children than adults (16% vs 9%, P < .001, and 61% vs 54%, P < .001, respectively). Fluoroquinolone nonsusceptibility was more common among travel-associated than domestically acquired cases (70% vs 17%, P < .001). CONCLUSIONS: Approximately 95% of currently vaccine-eligible pediatric travelers were unvaccinated, and antimicrobial-resistant infections were common. New public health strategies are needed to improve coverage with currently licensed vaccines. Introduction of an effective pretravel typhoid vaccine for children <2 years could reduce disease burden and prevent drug-resistant infections.

Positive Correlation Between Candida auris Skin-Colonization Burden and Environmental Contamination at a Ventilator-Capable Skilled Nursing Facility in Chicago.

BACKGROUND: Candida auris is an emerging multidrug-resistant yeast that contaminates healthcare environments causing healthcare-associated outbreaks. The mechanisms facilitating contamination are not established. METHODS: C. auris was quantified in residents' bilateral axillary/inguinal composite skin swabs and environmental samples during a point-prevalence survey at a ventilator-capable skilled-nursing facility (vSNF A) with documented high colonization prevalence. Environmental samples were collected from all doorknobs, windowsills and handrails of each bed in 12 rooms. C. auris concentrations were measured using culture and C. auris-specific quantitative polymerase chain reaction (qPCR) The relationship between C. auris concentrations in residents' swabs and associated environmental samples were evaluated using Kendall's tau-b (τ b) correlation coefficient. RESULTS: C. auris was detected in 70/100 tested environmental samples and 31/57 tested resident skin swabs. The mean C. auris concentration in skin swabs was 1.22 × 105 cells/mL by culture and 1.08 × 106 cells/mL by qPCR. C. auris was detected on all handrails of beds occupied by colonized residents, as well as 10/24 doorknobs and 9/12 windowsills. A positive correlation was identified between the concentrations of C. auris in skin swabs and associated handrail samples based on culture (τ b = 0.54, P = .0004) and qPCR (τ b = 0.66, P = 3.83e-6). Two uncolonized residents resided in beds contaminated with C. auris. CONCLUSIONS: Colonized residents can have high C. auris burdens on their skin, which was positively related with contamination of their surrounding healthcare environment. These findings underscore the importance of hand hygiene, transmission-based precautions, and particularly environmental disinfection in preventing spread in healthcare facilities.

Risk Factors for Coronavirus Disease 2019 (COVID-19)-Associated Hospitalization: COVID-19-Associated Hospitalization Surveillance Network and Behavioral Risk Factor Surveillance System.

BACKGROUND: Data on risk factors for coronavirus disease 2019 (COVID-19)-associated hospitalization are needed to guide prevention efforts and clinical care. We sought to identify factors independently associated with COVID-19-associated hospitalizations. METHODS: Community-dwelling adults (aged ≥18 years) in the United States hospitalized with laboratory-confirmed COVID-19 during 1 March-23 June 2020 were identified from the COVID-19-Associated Hospitalization Surveillance Network (COVID-NET), a multistate surveillance system. To calculate hospitalization rates by age, sex, and race/ethnicity strata, COVID-NET data served as the numerator and Behavioral Risk Factor Surveillance System estimates served as the population denominator for characteristics of interest. Underlying medical conditions examined included hypertension, coronary artery disease, history of stroke, diabetes, obesity, severe obesity, chronic kidney disease, asthma, and chronic obstructive pulmonary disease. Generalized Poisson regression models were used to calculate adjusted rate ratios (aRRs) for hospitalization. RESULTS: Among 5416 adults, hospitalization rates (all reported as aRR [95% confidence interval]) were higher among those with ≥3 underlying conditions (vs without) (5.0 [3.9-6.3]), severe obesity (4.4 [3.4-5.7]), chronic kidney disease (4.0 [3.0-5.2]), diabetes (3.2 [2.5-4.1]), obesity (2.9 [2.3-3.5]), hypertension (2.8 [2.3-3.4]), and asthma (1.4 [1.1-1.7]), after adjusting for age, sex, and race/ethnicity. Adjusting for the presence of an individual underlying medical condition, higher hospitalization rates were observed for adults aged ≥65 or 45-64 years (vs 18-44 years), males (vs females), and non-Hispanic black and other race/ethnicities (vs non-Hispanic whites). CONCLUSIONS: Our findings elucidate groups with higher hospitalization risk that may benefit from targeted preventive and therapeutic interventions.

Estimate of Burden and Direct Healthcare Cost of Infectious Waterborne Disease in the United States.

Provision of safe drinking water in the United States is a great public health achievement. However, new waterborne disease challenges have emerged (e.g., aging infrastructure, chlorine-tolerant and biofilm-related pathogens, increased recreational water use). Comprehensive estimates of the health burden for all water exposure routes (ingestion, contact, inhalation) and sources (drinking, recreational, environmental) are needed. We estimated total illnesses, emergency department (ED) visits, hospitalizations, deaths, and direct healthcare costs for 17 waterborne infectious diseases. About 7.15 million waterborne illnesses occur annually (95% credible interval [CrI] 3.88 million-12.0 million), results in 601,000 ED visits (95% CrI 364,000-866,000), 118,000 hospitalizations (95% CrI 86,800-150,000), and 6,630 deaths (95% CrI 4,520-8,870) and incurring US $3.33 billion (95% CrI 1.37 billion-8.77 billion) in direct healthcare costs. Otitis externa and norovirus infection were the most common illnesses. Most hospitalizations and deaths were caused by biofilm-associated pathogens (nontuberculous mycobacteria, Pseudomonas, Legionella), costing US $2.39 billion annually.

Effectiveness of the Pfizer-BioNTech COVID-19 Vaccine Among Residents of Two Skilled Nursing Facilities Experiencing COVID-19 Outbreaks - Connecticut, December 2020-February 2021.

Residents of long-term care facilities (LTCFs), particularly those in skilled nursing facilities (SNFs), have experienced disproportionately high levels of COVID-19-associated morbidity and mortality and were prioritized for early COVID-19 vaccination (1,2). However, this group was not included in COVID-19 vaccine clinical trials, and limited postauthorization vaccine effectiveness (VE) data are available for this critical population (3). It is not known how well COVID-19 vaccines protect SNF residents, who typically are more medically frail, are older, and have more underlying medical conditions than the general population (1). In addition, immunogenicity of the Pfizer-BioNTech vaccine was found to be lower in adults aged 65-85 years than in younger adults (4). Through the CDC Pharmacy Partnership for Long-Term Care Program, SNF residents and staff members in Connecticut began receiving the Pfizer-BioNTech COVID-19 vaccine on December 18, 2020 (5). Administration of the vaccine was conducted during several on-site pharmacy clinics. In late January 2021, the Connecticut Department of Public Health (CT DPH) identified two SNFs experiencing COVID-19 outbreaks among residents and staff members that occurred after each facility's first vaccination clinic. CT DPH, in partnership with CDC, performed electronic chart review in these facilities to obtain information on resident vaccination status and infection with SARS-CoV-2, the virus that causes COVID-19. Partial vaccination, defined as the period from >14 days after the first dose through 7 days after the second dose, had an estimated effectiveness of 63% (95% confidence interval [CI] = 33%-79%) against SARS-CoV-2 infection (regardless of symptoms) among residents within these SNFs. This is similar to estimated effectiveness for a single dose of the Pfizer-BioNTech COVID-19 vaccine in adults across a range of age groups in noncongregate settings (6) and suggests that to optimize vaccine impact among this population, high coverage with the complete 2-dose series should be recommended for SNF residents and staff members.

Effectiveness of Pfizer-BioNTech and Moderna Vaccines in Preventing SARS-CoV-2 Infection Among Nursing Home Residents Before and During Widespread Circulation of the SARS-CoV-2 B.1.617.2 (Delta) Variant - National Healthcare Safety Network, March 1-August 1, 2021.

Nursing home and long-term care facility residents live in congregate settings and are often elderly and frail, putting them at high risk for infection with SARS-CoV-2, the virus that causes COVID-19, and severe COVID-19-associated outcomes; therefore, this population was prioritized for early vaccination in the United States (1). Following rapid distribution and administration of the mRNA COVID-19 vaccines (Pfizer-BioNTech and Moderna) under an Emergency Use Authorization by the Food and Drug Administration (2), observational studies among nursing home residents demonstrated vaccine effectiveness (VE) ranging from 53% to 92% against SARS-CoV-2 infection (3-6). However, concerns about the potential for waning vaccine-induced immunity and the recent emergence of the highly transmissible SARS-CoV-2 B.1.617.2 (Delta) variant† highlight the need to continue to monitor VE (7). Weekly data reported by the Centers for Medicaid & Medicare (CMS)-certified skilled nursing facilities or nursing homes to CDC's National Healthcare Safety Network (NHSN)§ were analyzed to evaluate effectiveness of full vaccination (2 doses received ≥14 days earlier) with any of the two currently authorized mRNA COVID-19 vaccines during the period soon after vaccine introduction and before the Delta variant was circulating (pre-Delta [March 1-May 9, 2021]), and when the Delta variant predominated¶ (Delta [June 21-August 1, 2021]). Using 17,407 weekly reports from 3,862 facilities from the pre-Delta period, adjusted effectiveness against infection for any mRNA vaccine was 74.7% (95% confidence interval [CI] = 70.0%-78.8%). Analysis using 33,160 weekly reports from 11,581 facilities during an intermediate period (May 10-June 20) found that the adjusted effectiveness was 67.5% (95% CI = 60.1%-73.5%). Analysis using 85,593 weekly reports from 14,917 facilities during the Delta period found that the adjusted effectiveness was 53.1% (95% CI = 49.1%-56.7%). Effectiveness estimates were similar for Pfizer-BioNTech and Moderna vaccines. These findings indicate that mRNA vaccines provide protection against SARS-CoV-2 infection among nursing home residents; however, VE was lower after the Delta variant became the predominant circulating strain in the United States. This analysis assessed VE against any infection, without being able to distinguish between asymptomatic and symptomatic presentations. Additional evaluations are needed to understand protection against severe disease in nursing home residents over time. Because nursing home residents might remain at some risk for SARS-CoV-2 infection despite vaccination, multiple COVID-19 prevention strategies, including infection control, testing, and vaccination of nursing home staff members, residents, and visitors, are critical. An additional dose of COVID-19 vaccine might be considered for nursing home and long-term care facility residents to optimize a protective immune response.

Case-Case Comparison of Candida auris Versus Other Candida Species Bloodstream Infections: Results of an Outbreak Investigation in Colombia.

BACKGROUND: Candida auris is an emerging multidrug-resistant yeast that causes outbreaks in healthcare settings around the world. In 2016, clinicians and public health officials identified patients with C. auris bloodstream infections (BSI) in Colombian healthcare facilities. To evaluate potential risk factors and outcomes for these infections, we investigated epidemiologic and clinical features of patients with C. auris and other Candida species BSI. METHODS: We performed a retrospective case-case investigation in four Colombian acute care hospitals, defining a case as Candida spp. isolated from blood culture during January 2015-September 2016. C. auris BSI cases were compared to other Candida species BSI cases. Odds ratio (OR), estimated using logistic regression, was used to assess the association between risk factors and outcomes. RESULTS: We analyzed 90 patients with BSI, including 40 with C. auris and 50 with other Candida species. All had been admitted to the intensive care unit (ICU). No significant demographic differences existed between the two groups. The following variables were independently associated with C. auris BSI: ≥ 15 days of pre-infection ICU stay (OR: 5.62, CI: 2.04-15.5), evidence of severe sepsis (OR: 3.70, CI 1.19-11.48), and diabetes mellitus (OR 5.69, CI 1.01-31.9). CONCLUSION: Patients with C. auris BSI had longer lengths of ICU stay than those with other candidemias, suggesting that infections are acquired during hospitalization. This is different from other Candida infections, which are usually thought to result from autoinfection with host flora.

PCR-Based Method for Shigella flexneri Serotyping: International Multicenter Validation.

Shigella spp. are a leading cause of human diarrheal disease worldwide, with Shigella flexneri being the most frequently isolated species in developing countries. This serogroup is presently classified into 19 serotypes worldwide. We report here a multicenter validation of a multiplex-PCR-based strategy previously developed by Q. Sun, R. Lan, Y. Wang, A. Zhao, et al. (J Clin Microbiol 49:3766-3770, 2011) for molecular serotyping of S. flexneri This study was performed by seven international laboratories, with a panel of 71 strains (researchers were blind to their identity) as well as 279 strains collected from each laboratory's own local culture collections. This collaborative work found a high extent of agreement among laboratories, calculated through interrater reliability (IRR) measures for the PCR test that proved its robustness. Agreement with the traditional method (serology) was also observed in all laboratories for 14 serotypes studied, while specific genetic events could be responsible for the discrepancies among methodologies in the other 5 serotypes, as determined by PCR product sequencing in most of the cases. This work provided an empirical framework that allowed the use of this molecular method to serotype S. flexneri and showed several advantages over the traditional method of serological typing. These advantages included overcoming the problem of availability of suitable antisera in testing laboratories as well as facilitating the analysis of multiple samples at the same time. The method is also less time-consuming for completion and easier to implement in routine laboratories. We recommend that this PCR be adopted, as it is a reliable diagnostic and characterization methodology that can be used globally for laboratory-based shigella surveillance.

Cholera Epidemic - Lusaka, Zambia, October 2017-May 2018.

On October 6, 2017, an outbreak of cholera was declared in Zambia after laboratory confirmation of Vibrio cholerae O1, biotype El Tor, serotype Ogawa, from stool specimens from two patients with acute watery diarrhea. The two patients had gone to a clinic in Lusaka, the capital city, on October 4. Cholera cases increased rapidly, from several hundred cases in early December 2017 to approximately 2,000 by early January 2018 (Figure). In collaboration with partners, the Zambia Ministry of Health (MoH) launched a multifaceted public health response that included increased chlorination of the Lusaka municipal water supply, provision of emergency water supplies, water quality monitoring and testing, enhanced surveillance, epidemiologic investigations, a cholera vaccination campaign, aggressive case management and health care worker training, and laboratory testing of clinical samples. In late December 2017, a number of water-related preventive actions were initiated, including increasing chlorine levels throughout the city's water distribution system and placing emergency tanks of chlorinated water in the most affected neighborhoods; cholera cases declined sharply in January 2018. During January 10-February 14, 2018, approximately 2 million doses of oral cholera vaccine were administered to Lusaka residents aged ≥1 year. However, in mid-March, heavy flooding and widespread water shortages occurred, leading to a resurgence of cholera. As of May 12, 2018, the outbreak had affected seven of the 10 provinces in Zambia, with 5,905 suspected cases and a case fatality rate (CFR) of 1.9%. Among the suspected cases, 5,414 (91.7%), including 98 deaths (CFR = 1.8%), occurred in Lusaka residents.

Association of water quality with soil-transmitted helminthiasis and diarrhea in Nueva Santa Rosa, Guatemala, 2010.

Improved water quality reduces diarrhea, but the impact of improved water quality on Ascaris and Trichuris, soil-transmitted helminths (STH) conveyed by the fecal-oral route, is less well described. To assess water quality associations with diarrhea and STH, we conducted a cross-sectional survey in households of south-eastern Guatemala. Diarrhea was self-reported in the past week and month. STH was diagnosed by stool testing using a fecal parasite concentrator method. We explored associations between Escherichia coli-positive source water (water quality) and disease outcomes using survey logistic regression models. Overall, 732 persons lived in 167 households where water was tested. Of these, 79.4% (581/732) had E. coli-positive water, 7.9% (58/732) had diarrhea within the week, 14.1% (103/732) had diarrhea within the month, and 6.6% (36/545) tested positive for Ascaris or Trichuris, including 1% (6/536) who also reported diarrhea. Univariable analysis found a statistically significant association between water quality and STH (odds ratio [OR] = 5.1, 95% confidence interval [CI] = 1.1-24.5) but no association between water quality and diarrhea. Waterborne transmission and effects of water treatment on STH prevalence should be investigated further. If a causal relationship is found, practices such as household water treatment including filtration might be useful adjuncts to sanitation, hygiene, and deworming in STH control programs.

Sporotrichosis-Associated Hospitalizations, United States, 2000-2013.

To determine frequency and risk for sporotrichosis-associated hospitalizations, we analyzed the US 2000-2013 National (Nationwide) Inpatient Sample. An estimated 1,471 hospitalizations occurred (average annual rate 0.35/1 million persons). Hospitalizations were associated with HIV/AIDS, immune-mediated inflammatory diseases, and chronic obstructive pulmonary disease. Although rare, severe sporotrichosis should be considered for at-risk patients.