Last data update: Apr 22, 2024. (Total: 46599 publications since 2009)
Records 1-30 (of 40 Records) |
Query Trace: Kniss K[original query] |
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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. |
Effectiveness of 2 and 3 mRNA COVID-19 Vaccines Doses against Omicron and Delta-Related Outpatient Illness among Adults, October 2021 - February 2022 (preprint)
Kim SS , Chung JR , Talbot HK , Grijalva CG , Wernli KJ , Martin ET , Monto AS , Belongia EA , McLean HQ , Gaglani M , Mamawala M , Nowalk MP , Geffel KM , Tartof SY , Florea A , Lee JS , Tenforde MW , Patel MM , Flannery B , Bentz ML , Burgin A , Burroughs M , Davis ML , Howard D , Lacek K , Madden JC , Nobles S , Padilla J , Sheth M , Arroliga A , Beeram M , Dunnigan K , Ettlinger J , Graves A , Hoffman E , Jatla M , McKillop A , Murthy K , Mutnal M , Priest E , Raiyani C , Rao A , Requenez L , Settele N , Smith M , Stone K , Thomas J , Volz M , Walker K , Zayed M , Annan E , Daley P , Kniss K , Merced-Morales A , Ayala E , Amundsen B , Aragones M , Calderon R , Hong V , Jimenez G , Kim J , Ku J , Lewin B , McDaniel A , Reyes A , Shaw S , Takhar H , Torres A , Burganowski R , Kiniry E , Moser KA , Nguyen M , Park S , Wellwood S , Wickersham B , Alvarado-Batres J , Benz S , Berger H , Bissonnette A , Blake J , Boese K , Botten E , Boyer J , Braun M , Breu B , Burbey G , Cravillion C , Delgadillo C , Donnerbauer A , Dziedzic T , Eddy J , Edgren H , Ermeling A , Ewert K , Fehrenbach C , Fernandez R , Frome W , Guzinski S , Heeren L , Herda D , Hertel M , Heuer G , Higdon E , Ivacic L , Jepsen L , Kaiser S , Karl J , Keffer B , King J , Koepel TK , Kohl S , Kohn S , Kohnhorst D , Kronholm E , Le T , Lemieux A , Marcis C , Maronde M , McCready I , McGreevey K , Meece J , Mehta N , Miesbauer D , Moon V , Moran J , Nikolai C , Olson B , Olstadt J , Ott L , Pan N , Pike C , Polacek D , Presson M , Price N , Rayburn C , Reardon C , Rotar M , Rottscheit C , Salzwedel J , Saucedo J , Scheffen K , Schug C , Seyfert K , Shrestha R , Slenczka A , Stefanski E , Strupp M , Tichenor M , Watkins L , Zachow A , Zimmerman B , Bauer S , Beney K , Cheng CK , Faraj N , Getz A , Grissom M , Groesbeck M , Harrison S , Henson K , Jermanus K , Johnson E , Kaniclides A , Kimberly A , Lamerato LE , Lauring A , Lehmann-Wandell R , McSpadden EJ , Nabors L , Truscon R , Balasubramani GK , Bear T , Bobeck J , Bowser E , Clarke K , Clarke LG , Dauer K , Deluca C , Dierks B , Haynes L , Hickey R , Johnson M , Jonsson A , Luosang N , McKown L , Peterson A , Phaturos D , Rectenwald A , Sax TM , Stiegler M , Susick M , Suyama J , Taylor L , Walters S , Weissman A , Williams JV , Blair M , Carter J , Chappell J , Copen E , Denney M , Graes K , Halasa N , Lindsell C , Liu Z , Longmire S , McHenry R , Short L , Tan HN , Vargas D , Wrenn J , Wyatt D , Zhu Y . medRxiv 2022 10 Background: We estimated SARS-CoV-2 Delta and Omicron-specific effectiveness of 2 and 3 mRNA COVID-19 vaccine doses in adults against symptomatic illness in US outpatient settings. Method(s): Between October 1, 2021, and February 12, 2022, research staff consented and enrolled eligible participants who had fever, cough, or loss of taste or smell and sought outpatient medical care or clinical SARS-CoV-2 testing within 10 days of illness onset. Using the test-negative design, we compared the odds of receiving 2 or 3 mRNA COVID-19 vaccine doses among SARS-CoV-2 cases versus controls using logistic regression. Regression models were adjusted for study site, age, onset week, and prior SARS-CoV-2 infection. Vaccine effectiveness (VE) was calculated as (1 - adjusted odds ratio) x 100%. Result(s): Among 3847 participants included for analysis, 574 (32%) of 1775 tested positive for SARS-CoV-2 during the Delta predominant period and 1006 (56%) of 1794 participants tested positive during the Omicron predominant period. When Delta predominated, VE against symptomatic illness in outpatient settings was 63% (95% CI: 51% to 72%) among mRNA 2-dose recipients and 96% (95% CI: 93% to 98%) for 3-dose recipients. When Omicron predominated, VE was 21% (95% CI: -6% to 41%) among 2-dose recipients and 62% (95% CI: 48% to 72%) among 3-dose recipients. Conclusion(s): In this adult population, 3 mRNA COVID-19 vaccine doses provided substantial protection against symptomatic illness in outpatient settings when the Omicron variant became the predominant cause of COVID-19 in the U.S. These findings support the recommendation for a 3rd mRNA COVID-19 vaccine dose. 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. |
Risk for infection in humans after exposure to birds infected with highly pathogenic avian influenza A(H5N1) virus, United States, 2022
Kniss K , Sumner KM , Tastad KJ , Lewis NM , Jansen L , Julian D , Reh M , Carlson E , Williams R , Koirala S , Buss B , Donahue M , Palm J , Kollmann L , Holzbauer S , Levine MZ , Davis T , Barnes JR , Flannery B , Brammer L , Fry A . Emerg Infect Dis 2023 29 (6) 1215-1219 During February 7─September 3, 2022, a total of 39 US states experienced outbreaks of highly pathogenic avian influenza A(H5N1) virus in birds from commercial poultry farms and backyard flocks. Among persons exposed to infected birds, highly pathogenic avian influenza A(H5) viral RNA was detected in 1 respiratory specimen from 1 person. |
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. |
Prevalence of SARS-CoV-2 and Influenza Coinfection and Clinical Characteristics Among Children and Adolescents Aged <18 Years Who Were Hospitalized or Died with Influenza - United States, 2021-22 Influenza Season.
Adams K , Tastad KJ , Huang S , Ujamaa D , Kniss K , Cummings C , Reingold A , Roland J , Austin E , Kawasaki B , Meek J , Yousey-Hindes K , Anderson EJ , Openo KP , Reeg L , Leegwater L , McMahon M , Bye E , Poblete M , Landis Z , Spina NL , Engesser K , Bennett NM , Gaitan MA , Shiltz E , Moran N , Sutton M , Abdullah N , Schaffner W , Talbot HK , Olsen K , Staten H , Taylor CA , Havers FP , Reed C , Budd A , Garg S , O'Halloran A , Brammer L . MMWR Morb Mortal Wkly Rep 2022 71 (50) 1589-1596 The 2022-23 influenza season shows an early rise in pediatric influenza-associated hospitalizations (1). SARS-CoV-2 viruses also continue to circulate (2). The current influenza season is the first with substantial co-circulation of influenza viruses and SARS-CoV-2 (3). Although both seasonal influenza viruses and SARS-CoV-2 can contribute to substantial pediatric morbidity (3-5), whether coinfection increases disease severity compared with that associated with infection with one virus alone is unknown. This report describes characteristics and prevalence of laboratory-confirmed influenza virus and SARS-CoV-2 coinfections among patients aged <18 years who had been hospitalized or died with influenza as reported to three CDC surveillance platforms during the 2021-22 influenza season. Data from two Respiratory Virus Hospitalizations Surveillance Network (RESP-NET) platforms (October 1, 2021-April 30, 2022),(§) and notifiable pediatric deaths associated(¶) with influenza virus and SARS-CoV-2 coinfection (October 3, 2021-October 1, 2022)** were analyzed. SARS-CoV-2 coinfections occurred in 6% (32 of 575) of pediatric influenza-associated hospitalizations and in 16% (seven of 44) of pediatric influenza-associated deaths. Compared with patients without coinfection, a higher proportion of those hospitalized with coinfection received invasive mechanical ventilation (4% versus 13%; p = 0.03) and bilevel positive airway pressure or continuous positive airway pressure (BiPAP/CPAP) (6% versus 16%; p = 0.05). Among seven coinfected patients who died, none had completed influenza vaccination, and only one received influenza antivirals.(††) To help prevent severe outcomes, clinicians should follow recommended respiratory virus testing algorithms to guide treatment decisions and consider early antiviral treatment initiation for pediatric patients with suspected or confirmed influenza, including those with SARS-CoV-2 coinfection who are hospitalized or at increased risk for severe illness. The public and parents should adopt prevention strategies including considering wearing well-fitted, high-quality masks when respiratory virus circulation is high and staying up-to-date with recommended influenza and COVID-19 vaccinations for persons aged ≥6 months. |
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. |
Influenza Activity and Composition of the 2022-23 Influenza Vaccine - United States, 2021-22 Season.
Merced-Morales A , Daly P , Abd Elal AI , Ajayi N , Annan E , Budd A , Barnes J , Colon A , Cummings CN , Iuliano AD , DaSilva J , Dempster N , Garg S , Gubareva L , Hawkins D , Howa A , Huang S , Kirby M , Kniss K , Kondor R , Liddell J , Moon S , Nguyen HT , O'Halloran A , Smith C , Stark T , Tastad K , Ujamaa D , Wentworth DE , Fry AM , Dugan VG , Brammer L . MMWR Morb Mortal Wkly Rep 2022 71 (29) 913-919 Before the emergence of SARS-CoV-2, the virus that causes COVID-19, influenza activity in the United States typically began to increase in the fall and peaked in February. During the 2021-22 season, influenza activity began to increase in November and remained elevated until mid-June, featuring two distinct waves, with A(H3N2) viruses predominating for the entire season. This report summarizes influenza activity during October 3, 2021-June 11, 2022, in the United States and describes the composition of the Northern Hemisphere 2022-23 influenza vaccine. Although influenza activity is decreasing and circulation during summer is typically low, remaining vigilant for influenza infections, performing testing for seasonal influenza viruses, and monitoring for novel influenza A virus infections are important. An outbreak of highly pathogenic avian influenza A(H5N1) is ongoing; health care providers and persons with exposure to sick or infected birds should remain vigilant for onset of symptoms consistent with influenza. Receiving a seasonal influenza vaccine each year remains the best way to protect against seasonal influenza and its potentially severe consequences. |
Estimating Under-recognized COVID-19 Deaths, United States, March 2020-May 2021 using an Excess Mortality Modelling Approach.
Iuliano AD , Chang HH , Patel NN , Threlkel R , Kniss K , Reich J , Steele M , Hall AJ , Fry AM , Reed C . Lancet Reg Health Am 2021 1 100019 BACKGROUND: In the United States, Coronavirus Disease 2019 (COVID-19) deaths are captured through the National Notifiable Disease Surveillance System and death certificates reported to the National Vital Statistics System (NVSS). However, not all COVID-19 deaths are recognized and reported because of limitations in testing, exacerbation of chronic health conditions that are listed as the cause of death, or delays in reporting. Estimating deaths may provide a more comprehensive understanding of total COVID-19-attributable deaths. METHODS: We estimated COVID-19 unrecognized attributable deaths, from March 2020-April 2021, using all-cause deaths reported to NVSS by week and six age groups (0-17, 18-49, 50-64, 65-74, 75-84, and ≥85 years) for 50 states, New York City, and the District of Columbia using a linear time series regression model. Reported COVID-19 deaths were subtracted from all-cause deaths before applying the model. Weekly expected deaths, assuming no SARS-CoV-2 circulation and predicted all-cause deaths using SARS-CoV-2 weekly percent positive as a covariate were modelled by age group and including state as a random intercept. COVID-19-attributable unrecognized deaths were calculated for each state and age group by subtracting the expected all-cause deaths from the predicted deaths. FINDINGS: We estimated that 766,611 deaths attributable to COVID-19 occurred in the United States from March 8, 2020-May 29, 2021. Of these, 184,477 (24%) deaths were not documented on death certificates. Eighty-two percent of unrecognized deaths were among persons aged ≥65 years; the proportion of unrecognized deaths were 0•24-0•31 times lower among those 0-17 years relative to all other age groups. More COVID-19-attributable deaths were not captured during the early months of the pandemic (March-May 2020) and during increases in SARS-CoV-2 activity (July 2020, November 2020-February 2021). DISCUSSION: Estimating COVID-19-attributable unrecognized deaths provides a better understanding of the COVID-19 mortality burden and may better quantify the severity of the COVID-19 pandemic. FUNDING: None. |
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 . MMWR Morb Mortal Wkly Rep 2021 70 (29) 1013-1019 The COVID-19 pandemic and subsequent implementation of nonpharmaceutical interventions (e.g., cessation of global travel, mask use, physical distancing, and staying home) reduced 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. |
Cluster of Oseltamivir-Resistant and Hemagglutinin Antigenically Drifted Influenza A(H1N1)pdm09 Viruses, Texas, USA, January 2020
Mohan T , Nguyen HT , Kniss K , Mishin VP , Merced-Morales AA , Laplante J , St George K , Blevins P , Chesnokov A , De La Cruz JA , Kondor R , Wentworth DE , Gubareva LV . Emerg Infect Dis 2021 27 (7) 1953-1957 Four cases of oseltamivir-resistant influenza A(H1N1)pdm09 virus infection were detected among inhabitants of a border detention center in Texas, USA. Hemagglutinin of these viruses belongs to 6B.1A5A-156K subclade, which may enable viral escape from preexisting immunity. Our finding highlights the necessity to monitor both drug resistance and antigenic drift of circulating viruses. |
Spread of antigenically drifted influenza A(H3N2) viruses and vaccine effectiveness in the United States during the 2018-2019 season
Flannery B , Kondor RJG , Chung JR , Gaglani M , Reis M , Zimmerman RK , Nowalk MP , Jackson ML , Jackson LA , Monto AS , Martin ET , Belongia EA , McLean HQ , Kim SS , Blanton L , Kniss K , Budd AP , Brammer L , Stark TJ , Barnes JR , Wentworth DE , Fry AM , Patel M . J Infect Dis 2019 221 (1) 8-15 BACKGROUND: Increased illness due to antigenically drifted A(H3N2) clade 3C.3a influenza viruses prompted concerns about vaccine effectiveness and vaccine strain selection. We used U.S. virologic surveillance and Influenza Vaccine Effectiveness (VE) Network data to evaluate consequences of this clade. METHODS: Distribution of influenza viruses was described using virologic surveillance data. The VE Network enrolled ambulatory patients aged >/=6 months with acute respiratory illness at five sites. Respiratory specimens were tested by RT-PCR for influenza and sequenced. Using a test-negative design, we estimated VE comparing odds of influenza among vaccinated versus unvaccinated participants. RESULTS: During the 2018-2019 influenza season, A(H3N2) clade 3C.3a viruses caused an increasing proportion of influenza cases. Among 2,763 VE Network case patients, 1,325 (48%) were infected with A(H1N1)pdm09 and 1,350 (49%) with A(H3N2); clade 3C.3a accounted for 977 (93%) of 1,054 sequenced A(H3N2) viruses. VE was 44% (95% confidence interval [CI], 37 to 51%) against A(H1N1)pdm09 and 9% (95% CI, -4 to 20%) against A(H3N2); effectiveness was 5% (95% CI, -10 to 19%) against A(H3N2) clade 3C.3a viruses. CONCLUSIONS: Predominance of A(H3N2) clade 3C.3a viruses during the latter part of the 2018-2019 season was associated with decreased vaccine effectiveness, supporting the A(H3N2) vaccine component update for 2019-2020 northern hemisphere influenza vaccines. |
Update: Influenza Activity - United States and Worldwide, May 19-September 28, 2019, and Composition of the 2020 Southern Hemisphere Influenza Vaccine
Epperson S , Davis CT , Brammer L , Abd Elal AI , Ajayi N , Barnes J , Budd AP , Burns E , Daly P , Dugan VG , Fry AM , Jang Y , Johnson SJ , Kniss K , Kondor R , Grohskopf LA , Gubareva L , Merced-Morales A , Sessions W , Stevens J , Wentworth DE , Xu X , Jernigan D . MMWR Morb Mortal Wkly Rep 2019 68 (40) 880-884 During May 19-September 28, 2019,* low levels of influenza activity were reported in the United States, with cocirculation of influenza A and influenza B viruses. In the Southern Hemisphere seasonal influenza viruses circulated widely, with influenza A(H3) predominating in many regions; however, influenza A(H1N1)pdm09 and influenza B viruses were predominant in some countries. In late September, the World Health Organization (WHO) recommended components for the 2020 Southern Hemisphere influenza vaccine and included an update to the A(H3N2) and B/Victoria-lineage components. Annual influenza vaccination is the best means for preventing influenza illness and its complications, and vaccination before influenza activity increases is optimal. Health care providers should recommend vaccination for all persons aged >/=6 months who do not have contraindications to vaccination (1). |
Update: Influenza activity in the United States during the 2018-19 season and composition of the 2019-20 influenza vaccine
Xu X , Blanton L , Elal AIA , Alabi N , Barnes J , Biggerstaff M , Brammer L , Budd AP , Burns E , Cummings CN , Garg S , Kondor R , Gubareva L , Kniss K , Nyanseor S , O'Halloran A , Rolfes M , Sessions W , Dugan VG , Fry AM , Wentworth DE , Stevens J , Jernigan D . MMWR Morb Mortal Wkly Rep 2019 68 (24) 544-551 Influenza activity* in the United States during the 2018-19 season (September 30, 2018-May 18, 2019) was of moderate severity (1). Nationally, influenza-like illness (ILI)(dagger) activity began increasing in November, peaked during mid-February, and returned to below baseline in mid-April; the season lasted 21 weeks,( section sign) making it the longest season in 10 years. Illness attributed to influenza A viruses predominated, with very little influenza B activity. Two waves of influenza A were notable during this extended season: influenza A(H1N1)pdm09 viruses from October 2018 to mid-February 2019 and influenza A(H3N2) viruses from February through May 2019. Compared with the 2017-18 influenza season, rates of hospitalization this season were lower for adults, but were similar for children. Although influenza activity is currently below surveillance baselines, testing for seasonal influenza viruses and monitoring for novel influenza A virus infections should continue year-round. Receiving a seasonal influenza vaccine each year remains the best way to protect against seasonal influenza and its potentially severe consequences. |
Birth cohort effects in influenza surveillance data: Evidence that first influenza infection affects later influenza-associated illness
Budd AP , Beacham L , Smith CB , Garten RJ , Reed C , Kniss K , Mustaquim D , Ahmad FB , Cummings CN , Garg S , Levine MZ , Fry AM , Brammer L . J Infect Dis 2019 220 (5) 820-829 BACKGROUND: The evolution of influenza A viruses results in birth cohorts that have different initial influenza virus exposures. Historically, A/H3 predominant seasons have been associated with more severe influenza-associated disease; however, since the 2009 pandemic there are suggestions that some birth cohorts experience more severe illness in A/H1 predominant seasons. METHODS: U.S. influenza virologic, hospitalization and mortality surveillance data during 2000-2017 were analyzed for cohorts born between 1918 and 1989 that likely had different initial influenza virus exposures based on viruses circulating during early childhood. Relative risk/rate during H3 compared to H1 predominant seasons during pre-pandemic versus pandemic and later periods were calculated for each cohort. RESULTS: During the pre-pandemic period, all cohorts had more influenza-associated disease during H3 predominant seasons than H1 predominant seasons. During the pandemic and later period, four cohorts had higher hospitalization and mortality rates during H1 predominant seasons than H3 predominant seasons. DISCUSSION: Birth cohort differences in risk of influenza-associated disease by influenza A virus subtype can be seen in U.S. influenza surveillance data and differ between pre-pandemic and pandemic and later periods. As the population ages, the amount of influenza-associated disease may be greater in future H1 predominant seasons than H3 predominant seasons. |
Update: Influenza activity - United States, September 30, 2018-February 2, 2019
Blanton L , Dugan VG , Abd Elal AI , Alabi N , Barnes J , Brammer L , Budd AP , Burns E , Cummings CN , Garg S , Garten R , Gubareva L , Kniss K , Kramer N , O'Halloran A , Reed C , Rolfes M , Sessions W , Taylor C , Xu X , Fry AM , Wentworth DE , Katz J , Jernigan D . MMWR Morb Mortal Wkly Rep 2019 68 (6) 125-134 CDC collects, compiles, and analyzes data on influenza activity and viruses in the United States. During September 30, 2018-February 2, 2019,* influenza activity(dagger) in the United States was low during October and November, increased in late December, and remained elevated through early February. As of February 2, 2019, this has been a low-severity influenza season (1), with a lower percentage of outpatient visits for influenza-like illness (ILI), lower rates of hospitalization, and fewer deaths attributed to pneumonia and influenza, compared with recent seasons. Influenza-associated hospitalization rates among children are similar to those observed in influenza A(H1N1)pdm09 predominant seasons; 28 influenza-associated pediatric deaths occurring during the 2018-19 season have been reported to CDC. Whereas influenza A(H1N1)pdm09 viruses predominated in most areas of the country, influenza A(H3N2) viruses have predominated in the southeastern United States, and in recent weeks accounted for a growing proportion of influenza viruses detected in several other regions. Small numbers of influenza B viruses (<3% of all influenza-positive tests performed by public health laboratories) also were reported. The majority of the influenza viruses characterized antigenically are similar to the cell culture-propagated reference viruses representing the 2018-19 Northern Hemisphere influenza vaccine viruses. Health care providers should continue to offer and encourage vaccination to all unvaccinated persons aged >/=6 months as long as influenza viruses are circulating. Finally, regardless of vaccination status, it is important that persons with confirmed or suspected influenza who have severe, complicated, or progressive illness; who require hospitalization; or who are at high risk for influenza complications be treated with antiviral medications. |
Update: Influenza activity - United States and worldwide, May 20-October 13, 2018
Chow EJ , Davis CT , Abd Elal AI , Alabi N , Azziz-Baumgartner E , Barnes J , Blanton L , Brammer L , Budd AP , Burns E , Davis WW , Dugan VG , Fry AM , Garten R , Grohskopf LA , Gubareva L , Jang Y , Jones J , Kniss K , Lindstrom S , Mustaquim D , Porter R , Rolfes M , Sessions W , Taylor C , Wentworth DE , Xu X , Zanders N , Katz J , Jernigan D . MMWR Morb Mortal Wkly Rep 2018 67 (42) 1178-1185 During May 20-October 13, 2018,* low levels of influenza activity were reported in the United States, with a mix of influenza A and B viruses circulating. Seasonal influenza activity in the Southern Hemisphere was low overall, with influenza A(H1N1)pdm09 predominating in many regions. Antigenic testing of available influenza A and B viruses indicated that no significant antigenic drift in circulating viruses had emerged. In late September, the components for the 2019 Southern Hemisphere influenza vaccine were selected and included an incremental update to the A(H3N2) vaccine virus used in egg-based vaccine manufacturing; no change was recommended for the A(H3N2) component of cell-manufactured or recombinant influenza vaccines. Annual influenza vaccination is the best method for preventing influenza illness and its complications, and all persons aged >/=6 months who do not have contraindications should receive influenza vaccine, preferably before the onset of influenza circulation in their community, which often begins in October and peaks during December-February. Health care providers should offer vaccination by the end of October and should continue to recommend and administer influenza vaccine to previously unvaccinated patients throughout the 2018-19 influenza season (1). In addition, during May 20-October 13, a small number of nonhuman influenza "variant" virus infections(dagger) were reported in the United States; most were associated with exposure to swine. Although limited human-to-human transmission might have occurred in one instance, no ongoing community transmission was identified. Vulnerable populations, especially young children and other persons at high risk for serious influenza complications, should avoid swine barns at agricultural fairs, or close contact with swine. |
Update: Influenza Activity in the United States During the 2017-18 Season and Composition of the 2018-19 Influenza Vaccine.
Garten R , Blanton L , Elal AIA , Alabi N , Barnes J , Biggerstaff M , Brammer L , Budd AP , Burns E , Cummings CN , Davis T , Garg S , Gubareva L , Jang Y , Kniss K , Kramer N , Lindstrom S , Mustaquim D , O'Halloran A , Sessions W , Taylor C , Xu X , Dugan VG , Fry AM , Wentworth DE , Katz J , Jernigan D . MMWR Morb Mortal Wkly Rep 2018 67 (22) 634-642 The United States 2017-18 influenza season (October 1, 2017-May 19, 2018) was a high severity season with high levels of outpatient clinic and emergency department visits for influenza-like illness (ILI), high influenza-related hospitalization rates, and elevated and geographically widespread influenza activity across the country for an extended period. Nationally, ILI activity began increasing in November, reaching an extended period of high activity during January-February, and remaining elevated through March. Influenza A(H3N2) viruses predominated through February and were predominant overall for the season; influenza B viruses predominated from March onward. This report summarizes U.S. influenza activity* during October 1, 2017-May 19, 2018.(dagger). |
Systematic assessment of multiple routine and near real-time indicators to classify the severity of influenza seasons and pandemics in the United States, 2003-2004 through 2015-2016
Biggerstaff M , Kniss K , Jernigan DB , Brammer L , Bresee J , Garg S , Burns E , Reed C . Am J Epidemiol 2018 187 (5) 1040-1050 Assessments of influenza season severity can guide public health action. We used the moving epidemic method to develop intensity thresholds (ITs) for 3 US surveillance indicators from the 2003-2004 through 2014-2015 influenza seasons (excluding the 2009 pandemic). The indicators were: 1) outpatient visits for influenza-like illness; 2) influenza-related hospitalizations; and 3) influenza- and pneumonia-related deaths. ITs were developed for the population overall and separately for children, adults, and older adults, and they were set at the upper limit of the 50% (IT50), 90% (IT90), and 98% (IT98) 1-sided confidence intervals of the geometric mean of each season's 3 highest values. Severity was classified as low if >/=2 systems peaked below IT50, moderate if >/=2 peaked between IT50 and IT90, high if >/=2 peaked between IT90 and IT98, and very high if >/=2 peaked above IT98. We pilot-tested this method with the 2015-2016 season and the 2009 pandemic. Overall, 4 seasons were classified as low severity, 7 as moderate, 2 as high, and none as very high. Among the age groups, older adults had the most seasons (n = 3) classified as high, and children were the only group to have seasons (n = 2) classified as very high. We will apply this method to classify the severity of future seasons and inform pandemic response. |
Update: Influenza activity - United States, October 1, 2017-February 3, 2018
Budd AP , Wentworth DE , Blanton L , Elal AIA , Alabi N , Barnes J , Brammer L , Burns E , Cummings CN , Davis T , Flannery B , Fry AM , Garg S , Garten R , Gubareva L , Jang Y , Kniss K , Kramer N , Lindstrom S , Mustaquim D , O'Halloran A , Olsen SJ , Sessions W , Taylor C , Xu X , Dugan VG , Katz J , Jernigan D . MMWR Morb Mortal Wkly Rep 2018 67 (6) 169-179 Influenza activity in the United States began to increase in early November 2017 and rose sharply from December through February 3, 2018; elevated influenza activity is expected to continue for several more weeks. Influenza A viruses have been most commonly identified, with influenza A(H3N2) viruses predominating, but influenza A(H1N1)pdm09 and influenza B viruses were also reported. This report summarizes U.S. influenza activity* during October 1, 2017-February 3, 2018,(dagger) and updates the previous summary (1). |
Update: Influenza activity - United States, October 1-November 25, 2017
Dugan VG , Blanton L , Elal AIA , Alabi N , Barnes J , Brammer L , Burns E , Cummings CN , Davis T , Flannery B , Fry AM , Garg S , Garten R , Gubareva L , Jang Y , Kniss K , Kramer N , Lindstrom S , Mustaquim D , O'Halloran A , Olsen SJ , Sessions W , Taylor C , Trock S , Xu X , Wentworth DE , Katz J , Jernigan D . MMWR Morb Mortal Wkly Rep 2017 66 (48) 1318-1326 Influenza activity in the United States was low during October 2017, but has been increasing since the beginning of November. Influenza A viruses have been most commonly identified, with influenza A(H3N2) viruses predominating. Several influenza activity indicators were higher than is typically seen for this time of year. The majority of influenza viruses characterized during this period were genetically or antigenically similar to the 2017-18 Northern Hemisphere cell-grown vaccine reference viruses. These data indicate that currently circulating viruses have not undergone significant antigenic drift; however, circulating A(H3N2) viruses are antigenically less similar to egg-grown A(H3N2) viruses used for producing the majority of influenza vaccines in the United States. It is difficult to predict which influenza viruses will predominate in the 2017-18 influenza season; however, in recent past seasons in which A(H3N2) viruses predominated, hospitalizations and deaths were more common, and the effectiveness of the vaccine was lower. Annual influenza vaccination is recommended for all persons aged ≥6 months who do not have contraindications. Multiple influenza vaccines are approved and recommended for use during the 2017-18 season, and vaccination should continue to be offered as long as influenza viruses are circulating and unexpired vaccine is available. This report summarizes U.S. influenza activity* during October 1-November 25, 2017 (surveillance weeks 40-47).(dagger). |
Update: Influenza activity - United States and worldwide, May 21-September 23, 2017
Blanton L , Wentworth DE , Alabi N , Azziz-Baumgartner E , Barnes J , Brammer L , Burns E , Davis CT , Dugan VG , Fry AM , Garten R , Grohskopf LA , Gubareva L , Kniss K , Lindstrom S , Mustaquim D , Olsen SJ , Roguski K , Taylor C , Trock S , Xu X , Katz J , Jernigan D . MMWR Morb Mortal Wkly Rep 2017 66 (39) 1043-1051 During May 21-September 23, 2017, the United States experienced low-level seasonal influenza virus activity; however, beginning in early September, CDC received reports of a small number of localized influenza outbreaks caused by influenza A(H3N2) viruses. In addition to influenza A(H3N2) viruses, influenza A(H1N1)pdm09 and influenza B viruses were detected during May-September worldwide and in the United States. Influenza B viruses predominated in the United States from late May through late June, and influenza A viruses predominated beginning in early July. The majority of the influenza viruses collected and received from the United States and other countries during that time have been characterized genetically or antigenically as being similar to the 2017 Southern Hemisphere and 2017-18. Northern Hemisphere cell-grown vaccine reference viruses; however, a smaller proportion of the circulating A(H3N2) viruses showed similarity to the egg-grown A(H3N2) vaccine reference virus which represents the A(H3N2) viruses used for the majority of vaccine production in the United States. Also, during May 21-September 23, 2017, CDC confirmed a total of 33 influenza variant virus infections; two were influenza A(H1N2) variant (H1N2v) viruses (Ohio) and 31 were influenza A(H3N2) variant (H3N2v) viruses (Delaware [1], Maryland [13], North Dakota [1], Pennsylvania [1], and Ohio [15]). An additional 18 specimens from Maryland have tested presumptive positive for H3v and further analysis is being conducted at CDC. |
Update: Influenza activity in the United States during the 2016-17 season and composition of the 2017-18 influenza vaccine
Blanton L , Alabi N , Mustaquim D , Taylor C , Kniss K , Kramer N , Budd A , Garg S , Cummings CN , Chung J , Flannery B , Fry AM , Sessions W , Garten R , Xu X , Elal AIA , Gubareva L , Barnes J , Dugan V , Wentworth DE , Burns E , Katz J , Jernigan D , Brammer L . MMWR Morb Mortal Wkly Rep 2017 66 (25) 668-676 During the 2016-17 influenza season (October 2, 2016-May 20, 2017) in the United States, influenza activity* was moderate. Activity remained low through November, increased during December, and peaked in February nationally, although there were regional differences in the timing of influenza activity. Influenza A(H3N2) viruses predominated through mid-March and were predominant overall for the season, but influenza B viruses were most commonly reported from late March through May. This report summarizes influenza activity in the United States during October 2, 2016-May 20, 2017dagger and updates the previous summary (1). |
Update: Influenza activity - United States, October 2, 2016-February 4, 2017
Blanton L , Mustaquim D , Alabi N , Kniss K , Kramer N , Budd A , Garg S , Cummings CN , Fry AM , Bresee J , Sessions W , Garten R , Xu X , Elal AI , Gubareva L , Barnes J , Wentworth DE , Burns E , Katz J , Jernigan D , Brammer L . MMWR Morb Mortal Wkly Rep 2017 66 (6) 159-166 This report summarizes U.S. influenza activity during October 2, 2016-February 4, 2017, and updates the previous summary. Influenza activity in the United States began to increase in mid-December, remained elevated through February 4, 2017, and is expected to continue for several more weeks. To date, influenza A (H3N2) viruses have predominated overall, but influenza A (H1N1)pdm09 and influenza B viruses have also been identified. |
Guillain-Barre Syndrome and healthcare needs during Zika virus transmission, Puerto Rico, 2016
Dirlikov E , Kniss K , Major C , Thomas D , Virgen CA , Mayshack M , Asher J , Mier-Y-Teran-Romero L , Salinas JL , Pastula DM , Sharp TM , Sejvar J , Johansson MA , Rivera-Garcia B . Emerg Infect Dis 2017 23 (1) 134-136 To assist with public health preparedness activities, we estimated the number of expected cases of Zika virus in Puerto Rico and associated healthcare needs. Estimated annual incidence is 3.2-5.1 times the baseline, and long-term care needs are predicted to be 3-5 times greater than in years with no Zika virus. |
Update: Influenza activity - United States, October 2-December 17, 2016
Shang M , Blanton L , Kniss K , Mustaquim D , Alabi N , Barnes S , Budd A , Davlin SL , Kramer N , Garg S , Cummings CN , Flannery B , Fry AM , Grohskopf LA , Olsen SJ , Bresee J , Sessions W , Garten R , Xu X , Elal AI , Gubareva L , Barnes J , Wentworth DE , Burns E , Katz J , Jernigan D , Brammer L . MMWR Morb Mortal Wkly Rep 2016 65 (5051) 1439-1444 This report summarizes U.S. influenza activity during October 2-December 17, 2016. Influenza activity in the United States remained low in October and has been slowly increasing since November. Influenza A viruses were identified most frequently, with influenza A (H3N2) viruses predominating. Most influenza viruses characterized during this period were genetically or antigenically similar to the reference viruses representing vaccine components recommended for production in the 2016-17 Northern Hemisphere influenza vaccines. |
Update: Influenza activity - United States and worldwide, May 22-September 10, 2016
Budd A , Blanton L , Kniss K , Smith S , Mustaquim D , Davlin SL , Kramer N , Flannery B , Fry AM , Grohskopf LA , Olsen SJ , Bresee J , Sessions W , Garten R , Xu X , Elal AI , Gubareva L , Barnes J , Wentworth DE , Burns E , Katz J , Jernigan D , Brammer L . MMWR Morb Mortal Wkly Rep 2016 65 (37) 1008-1014 During May 22-September 10, 2016, the United States experienced typical low levels of seasonal influenza activity overall; beginning in late August, clinical laboratories reported a slight increase in influenza positive test results and CDC received reports of a small number of localized influenza outbreaks caused by influenza A (H3N2) viruses. Influenza A (H1N1)pdm09, influenza A (H3N2), and influenza B viruses were detected during May-September in the United States and worldwide. The majority of the influenza viruses collected from the United States and other countries during that time have been characterized antigenically or genetically or both as being similar to the reference viruses representing vaccine components recommended for the 2016-17 Northern Hemisphere vaccine. During May 22-September 10, 2016, 20 influenza variant virusdagger infections were reported; two were influenza A (H1N2) variant (H1N2v) viruses (Minnesota and Wisconsin) and 18 were influenza A (H3N2) variant (H3N2v) viruses (12 from Michigan and six from Ohio). |
Influenza activity - United States, 2015-16 season and composition of the 2016-17 influenza vaccine
Davlin SL , Blanton L , Kniss K , Mustaquim D , Smith S , Kramer N , Cohen J , Cummings CN , Garg S , Flannery B , Fry AM , Grohskopf LA , Bresee J , Wallis T , Sessions W , Garten R , Xu X , Elal AI , Gubareva L , Barnes J , Wentworth DE , Burns E , Katz J , Jernigan D , Brammer L . MMWR Morb Mortal Wkly Rep 2016 65 (22) 567-575 During the 2015-16 influenza season (October 4, 2015-May 21, 2016) in the United States, influenza activity was lower and peaked later compared with the previous three seasons (2012-13, 2013-14, and 2014-15). Activity remained low from October 2015 until late December 2015 and peaked in mid-March 2016. During the most recent 18 influenza seasons (including this season), only two other seasons have peaked in March (2011-12 and 2005-06). Overall influenza activity was moderate this season, with a lower percentage of outpatient visits for influenza-like illness (ILI), lower hospitalization rates, and a lower percentage of deaths attributed to pneumonia and influenza (P&I) compared with the preceding three seasons. Influenza A(H1N1)pdm09 viruses predominated overall, but influenza A(H3N2) viruses were more commonly identified from October to early December, and influenza B viruses were more commonly identified from mid-April through mid-May. The majority of viruses characterized this season were antigenically similar to the reference viruses representing the recommended components of the 2015-16 Northern Hemisphere influenza vaccine. This report summarizes influenza activity in the United States during the 2015-16 influenza season (October 4, 2015-May 21, 2016) section sign and reports the vaccine virus components recommended for the 2016-17 Northern Hemisphere influenza vaccines. |
Patterns in Zika Virus Testing and Infection, by Report of Symptoms and Pregnancy Status - United States, January 3-March 5, 2016
Dasgupta S , Reagan-Steiner S , Goodenough D , Russell K , Tanner M , Lewis L , Petersen EE , Powers AM , Kniss K , Meaney-Delman D , Oduyebo T , O'Leary D , Chiu S , Talley P , Hennessey M , Hills S , Cohn A , Gregory C . MMWR Morb Mortal Wkly Rep 2016 65 (15) 395-9 CDC recommends Zika virus testing for potentially exposed persons with signs or symptoms consistent with Zika virus disease, and recommends that health care providers offer testing to asymptomatic pregnant women within 12 weeks of exposure. During January 3-March 5, 2016, Zika virus testing was performed for 4,534 persons who traveled to or moved from areas with active Zika virus transmission; 3,335 (73.6%) were pregnant women. Among persons who received testing, 1,541 (34.0%) reported at least one Zika virus-associated sign or symptom (e.g., fever, rash, arthralgia, or conjunctivitis), 436 (9.6%) reported at least one other clinical sign or symptom only, and 2,557 (56.4%) reported no signs or symptoms. Among 1,541 persons with one or more Zika virus-associated symptoms who received testing, 182 (11.8%) had confirmed Zika virus infection. Among the 2,557 asymptomatic persons who received testing, 2,425 (94.8%) were pregnant women, seven (0.3%) of whom had confirmed Zika virus infection. Although risk for Zika virus infection might vary based on exposure-related factors (e.g., location and duration of travel), in the current setting in U.S. states, where there is no local transmission, most asymptomatic pregnant women who receive testing do not have Zika virus infection. |
Update: influenza activity - United States, October 4, 2015-February 6, 2016
Russell K , Blanton L , Kniss K , Mustaquim D , Smith S , Cohen J , Garg S , Flannery B , Fry AM , Grohskopf LA , Bresee J , Wallis T , Sessions W , Garten R , Xu X , Elal AI , Gubareva L , Barnes J , Wentworth DE , Burns E , Katz J , Jernigan D , Brammer L . MMWR Morb Mortal Wkly Rep 2016 65 (6) 146-53 From October through mid-December 2015, influenza activity remained low in most regions of the United States. Activity began to increase in late December 2015 and continued to increase slowly through early February 2016. Influenza A viruses have been most frequently identified, with influenza A (H3N2) viruses predominating during October until early December, and influenza A (H1N1)pdm09 viruses predominating from mid-December until early February. Most of the influenza viruses characterized during that time are antigenically similar to vaccine virus strains recommended for inclusion in the 2015-16 Northern Hemisphere vaccines. This report summarizes U.S. influenza activity* during October 4, 2015-February 6, 2016, and updates the previous summary. |
Infection risk for persons exposed to highly pathogenic avian influenza A H5 virus-infected birds, United States, December 2014-March 2015
Arriola CS , Nelson DI , Deliberto TJ , Blanton L , Kniss K , Levine MZ , Trock SC , Finelli L , Jhung MA . Emerg Infect Dis 2015 21 (12) 2135-40 Newly emerged highly pathogenic avian influenza (HPAI) A H5 viruses have caused outbreaks among birds in the United States. These viruses differ genetically from HPAI H5 viruses that previously caused human illness, most notably in Asia and Africa. To assess the risk for animal-to-human HPAI H5 virus transmission in the United States, we determined the number of persons with self-reported exposure to infected birds, the number with an acute respiratory infection (ARI) during a 10-day postexposure period, and the number with ARI who tested positive for influenza by real-time reverse transcription PCR or serologic testing for each outbreak during December 15, 2014-March 31, 2015. During 60 outbreaks in 13 states, a total of 164 persons were exposed to infected birds. ARI developed in 5 of these persons within 10 days of exposure. H5 influenza virus infection was not identified in any persons with ARI, suggesting a low risk for animal-to-human HPAI H5 virus transmission. |
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