Last data update: Jan 27, 2025. (Total: 48650 publications since 2009)
Records 1-30 (of 70 Records) |
Query Trace: Silk BJ[original query] |
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Surveillance of human adenovirus types and the impact of the COVID-19 pandemic on reporting - United States, 2017-2023
Abdirizak F , Winn AK , Parikh R , Scobie HM , Lu X , Vega E , Almendares O , Kirking HL , Rose EB , Silk BJ . MMWR Morb Mortal Wkly Rep 2024 73 (50) 1136-1141 Human adenoviruses (HAdVs) are typically associated with mild respiratory illnesses, although severe disease and outbreaks in congregate settings occur. The National Adenovirus Type Reporting System (NATRS) is a passive, laboratory-based surveillance system that monitors trends in circulation of HAdV types in the United States. This report summarizes the distribution of HAdV types reported to NATRS during 2017-2023. During this 7-year period, 2,241 HAdV specimens with typing results were reported to NATRS. The number of specimens with HAdV typing results reported varied annually during 2017-2019 (range = 389-562) and declined during 2020-2023 (range = 58-356). During 2017-2023, six HAdV types (1-4, 7, and 14) accounted for 88.3% of typed specimens reported; 17.0% of specimens were identified as outbreak-related. An increase in type 41 reporting was associated with a hepatitis cluster during 2021-2022. Reporting to NATRS has declined since the COVID-19 pandemic, despite continued HAdV circulation reported through passive laboratory surveillance to the National Respiratory and Enteric Virus Surveillance System. Enhanced participation in NATRS is needed to improve monitoring of circulating HAdV types. |
Genomic surveillance for SARS-CoV-2 variants: Circulation of Omicron XBB and JN.1 lineages - United States, May 2023-September 2024
Ma KC , Castro J , Lambrou AS , Rose EB , Cook PW , Batra D , Cubenas C , Hughes LJ , MacCannell DR , Mandal P , Mittal N , Sheth M , Smith C , Winn A , Hall AJ , Wentworth DE , Silk BJ , Thornburg NJ , Paden CR . MMWR Morb Mortal Wkly Rep 2024 73 (42) 938-945 ![]() ![]() CDC continues to track the evolution of SARS-CoV-2, including the Omicron variant and its descendants, using national genomic surveillance. This report summarizes U.S. trends in variant proportion estimates during May 2023-September 2024, a period when SARS-CoV-2 lineages primarily comprised descendants of Omicron variants XBB and JN.1. During summer and fall 2023, multiple descendants of XBB with immune escape substitutions emerged and reached >10% prevalence, including EG.5-like lineages by June 24, FL.1.5.1-like lineages by August 5, HV.1 lineage by September 30, and HK.3-like lineages by November 11. In winter 2023, the JN.1 variant emerged in the United States and rapidly attained predominance nationwide, representing a substantial genetic shift (>30 spike protein amino acid differences) from XBB lineages. Descendants of JN.1 subsequently circulated and reached >10% prevalence, including KQ.1-like and KP.2-like lineages by April 13, KP.3 and LB.1-like lineages by May 25, and KP.3.1.1 by July 20. Surges in COVID-19 cases occurred in winter 2024 during the shift to JN.1 predominance, as well as in summer 2023 and 2024 during circulation of multiple XBB and JN.1 descendants, respectively. The ongoing evolution of the Omicron variant highlights the importance of continued genomic surveillance to guide medical countermeasure development, including the selection of antigens for updated COVID-19 vaccines. |
A health equity science approach to assessing drivers of COVID-19 vaccination coverage disparities over the course of the COVID-19 pandemic, United States, December 2020-December 2022
Woolfork MN , Haire K , Farinu O , Ruffin J , Nelson JM , Coronado F , Silk BJ , Harris L , Walker C , Manns BJ . Vaccine 2024 126158 INTRODUCTION: Health equity science examines underlying social determinants, or drivers, of health inequities by building an evidence base to guide action across programs, public health surveillance, policy, and communications efforts. A Social Vulnerability Index (SVI) was utilized during the COVID-19 response to identify areas where inequities exist and support communities with vaccination. We set out to assess COVID-19 vaccination coverage by two SVI themes, Racial and Ethnicity Minority Status and Housing Type and Transportation to examine disparities. METHODS: US county-level COVID-19 vaccine administration data among persons aged 5 years and older reported to the Centers for Disease Control and Prevention from December 14, 2020 to December 14, 2022, were analyzed. Counties were categorized 1) into tertiles (low, moderate, high) according to each SVI theme's level of vulnerability or 2) dichotomized by urban or rural classification. Primary series vaccination coverage per age group were assessed for SVI social factors by SVI theme tertiles or urbanicity. RESULTS: Older adults aged 65 years and older had the highest vaccination coverage across all vulnerability factors compared with children aged 5-17 years and adults aged 18-64 years. Overall, children and adults had higher vaccination coverage in counties of high vulnerability. Greater vaccination coverage differences were observed by urbanicity as rural counties had some of the lowest vaccination coverage for children and adults. CONCLUSION: COVID-19 vaccination efforts narrowed gaps in coverage for adults aged 65 years and older but larger vaccination coverage differences remained among younger populations. Moreover, greater disparities in coverage existed in rural counties. Health equity science approaches to analyses should extend beyond identifying differences by basic demographics such as race and ethnicity and include factors that provide context (housing, transportation, age, and geography) to assist with prioritization of vaccination efforts where true disparities in vaccination coverage exist. |
Characterizing the etiology of recurrent tuberculosis using whole genome sequencing-Alaska, USA, 2008-2020
Springer YP , Tompkins ML , Newell K , Jones M , Burns S , Chandler B , Cowan LS , Kammerer JS , Posey JE , Raz KM , Rothoff M , Silk BJ , Vergnetti YL , McLaughlin JB , Talarico S . J Infect Dis 2024 ![]() ![]() BACKGROUND: Understanding the etiology of recurrent tuberculosis (rTB) is important for effective TB control. Prior to the advent of whole genome sequencing (WGS), attributing rTB to relapse or reinfection using genetic information was complicated by the limited resolution of conventional genotyping methods. METHODS: We applied a systematic method of evaluating whole genome single nucleotide polymorphism (wgSNP) distances and results of phylogenetic analyses to characterize the etiology of rTB in American Indian and Alaska Native (AIAN) persons in Alaska during 2008-2020. We contextualized our findings through descriptive analyses of surveillance data and results of a literature search for investigations that characterized rTB etiology using WGS. RESULTS: The percentage of TB cases in AIAN persons in Alaska classified as recurrent episodes (11.8%) was three times the national percentage (3.9%). Of 38 recurrent episodes included in genetic analyses, we attributed 25 (65.8%) to reinfection based on wgSNP distances and phylogenetic analyses; this proportion was the highest among 16 published point estimates identified through the literature search. By comparison, we attributed 11 of 38 (28.9%) and 6 of 38 (15.8%) recurrent episodes to reinfection based on wgSNP distances alone and on conventional genotyping methods, respectively. CONCLUSIONS: WGS and attribution criteria involving genetic distances and patterns of relatedness can provide an effective means of elucidating rTB etiology. Our findings indicate that rTB occurs at high proportions among AIAN persons in Alaska and is frequently attributable to reinfection, reinforcing the importance of active surveillance and control measures to limit the spread of TB disease in Alaskan AIAN communities. |
Characteristics of TB cases without documented sputum culture in the United States, 2011-2021
Rautman LH , Kammerer JS , Silk BJ , Marconi VC , Youngblood ME , Edwards JA , Wortham JM , Self JL . Int J Tuberc Lung Dis 2024 28 (5) 231-236 <sec id="st1"><title>BACKGROUND</title>Culture-based diagnostics are the gold standard for diagnosing pulmonary TB (PTB). We characterized culture practices by comparing cases with documented sputum culture to those without.</sec><sec id="st2"><title>METHODS</title>Using multivariable logistic regression, we examined associations between PTB case characteristics and no documented sputum culture reported to the U.S. National TB Surveillance System during 2011-2021.</sec><sec id="st3"><title>RESULTS</title>Among 69,538 PTB cases analyzed, no sputum culture attempt was documented for 5,869 (8%). Non-sputum culture specimens were documented for 54%, 80%, and 89% of cases without documented sputum culture attempts among persons aged <15 years, 15-64, and 65+ years, respectively; bronchial fluid and lung tissue were common non-sputum specimens among cases in persons >15 years old. Having no documented sputum culture was associated with age <15 years (aOR 23.84, 99% CI 20.09-28.27) or ≥65 years (aOR 1.22, 99% CI 1.07-1.39), culture of a non-sputum specimen (aOR 6.57, 99% CI 5.93-7.28), residence in a long-term care facility (aOR 1.58, 99% CI 1.23-2.01), and receiving TB care outside of a health department (aOR 1.79, 99% CI 1.61-1.98).</sec><sec id="st4"><title>CONCLUSIONS</title>Inability to obtain sputum from children and higher diagnostic suspicion for disease processes that require tissue-based diagnostics could explain these findings.</sec>. |
Using geographic disaggregation to compare tuberculosis epidemiology among American Indian and Alaska native persons-USA, 2010-2020
Springer YP , Kammerer JS , Felix D , Newell K , Tompkins ML , Allison J , Castrodale LJ , Chandler B , Helfrich K , Rothoff M , McLaughlin JB , Silk BJ . J Racial Ethn Health Disparities 2024 BACKGROUND: American Indian and Alaska Native (AIAN) populations are frequently associated with the highest rates of tuberculosis (TB) disease of any racial/ethnic group in the USA. We systematically investigated variation in patterns and potential drivers of TB epidemiology among geographically distinct AIAN subgroups. METHODS: Using data reported to the National Tuberculosis Surveillance System during 2010-2020, we applied a geographic method of data disaggregation to compare annual TB incidence and the frequency of TB patient characteristics among AIAN persons in Alaska with AIAN persons in other states. We used US Census data to compare the prevalence of substandard housing conditions in AIAN communities in these two geographic areas. RESULTS: The average annual age-adjusted TB incidence among AIAN persons in Alaska was 21 times higher than among AIAN persons in other states. Compared to AIAN TB patients in other states, AIAN TB patients in Alaska were associated with significantly higher frequencies of multiple epidemiologic TB risk factors (e.g., attribution of TB disease to recent transmission, previous diagnosis of TB disease) and significantly lower frequencies of multiple clinical risk factors for TB disease (e.g., diagnosis with diabetes mellitus, end-stage renal disease). Occupied housing units in AIAN communities in Alaska were associated with significantly higher frequencies of multiple measures of substandard housing conditions compared to AIAN communities in other states. CONCLUSIONS: Observed differences in patient characteristics and substandard housing conditions are consistent with contrasting syndromes of TB epidemiology in geographically distinct AIAN subgroups and suggest ways that associated public health interventions could be tailored to improve efficacy. |
Early estimates of updated 2023-2024 (monovalent XBB.1.5) COVID-19 vaccine effectiveness against symptomatic SARS-CoV-2 infection attributable to co-circulating Omicron variants among immunocompetent adults - increasing community access to testing program, United States, September 2023-January 2024
Link-Gelles R , Ciesla AA , Mak J , Miller JD , Silk BJ , Lambrou AS , Paden CR , Shirk P , Britton A , Smith ZR , Fleming-Dutra KE . MMWR Morb Mortal Wkly Rep 2024 73 (4) 77-83 ![]() ![]() On September 12, 2023, CDC's Advisory Committee on Immunization Practices recommended updated 2023-2024 (updated) COVID-19 vaccination with a monovalent XBB.1.5-derived vaccine for all persons aged ≥6 months to prevent COVID-19, including severe disease. During fall 2023, XBB lineages co-circulated with JN.1, an Omicron BA.2.86 lineage that emerged in September 2023. These variants have amino acid substitutions that might increase escape from neutralizing antibodies. XBB lineages predominated through December 2023, when JN.1 became predominant in the United States. Reduction or failure of spike gene (S-gene) amplification (i.e., S-gene target failure [SGTF]) in real-time reverse transcription-polymerase chain reaction testing is a time-dependent, proxy indicator of JN.1 infection. Data from the Increasing Community Access to Testing SARS-CoV-2 pharmacy testing program were analyzed to estimate updated COVID-19 vaccine effectiveness (VE) (i.e., receipt versus no receipt of updated vaccination) against symptomatic SARS-CoV-2 infection, including by SGTF result. Among 9,222 total eligible tests, overall VE among adults aged ≥18 years was 54% (95% CI = 46%-60%) at a median of 52 days after vaccination. Among 2,199 tests performed at a laboratory with SGTF testing, VE 60-119 days after vaccination was 49% (95% CI = 19%-68%) among tests exhibiting SGTF and 60% (95% CI = 35%-75%) among tests without SGTF. Updated COVID-19 vaccines provide protection against symptomatic infection, including against currently circulating lineages. CDC will continue monitoring VE, including for expected waning and against severe disease. All persons aged ≥6 months should receive an updated COVID-19 vaccine dose. |
Seasonality of Common Human Coronaviruses in the United States, 2014-2021 (preprint)
Shah MM , Winn A , Dahl RM , Kniss KL , Silk BJ , Killerby ME . medRxiv 2022 22 (10) 1970-1976 The four common human coronaviruses (HCoVs), including two alpha (HCoV-NL63 and HCoV-229E) and two beta (HCoV-HKU1 and HCoV-OC43) types, generally cause mild, upper respiratory illness. HCoVs are known to have seasonal patterns and variation in predominant types each year, but defined measures of seasonality are needed. We defined seasonality of HCoVs during July 2014 to November 2021 in the United States using a retrospective method applied to National Respiratory and Enteric Virus Surveillance System (NREVSS) data. In the six HCoV seasons prior to 2020-2021, onsets ranged from October to November, peaks from January to February, and offsets from April to June; most (>93%) HCoV detections occurred within the defined seasonal onsets and offsets. The 2020-2021 HCoV season onset was delayed by 11 weeks compared to prior seasons, likely due to COVID-19 mitigation efforts. Better defining HCoV seasonality can inform clinical preparedness and the expected patterns of emerging HCoVs. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available for use under a CC0 license. |
Trends in laboratory-confirmed SARS-CoV-2 reinfections and associated hospitalizations and deaths among adults aged 18 years - 18 U.S. Jurisdictions, September 2021-December 2022
Ma KC , Dorabawila V , León TM , Henry H , Johnson AG , Rosenberg E , Mansfield JA , Midgley CM , Plumb ID , Aiken J , Khanani QA , Auche S , Bayoumi NS , Bennett SA , Bernu C , Chang C , Como-Sabetti KJ , Cueto K , Cunningham S , Eddy M , Falender RA , Fleischauer A , Frank DM , Harrington P , Hoskins M , Howsare A , Ingaiza LM , Islam AS , Jensen SA , Jones JM , Kambach G , Kanishka F , Levin Y , Masarik JF 3rd , Meyer SD , Milroy L , Morris KJ , Olmstead J , Olsen NS , Omoike E , Patel K , Pettinger A , Pike MA , Reed IG , Slocum E , Sutton M , Tilakaratne BP , Vest H , Vostok J , Wang JS , Watson-Lewis L , Wienkes HN , Hagen MB , Silk BJ , Scobie HM . MMWR Morb Mortal Wkly Rep 2023 72 (25) 683-689 ![]() Although reinfections with SARS-CoV-2 have occurred in the United States with increasing frequency, U.S. epidemiologic trends in reinfections and associated severe outcomes have not been characterized. Weekly counts of SARS-CoV-2 reinfections, total infections, and associated hospitalizations and deaths reported by 18 U.S. jurisdictions during September 5, 2021-December 31, 2022, were analyzed overall, by age group, and by five periods of SARS-CoV-2 variant predominance (Delta and Omicron [BA.1, BA.2, BA.4/BA.5, and BQ.1/BQ.1.1]). Among reported reinfections, weekly trends in the median intervals between infections and frequencies of predominant variants during previous infections were calculated. As a percentage of all infections, reinfections increased substantially from the Delta (2.7%) to the Omicron BQ.1/BQ.1.1 (28.8%) periods; during the same periods, increases in the percentages of reinfections among COVID-19-associated hospitalizations (from 1.9% [Delta] to 17.0% [Omicron BQ.1/BQ.1.1]) and deaths (from 1.2% [Delta] to 12.3% [Omicron BQ.1/BQ.1.1]) were also substantial. Percentages of all COVID-19 cases, hospitalizations, and deaths that were reinfections were consistently higher across variant periods among adults aged 18-49 years compared with those among adults aged ≥50 years. The median interval between infections ranged from 269 to 411 days by week, with a steep decline at the start of the BA.4/BA.5 period, when >50% of reinfections occurred among persons previously infected during the Alpha variant period or later. To prevent severe COVID-19 outcomes, including those following reinfection, CDC recommends staying up to date with COVID-19 vaccination and receiving timely antiviral treatments, when eligible. |
Notes from the field: Comparison of COVID-19 mortality rates among adults aged 65 years who were unvaccinated and those who received a bivalent booster dose within the preceding 6 months - 20 U.S. Jurisdictions, September 18, 2022-April 1, 2023
Johnson AG , Linde L , Payne AB , Ali AR , Aden V , Armstrong B , Armstrong B , Auche S , Bayoumi NS , Bennett S , Boulton R , Chang C , Collingwood A , Cueto K , Davidson SL , Du Y , Fleischauer A , Force V , Frank D , Hamilton R , Harame K , Harrington P , Hicks L , Hodis JD , Hoskins M , Jones A , Kanishka F , Kaur R , Kirkendall S , Khan SI , Klioueva A , Link-Gelles R , Lyons S , Mansfield J , Markelz A , Masarik J 3rd , Mendoza E , Morris K , Omoike E , Paritala S , Patel K , Pike M , Pompa XP , Praetorius K , Rammouni N , Razzaghi H , Riggs A , Shi M , Sigalo N , Stanislawski E , Tilakaratne BP , Turner KA , Wiedeman C , Silk BJ , Scobie HM . MMWR Morb Mortal Wkly Rep 2023 72 (24) 667-669 Updated (bivalent) COVID-19 vaccines were first recommended by CDC on September 1, 2022.* An analysis of case and death rates by vaccination status shortly after authorization of bivalent COVID-19 vaccines showed that receipt of a bivalent booster dose provided additional protection against SARS-CoV-2 infection and associated death (1). In this follow-up report on the durability of bivalent booster protection against death among adults aged ≥65 years, mortality rate ratios (RRs) were estimated among unvaccinated persons and those who received a bivalent booster dose by time since vaccination during three periods of Omicron lineage predominance (BA.5 [September 18–November 5, 2022], BQ.1/BQ.1.1 [November 6, 2022–January 21, 2023], and XBB.1.5 [January 22–April 1, 2023]).† | | During September 18, 2022–April 1, 2023, weekly counts of COVID-19–associated deaths§ among unvaccinated persons and those who received a bivalent booster dose¶ were reported from 20 U.S. jurisdictions** that routinely link case surveillance data to immunization registries and vital registration databases (1). Vaccinated persons who did not receive a bivalent COVID-19 booster dose were excluded. Rate denominators were calculated from vaccine administration data and 2019 U.S. intercensal population estimates,†† with numbers of unvaccinated persons estimated by subtracting numbers of vaccinated persons from the 2019 intercensal population estimates, as previously described§§ (1). Average weekly mortality rates were estimated based on date of specimen collection¶¶ during each variant period by vaccination status and time since bivalent booster dose receipt. RRs were calculated by dividing rates among unvaccinated persons by rates among bivalent booster dose recipients; after detrending the underlying linear changes in weekly rates, 95% CIs were estimated from the remaining variation in rates observed*** (1). SAS (version 9.4; SAS Institute) and R (version 4.1.2; R Foundation) software were used to conduct all analyses. This activity was reviewed by CDC and was conducted consistent with applicable federal law and CDC policy.††† |
Genomic surveillance for SARS-CoV-2 variants: Circulation of Omicron lineages - United States, January 2022-May 2023
Ma KC , Shirk P , Lambrou AS , Hassell N , Zheng XY , Payne AB , Ali AR , Batra D , Caravas J , Chau R , Cook PW , Howard D , Kovacs NA , Lacek KA , Lee JS , MacCannell DR , Malapati L , Mathew S , Mittal N , Nagilla RR , Parikh R , Paul P , Rambo-Martin BL , Shepard SS , Sheth M , Wentworth DE , Winn A , Hall AJ , Silk BJ , Thornburg N , Kondor R , Scobie HM , Paden CR . MMWR Morb Mortal Wkly Rep 2023 72 (24) 651-656 ![]() CDC has used national genomic surveillance since December 2020 to monitor SARS-CoV-2 variants that have emerged throughout the COVID-19 pandemic, including the Omicron variant. This report summarizes U.S. trends in variant proportions from national genomic surveillance during January 2022-May 2023. During this period, the Omicron variant remained predominant, with various descendant lineages reaching national predominance (>50% prevalence). During the first half of 2022, BA.1.1 reached predominance by the week ending January 8, 2022, followed by BA.2 (March 26), BA.2.12.1 (May 14), and BA.5 (July 2); the predominance of each variant coincided with surges in COVID-19 cases. The latter half of 2022 was characterized by the circulation of sublineages of BA.2, BA.4, and BA.5 (e.g., BQ.1 and BQ.1.1), some of which independently acquired similar spike protein substitutions associated with immune evasion. By the end of January 2023, XBB.1.5 became predominant. As of May 13, 2023, the most common circulating lineages were XBB.1.5 (61.5%), XBB.1.9.1 (10.0%), and XBB.1.16 (9.4%); XBB.1.16 and XBB.1.16.1 (2.4%), containing the K478R substitution, and XBB.2.3 (3.2%), containing the P521S substitution, had the fastest doubling times at that point. Analytic methods for estimating variant proportions have been updated as the availability of sequencing specimens has declined. The continued evolution of Omicron lineages highlights the importance of genomic surveillance to monitor emerging variants and help guide vaccine development and use of therapeutics. |
Correlations and timeliness of COVID-19 surveillance data sources and indicators - United States, October 1, 2020-March 22, 2023
Scobie HM , Panaggio M , Binder AM , Gallagher ME , Duck WM , Graff P , Silk BJ . MMWR Morb Mortal Wkly Rep 2023 72 (19) 529-535 When the U.S. COVID-19 public health emergency declaration expires on May 11, 2023, national reporting of certain categories of COVID-19 public health surveillance data will be transitioned to other data sources or will be discontinued; COVID-19 hospitalization data will be the only data source available at the county level (1). In anticipation of the transition, national COVID-19 surveillance data sources and indicators were evaluated for purposes of ongoing monitoring. The timeliness and correlations among surveillance indicators were analyzed to assess the usefulness of COVID-19-associated hospital admission rates as a primary indicator for monitoring COVID-19 trends, as well as the suitability of other replacement data sources. During April 2022-March 2023, COVID-19 hospital admission rates from the National Healthcare Safety Network (NHSN)(†) lagged 1 day behind case rates and 4 days behind percentages of positive test results and COVID-19 emergency department (ED) visits from the National Syndromic Surveillance Program (NSSP). In the same analysis, National Vital Statistics System (NVSS) trends in the percentage of deaths that were COVID-19-associated, which is tracked by date of death rather than by report date, were observable 13 days earlier than those from aggregate death count data, which will be discontinued (1). During October 2020-March 2023, strong correlations were observed between NVSS and aggregate death data (0.78) and between the percentage of positive SARS-CoV-2 test results from the National Respiratory and Enteric Viruses Surveillance System (NREVSS) and COVID-19 electronic laboratory reporting (CELR) (0.79), which will also be discontinued (1). Weekly COVID-19 Community Levels (CCLs) will be replaced with levels of COVID-19 hospital admission rates (low, medium, or high) which demonstrated >99% concordance by county during February 2022-March 2023. COVID-19-associated hospital admission levels are a suitable primary metric for monitoring COVID-19 trends, the percentage of COVID-19 deaths is a timely disease severity indicator, and the percentages of positive SARS-CoV-2 test results from NREVSS and ED visits serve as early indicators for COVID-19 monitoring. Collectively, these surveillance data sources and indicators can support monitoring of the impact of COVID-19 and related prevention and control strategies as ongoing public health priorities. |
COVID-19 surveillance after expiration of the public health emergency declaration - United States, May 11, 2023
Silk BJ , Scobie HM , Duck WM , Palmer T , Ahmad FB , Binder AM , Cisewski JA , Kroop S , Soetebier K , Park M , Kite-Powell A , Cool A , Connelly E , Dietz S , Kirby AE , Hartnett K , Johnston J , Khan D , Stokley S , Paden CR , Sheppard M , Sutton P , Razzaghi H , Anderson RN , Thornburg N , Meyer S , Womack C , Weakland AP , McMorrow M , Broeker LR , Winn A , Hall AJ , Jackson B , Mahon BE , Ritchey MD . MMWR Morb Mortal Wkly Rep 2023 72 (19) 523-528 On January 31, 2020, the U.S. Department of Health and Human Services (HHS) declared, under Section 319 of the Public Health Service Act, a U.S. public health emergency because of the emergence of a novel virus, SARS-CoV-2.* After 13 renewals, the public health emergency will expire on May 11, 2023. Authorizations to collect certain public health data will expire on that date as well. Monitoring the impact of COVID-19 and the effectiveness of prevention and control strategies remains a public health priority, and a number of surveillance indicators have been identified to facilitate ongoing monitoring. After expiration of the public health emergency, COVID-19-associated hospital admission levels will be the primary indicator of COVID-19 trends to help guide community and personal decisions related to risk and prevention behaviors; the percentage of COVID-19-associated deaths among all reported deaths, based on provisional death certificate data, will be the primary indicator used to monitor COVID-19 mortality. Emergency department (ED) visits with a COVID-19 diagnosis and the percentage of positive SARS-CoV-2 test results, derived from an established sentinel network, will help detect early changes in trends. National genomic surveillance will continue to be used to estimate SARS-CoV-2 variant proportions; wastewater surveillance and traveler-based genomic surveillance will also continue to be used to monitor SARS-CoV-2 variants. Disease severity and hospitalization-related outcomes are monitored via sentinel surveillance and large health care databases. Monitoring of COVID-19 vaccination coverage, vaccine effectiveness (VE), and vaccine safety will also continue. Integrated strategies for surveillance of COVID-19 and other respiratory viruses can further guide prevention efforts. COVID-19-associated hospitalizations and deaths are largely preventable through receipt of updated vaccines and timely administration of therapeutics (1-4). |
Erratum: Vol. 71, No. 6.
Lambrou AS , Shirk P , Steele MK , Paul P , Paden CR , Cadwell B , Reese HE , Aoki Y , Hassell N , Caravas J , Kovacs NA , Gerhart JG , Ng HJ , Zheng XY , Beck A , Chau R , Cintron R , Cook PW , Gulvik CA , Howard D , Jang Y , Knipe K , Lacek KA , Moser KA , Paskey AC , Rambo-Martin BL , Nagilla RR , Rethchless AC , Schmerer MW , Seby S , Shephard SS , Stanton RA , Stark TJ , Uehara A , Unoarumhi Y , Bentz ML , Burhgin A , Burroughs M , Davis ML , Keller MW , Keong LM , Le SS , Lee JS , Madden Jr JC , Nobles S , Owouor DC , Padilla J , Sheth M , Wilson MM , Talarico S , Chen JC , Oberste MS , Batra D , McMullan LK , Halpin AL , Galloway SE , MacCannell DR , Kondor R , Barnes J , MacNeil A , Silk BJ , Dugan VG , Scobie HM , Wentworth DE . MMWR Morb Mortal Wkly Rep 2022 71 (14) 528 The report “Genomic Surveillance for SARS-CoV-2 Variants: Predominance of the Delta (B.1.617.2) and Omicron (B.1.1.529) Variants — United States, June 2021–January 2022” contained several errors. |
Changes in influenza and other respiratory virus activity during the COVID-19 pandemic-United States, 2020-2021.
Olsen SJ , Winn AK , Budd AP , Prill MM , Steel J , Midgley CM , Kniss K , Burns E , Rowe T , Foust A , Jasso G , Merced-Morales A , Davis CT , Jang Y , Jones J , Daly P , Gubareva L , Barnes J , Kondor R , Sessions W , Smith C , Wentworth DE , Garg S , Havers FP , Fry AM , Hall AJ , Brammer L , Silk BJ . Am J Transplant 2021 21 (10) 3481-3486 The COVID-19 pandemic and subsequent implementation of nonpharmaceutical interventions (e.g., cessation of global travel, mask use, physical distancing, and staying home) reduced the transmission of some viral respiratory pathogens.1 In the United States, influenza activity decreased in March 2020, was historically low through the summer of 2020,2 and remained low during October 2020–May 2021 (<0.4% of respiratory specimens with positive test results for each week of the season). Circulation of other respiratory pathogens, including respiratory syncytial virus (RSV), common human coronaviruses (HCoVs) types OC43, NL63, 229E, and HKU1, and parainfluenza viruses (PIVs) types 1–4 also decreased in early 2020 and did not increase until spring 2021. Human metapneumovirus (HMPV) circulation decreased in March 2020 and remained low through May 2021. Respiratory adenovirus (RAdV) circulated at lower levels throughout 2020 and as of early May 2021. Rhinovirus and enterovirus (RV/EV) circulation decreased in March 2020, remained low until May 2020, and then increased to near prepandemic seasonal levels. Circulation of respiratory viruses could resume at prepandemic levels after COVID-19 mitigation practices become less stringent. Clinicians should be aware of increases in some respiratory virus activity and remain vigilant for off-season increases. In addition to the use of everyday preventive actions, fall influenza vaccination campaigns are an important component of prevention as COVID-19 mitigation measures are relaxed and schools and workplaces resume in-person activities. |
Seasonality of respiratory syncytial virus - United States, 2017-2023
Hamid S , Winn A , Parikh R , Jones JM , McMorrow M , Prill MM , Silk BJ , Scobie HM , Hall AJ . MMWR Morb Mortal Wkly Rep 2023 72 (14) 355-361 In the United States, respiratory syncytial virus (RSV) infections cause an estimated 58,000-80,000 hospitalizations among children aged <5 years (1,2) and 60,000-160,000 hospitalizations among adults aged ≥65 years each year (3-5). U.S. RSV epidemics typically follow seasonal patterns, peaking in December or January (6,7), but the COVID-19 pandemic disrupted RSV seasonality during 2020-2022 (8). To describe U.S. RSV seasonality during prepandemic and pandemic periods, polymerase chain reaction (PCR) test results reported to the National Respiratory and Enteric Virus Surveillance System (NREVSS)* during July 2017-February 2023 were analyzed. Seasonal RSV epidemics were defined as the weeks during which the percentage of PCR test results that were positive for RSV was ≥3% (9). Nationally, prepandemic seasons (2017-2020) began in October, peaked in December, and ended in April. During 2020-21, the typical winter RSV epidemic did not occur. The 2021-22 season began in May, peaked in July, and ended in January. The 2022-23 season started (June) and peaked (November) later than the 2021-22 season, but earlier than prepandemic seasons. In both prepandemic and pandemic periods, epidemics began earlier in Florida and the Southeast and later in regions further north and west. With several RSV prevention products in development,(†) ongoing monitoring of RSV circulation can guide the timing of RSV immunoprophylaxis and of clinical trials and postlicensure effectiveness studies. Although the timing of the 2022-23 season suggests that seasonal patterns are returning toward those observed in prepandemic years, clinicians should be aware that off-season RSV circulation might continue. |
COVID-19 incidence and mortality among unvaccinated and vaccinated persons aged 12 years by receipt of bivalent booster doses and time since vaccination - 24 U.S. jurisdictions, October 3, 2021-December 24, 2022
Johnson AG , Linde L , Ali AR , DeSantis A , Shi M , Adam C , Armstrong B , Armstrong B , Asbell M , Auche S , Bayoumi NS , Bingay B , Chasse M , Christofferson S , Cima M , Cueto K , Cunningham S , Delgadillo J , Dorabawila V , Drenzek C , Dupervil B , Durant T , Fleischauer A , Hamilton R , Harrington P , Hicks L , Hodis JD , Hoefer D , Horrocks S , Hoskins M , Husain S , Ingram LA , Jara A , Jones A , Kanishka FNU , Kaur R , Khan SI , Kirkendall S , Lauro P , Lyons S , Mansfield J , Markelz A , Masarik J 3rd , McCormick D , Mendoza E , Morris KJ , Omoike E , Patel K , Pike MA , Pilishvili T , Praetorius K , Reed IG , Severson RL , Sigalo N , Stanislawski E , Stich S , Tilakaratne BP , Turner KA , Wiedeman C , Zaldivar A , Silk BJ , Scobie HM . MMWR Morb Mortal Wkly Rep 2023 72 (6) 145-152 On September 1, 2022, CDC recommended an updated (bivalent) COVID-19 vaccine booster to help restore waning protection conferred by previous vaccination and broaden protection against emerging variants for persons aged ≥12 years (subsequently extended to persons aged ≥6 months).* To assess the impact of original (monovalent) COVID-19 vaccines and bivalent boosters, case and mortality rate ratios (RRs) were estimated comparing unvaccinated and vaccinated persons aged ≥12 years by overall receipt of and by time since booster vaccination (monovalent or bivalent) during Delta variant and Omicron sublineage (BA.1, BA.2, early BA.4/BA.5, and late BA.4/BA.5) predominance.(†) During the late BA.4/BA.5 period, unvaccinated persons had higher COVID-19 mortality and infection rates than persons receiving bivalent doses (mortality RR = 14.1 and infection RR = 2.8) and to a lesser extent persons vaccinated with only monovalent doses (mortality RR = 5.4 and infection RR = 2.5). Among older adults, mortality rates among unvaccinated persons were significantly higher than among those who had received a bivalent booster (65-79 years; RR = 23.7 and ≥80 years; 10.3) or a monovalent booster (65-79 years; 8.3 and ≥80 years; 4.2). In a second analysis stratified by time since booster vaccination, there was a progressive decline from the Delta period (RR = 50.7) to the early BA.4/BA.5 period (7.4) in relative COVID-19 mortality rates among unvaccinated persons compared with persons receiving who had received a monovalent booster within 2 weeks-2 months. During the early BA.4/BA.5 period, declines in relative mortality rates were observed at 6-8 (RR = 4.6), 9-11 (4.5), and ≥12 (2.5) months after receiving a monovalent booster. In contrast, bivalent boosters received during the preceding 2 weeks-2 months improved protection against death (RR = 15.2) during the late BA.4/BA.5 period. In both analyses, when compared with unvaccinated persons, persons who had received bivalent boosters were provided additional protection against death over monovalent doses or monovalent boosters. Restored protection was highest in older adults. All persons should stay up to date with COVID-19 vaccination, including receipt of a bivalent booster by eligible persons, to reduce the risk for severe COVID-19. |
Spike Gene Target Amplification in a Diagnostic Assay as a Marker for Public Health Monitoring of Emerging SARS-CoV-2 Variants - United States, November 2021-January 2023.
Scobie HM , Ali AR , Shirk P , Smith ZR , Paul P , Paden CR , Hassell N , Zheng XY , Lambrou AS , Kondor R , MacCannell D , Thornburg NJ , Miller J , Wentworth D , Silk BJ . MMWR Morb Mortal Wkly Rep 2023 72 (5) 125-127 ![]() ![]() Monitoring emerging SARS-CoV-2 lineages and their epidemiologic characteristics helps to inform public health decisions regarding vaccine policy, the use of therapeutics, and health care capacity. When the SARS-CoV-2 Alpha variant emerged in late 2020, a spike gene (S-gene) deletion (Δ69-70) in the N-terminal region, which might compensate for immune escape mutations that impair infectivity (1), resulted in reduced or failed S-gene target amplification in certain multitarget reverse transcription-polymerase chain reaction (RT-PCR) assays, a pattern referred to as S-gene target failure (SGTF) (2). The predominant U.S. SARS-CoV-2 lineages have generally alternated between SGTF and S-gene target presence (SGTP), which alongside genomic sequencing, has facilitated early monitoring of emerging variants. During a period when Omicron BA.5-related sublineages (which exhibit SGTF) predominated, an XBB.1.5 sublineage with SGTP has rapidly expanded in the northeastern United States and other regions. |
Seasonality of Common Human Coronaviruses, United States, 2014-2021.
Shah MM , Winn A , Dahl RM , Kniss KL , Silk BJ , Killerby ME . Emerg Infect Dis 2022 28 (10) 1970-1976 The 4 common types of human coronaviruses (HCoVs)-2 alpha (HCoV-NL63 and HCoV-229E) and 2 beta (HCoV-HKU1 and HCoV-OC43)-generally cause mild upper respiratory illness. Seasonal patterns and annual variation in predominant types of HCoVs are known, but parameters of expected seasonality have not been defined. We defined seasonality of HCoVs during July 2014-November 2021 in the United States by using a retrospective method applied to National Respiratory and Enteric Virus Surveillance System data. In the 6 HCoV seasons before 2020-21, season onsets occurred October 21-November 12, peaks January 6-February 13, and offsets April 18-June 27; most (>93%) HCoV detection was within the defined seasonal onsets and offsets. The 2020-21 HCoV season onset was 11 weeks later than in prior seasons, probably associated with COVID-19 mitigation efforts. Better definitions of HCoV seasonality can be used for clinical preparedness and for determining expected patterns of emerging coronaviruses. |
Increase in Acute Respiratory Illnesses Among Children and Adolescents Associated with Rhinoviruses and Enteroviruses, Including Enterovirus D68 - United States, July-September 2022.
Ma KC , Winn A , Moline HL , Scobie HM , Midgley CM , Kirking HL , Adjemian J , Hartnett KP , Johns D , Jones JM , Lopez A , Lu X , Perez A , Perrine CG , Rzucidlo AE , McMorrow ML , Silk BJ , Stein Z , Vega E , Hall AJ . MMWR Morb Mortal Wkly Rep 2022 71 (40) 1265-1270 Increases in severe respiratory illness and acute flaccid myelitis (AFM) among children and adolescents resulting from enterovirus D68 (EV-D68) infections occurred biennially in the United States during 2014, 2016, and 2018, primarily in late summer and fall. Although EV-D68 annual trends are not fully understood, EV-D68 levels were lower than expected in 2020, potentially because of implementation of COVID-19 mitigation measures (e.g., wearing face masks, enhanced hand hygiene, and physical distancing) (1). In August 2022, clinicians in several geographic areas notified CDC of an increase in hospitalizations of pediatric patients with severe respiratory illness and positive rhinovirus/enterovirus (RV/EV) test results.* Surveillance data were analyzed from multiple national data sources to characterize reported trends in acute respiratory illness (ARI), asthma/reactive airway disease (RAD) exacerbations, and the percentage of positive RV/EV and EV-D68 test results during 2022 compared with previous years. These data demonstrated an increase in emergency department (ED) visits by children and adolescents with ARI and asthma/RAD in late summer 2022. The percentage of positive RV/EV test results in national laboratory-based surveillance and the percentage of positive EV-D68 test results in pediatric sentinel surveillance also increased during this time. Previous increases in EV-D68 respiratory illness have led to substantial resource demands in some hospitals and have also coincided with increases in cases of AFM (2), a rare but serious neurologic disease affecting the spinal cord. Therefore, clinicians should consider AFM in patients with acute flaccid limb weakness, especially after respiratory illness or fever, and ensure prompt hospitalization and referral to specialty care for such cases. Clinicians should also test for poliovirus infection in patients suspected of having AFM because of the clinical similarity to acute flaccid paralysis caused by poliovirus. Ongoing surveillance for EV-D68 is critical to ensuring preparedness for possible future increases in ARI and AFM. |
Notes from the Field: School-Based and Laboratory-Based Reporting of Positive COVID-19 Test Results Among School-Aged Children - New York, September 11, 2021-April 29, 2022.
Shircliff EJ , Rosenberg ES , Collens LM , Hoefer D , Lutterloh E , Silk BJ , Winn AK , O'Donnell TT . MMWR Morb Mortal Wkly Rep 2022 71 (32) 1029-1031 By April 29, 2022, a total of 702,686 COVID-19 cases were reported among children and adolescents aged 5–17 years in the state of New York.* Pediatric COVID-19 cases and hospitalizations increased during the 2021–22 school year, driven by transmission of the Omicron variant† (1). In late 2021, during the surge in Omicron BA.1 variant cases, state§ and federal¶ authorities expanded access to self-administered, at-home rapid antigen tests, which can increase a person’s knowledge of their COVID-19 status and guide risk-reduction behaviors. New York government agencies sent millions of these tests to schools for distribution to teachers, students, and staff members. Because results of self-administered, at-home tests are not captured by electronic laboratory reporting (in contrast to health care provider–administered tests at a physician’s office or laboratory that are reported through electronic health records or other means), expanded use of these tests might affect interpretation of trends in reported COVID-19 cases; however, this has yet to be assessed** (2). Furthermore, understanding changes in testing behavior before and after the Omicron variant surge might help public health officials better use available COVID-19 data to guide future policy. |
Molecular surveillance for large outbreaks of tuberculosis in the United States, 2014-2018.
Raz KM , Talarico S , Althomsons SP , Kammerer JS , Cowan LS , Haddad MB , McDaniel CJ , Wortham JM , France AM , Powell KM , Posey JE , Silk BJ . Tuberculosis (Edinb) 2022 136 102232 ![]() ![]() OBJECTIVE: This study describes characteristics of large tuberculosis (TB) outbreaks in the United States detected using novel molecular surveillance methods during 2014-2016 and followed for 2 years through 2018. METHODS: We developed 4 genotype-based detection algorithms to identify large TB outbreaks of ≥10 cases related by recent transmission during a 3-year period. We used whole-genome sequencing and epidemiologic data to assess evidence of recent transmission among cases. RESULTS: There were 24 large outbreaks involving 518 cases; patients were primarily U.S.-born (85.1%) racial/ethnic minorities (84.1%). Compared with all other TB patients, patients associated with large outbreaks were more likely to report substance use, homelessness, and having been diagnosed while incarcerated. Most large outbreaks primarily occurred within residences among families and nonfamilial social contacts. A source case with a prolonged infectious period and difficulties in eliciting contacts were commonly reported contributors to transmission. CONCLUSION: Large outbreak surveillance can inform targeted interventions to decrease outbreak-associated TB morbidity. |
Tuberculosis Outbreaks in State Prisons, United States, 2011-2019.
Stewart RJ , Raz KM , Burns SP , Kammerer JS , Haddad MB , Silk BJ , Wortham JM . Am J Public Health 2022 112 (8) 1170-1179 ![]() ![]() Objectives. To understand the frequency, magnitude, geography, and characteristics of tuberculosis outbreaks in US state prisons. Methods. Using data from the National Tuberculosis Surveillance System, we identified all cases of tuberculosis during 2011 to 2019 that were reported as occurring among individuals incarcerated in a state prison at the time of diagnosis. We used whole-genome sequencing to define 3 or more cases within 2 single nucleotide polymorphisms within 3 years as clustered; we classified clusters with 6 or more cases during a 3-year period as tuberculosis outbreaks. Results. During 2011 to 2019, 566 tuberculosis cases occurred in 41 state prison systems (a median of 3 cases per state). A total of 19 tuberculosis genotype clusters comprising 134 cases were identified in 6 state prison systems; these clusters included a subset of 5 outbreaks in 2 states. Two Alabama outbreaks during 2011 to 2017 totaled 20 cases; 3 Texas outbreaks during 2014 to 2019 totaled 51 cases. Conclusions. Only Alabama and Texas reported outbreaks during the 9-year period; only Texas state prisons had ongoing transmission in 2019. Effective interventions are needed to stop tuberculosis outbreaks in Texas state prisons. (Am J Public Health. 2022;112(8):1170-1179. https://doi.org/10.2105/AJPH.2022.306864). |
Point Prevalence Estimates of Activity-Limiting Long-Term Symptoms among U.S. Adults ≥1 Month After Reported SARS-CoV-2 Infection, November 1, 2021.
Tenforde MW , Devine OJ , Reese HE , Silk BJ , Iuliano AD , Threlkel R , Vu QM , Plumb ID , Cadwell BL , Rose C , Steele MK , Briggs-Hagen M , Ayoubkhani D , Pawelek P , Nafilyan V , Saydah SH , Bertolli J . J Infect Dis 2023 227 (7) 855-863 BACKGROUND: Although most adults infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) fully recover, a proportion have ongoing symptoms, or post-COVID conditions (PCC), after infection. The objective of this analysis was to estimate the number of United States (US) adults with activity-limiting PCC on 1 November 2021. METHODS: We modeled the prevalence of PCC using reported infections occurring from 1 February 2020 to 30 September 2021, and population-based, household survey data on new activity-limiting symptoms ≥1 month following SARS-CoV-2 infection. From these data sources, we estimated the number and proportion of US adults with activity-limiting PCC on 1 November 2021 as 95% uncertainty intervals, stratified by sex and age. Sensitivity analyses adjusted for underascertainment of infections and uncertainty about symptom duration. RESULTS: On 1 November 2021, at least 3.0-5.0 million US adults, or 1.2%-1.9% of the US adult population, were estimated to have activity-limiting PCC of ≥1 month's duration. Population prevalence was higher in females (1.4%-2.2%) than males. The estimated prevalence after adjusting for underascertainment of infections was 1.7%-3.8%. CONCLUSIONS: Millions of US adults were estimated to have activity-limiting PCC. These estimates can support future efforts to address the impact of PCC on the US population. |
Estimated Number of COVID-19 Infections, Hospitalizations, and Deaths Prevented Among Vaccinated Persons in the US, December 2020 to September 2021.
Steele MK , Couture A , Reed C , Iuliano D , Whitaker M , Fast H , Hall AJ , MacNeil A , Cadwell B , Marks KJ , Silk BJ . JAMA Netw Open 2022 5 (7) e2220385 IMPORTANCE: The number of SARS-CoV-2 infections and COVID-19-associated hospitalizations and deaths prevented among vaccinated persons, independent of the effect of reduced transmission, is a key measure of vaccine impact. OBJECTIVE: To estimate the number of SARS-CoV-2 infections and COVID-19-associated hospitalizations and deaths prevented among vaccinated adults in the US. DESIGN, SETTING, AND PARTICIPANTS: In this modeling study, a multiplier model was used to extrapolate the number of SARS-CoV-2 infections and COVID-19-associated deaths from data on the number of COVID-19-associated hospitalizations stratified by state, month, and age group (18-49, 50-64, and ≥65 years) in the US from December 1, 2020, to September 30, 2021. These estimates were combined with data on vaccine coverage and effectiveness to estimate the risks of infections, hospitalizations, and deaths. Risks were applied to the US population 18 years or older to estimate the expected burden in that population without vaccination. The estimated burden in the US population 18 years or older given observed levels of vaccination was subtracted from the expected burden in the US population 18 years or older without vaccination (ie, counterfactual) to estimate the impact of vaccination among vaccinated persons. EXPOSURES: Completion of the COVID-19 vaccination course, defined as 2 doses of messenger RNA (BNT162b2 or mRNA-1273) vaccines or 1 dose of JNJ-78436735 vaccine. MAIN OUTCOMES AND MEASURES: Monthly numbers and percentages of SARS-CoV-2 infections and COVID-19-associated hospitalizations and deaths prevented were estimated among those who have been vaccinated in the US. RESULTS: COVID-19 vaccination was estimated to prevent approximately 27 million (95% uncertainty interval [UI], 22 million to 34 million) infections, 1.6 million (95% UI, 1.4 million to 1.8 million) hospitalizations, and 235 000 (95% UI, 175 000-305 000) deaths in the US from December 1, 2020, to September 30, 2021, among vaccinated adults 18 years or older. From September 1 to September 30, 2021, vaccination was estimated to prevent 52% (95% UI, 45%-62%) of expected infections, 56% (95% UI, 52%-62%) of expected hospitalizations, and 58% (95% UI, 53%-63%) of expected deaths in adults 18 years or older. CONCLUSIONS AND RELEVANCE: These findings indicate that the US COVID-19 vaccination program prevented a substantial burden of morbidity and mortality through direct protection of vaccinated individuals. |
Genomic Surveillance for SARS-CoV-2 Variants: Predominance of the Delta (B.1.617.2) and Omicron (B.1.1.529) Variants - United States, June 2021-January 2022.
Lambrou AS , Shirk P , Steele MK , Paul P , Paden CR , Cadwell B , Reese HE , Aoki Y , Hassell N , Caravas J , Kovacs NA , Gerhart JG , Ng HJ , Zheng XY , Beck A , Chau R , Cintron R , Cook PW , Gulvik CA , Howard D , Jang Y , Knipe K , Lacek KA , Moser KA , Paskey AC , Rambo-Martin BL , Nagilla RR , Rethchless AC , Schmerer MW , Seby S , Shephard SS , Stanton RA , Stark TJ , Uehara A , Unoarumhi Y , Bentz ML , Burhgin A , Burroughs M , Davis ML , Keller MW , Keong LM , Le SS , Lee JS , Madden Jr JC , Nobles S , Owouor DC , Padilla J , Sheth M , Wilson MM , Talarico S , Chen JC , Oberste MS , Batra D , McMullan LK , Halpin AL , Galloway SE , MacCannell DR , Kondor R , Barnes J , MacNeil A , Silk BJ , Dugan VG , Scobie HM , Wentworth DE . MMWR Morb Mortal Wkly Rep 2022 71 (6) 206-211 ![]() ![]() Genomic surveillance is a critical tool for tracking emerging variants of SARS-CoV-2 (the virus that causes COVID-19), which can exhibit characteristics that potentially affect public health and clinical interventions, including increased transmissibility, illness severity, and capacity for immune escape. During June 2021-January 2022, CDC expanded genomic surveillance data sources to incorporate sequence data from public repositories to produce weighted estimates of variant proportions at the jurisdiction level and refined analytic methods to enhance the timeliness and accuracy of national and regional variant proportion estimates. These changes also allowed for more comprehensive variant proportion estimation at the jurisdictional level (i.e., U.S. state, district, territory, and freely associated state). The data in this report are a summary of findings of recent proportions of circulating variants that are updated weekly on CDC's COVID Data Tracker website to enable timely public health action.(†) The SARS-CoV-2 Delta (B.1.617.2 and AY sublineages) variant rose from 1% to >50% of viral lineages circulating nationally during 8 weeks, from May 1-June 26, 2021. Delta-associated infections remained predominant until being rapidly overtaken by infections associated with the Omicron (B.1.1.529 and BA sublineages) variant in December 2021, when Omicron increased from 1% to >50% of circulating viral lineages during a 2-week period. As of the week ending January 22, 2022, Omicron was estimated to account for 99.2% (95% CI = 99.0%-99.5%) of SARS-CoV-2 infections nationwide, and Delta for 0.7% (95% CI = 0.5%-1.0%). The dynamic landscape of SARS-CoV-2 variants in 2021, including Delta- and Omicron-driven resurgences of SARS-CoV-2 transmission across the United States, underscores the importance of robust genomic surveillance efforts to inform public health planning and practice. |
Model-based analysis of tuberculosis genotype clusters in the United States reveals high degree of heterogeneity in transmission, and state-level differences across California, Florida, New York, and Texas.
Shrestha S , Winglee K , Hill A , Shaw T , Smith J , Kammerer JS , Silk BJ , Marks S , Dowdy D . Clin Infect Dis 2022 75 (8) 1433-1441 ![]() ![]() BACKGROUND: Reductions in tuberculosis (TB) transmission have been instrumental in lowering TB incidence in the United States. Sustaining and augmenting these reductions are key public health priorities. METHODS: We fit mechanistic transmission models to distributions of genotype clusters of TB cases reported to CDC during 2012-2016 in the United States and separately in California, Florida, New York, and Texas. Using these models, we estimated the mean number of secondary cases generated per infectious case (R0) and individual-level heterogeneity in R0 at state and national levels. We also assessed how different definitions of clustering and variation in case ascertainment affected these estimates. RESULTS: In clusters of genotypically linked TB cases occurring within a state over a 5-year period (reference scenario), the estimated R0 was 0.29 (95% CI: 0.28-0.31) in the United States. Transmission was highly heterogeneous: 0.24% of simulated cases with individual R0>10 generated 19% of all recent secondary transmissions. R0 estimate was 0.16 (0.15-0.17) when a cluster was defined as cases occurring within the same county over a 3-year period. Transmission varied across states: estimated R0s were 0.34 (0.3-0.4) in California, 0.28 (0.24-0.36) in Florida, 0.19 (0.15-0.27) in New York, and 0.38 (0.33-0.46) in Texas. CONCLUSIONS: TB transmission in the United States is characterized by pronounced heterogeneity at the individual and state levels. Improving detection of transmission clusters through incorporation of whole-genome sequencing and identifying the drivers of this heterogeneity will be essential to reducing TB transmission in the United States and worldwide. |
Mutation of Mycobacterium tuberculosis and Implications for Using Whole-Genome Sequencing for Investigating Recent Tuberculosis Transmission.
Nelson KN , Talarico S , Poonja S , McDaniel CJ , Cilnis M , Chang AH , Raz K , Noboa WS , Cowan L , Shaw T , Posey J , Silk BJ . Front Public Health 2021 9 790544 ![]() ![]() Tuberculosis (TB) control programs use whole-genome sequencing (WGS) of Mycobacterium tuberculosis (Mtb) for detecting and investigating TB case clusters. Existence of few genomic differences between Mtb isolates might indicate TB cases are the result of recent transmission. However, the variable and sometimes long duration of latent infection, combined with uncertainty in the Mtb mutation rate during latency, can complicate interpretation of WGS results. To estimate the association between infection duration and single nucleotide polymorphism (SNP) accumulation in the Mtb genome, we first analyzed pairwise SNP differences among TB cases from Los Angeles County, California, with strong epidemiologic links. We found that SNP distance alone was insufficient for concluding that cases are linked through recent transmission. Second, we describe a well-characterized cluster of TB cases in California to illustrate the role of genomic data in conclusions regarding recent transmission. Longer presumed latent periods were inconsistently associated with larger SNP differences. Our analyses suggest that WGS alone cannot be used to definitively determine that a case is attributable to recent transmission. Methods for integrating clinical, epidemiologic, and genomic data can guide conclusions regarding the likelihood of recent transmission, providing local public health practitioners with better tools for monitoring and investigating TB transmission. |
COVID-19 Incidence and Death Rates Among Unvaccinated and Fully Vaccinated Adults with and Without Booster Doses During Periods of Delta and Omicron Variant Emergence - 25 U.S. Jurisdictions, April 4-December 25, 2021.
Johnson AG , Amin AB , Ali AR , Hoots B , Cadwell BL , Arora S , Avoundjian T , Awofeso AO , Barnes J , Bayoumi NS , Busen K , Chang C , Cima M , Crockett M , Cronquist A , Davidson S , Davis E , Delgadillo J , Dorabawila V , Drenzek C , Eisenstein L , Fast HE , Gent A , Hand J , Hoefer D , Holtzman C , Jara A , Jones A , Kamal-Ahmed I , Kangas S , Kanishka F , Kaur R , Khan S , King J , Kirkendall S , Klioueva A , Kocharian A , Kwon FY , Logan J , Lyons BC , Lyons S , May A , McCormick D , Mendoza E , Milroy L , O'Donnell A , Pike M , Pogosjans S , Saupe A , Sell J , Smith E , Sosin DM , Stanislawski E , Steele MK , Stephenson M , Stout A , Strand K , Tilakaratne BP , Turner K , Vest H , Warner S , Wiedeman C , Zaldivar A , Silk BJ , Scobie HM . MMWR Morb Mortal Wkly Rep 2022 71 (4) 132-138 Previous reports of COVID-19 case, hospitalization, and death rates by vaccination status() indicate that vaccine protection against infection, as well as serious COVID-19 illness for some groups, declined with the emergence of the B.1.617.2 (Delta) variant of SARS-CoV-2, the virus that causes COVID-19, and waning of vaccine-induced immunity (1-4). During August-November 2021, CDC recommended() additional primary COVID-19 vaccine doses among immunocompromised persons and booster doses among persons aged 18 years (5). The SARS-CoV-2 B.1.1.529 (Omicron) variant emerged in the United States during December 2021 (6) and by December 25 accounted for 72% of sequenced lineages (7). To assess the impact of full vaccination with additional and booster doses (booster doses),() case and death rates and incidence rate ratios (IRRs) were estimated among unvaccinated and fully vaccinated adults by receipt of booster doses during pre-Delta (April-May 2021), Delta emergence (June 2021), Delta predominance (July-November 2021), and Omicron emergence (December 2021) periods in the United States. During 2021, averaged weekly, age-standardized case IRRs among unvaccinated persons compared with fully vaccinated persons decreased from 13.9 pre-Delta to 8.7 as Delta emerged, and to 5.1 during the period of Delta predominance. During October-November, unvaccinated persons had 13.9 and 53.2 times the risks for infection and COVID-19-associated death, respectively, compared with fully vaccinated persons who received booster doses, and 4.0 and 12.7 times the risks compared with fully vaccinated persons without booster doses. When the Omicron variant emerged during December 2021, case IRRs decreased to 4.9 for fully vaccinated persons with booster doses and 2.8 for those without booster doses, relative to October-November 2021. The highest impact of booster doses against infection and death compared with full vaccination without booster doses was recorded among persons aged 50-64 and 65 years. Eligible persons should stay up to date with COVID-19 vaccinations. |
Risk Factors for Severe COVID-19 Outcomes Among Persons Aged ≥18 Years Who Completed a Primary COVID-19 Vaccination Series - 465 Health Care Facilities, United States, December 2020-October 2021.
Yek C , Warner S , Wiltz JL , Sun J , Adjei S , Mancera A , Silk BJ , Gundlapalli AV , Harris AM , Boehmer TK , Kadri SS . MMWR Morb Mortal Wkly Rep 2022 71 (1) 19-25 Vaccination against SARS-CoV-2, the virus that causes COVID-19, is highly effective at preventing COVID-19-associated hospitalization and death; however, some vaccinated persons might develop COVID-19 with severe outcomes(†) (1,2). Using data from 465 facilities in a large U.S. health care database, this study assessed the frequency of and risk factors for developing a severe COVID-19 outcome after completing a primary COVID-19 vaccination series (primary vaccination), defined as receipt of 2 doses of an mRNA vaccine (BNT162b2 [Pfizer-BioNTech] or mRNA-1273 [Moderna]) or a single dose of JNJ-78436735 [Janssen (Johnson & Johnson)] ≥14 days before illness onset. Severe COVID-19 outcomes were defined as hospitalization with a diagnosis of acute respiratory failure, need for noninvasive ventilation (NIV), admission to an intensive care unit (ICU) including all persons requiring invasive mechanical ventilation, or death (including discharge to hospice). Among 1,228,664 persons who completed primary vaccination during December 2020-October 2021, a total of 2,246 (18.0 per 10,000 vaccinated persons) developed COVID-19 and 189 (1.5 per 10,000) had a severe outcome, including 36 who died (0.3 deaths per 10,000). Risk for severe outcomes was higher among persons who were aged ≥65 years, were immunosuppressed, or had at least one of six other underlying conditions. All persons with severe outcomes had at least one of these risk factors, and 77.8% of those who died had four or more risk factors. Severe COVID-19 outcomes after primary vaccination are rare; however, vaccinated persons who are aged ≥65 years, are immunosuppressed, or have other underlying conditions might be at increased risk. These persons should receive targeted interventions including chronic disease management, precautions to reduce exposure, additional primary and booster vaccine doses, and effective pharmaceutical therapy as indicated to reduce risk for severe COVID-19 outcomes. Increasing COVID-19 vaccination coverage is a public health priority. |
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