scholarly journals High secondary attack rate and persistence of SARS-CoV-2 antibodies in household transmission study participants, Finland 2020

2021 ◽  
Author(s):  
Timothee Dub ◽  
Hanna Nohynek ◽  
Lotta Hagberg ◽  
Oona Liedes ◽  
Anu Haveri ◽  
...  
Keyword(s):  
Attack Rate ◽  
Neutralizing Antibodies ◽  
Serum Samples ◽  
Household Transmission ◽  
Transmission Study ◽  
Household Members ◽  
Transmission Studies ◽  
Study Participants ◽  
Index Cases

Background Household transmission studies offer the opportunity to assess both secondary attack rate and persistence of SARS-CoV-2 antibodies over time. Methods We invited confirmed COVID-19 cases and their household members to attend up to four household visits with collection of nasopharyngeal and serum samples over 28 days after index case onset. We calculated secondary attack rates (SAR) based on the presence of SARS-CoV-2 nucleoprotein IgG antibodies (IgG Ab) and/or neutralizing antibodies (NAb) overall and per households. Three and six months later, we assessed the persistence of SARS-CoV-2 antibodies. Findings We recruited 39 index cases and 90 household members. Among 87 household members evaluated, SAR was 48% (n=42), including 37 symptomatic secondary cases. In total, 80/129 (62%) participants developed both IgG Ab and NAb, while three participants only developed IgG Ab. Among participants who had both IgG Ab and NAb during the initial follow-up, 68/69 (99%) and 63/70 (90%) had IgG Ab and NAb at 3 months, while at 6 months, 59/75 (79%) and 63/75 (84%) had IgG Ab and NAb, respectively. Participants who required hospital care had initially 5-fold IgG Ab concentrations compared to cases with mild symptoms and 8-fold compared to asymptomatic cases. Interpretation Following detection of a COVID-19 case in a household, other members had a high risk of becoming infected. Follow-up of participants showed strong persistence of antibodies in most cases. Funding This study was supported by THL coordinated funding for COVID-19 research (Finnish Government's supplementary budget) and by the Academy of Finland (Decision number 336431).

scholarly journals SARS-CoV-2 B.1.1.7 variant of concern detected in a pet dog and cat after exposure to a person with COVID-19, USA

2021 ◽  
Author(s):  
Sarah Hamer ◽  
Ria Ghai ◽  
Italo B. Zecca ◽  
Lisa D. Auckland ◽  
Christopher M. Roundy ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Nasal Swab ◽  
Companion Animals ◽  
The United States ◽  
Genome Sequences ◽  
Oral Swab ◽  
Qrt Pcr ◽  
Household Transmission ◽  
Transmission Study

Abstract As part of a longitudinal household transmission study of pets living with persons with COVID-19 in Texas, two pets were confirmed to be infected with the SARS-CoV-2 B.1.1.7 variant of concern (VOC). The pets were a dog and a cat from the same household, sampled two days after their owner tested positive for COVID-19. The oral, nasal, and fur swabs for both pets tested positive for SARS-CoV-2 by qRT-PCR and consensus whole genome sequences from the dog and cat were 100 % identical and matched the B.1.1.7 VOC. Virus was isolated from the cat’s nasal swab. One month after initial detection of infection, the pets were re-tested twice at which time only the fur swabs (both pets) and oral swab (dog only) remained positive, and neutralizing antibodies for SARS-CoV-2 were present in both animals. Sneezing by both pets was noted by the owner in the weeks between initial and follow-up testing. This study documents the first detection of B.1.1.7. in companion animals in the United States, and the first genome recovery and isolation of B.1.1.7 variant of concern globally in any animal.

scholarly journals Role of children in household transmission of COVID-19

2020 ◽  
pp. archdischild-2020-319910 ◽  
Author(s):  
Jieun Kim ◽  
Young June Choe ◽  
Jin Lee ◽  
Young Joon Park ◽  
Ok Park ◽  
...  
Keyword(s):  
Attack Rate ◽  
Index Case ◽  
Clinical Findings ◽  
International Travel ◽  
Contact Tracing ◽  
Secondary Case ◽  
Household Transmission ◽  
Household Members ◽  
Index Cases

ObjectiveTransmissibility of COVID-19 by children in the household is not clear. Herein, we describe children’s role in household transmission of COVID-19.Design and settingAll paediatric COVID-19 index cases and their household members reported from 20 January to 6 April 2020 in South Korea were reviewed. The secondary attack rate (SAR) from child index case to household secondary case was calculated. Epidemiological and clinical findings of child index case-household secondary case pair was assessed.ResultsA total of 107 paediatric COVID-19 index cases and 248 of their household members were identified. One pair of paediatric index-secondary household case was identified, giving a household SAR of 0.5% (95% CI 0.0% to 2.6%). The index case was self-quarantined at home after international travel, stayed in her room, but shared a meal table with the secondary case.ConclusionThe SAR from children to household members was low in the setting of social distancing, underscoring the importance of rigorous contact tracing and early isolation in limiting transmission within households.

scholarly journals Transmission and serotype features of hand foot mouth disease in household contacts in Dong Thap, Vietnam

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Cuong Quoc Hoang ◽  
Thao Thanh Thi Nguyen ◽  
Nguyen Xuan Ho ◽  
Hai Duc Nguyen ◽  
An Binh Nguyen ◽  
...  
Keyword(s):  
Attack Rate ◽  
Neutralizing Antibodies ◽  
Index Case ◽  
Fold Increase ◽  
Mouth Disease ◽  
Rt Pcr ◽  
Household Contacts ◽  
Two Samples ◽  
Household Members ◽  
Index Cases

Abstract Background Hand, foot and mouth disease (HFMD) has emerged as a major public health issue in Vietnam since 2003. We aimed to investigate the household transmission of HFMD and its causative viruses from 150 households in a high incidence province in Vietnam. Methods A longitudinal study was conducted in patients presenting to the provincial hospital with a HFMD-like syndrome, along with their household members between April and August 2014 in Dong Thap Province. Each participant was followed up for 2 weeks. We enrolled 150 patients aged under 15 who were clinically diagnosed with HFMD in Dong Thap Hospital, 600 household members, and 581/600 household members completed the study. All participants were interviewed using a standard questionnaire. Throat swabs and blood samples were taken for molecular detection of viruses and assessment of neutralizing antibodies, respectively. Index cases were defined using a clinical case definition, household contact cases were defined using a similar definition applied to the 2 weeks before admission and 2 weeks after discharge of the index case. Characteristics of index cases, household contacts, the attack rate, serotype features and related factors of HFMD were reported. Result Among 150 index cases, 113 were laboratory confirmed: 90/150 were RT-PCR-positive, 101/142 had a ≥ 4-fold increase of neutralizing antibody against Enterovirus A71 (EV-A71), Coxsackievirus (CV) A6 or CV-A16 across the two samples collected. 80/150 (53%) were males, and 45/150 (30%) were under the age of 1. The predominant serotype was CV-A6, identified in 57/87 (65.5%) of the specimens. No deaths were reported. Among 581 household contacts, 148 were laboratory confirmed: 12/581 were RT-PCR-positive, 142/545 had a ≥ 4-fold increase of neutralizing antibodies against EV-A71, CV-A6 or CV-A16; 4 cases experienced HFMD in the past 4 weeks. Attack rate among household contacts was 148/581 (25.5%). In 7/12 (58%) instances, the index and secondary cases were infected with the same serotype. Having a relationship to index case was significantly associated with EV infection. Conclusion The attack rate among household contacts was relatively high (25.5%) in this study and it seems justified to also consider the household setting as an additional target for intervention programs.

scholarly journals Characteristics of Household Transmission of COVID-19

2020 ◽  
Vol 71 (8) ◽  
pp. 1943-1946 ◽  
Author(s):  
Wei Li ◽  
Bo Zhang ◽  
Jianhua Lu ◽  
Shihua Liu ◽  
Zhiqiang Chang ◽  
...  
Keyword(s):  
Risk Factors ◽  
Attack Rate ◽  
Rt Pcr ◽  
Spousal Relationship ◽  
Telephone Interviews ◽  
Household Contacts ◽  
Household Transmission ◽  
Household Members ◽  
Baseline Characteristics ◽  
Index Cases

Abstract Background Since December 2019, SARS-CoV-2 has extended to most parts of China with >80 000 cases and to at least 100 countries with >60 000 international cases as of 15 March 2020. Here we used a household cohort study to determine the features of household transmission of COVID-19. Methods A total of 105 index patients and 392 household contacts were enrolled. Both index patients and household members were tested by SARS-CoV-2 RT-PCR. Information on all recruited individuals was extracted from medical records and confirmed or supplemented by telephone interviews. The baseline characteristics of index cases and contact patients were described. Secondary attack rates of SARS-CoV-2 to contact members were computed and the risk factors for transmission within the household were estimated. Results Secondary transmission of SARS-CoV-2 developed in 64 of 392 household contacts (16.3%). The secondary attack rate to children was 4% compared with 17.1% for adults. The secondary attack rate to the contacts within the households with index patients quarantined by themselves since onset of symptoms was 0% compared with 16.9% for contacts without quarantined index patients. The secondary attack rate to contacts who were spouses of index cases was 27.8% compared with 17.3% for other adult members in the households. Conclusions The secondary attack rate of SARS-CoV-2 in household is 16.3%. Age of household contacts and spousal relationship to the index case are risk factors for transmission of SARS-CoV-2 within a household. Quarantine of index patients at home since onset of symptoms is useful to prevent the transmission of SARS-Co-2 within a household.

scholarly journals SARS-CoV-2 Infections and Viral Isolations among Serially Tested Cats and Dogs in Households with Infected Owners in Texas, USA

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 938
Author(s):  
Sarah A. Hamer ◽  
Alex Pauvolid-Corrêa ◽  
Italo B. Zecca ◽  
Edward Davila ◽  
Lisa D. Auckland ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Case Definition ◽  
Initial Test ◽  
Rt Pcr ◽  
Genome Sequences ◽  
Infected People ◽  
Household Transmission ◽  
Transmission Study ◽  
Initial Sampling

Understanding the ecological and epidemiological roles of pets in the transmission of SARS-CoV-2 is critical for animal and human health, identifying household reservoirs, and predicting the potential enzootic maintenance of the virus. We conducted a longitudinal household transmission study of 76 dogs and cats living with at least one SARS-CoV-2-infected human in Texas and found that 17 pets from 25.6% of 39 households met the national case definition for SARS-CoV-2 infections in animals. This includes three out of seventeen (17.6%) cats and one out of fifty-nine (1.7%) dogs that were positive by RT-PCR and sequencing, with the virus successfully isolated from the respiratory swabs of one cat and one dog. Whole-genome sequences of SARS-CoV-2 obtained from all four PCR-positive animals were unique variants grouping with genomes circulating among people with COVID-19 in Texas. Re-sampling showed persistence of viral RNA for at least 25 d-post initial test. Additionally, seven out of sixteen (43.8%) cats and seven out of fifty-nine (11.9%) dogs harbored SARS-CoV-2 neutralizing antibodies upon initial sampling, with relatively stable or increasing titers over the 2–3 months of follow-up and no evidence of seroreversion. The majority (82.4%) of infected pets were asymptomatic. ‘Reverse zoonotic’ transmission of SARS-CoV-2 from infected people to animals may occur more frequently than recognized.

scholarly journals Weight changes in hypertensive patients with phlegm-dampness syndrome: an integrated proteomics and metabolomics approach

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Chi Zhang ◽  
Li Li ◽  
Shiping Cheng ◽  
Debajyoti Chowdhury ◽  
Yong Tan ◽  
...  
Keyword(s):  
Pathway Analysis ◽  
Complement C3 ◽  
Integrative Approach ◽  
Weight Changes ◽  
Serum Samples ◽  
Phosphorylated Proteins ◽  
Circulating Markers ◽  
One Year ◽  
Study Participants

Abstract Background Hypertension (HTN) patients who have phlegm-dampness syndrome (PDS) tend to be obese and have worse outcomes. However, the association of body weight (BW) changes and mechanisms underlying the pathophysiology of HTN-PDS are not well elucidated. This study aims to identify the longitudinal observations associated with the circulating markers discriminating BW changes of individuals with HTN-PDS. Methods An integrative approach relying on metabolomics and proteomics was applied to serum samples from HTN-PDS patients in a prospective cohort to identify the plausible mechanistic pathways underpinning HTN-PDS pathophysiology. Study participants were determined to have experienced a weight change if they showed a 5%–15% increase/reduction in BW at the end of the follow-up period. The joint pathway analysis and network analysis were performed using Ingenuity Pathway Analysis (IPA®) on the serum samples obtained from the participants over the period. Results The study involved 22 HTN-PDS patients who were overweight initially and were able to lose enough weight and 24 HTN-PDS individuals who developed overweight from normal BMI during a one-year follow-up. Our analysis suggested three types of phosphatidylcholine (PC) were altered. PC (22:2(13Z,16Z)/24:1(15Z)) and LysoPC (16:1(9Z)) were decreased in Queryweight gain samples, whereas the levels of PC (14:0/16:0) were increased in weight loss samples. The metabolomic analysis suggested 24 metabolites associated with HTN-PDS. Of them, 13 were up-regulated and 11 were down-regulated. The two-dimensional difference gel electrophoresis (2D DIGE) identified 45 phosphorylated proteins got altered in the HTN-PDS patients, wherein 23 were up-regulated and 22 were down-regulated. Integrated proteomic and metabolomics analyse acknowledged biomarkers PC, Complement C3, C4a/C4b, A2M and SERPINF1 as strong predictors for BW changes in HTN-PDS patients. Conclusion The combined serum proteomic and metabolomic profiling reveals a link between BW change and the complement system activity, altered phosphatidylcholine metabolism in HTN-PDS patients. Future studies with larger cohorts are required to strengthen and validate these findings.

scholarly journals Incidence of Infection of Enterovirus 71 and Coxsackieviruses A6 and A16 among Household Contacts of Index Cases in Dong Thap Province, Southern Vietnam

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
C. Q. Hoang ◽  
H. D. Nguyen ◽  
N. X. Ho ◽  
T. H. T. Vu ◽  
T. T. M. Pham ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Geometric Mean ◽  
Age Groups ◽  
Enterovirus 71 ◽  
Foot And Mouth Disease ◽  
Household Contacts ◽  
Significant Difference ◽  
Antibody Titers ◽  
Index Cases

Background. Scarce information exists about immunity to hand, foot, and mouth disease (HFMD) among household contacts of index cases in Vietnam and what that means for reducing ongoing HFMD transmission in the community. Methods. We analyzed neutralizing antibodies (NT) and the incidence of enterovirus (EVs) infection among household contacts of index cases in a province where HFMD remains endemic. Throat swab and 2 mL blood samples from household contacts were collected at enrollment, during and after 2 weeks follow-up. Results. The incidence of EV-A71 infection among household contacts was 40/84 (47.6%, 95% Cl: 36.9-58.3%), compared with 106/336 (31.5%, 95% Cl: 26.6-36.5%) for CV-A6 and 36/107 (33.6%, 95% Cl: 24.7-42.6%) for CV-A16. The incidence of CV-A6 infection was fairly constant across ages; in contrast, CV-A71 and CV-A16 had some variation across ages. At baseline, higher geometric mean titer (GMT) of EV-A71, CV-A6, and CV-A16 antibody titers was found for 25-34-year groups (range 216.3 to 305.0) compared to the other age groups. There was a statistically significant difference in GMT values of CV-A6 and CV-A16 between those who had an infection or did not have infection among households with an index case of these serotypes. Conclusions. Our results indicated that adults were becoming infected with HFMD and could be contributing to the transmission. There is, therefore, a need for considering the household setting as an additional target for intervention programs for HFMD.

Low Immunogenicity to Romiplostim in Clinical Studies with ITP Subjects.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3425-3425 ◽  
Author(s):  
Vibha Jawa ◽  
Martha Hokom ◽  
Jenny Hu ◽  
Yao Zhuang ◽  
Dietmar Berger ◽  
...  
Keyword(s):  
Clinical Studies ◽  
Neutralizing Antibodies ◽  
Single Chain ◽  
Serum Samples ◽  
Binding Domains ◽  
C Terminus ◽  
Before And After ◽  
Immunogenicity Assessment ◽  
Covalently Linked

Abstract Romiplostim, a member of the thrombopoietin (TPO) mimetic class, is an Fc-peptide fusion protein (peptibody) that activates intracellular transcriptional pathways leading to increased platelet production via the TPO receptor (also known as cMpl). The peptibody molecule contains two identical single-chain subunits each consisting of human immunoglobulin IgG1 Fc domain, covalently linked at the C-terminus to a peptide containing two TPO receptor-binding domains. Due to the general concern regarding the immunogenic potential for all therapeutic proteins and the specific concern for monitoring antibodies capable of neutralizing thrombopoietin (TPO), an extensive immunogenicity assessment program was developed to support romiplostim. Romiplostim has been engineered to have no amino acid sequence homology to endogenous TPO. A low theoretical risk of developing conformational antibodies that cross-react against TPO exists. This risk was addressed by using an immunogenicity assessment strategy that relied upon a surface plasmon resonance based biosensor immunoassay using the Biacore 3000 capable of simultaneously monitoring antibodies that bind to romiplostim, TPO, or the active peptide portion of romiplostim (TMP). Samples that tested positive for binding antibodies in the Biacore immunoassay were then tested in the definitive functional biological assay to identify any antibodies capable of neutralizing the biological effect of romiplostim or TPO. Serum samples from 236 actively treated subjects were obtained both before and after exposure to romiplostim and were tested for romiplostim and TPO antibodies. In baseline samples, seventeen subjects (7.1%) tested romiplostim antibody positive and 12 subjects (5.1%) tested TPO antibody positive for pre-existing binding antibodies. After romiplostim exposure, twenty-five out of 236 (10.5%) subjects with ITP developed binding antibodies against romiplostim (inclusive of antibodies to both peptide and the whole molecule) and 12 out of 236 (5.1%) subjects with ITP developed binding antibodies against TPO. The antibodies that developed against romiplostim did not cross react with TPO and the antibodies that developed against TPO did not cross react with romiplostim. The incidence of anti-romiplostim neutralizing antibodies among 236 subjects with ITP who were treated with romiplostim across 10 clinical studies was 0.4% (1 out of 236). No cases of anti-TPO neutralizing antibodies were detected in romiplostim treated samples. In conclusion, after thorough immunogenicity assessment of all subjects treated with romiplostim using sensitive methods to detect binding and neutralizing antibodies, only one subject was found positive for the presence of antibodies capable of neutralizing romiplostim that was negative at the time of follow up 4 months later. As expected, none of the subjects treated were positive for antibodies capable of neutralizing TPO. No clinical sequelae were observed in association to the presence of antibodies.

scholarly journals Impact of BNT162b2 vaccination and isolation on SARS-CoV-2 transmission in Israeli households: an observational study

2021 ◽  
Author(s):  
Maylis Layan ◽  
Mayan Gilboa ◽  
Tal Gonen ◽  
Miki Goldenfeld ◽  
Lilac Meltzer ◽  
...  
Keyword(s):  
Healthcare Workers ◽  
Data Augmentation ◽  
Medical Center ◽  
Credible Interval ◽  
Control Measures ◽  
Risk Of Infection ◽  
Household Transmission ◽  
Index Cases

Background Massive vaccination rollouts against SARS-CoV-2 infections have facilitated the easing of control measures in countries like Israel. While several studies have characterized the effectiveness of vaccines against severe forms of COVID-19 or SARS-CoV-2 infection, estimates of their impact on transmissibility remain limited. Here, we evaluated the role of vaccination and isolation on SARS-CoV-2 transmission within Israeli households. Methods From December 2020 to April 2021, confirmed cases were identified among healthcare workers of the Sheba Medical Centre and their family members. Households were recruited and followed up with repeated PCR for a minimum of ten days after case confirmation. Symptoms and vaccination information were collected at the end of follow-up. We developed a data augmentation Bayesian framework to ascertain how age, isolation and BNT162b2 vaccination with more than 7 days after the 2nd dose impacted household transmission of SARS-CoV-2. Findings 210 households with 215 index cases were enrolled. 269 out of 687 (39%) household contacts developed a SARS-CoV-2 infection. Of those, 170 (63%) developed symptoms. Children below 12 years old were less susceptible than adults/teenagers (Relative Risk RR=0.50, 95% Credible Interval CI 0.32-0.79). Vaccination reduced the risk of infection among adults/teenagers (RR=0.19, 95% CI 0.07-0.40). Isolation reduced the risk of infection of unvaccinated adult/teenager (RR=0.11, 95% CI 0.05-0.19) and child contacts (RR=0.16, 95% CI 0.07-0.31) compared to unvaccinated adults/teenagers that did not isolate. Infectivity was significantly reduced in vaccinated cases (RR=0.22, 95% CI 0.06-0.70). Interpretation Within households, vaccination reduces both the risk of infection and of transmission if infected. When contacts were not vaccinated, isolation also led to important reductions in the risk of transmission. Vaccinated contacts might reduce their risk of infection if they isolate, although this requires confirmation with additional data. Funding Sheba Medical Center.

Sign in / Sign up

Export Citation Format

Share Document