#SARS-CoV-2 #Prevalence, #Seroprevalence, and #Exposure Among Evacuees from #Wuhan, #China, 2020 (Emerg Infect Dis., abstract)

[Source: US Centers for Disease Control and Prevention (CDC), Emerging Infectious Diseases Journal, full page: (LINK). Abstract, edited.]

Volume 26, Number 9—September 2020 | Synopsis

Severe Acute Respiratory Syndrome Coronavirus 2 Prevalence, Seroprevalence, and Exposure Among Evacuees from Wuhan, China, 2020

Benjamin D. Hallowell1, Christina M. Carlson, Jesica R. Jacobs, Mary Pomeroy, Jonathan Steinberg, Mark Tenforde, Emily McDonald, Loretta Foster, Leora R. Feldstein, Melissa A. Rolfes, Amber Haynes, Glen R. Abedi, George S. Odongo, Kim Saruwatari, Errin C. Rider, Gina Douville, Neenaben Bhakta, Panagiotis Maniatis, Stephen Lindstrom, Natalie J. Thornburg, Xiaoyan Lu, Brett L. Whitaker, Shifaq Kamili, Senthilkumar K. Sakthivel, Lijuan Wang, Lakshmi Malapati, Janna R. Murray, Brian Lynch, Martin Cetron, Clive Brown, Shahrokh Roohi, Lisa Rotz, Denise Borntrager, Kenta Ishii, Kathleen Moser, Mohammad Rasheed, Brandi Freeman, Sandra Lester, Kizzmekia S. Corbett, Olubukola M. Abiona, Geoffrey B. Hutchinson, Barney S. Graham, Nicki Pesik, Barbara Mahon, Christopher Braden, Casey Barton Behravesh, Rebekah Stewart, Nancy Knight, Aron J. Hall, and Marie E. Killerby

Author affiliations: Centers for Disease Control and Prevention, Atlanta, Georgia, USA (B.D. Hallowell, C.M. Carlson, J.R. Jacobs, M. Pomeroy, J. Steinberg, M. Tenforde, E. McDonald, L. Foster, L.R. Feldstein, M.A. Rolfes, A. Haynes, G.R. Abedi, G.S. Odongo, P. Maniatis, S. Lindstrom, N.J. Thornburg, X. Lu, B.L. Whitaker, S. Kamili, S.K. Sakthivel, L. Wang, L. Malapati, J.R. Murray, B. Lynch, M. Cetron, C. Brown, S. Roohi, L. Rotz, D. Borntrager, K. Ishii, K. Moser, B. Freeman, N. Pesik, B. Mahon, C. Braden, C. Barton Behravesh, R. Stewart, N. Knight, A.J. Hall, M.E. Killerby); Riverside University Health System-Public Health, Riverside, California, USA (K. Saruwatari, E.C. Rider, G. Douville, N. Bhakta); Synergy America Inc., Duluth, Georgia, USA (M. Rasheed, S. Lester); National Institutes of Health, Bethesda, Maryland, USA (K.S. Corbett, O.M. Abiona, G.B. Hutchinson, B.S. Graham); 1Current affiliation: Department of Health, Providence, Rhode Island, USA



To determine prevalence of, seroprevalence of, and potential exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among a cohort of evacuees returning to the United States from Wuhan, China, in January 2020, we conducted a cross-sectional study of quarantined evacuees from 1 repatriation flight. Overall, 193 of 195 evacuees completed exposure surveys and submitted upper respiratory or serum specimens or both at arrival in the United States. Nearly all evacuees had taken preventive measures to limit potential exposure while in Wuhan, and none had detectable SARS-CoV-2 in upper respiratory tract specimens, suggesting the absence of asymptomatic respiratory shedding among this group at the time of testing. Evidence of antibodies to SARS-CoV-2 was detected in 1 evacuee, who reported experiencing no symptoms or high-risk exposures in the previous 2 months. These findings demonstrated that this group of evacuees posed a low risk of introducing SARS-CoV-2 to the United States.

Keywords: SARS-CoV-2; COVID-19; USA; China; Serology; Seroprevalence.


#Suppression of a #SARS-CoV-2 #outbreak in the #Italian #municipality of #Vo’ (Nature, abstract)

[Source: Nature, full page: (LINK). Abstract, edited.]

This is an unedited manuscript that has been accepted for publication. Nature Research are providing this early version of the manuscript as a service to our authors and readers. The manuscript will undergo copyediting, typesetting and a proof review before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers apply.

Suppression of a SARS-CoV-2 outbreak in the Italian municipality of Vo’

Enrico Lavezzo, Elisa Franchin, […] Andrea Crisanti

Nature (2020)



On the 21st of February 2020 a resident of the municipality of Vo’, a small town near Padua, died of pneumonia due to SARS-CoV-2 infection1. This was the first COVID-19 death detected in Italy since the emergence of SARS-CoV-2 in the Chinese city of Wuhan, Hubei province2. In response, the regional authorities imposed the lockdown of the whole municipality for 14 days3. We collected information on the demography, clinical presentation, hospitalization, contact network and presence of SARS-CoV-2 infection in nasopharyngeal swabs for 85.9% and 71.5% of the population of Vo’ at two consecutive time points. On the first survey, which was conducted around the time the town lockdown started, we found a prevalence of infection of 2.6% (95% confidence interval (CI) 2.1-3.3%). On the second survey, which was conducted at the end of the lockdown, we found a prevalence of 1.2% (95% Confidence Interval (CI) 0.8-1.8%). Notably, 42.5% (95% CI 31.5-54.6%) of the confirmed SARS-CoV-2 infections detected across the two surveys were asymptomatic (i.e. did not have symptoms at the time of swab testing and did not develop symptoms afterwards). The mean serial interval was 7.2 days (95% CI 5.9-9.6). We found no statistically significant difference in the viral load of symptomatic versus asymptomatic infections (p-values 0.62 and 0.74 for E and RdRp genes, respectively, Exact Wilcoxon-Mann-Whitney test). This study sheds new light on the frequency of asymptomatic SARS-CoV-2 infection, their infectivity (as measured by the viral load) and provides new insights into its transmission dynamics and the efficacy of the implemented control measures.

Keywords: SARS-CoV-2; COVID-19; Italy; Serology; Seroprevalence.


Prevalent #Eurasian #avian-like #H1N1 #swine #influenza virus with #H1N1pdm09 viral #genes facilitating #human infection (Proc Natl Acad Sci USA, abstract)

[Source: Proceedings of the National Academy of Sciences of the United States of America, full page: (LINK). Abstract, edited.]

Prevalent Eurasian avian-like H1N1 swine influenza virus with 2009 pandemic viral genes facilitating human infection

Honglei Sun, Yihong Xiao,  Jiyu Liu, Dayan Wang, Fangtao Li, Chenxi Wang, Chong Li, Junda Zhu, Jingwei Song, Haoran Sun,  Zhimin Jiang, Litao Liu, Xin Zhang, Kai Wei, Dongjun Hou, Juan Pu, Yipeng Sun, Qi Tong, Yuhai Bi, Kin-Chow Chang, Sidang Liu,  George F. Gao, and Jinhua Liu

PNAS first published June 29, 2020 https://doi.org/10.1073/pnas.1921186117

Contributed by George F. Gao, April 28, 2020 (sent for review December 9, 2019; reviewed by Ian H. Brown and Xiu-Feng Henry Wan)



Pigs are intermediate hosts for the generation of pandemic influenza virus. Thus, systematic surveillance of influenza viruses in pigs is a key measure for prewarning the emergence of the next pandemic influenza. Here, we identified a reassortant EA H1N1 virus possessing pdm/09 and TR-derived internal genes, termed as G4 genotype, which has become predominant in swine populations since 2016. Similar to pdm/09 virus, G4 viruses have all the essential hallmarks of a candidate pandemic virus. Of concern is that swine workers show elevated seroprevalence for G4 virus. Controlling the prevailing G4 EA H1N1 viruses in pigs and close monitoring in human populations, especially the workers in swine industry, should be urgently implemented.



Pigs are considered as important hosts or “mixing vessels” for the generation of pandemic influenza viruses. Systematic surveillance of influenza viruses in pigs is essential for early warning and preparedness for the next potential pandemic. Here, we report on an influenza virus surveillance of pigs from 2011 to 2018 in China, and identify a recently emerged genotype 4 (G4) reassortant Eurasian avian-like (EA) H1N1 virus, which bears 2009 pandemic (pdm/09) and triple-reassortant (TR)-derived internal genes and has been predominant in swine populations since 2016. Similar to pdm/09 virus, G4 viruses bind to human-type receptors, produce much higher progeny virus in human airway epithelial cells, and show efficient infectivity and aerosol transmission in ferrets. Moreover, low antigenic cross-reactivity of human influenza vaccine strains with G4 reassortant EA H1N1 virus indicates that preexisting population immunity does not provide protection against G4 viruses. Further serological surveillance among occupational exposure population showed that 10.4% (35/338) of swine workers were positive for G4 EA H1N1 virus, especially for participants 18 y to 35 y old, who had 20.5% (9/44) seropositive rates, indicating that the predominant G4 EA H1N1 virus has acquired increased human infectivity. Such infectivity greatly enhances the opportunity for virus adaptation in humans and raises concerns for the possible generation of pandemic viruses.

swine influenza – Eurasian avian-like H1N1 virus – 2009 pandemic H1N1 virus – reassortant – pandemic potential



1 H.S., Y.X., and J.L. contributed equally to this work.

2 To whom correspondence may be addressed. Email: gaof@im.ac.cn or ljh@cau.edu.cn.

Author contributions: Honglei Sun, Y.X., S.L., G.F.G., and Jinhua Liu designed research; Honglei Sun, Y.X., Jiyu Liu, F.L., C.L., J.Z., J.S., Haoran Sun, Z.J., L.L., X.Z., K.W., D.H., and Q.T. performed research; Honglei Sun, Jiyu Liu, D.W., C.W., J.P., Y.B., and Jinhua Liu analyzed data; and Honglei Sun, J.P., Y.S., K.-C.C., G.F.G., and Jinhua Liu wrote the paper.

Reviewers: I.H.B., Animal and Plant Health Agency; and X.-F.H.W., University of Missouri.

The authors declare no competing interest.

Data deposition: The sequences generated in this study have been deposited in the GenBank database (accession nos. are listed in SI Appendix, Table S3).

This article contains supporting information online at https://www.pnas.org/lookup/suppl/doi:10.1073/pnas.1921186117/-/DCSupplemental.

Published under the PNAS license.

Keywords: Influenza A; Reassortant strain; Avian Influenza; Swine Influenza; Pigs; Human; China; H1N1; H1N1pdm09.


#Antibody #Responses after #Classroom #Exposure to #Teacher with #Coronavirus Disease, March 2020 (Emerg Infect Dis., abstract)

[Source: US Centers for Disease Control and Prevention (CDC), Emerging Infectious Diseases Journal, full page: (LINK). Abstract, edited.]

Volume 26, Number 9—September 2020 | Research Letter

Antibody Responses after Classroom Exposure to Teacher with Coronavirus Disease, March 2020

Nicole E. Brown1  , Jonathan Bryant-Genevier1, Uptala Bandy, Carol A. Browning, Abby L. Berns, Mary Dott, Michael Gosciminski, Sandra N. Lester, Ruth Link-Gelles, Daniela N. Quilliam, James Sejvar, Natalie J. Thornburg, Bernard J. Wolff, and John Watson

Author affiliations: Centers for Disease Control and Prevention, Atlanta, Georgia, USA (N.E. Brown, J. Bryant-Genevier, M. Dott, S.N. Lester, R. Link-Gelles, J. Sejvar, N.J. Thornburg, B.J. Wolff, J. Watson); Rhode Island Department of Health, Providence, Rhode Island, USA (U. Bandy, C.A. Browning, A.L. Berns, M. Gosciminski, D.N. Quilliam); US Public Health Service Commissioned Corps, Rockville, Maryland, USA (M. Dott, R. Link-Gelles, J. Sejvar)



After returning from Europe to the United States, on March 1, 2020, a symptomatic teacher received positive test results for severe acute respiratory syndrome coronavirus 2. Of the 21 students exposed to the teacher in the classroom, serologic results suggested past infection for 2. Classroom contact may result in virus transmission.

Keywords: SARS-CoV-2; COVID-19; Serology; Seroprevalence; USA.


#Prevalence of #serum #IgG #antibodies against #SARS-CoV-2 among #clinic #staff (PLOS One, abstract)

[Source: PLOS One, full page: (LINK). Abstract, edited.]


Prevalence of serum IgG antibodies against SARS-CoV-2 among clinic staff

Simone B. Schmidt , Ludwig Grüter, Melanie Boltzmann, Jens D. Rollnik

Published: June 25, 2020 | DOI: https://doi.org/10.1371/journal.pone.0235417



The SARS-CoV-2 pandemic threatens health care providers and society. For planning of treatment capacities, it is of major importance to obtain reliable information on infection and fatality rates of the novel coronavirus. A German community study, the so-called Heinsberg study, found a 5-fold higher infection rate (and thus a remarkably lower fatality rate) than the officially reported cases suggest. We were interested to examine the SARS-CoV-2-IgG antibody status among clinic staff of a large neurological center in Northern Germany. Blood samples and questionnaires (demographic data, medical history) were collected pseudonymously. In total, 406 out of 525 (77.3%) of our employees participated in the study. The infection rate among the staff was as high as 2.7%. Including drop-outs (missing questionnaire but test result available), the infection rate was even higher (2.9%). Only 36% of the positively tested employees did suffer from flu-like symptoms in 2020. None of the nurses–having closest and longest contact to patients—were found to be positive. Despite the fact that the infection rate among clinic staff may not be directly compared to the situation in the surrounding county (due to different testing procedures), one might hypothesize that the infection rate could be more than 30-fold higher than the number of officially reported cases for the county of Hameln-Pyrmont. The high rate of IgG-positive, asymptomatic healthcare workers might help to overcome fears in daily work.


Citation: Schmidt SB, Grüter L, Boltzmann M, Rollnik JD (2020) Prevalence of serum IgG antibodies against SARS-CoV-2 among clinic staff. PLoS ONE 15(6): e0235417. https://doi.org/10.1371/journal.pone.0235417

Editor: Muhammad Adrish, BronxCare Health System, Affiliated with Icahn School of Medicine at Mount Sinai, NY, UNITED STATES

Received: May 8, 2020; Accepted: June 15, 2020; Published: June 25, 2020

Copyright: © 2020 Schmidt et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the paper and its Supporting Information files.

Funding: The author(s) received no specific funding for this work.

Competing interests: The authors have declared that no competing interests exist.

Keywords: SARS-CoV-2; COVID-19; Germany; Institutional outbreaks; Serology; Seroprevalence.


#Prevalence of #SARS-CoV-2 specific neutralising #antibodies in #blood #donors from the #Lodi Red Zone in #Lombardy, #Italy, as at 06 April 2020 (Euro Surveill., abstract)

[Source: Eurosurveillance, full page: (LINK). Abstract, edited.]

Prevalence of SARS-CoV-2 specific neutralising antibodies in blood donors from the Lodi Red Zone in Lombardy, Italy, as at 06 April 2020

Elena Percivalle1 , Giuseppe Cambiè2 , Irene Cassaniti1,3 , Edoardo Vecchio Nepita1,3 , Roberta Maserati1 , Alessandro Ferrari1,3 , Raffaella Di Martino1,3 , Paola Isernia4 , Francesco Mojoli3,5 , Raffaele Bruno3,6 , Marcello Tirani7,8 , Danilo Cereda8 , Carlo Nicora9 , Massimo Lombardo10 , Fausto Baldanti1,3

Affiliations: 1 Molecular Virology Unit, Microbiology and Virology Department, IRCCS Policlinico San Matteo, Pavia, Italy; 2 Immunohematology and Transfusion Medicine Unit, Ospedale Maggiore di Lodi, Lodi, Italy; 3 Department of Clinical Surgical Diagnostic and Pediatric Sciences, University of Pavia, Pavia, Italy; 4 SIMT, Centro Lavorazione e Validazione, IRCCS Policlinico San Matteo, Pavia, Italy; 5 ICU1 Department of Intensive Medicine, IRCCS Policlinico San Matteo, Pavia, Italy; 6 Infectious Diseases I, Department of Medical Sciences and Infectious Diseases, IRCCS Policlinico San Matteo, Pavia, Italy; 7 Health Protection Agency of Pavia, Department of Hygiene and Preventive Medicine, Pavia, Italy; 8 Lombardy Region, Directorate General for Health, UO Prevenzione, Milan, Italy; 9 Chief Executive Office, IRCCS Policlinico San Matteo, Pavia, Italy; 10 Chief Executive Office, ASST Lodi, Lodi, Italy

Correspondence:  Fausto Baldanti

Citation style for this article: Percivalle Elena , Cambiè Giuseppe , Cassaniti Irene , Nepita Edoardo Vecchio , Maserati Roberta , Ferrari Alessandro , Di Martino Raffaella , Isernia Paola , Mojoli Francesco , Bruno Raffaele , Tirani Marcello , Cereda Danilo , Nicora Carlo , Lombardo Massimo , Baldanti Fausto . Prevalence of SARS-CoV-2 specific neutralising antibodies in blood donors from the Lodi Red Zone in Lombardy, Italy, as at 06 April 2020. Euro Surveill. 2020;25(24):pii=2001031. https://doi.org/10.2807/1560-7917.ES.2020.25.24.2001031

Received: 26 May 2020;   Accepted: 18 Jun 2020



We evaluated SARS-CoV-2 RNA and neutralising antibodies in blood donors (BD) residing in the Lodi Red Zone, Italy. Of 390 BDs recruited after 20 February 2020 − when the first COVID-19 case in Lombardy was identified, 91 (23%) aged 19–70 years were antibody positive. Viral RNA was detected in an additional 17 (4.3%) BDs, yielding ca 28% (108/390) with evidence of virus exposure. Five stored samples collected as early as 12 February were seropositive.

©  This work is licensed under a Creative Commons Attribution 4.0 International License.

Keywords: SARS-CoV-2; COVID-19; Serology; Seroprevalence; Diagnostic tests; Italy.


#Seroconversion in #household #members of #COVID19 outpatients (Lancet Infect Dis., summary)

[Source: The Lancet Infectious Diseases, full page: (LINK). Summary, edited.]

Seroconversion in household members of COVID-19 outpatients

Rebecca J Cox, Karl A Brokstad, Florian Krammer, Nina Langeland, for the Bergen COVID-19 Research Group †

Published: June 15, 2020 | DOI: https://doi.org/10.1016/S1473-3099(20)30466-7


We read with interest the Article by Qifang Bi and colleagues,1  in which they reported a  household secondary attack rate, as detected by repeated RT-PCR tests, of approximately  11%. We have found substantially higher attacks rates in western Norway through  detection of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).


Keywords: SARS-CoV-2; COVID-19; Serology; Seroprevalence; Norway.


#Hospital-Wide #SARS-CoV-2 #Antibody #Screening in 3056 #Staff in a Tertiary Center in #Belgium (JAMA, summary)

[Source: JAMA, full page: (LINK). Summary, edited.]

Hospital-Wide SARS-CoV-2 Antibody Screening in 3056 Staff in a Tertiary Center in Belgium

Deborah Steensels, PharmD, PhD1; Els Oris, MD1; Laura Coninx, MSc, PhD1;  Dieter Nuyens, MD, PhD1; Marie-Luce Delforge, MD, PhD2; Pieter Vermeersch, MD, PhD3; Line Heylen, MD, PhD1,4

Author Affiliations: 1 Ziekenhuis Oost-Limburg, Genk, Belgium; 2 Université Libre de Bruxelles, Brussels, Belgium; 3 University Hospitals Leuven, Leuven, Belgium; 4 Hasselt University, Hasselt, Belgium

JAMA. Published online June 15, 2020. doi:10.1001/jama.2020.11160


Belgium has a high burden of coronavirus disease 2019 (COVID-19), especially the region surrounding the Hospital East-Limburg, a tertiary care center.1 Infection prevention measures were instituted in the hospital beginning March 4, 2020, including testing and contact tracing of all symptomatic patients and staff, changes in hospital operations, and provision of personal protective equipment (PPE). The first case was detected March 13 (Figure 1). We investigated the prevalence of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among hospital staff.


Keywords: SARS-CoV-2; COVID-19; Serology; Seroprevalence; HCWs; Belgium.


#Seroprevalence of anti- #SARS-CoV-2 #IgG #antibodies in #Geneva, #Switzerland (SEROCoV-POP): a population-based study (Lancet, abstract)

[Source: The Lancet, full page: (LINK). Abstract, edited.]

Seroprevalence of anti-SARS-CoV-2 IgG antibodies in Geneva, Switzerland (SEROCoV-POP): a population-based study

Silvia Stringhini, PhD, Ania Wisniak, MS †, Giovanni Piumatti, PhD †, Andrew S Azman, PhD †, Stephen A Lauer, PhD, Hélène Baysson, PhD, David De Ridder, MSc, Dusan Petrovic, PhD, Stephanie Schrempft, PhD, Kailing Marcus, MSc, Sabine Yerly, MSc, Isabelle Arm Vernez, MSc, Prof Olivia Keiser, PhD, Prof Samia Hurst, MD, Prof Klara M Posfay-Barbe, MD, Prof Didier Trono, MD, Prof Didier Pittet, MD, Laurent Gétaz, MD, Prof François Chappuis, MD, Prof Isabella Eckerle, MD, Prof Nicolas Vuilleumier, MD, Benjamin Meyer, PhD, Prof Antoine Flahault, MD, Prof Laurent Kaiser, MD, Prof Idris Guessous, PhD

Published: June 11, 2020 | DOI: https://doi.org/10.1016/S0140-6736(20)31304-0




Assessing the burden of COVID-19 on the basis of medically attended case numbers is suboptimal given its reliance on testing strategy, changing case definitions, and disease presentation. Population-based serosurveys measuring anti-severe acute respiratory syndrome coronavirus 2 (anti-SARS-CoV-2) antibodies provide one method for estimating infection rates and monitoring the progression of the epidemic. Here, we estimate weekly seroprevalence of anti-SARS-CoV-2 antibodies in the population of Geneva, Switzerland, during the epidemic.


The SEROCoV-POP study is a population-based study of former participants of the Bus Santé study and their household members. We planned a series of 12 consecutive weekly serosurveys among randomly selected participants from a previous population-representative survey, and their household members aged 5 years and older. We tested each participant for anti-SARS-CoV-2-IgG antibodies using a commercially available ELISA. We estimated seroprevalence using a Bayesian logistic regression model taking into account test performance and adjusting for the age and sex of Geneva’s population. Here we present results from the first 5 weeks of the study.


Between April 6 and May 9, 2020, we enrolled 2766 participants from 1339 households, with a demographic distribution similar to that of the canton of Geneva. In the first week, we estimated a seroprevalence of 4·8% (95% CI 2·4–8·0, n=341). The estimate increased to 8·5% (5·9–11·4, n=469) in the second week, to 10·9% (7·9–14·4, n=577) in the third week, 6·6% (4·3–9·4, n=604) in the fourth week, and 10·8% (8·2–13·9, n=775) in the fifth week. Individuals aged 5–9 years (relative risk [RR] 0·32 [95% CI 0·11–0·63]) and those older than 65 years (RR 0·50 [0·28–0·78]) had a significantly lower risk of being seropositive than those aged 20–49 years. After accounting for the time to seroconversion, we estimated that for every reported confirmed case, there were 11·6 infections in the community.


These results suggest that most of the population of Geneva remained uninfected during this wave of the pandemic, despite the high prevalence of COVID-19 in the region (5000 reported clinical cases over <2·5 months in the population of half a million people). Assuming that the presence of IgG antibodies is associated with immunity, these results highlight that the epidemic is far from coming to an end by means of fewer susceptible people in the population. Further, a significantly lower seroprevalence was observed for children aged 5–9 years and adults older than 65 years, compared with those aged 10–64 years. These results will inform countries considering the easing of restrictions aimed at curbing transmission.


Swiss Federal Office of Public Health, Swiss School of Public Health (Corona Immunitas research program), Fondation de Bienfaisance du Groupe Pictet, Fondation Ancrage, Fondation Privée des Hôpitaux Universitaires de Genève, and Center for Emerging Viral Diseases.

Keywords: SARS-CoV-2; COVID-19; Serology; Seroprevalence; Switzerland.


#SARS-CoV-2 #Infections and #Serologic #Responses from a Sample of #US #Navy Service #Members — USS Theodore #Roosevelt, April 2020 (MMWR Morb Mortal Wkly Rep., abstract)

[Source: US Centers for Disease Control and Prevention (CDC), MMWR Morbidity and Mortality Weekly Report, full page: (LINK). Abstract, edited.]

SARS-CoV-2 Infections and Serologic Responses from a Sample of U.S. Navy Service Members — USS Theodore Roosevelt, April 2020

Early Release / June 9, 2020 / 69

Daniel C. Payne, PhD1; Sarah E. Smith-Jeffcoat, MPH1; Gosia Nowak, MPH2; Uzo Chukwuma, MPH2; Jesse R. Geibe, MD2; Robert J. Hawkins, PhD, DNP2; Jeffrey A. Johnson, PhD1; Natalie J. Thornburg, PhD1; Jarad Schiffer, MS1; Zachary Weiner, PhD1; Bettina Bankamp, PhD1; Michael D. Bowen, PhD1; Adam MacNeil, PhD1; Monita R. Patel, PhD1; Eric Deussing, MD2; CDC COVID-19 Surge Laboratory Group; Bruce L. Gillingham, MD2

Corresponding author: Daniel C. Payne, dvp6@cdc.gov, 404-639-2784.

1 CDC; 2U.S. Navy.

All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

Suggested citation for this article: Payne DC, Smith-Jeffcoat SE, Nowak G, et al. SARS-CoV-2 Infections and Serologic Responses from a Sample of U.S. Navy Service Members — USS Theodore Roosevelt, April 2020. MMWR Morb Mortal Wkly Rep. ePub: 9 June 2020. DOI: http://dx.doi.org/10.15585/mmwr.mm6923e4



  • What is already known about this topic?
    • Information about COVID-19 among young adults is limited.
  • What is added by this report?
    • Among a convenience sample of 382 young adult U.S. service members aboard an aircraft carrier experiencing a COVID-19 outbreak, 60% had reactive antibodies, and 59% of those also had neutralizing antibodies at the time of specimen collection. One fifth of infected participants reported no symptoms. Preventive measures, such as using face coverings and observing social distancing, reduced risk for infection.
  • What are the implications for public health practice?
    • Young, healthy adults with COVID-19 might have mild or no symptoms; therefore, symptom-based surveillance might not detect all infections. Use of face coverings and other preventive measures could mitigate transmission. The presence of neutralizing antibodies among the majority is a promising indicator of at least short-term immunity.



Compared with the volume of data on coronavirus disease 2019 (COVID-19) outbreaks among older adults, relatively few data are available concerning COVID-19 in younger, healthy persons in the United States (1,2). In late March 2020, the aircraft carrier USS Theodore Roosevelt arrived at port in Guam after numerous U.S. service members onboard developed COVID-19. In April, the U.S. Navy and CDC investigated this outbreak, and the demographic, epidemiologic, and laboratory findings among a convenience sample of 382 service members serving aboard the aircraft carrier are reported in this study. The outbreak was characterized by widespread transmission with relatively mild symptoms and asymptomatic infection among this sample of mostly young, healthy adults with close, congregate exposures. Service members who reported taking preventive measures had a lower infection rate than did those who did not report taking these measures (e.g., wearing a face covering, 55.8% versus 80.8%; avoiding common areas, 53.8% versus 67.5%; and observing social distancing, 54.7% versus 70.0%, respectively). The presence of neutralizing antibodies, which represent antibodies that inhibit SARS-CoV-2, among the majority (59.2%) of those with antibody responses is a promising indicator of at least short-term immunity. This report improves the understanding of COVID-19 in the U.S. military and among young adults in congregate settings and reinforces the importance of preventive measures to lower risk for infection in similar environments.


Keywords: SARS-CoV-2; COVID-19; USA; Institutional outbreaks; Serology; Seroprevalence.