scholarly journals Transmission of SARS-CoV-2 within households: a prospective cohort study in the Netherlands and Belgium – Interim results

2021 ◽  
Author(s):  
JDM Verberk ◽  
MLA de Hoog ◽  
I Westerhof ◽  
S Van Goethem ◽  
C Lammens ◽  
...  
Keyword(s):  
The Netherlands ◽  
Index Case ◽  
Respiratory Illness ◽  
Dried Blood Spots ◽  
Case Definition ◽  
Rt Pcr ◽  
Index Cases ◽  
New Onset ◽  
Subject Characteristics

ABSTRACTBackgroundHousehold transmission studies are useful to obtain granular data on SARS-CoV-2 transmission dynamics and to gain insight into the main determinants. In this interim report we investigated secondary attack rates (SAR) by household and subject characteristics in the Netherlands and Belgium.MethodsHouseholds with a real-time reverse transcription polymerase chain reaction (RT-PCR) confirmed SARS-CoV-2 index case were enrolled <48 hours following report of the positive test result. Daily symptom follow-up, standardized nose-throat sampling at enrollment and at new-onset acute respiratory illness (ARI) and paired dried blood spots (DBS) were collected from each participant. Children 0-2 years of age were additionally requested to collect a stool sample 7 days after enrollment and at new-onset of ARI. Swabs and stool samples were tested by RT-PCR for virus detection and DBS by multiplex protein microarray for detection of SARS-CoV-2 antibodies. The SAR was calculated 1) per-household as the proportion of households with ≥1 secondary SARS-CoV-2 case and 2) per-person as the probability of infection in household members at risk. We explored differences in SARs by household and subject characteristics.ResultsThis analysis includes 117 households that completed follow-up between April-December 2020. Among 382 subjects, 74 secondary infections were detected, of which 13 (17.6%) were asymptomatic and 20 (27.0%) infections were detected by seroconversion only. Of cases detected by RT-PCR, 50 (67.6%) were found at enrollment. The household SAR was 44.4% (95%-CI: 35.4-53.9%) and was higher for index cases meeting the ARI case definition (52.3%; 95%-CI 41.4-62.9%) compared to mildly symptomatic (22.2%; 95%-CI: 9.4-42.7%) and asymptomatic index cases (0.0%; 95%-CI: 0.0-80.2%). The per-person SAR was 27.9% (95%-CI: 22.7-33.8%). Transmission was lowest from child to parent (9.1%; 95%-CI: 2.4-25.5%) and highest from parent to child (28.1%; 95%-CI: 19.7-38.4%) and in children 6-12 years (34.2%; 95%-CI: 20.1-51.4%). Among 141 subjects with RT-PCR confirmed SARS-CoV-2 infections, seroconversion was detected in 111 (78.7%).ConclusionWe found a high household SAR, with the large majority of transmissions detected early after identification of the index case. Our findings confirm differential SAR by symptom status of the index. In almost a quarter of RT-PCR positive cases, no antibodies were detected. Other factors influencing transmission will be further explored as more data accumulate.

scholarly journals Nucleic Acid Testing for Diagnosis of Perinatally Acquired Hepatitis C Virus Infection in Early Infancy

2020 ◽  
Author(s):  
Charitha Gowda ◽  
Stephanie Smith ◽  
Linda Crim ◽  
Katherine Moyer ◽  
Pablo J Sánchez ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Antibody Test ◽  
Case Definition ◽  
Hcv Rna ◽  
Rt Pcr ◽  
Case Definitions ◽  
Loss To Follow Up ◽  
Perinatally Acquired

Abstract Background Most US children with perinatal hepatitis C virus (HCV) exposure fail to receive the recommended anti-HCV antibody test at age ≥18 months. Earlier testing for viral RNA might facilitate increased screening, but sensitivity of this approach has not been established. We hypothesized that modern HCV-RNA RT-PCR platforms would adequately detect infected infants. Methods Nationwide Children’s Hospital electronic health records from 1/1/2008 to 30/6/2018 were reviewed to identify perinatally exposed infants tested by HCV-RNA RT-PCR at age 2–6 months. Diagnostic performance was determined using a composite case definition: (1) infected children had positive repeat HCV-RNA testing or positive anti-HCV at age ≥24 months; (2) uninfected children lacked these criteria and had negative anti-HCV at age ≥18 months. Results 770 perinatally exposed infants underwent HCV-RNA testing at age 2–6 months. Of these, 28 (3.6%) tested positive; viremia was confirmed in all who underwent repeat testing (n = 27). Among 742 infants with negative HCV-RNA results, 226 received follow-up anti-HCV testing at age ≥18 months, of whom 223 tested negative. Three children had low-positive anti-HCV results at age 18–24 months that were negative upon retesting after age 24 months, possibly indicating waning maternal antibodies. Using the composite case definitions, early HCV-RNA screening demonstrated sensitivity of 100% (87.5–100%, Wilson-Brown 95% CI) and specificity of 100% (98.3–100%). Conclusions Modern HCV-RNA RT-PCR assays have excellent sensitivity for early diagnosis of perinatally acquired infection and could aid HCV surveillance given the substantial loss to follow-up at ≥18 months of age.

Twenty-one Psychiatric Cases and their MZ Cotwins A thirty years' follow-up

1970 ◽  
Vol 19 (1-2) ◽  
pp. 315-317 ◽  
Author(s):  
Erik Essen-Möller
Keyword(s):  
General Hospital ◽  
Index Case ◽  
Psychiatric Ward ◽  
Degree Of Certainty ◽  
South Sweden ◽  
Proper Diagnosis ◽  
Clinical Pictures ◽  
Short Time ◽  
Index Cases

In 1941, I published a psychiatric study of 69 same-sexed pairs of twins. The index cases were derived from 8596 consecutive admissions to three mental hospitals and one psychiatric unit of a general hospital in South Sweden, every patient being checked for twin birth in the official birth registers. There was no pair with more than one index case. Upon examination, 21 pairs were considered more or less certainly MZ, and 48 DZ. The degree of certainty of the zygosity diagnosis was expressed by a special formula (Essen-Möller, 1941b).Of the 21 index cases, 7 (N. 1-7 of the monograph) were at that time judged schizophrenic. The later course revaled that one more index case (N. 12) was a schizophrenic and should have been included into this diagnostic group, which I shall have to concentrate upon in this brief presentation.Out of the 8 cotwins of the schizophrenic index cases, 5 had presented symptoms of mental disorder up to the time of my investigation, which took place almost thirty years ago. This corresponds so far to a concordance rate of 62%. However, all of the cotwin disorders were relatively mild and transient in nature and consisted mainly of depressive or anxiety states. Even if some of the disordered cotwins had spent some time in a nursing home or in a psychiatric ward of a general hospital, none of them had been admitted to a mental hospital. And, although several of the clinical pictures contained some single trait suggestive of schizophrenia — such as ideas of reference (N. 2 and 7) or hallucinations (N. 5) — in no case a proper diagnosis of schizophrenia could be made. The cotwin who came closest to this diagnosis was a man aged 35 (N. 1), who gave much thought to telepathic phenomena and the like; yet, he was comparatively open-minded and accessible to discussion of his ideas, and he had never been incapacitated by them. Thus, at the time of the first investigation, the correct rate of concordance for schizophrenia in fact was zero. This finding was the more striking as the two other samples published up to that time, those of Luxenburger (1928) and Rosanoff (1934), showed rates of concordance at about 70%, although Luxenburger (1934) later corrected his figure to 33%, for diagnostic reasons. Personally, I was inclined to attribute my zero finding to chance, the number of pairs being small, and also to the relatively short time of observation.

scholarly journals Comparison of clinical characteristics of Zika and dengue symptomatic infections and other acute illnesses of unidentified origin in Mexico

2021 ◽  
Vol 15 (2) ◽  
pp. e0009133
Author(s):  
Pablo F. Belaunzarán-Zamudio ◽  
Allyson Mateja ◽  
Paola del Carmen Guerra-de-Blas ◽  
Héctor A. Rincón-León ◽  
Karla Navarro-Fuentes ◽  
...  
Keyword(s):  
Liver Function Tests ◽  
Case Definition ◽  
Abnormal Liver Function ◽  
Rt Pcr ◽  
Macular Rash ◽  
Observational Prospective Cohort Study ◽  
Pan American ◽  
Clinical Description ◽  
Definition Of

Background Our purpose was to provide a detailed clinical description, of symptoms and laboratory abnormalities, and temporality in patients with confirmed Zika and dengue infections, and other acute illnesses of unidentified origin (AIUO). Methods/ Principal findings This was a two-year, multicenter, observational, prospective, cohort study. We collected data from patients meeting the Pan American Health Organization’s modified case-definition criteria for probable Zika infection. We identified Zika, dengue chikungunya by RT-PCR in serum and urine. We compared characteristics between patients with confirmed Zika and dengue infections, Zika and AIUO, and Dengue and AIUO at baseline, Days 3,7,28 and 180 of follow-up. Most episodes (67%) consistent with the PAHO definition of probable Zika could not be confirmed as due to any flavivirus and classified as Acute Illnesses of Unidentified Origin (AIUO). Infections by Zika and dengue accounted for 8.4% and 16% of episodes. Dengue patients presented with fever, generalized non-macular rash, arthralgia, and petechiae more frequently than patients with Zika during the first 10 days of symptoms. Dengue patients presented with more laboratory abnormalities (lower neutrophils, lymphocytosis, thrombocytopenia and abnormal liver function tests), with thrombocytopenia lasting for 28 days. Zika patients had conjunctivitis, photophobia and localized macular rash more frequently than others. Few differences persisted longer than 10 days after symptoms initiation: conjunctivitis in Zika infections, and self-reported rash and petechia in dengue infections. Conclusions Our study helps characterize the variety and duration of clinical features in patients with Zika, dengue and AIUO. The lack of diagnosis in most patients points to need for better diagnostics to assist clinicians in making specific etiologic diagnoses.

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 An outbreak of influenza A(H3N2) in Alappuzha district, Kerala, India, in 2011

2015 ◽  
Vol 9 (04) ◽  
pp. 362-367 ◽  
Author(s):  
Sam Peter ◽  
Anukumar Balakrishnan ◽  
Varsha A Potdar ◽  
Mandeep S Chadha ◽  
Santhosh M Jadhav
Keyword(s):  
Phylogenetic Analysis ◽  
Influenza A ◽  
Respiratory Illness ◽  
Case Definition ◽  
World Health ◽  
Rt Pcr ◽  
The World ◽  
Kerala State ◽  
Ha1 Gene ◽  
Epidemiological Characteristics

Introduction: Influenza is an RNA virus that belongs to the Orthomyxoviridae family. It causes a highly contagious acute respiratory illness, has been recognized since ancient times, and is a major health threat throughout the world. An outbreak of influenza-like illness (ILI) was reported from Alappuzha district of Kerala State between late June and July 2011. This investigation was conducted to determine the clinical picture, causative agents, and epidemiological characteristics of the illness. Methodology: The World Health Organization (WHO)’s case definition for ILI was followed throughout the investigation. Nasal or throat swabs were collected from 204 suspected patients. Real-time reverse transcription polymerase chain reaction (RT-PCR)-based diagnosis was performed to detect influenza A and B viruses and their subtypes. Madin-Darby canine kidney (MDCK) cell line was used for virus isolation. One-step RT-PCR was performed to amplify the HA1 gene of influenza A(H3N2). The amplicons for the HA1 gene of influenza A(H3N2) were sequenced, and phylogenetic analysis was done. Results: Analysis of the data revealed that 96 (47.05%) of the 204 respiratory specimens collected were influenza A(H3N2) and only 6 (2.94%) were A(H1N1)pdm09. Phylogenetic analysis revealed that the isolated A(H3N2) was closely related to the 2012–2013 northern hemisphere vaccine strain (A/Victoria/361/2011/H3N2). Conclusions: An influenza A(H3N2) outbreak was confirmed in Alappuzha district of Kerala state with a co-circulation of A(H1N1)pdm09. No substantial difference in the sequence was observed in the etiological agent, and the virus was found to be sensitive to oseltamivir.

scholarly journals Clinical characteristics and predictors of hospitalization among 7,108 ambulatory patients with positive RT-PCR for SARS-CoV-2 during the acute pandemic period

2021 ◽  
pp. e20210131
Author(s):  
Daniela Simian1 ◽  
Maripaz Martínez1 ◽  
Jorge Dreyse2 ◽  
May Chomali3 ◽  
Marcelo Retamal4 ◽  
...  
Keyword(s):  
Chest Pain ◽  
Medical Center ◽  
Red Flags ◽  
Rt Pcr ◽  
Medical Evaluation ◽  
Hazard Ratios ◽  
Isolation Period ◽  
Clinical Worsening ◽  
New Onset

Objective: To describe baseline characteristics of outpatients with a positive RT-PCR for SARS-CoV-2 and to define whether "red flags" (new-onset fever, dyspnea, and chest pain) can predict clinical worsening during the isolation period. Methods: This was an epidemiological, observational, descriptive study. Between March and September of 2020, all outpatients who tested positive for SARS-CoV-2 at a tertiary medical center located in Santiago de Chile were included. Demographic variables, comorbidities, red flags, and other symptoms were compiled using follow-up surveys at specific time points. The risk of clinical worsening (hospitalization) and adjusted hazard ratios (HRs) were calculated. Results: A total of 7,108 patients were included. The median age was 38 years (range, 0-101), and 52% were men. At baseline, 77% of the patients reported having characteristic symptoms of SARS-CoV-2 infection. The most prevalent onset symptoms were headache (53%), myalgia (47%), and fever (33%). According to the follow-up surveys, the incidence of symptoms decreased during the isolation period; however, 28% of the patients still presented with symptoms on day 14. The risk of hospitalization for patients with new-onset fever and dyspnea during the follow-up period was HR = 7.43 (95% CI, 3.85-14.3, p<0.01) and HR = 5.27 (95% CI, 1.52-18.30; p < 0.01 for both), respectively. New-onset chest pain showed no association with clinical worsening. Conclusions: In this sample of outpatients with a recent diagnosis of SARS-CoV-2 infection, a survey-based monitoring of symptoms was useful to identify those at risk of clinical worsening. New-onset fever and dyspnea during the isolation period were considered as red flags associated with clinical worsening and warrants prompt medical evaluation.

scholarly journals Incidence, household transmission, and neutralizing antibody seroprevalence of Coronavirus Disease 2019 in Egypt: Results of a community-based cohort

2021 ◽  
Vol 17 (3) ◽  
pp. e1009413
Author(s):  
Mokhtar R. Gomaa ◽  
Amira S. El Rifay ◽  
Mahmoud Shehata ◽  
Ahmed Kandeil ◽  
Mina Nabil Kamel ◽  
...  
Keyword(s):  
Serum Sample ◽  
Antibody Titer ◽  
Attack Rate ◽  
Index Case ◽  
Neutralizing Antibody ◽  
Respiratory Illness ◽  
Rt Pcr ◽  
Household Transmission ◽  
Study Sites ◽  
Transmission Studies

SARS-CoV-2 virus is transmitted in closed settings to people in contact with COVID-19 patients such as healthcare workers and household contacts. However, household person-to-person transmission studies are limited. Households participating in an ongoing cohort study of influenza incidence and prevalence in rural Egypt were followed. Baseline enrollment was done from August 2015 to March 2017. The study protocol was amended in April 2020 to allow COVID-19 incidence and seroprevalence studies. A total of 290 households including 1598 participants were enrolled and followed from April to October 2020 in four study sites. When a participant showed respiratory illness symptoms, a serum sample and a nasal and an oropharyngeal swab were obtained. Swabs were tested by RT-PCR for SARS-CoV-2 infection. If positive, the subject was followed and swabs collected on days three, six, nine, and 14 after the first swab day and a serum sample obtained on day 14. All subjects residing with the index case were swabbed following the same sampling schedule. Sera were collected from cohort participants in October 2020 to assess seroprevalence. Swabs were tested by RT-PCR. Sera were tested by Microneutralization Assay to measure the neutralizing antibody titer. Incidence of COVID-19, household secondary attack rate, and seroprevalence in the cohort were determined. The incidence of COVID-19 was 6.9% and the household secondary attack rate was 89.8%. Transmission within households occurred within two-days of confirming the index case. Infections were asymptomatic or mild with symptoms resolving within 10 days. The majority developed a neutralizing antibody titer by day 14 post onset. The overall seroprevalence among cohort participants was 34.8%. These results suggest that within-household transmission is high in Egypt. Asymptomatic or mild illness is common. Most infections seroconvert and have a durable neutralizing antibody titer.

scholarly journals 401. Natural History of Shedding and Household Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 Using Intensive High-Resolution Sampling

2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S302-S302
Author(s):  
Jonathan Altamirano ◽  
Prasanthi Govindarajan ◽  
Andra Blomkalns ◽  
Sean Leary ◽  
India Robinson ◽  
...  
Keyword(s):  
Risk Factors ◽  
Index Case ◽  
Socioeconomic Indicators ◽  
Rt Pcr ◽  
Viral Spread ◽  
Household Contacts ◽  
Household Transmission ◽  
Secondary Infections ◽  
History Of ◽  
Index Cases

Abstract Background In order to mitigate the spread of SARS-CoV-2 and the COVID-19 pandemic, public health officials have recommended self-isolation, self-quarantine of exposed household contacts (HHC), and mask use to limit viral spread within households and communities. While household transmission of SARS-CoV-2 is common, risk factors for HHC transmission are poorly understood. Methods In this prospective cohort study, we enrolled 37 households with at least one reverse transcription polymerase chain reaction-confirmed (RT-PCR) COVID-19 index case from March 2020 - March 2021, in order to calculate secondary attack rates (SAR) and define risk factors for secondary infections. Participants were tested daily for SARS-CoV-2 via RT-PCR, using self-collected lower nasal samples. Households were followed until all members tested negative for seven consecutive days. We collected demographics, medical conditions, relationship to index case, and socioeconomic indicators. Subgroup data analysis was conducted and stratified by positivity status. Results Of 99 enrolled participants, 37 were index cases and 62 were household contacts (HHC), of whom 25 HHC were infected (40.3%). Secondary attack rate (SAR) was highest among adults caring for a parent (n=4/4, 100%) and parents of index cases (5/10, 50%). Households whose income came from service work had greater risk of transmission compared to households whose primary income was technology (n=5/7; 71.4% vs 3/8; 37.5% respectively). Pediatric contacts were at lower risk of infection when compared to adult contacts (n=5/18, 27.8% vs n=20/44, 45.5% respectively). Conclusion This study suggests that household transmission represents a key source of community-based infection of SARS-CoV-2. Allocating resources for education/training regarding prevention among infected individuals and their close contacts will be critical for control of future outbreaks of SARS-CoV-2. Disclosures All Authors: No reported disclosures

scholarly journals Clinical spectrum of coronavirus disease 2019 in Iceland: population based cohort study

BMJ ◽  
2020 ◽  
pp. m4529
Author(s):  
Elias Eythorsson ◽  
Dadi Helgason ◽  
Ragnar Freyr Ingvarsson ◽  
Helgi K Bjornsson ◽  
Lovisa Bjork Olafsdottir ◽  
...  
Keyword(s):  
Cohort Study ◽  
Population Based ◽  
Case Definition ◽  
Population Screening ◽  
World Health ◽  
Rt Pcr ◽  
Case Definitions ◽  
Presenting Symptoms ◽  
Health Organization

Abstract Objective To characterise the symptoms of coronavirus disease 2019 (covid-19). Design Population based cohort study. Setting Iceland. Participants All individuals who tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by reverse transcription polymerase chain reaction (RT-PCR) between 17 March and 30 April 2020. Cases were identified by three testing strategies: targeted testing guided by clinical suspicion, open invitation population screening based on self referral, and random population screening. All identified cases were enrolled in a telehealth monitoring service, and symptoms were systematically monitored from diagnosis to recovery. Main outcome measures Occurrence of one or more of 19 predefined symptoms during follow-up. Results Among 1564 people positive for SARS-CoV-2, the most common presenting symptoms were myalgia (55%), headache (51%), and non-productive cough (49%). At the time of diagnosis, 83 (5.3%) individuals reported no symptoms, of whom 49 (59%) remained asymptomatic during follow-up. At diagnosis, 216 (14%) and 349 (22%) people did not meet the case definition of the Centers for Disease Control and Prevention and the World Health Organization, respectively. Most (67%) of the SARS-CoV-2-positive patients had mild symptoms throughout the course of their disease. Conclusion In the setting of broad access to RT-PCR testing, most SARS-CoV-2-positive people were found to have mild symptoms. Fever and dyspnoea were less common than previously reported. A substantial proportion of SARS-CoV-2-positive people did not meet recommended case definitions at the time of diagnosis.

scholarly journals Vaccine effectiveness against SARS-CoV-2 transmission to household contacts during dominance of Delta variant (B.1.617.2), the Netherlands, August to September 2021

2021 ◽  
Vol 26 (44) ◽  
Author(s):  
Brechje de Gier ◽  
Stijn Andeweg ◽  
Jantien A Backer ◽  
Susan JM Hahné ◽  
Susan van den Hof ◽  
...  
Keyword(s):  
The Netherlands ◽  
Confidence Interval ◽  
Index Case ◽  
Vaccine Effectiveness ◽  
Contact Tracing ◽  
Household Contacts ◽  
Household Members ◽  
Index Cases

We estimated SARS-CoV-2 vaccine effectiveness against onward transmission by comparing secondary attack rates among household members for vaccinated and unvaccinated index cases, based on source and contact tracing data collected when the Delta variant was dominant. Effectiveness of full vaccination of the index case against transmission to unvaccinated and fully vaccinated household contacts, respectively, was 63% (95% confidence interval (CI): 46–75) and 40% (95% CI: 20–54), in addition to the direct protection of vaccination of contacts against infection.

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