Role Of Children In Transmission Research Articles

The Role of Children in the Transmission of SARS-CoV-2, a Shifting Paradigm

Abstract Pediatric populations contribute to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission through a combination of exposure, susceptibility, and transmissibility. In this narrative review, SARS-CoV-2 infection in children is assessed to ascertain their role in transmission, by considering the characteristics of pediatric populations regarding their exposure and susceptibility to SARS-CoV-2 infection and COVID-19, and their transmission of the virus. A series of PubMed searches were conducted between November 2020 and February 2023 to identify articles describing SARS-CoV-2 transmission in children. The literature suggests that schools are key areas of exposure of children and adolescents to SARS-CoV-2, which contributed to school closures to mitigate spread and break transmission chains. However, the effectiveness of these measures is debated. Although SARS-CoV-2 appeared to infect children and adolescents less frequently than adults early in the pandemic, infection rates have risen considerably among the pediatric population with the emergence of variants of concern. Compared with adults and populations at high risk, children generally have a milder course of disease. The predominant role of children in transmission of SARS-CoV-2 is thought to involve household and school settings, although the relative contribution of each to transmission is questioned. Through their exposure, susceptibility, and transmissibility of SARS-CoV-2, children and adolescents are a key population contributing to the transmission of the virus. Our continued and evolving understanding of the role of children in transmission of SARS-CoV-2 has important implications to define appropriate preventive and therapeutic strategies for the pediatric population and the wider community.

The role of children in transmission of SARS-CoV-2 variants of concern within households: an updated systematic review and meta-analysis, as at 30 June 2022.

BackgroundMeta-analyses and single-site studies have established that children are less infectious than adults within a household when positive for ancestral SARS-CoV-2. In addition, children appear less susceptible to infection when exposed to ancestral SARS-CoV-2 within a household. The emergence of SARS-CoV-2 variants of concern (VOC) has been associated with an increased number of paediatric infections worldwide. However, the role of children in the household transmission of VOC, relative to the ancestral virus, remains unclear.AimWe aimed to evaluate children's role in household transmission of SARS-CoV-2 VOC.MethodsWe perform a meta-analysis of the role of children in household transmission of both ancestral SARS-CoV-2 and SARS-CoV-2 VOC.ResultsUnlike with the ancestral virus, children infected with VOC spread SARS-CoV-2 to an equivalent number of household contacts as infected adults and were equally as likely to acquire SARS-CoV-2 VOC from an infected family member. Interestingly, the same was observed when unvaccinated children exposed to VOC were compared with unvaccinated adults exposed to VOC.ConclusionsThese data suggest that the emergence of VOC was associated with a fundamental shift in the epidemiology of SARS-CoV-2. It is unlikely that this is solely the result of age-dependent differences in vaccination during the VOC period and may instead reflect virus evolution over the course of the pandemic.

Limited role of children in transmission of SARS‐CoV‐2 virus in households—Immunological analysis of 26 familial clusters

The impact of children on the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains uncertain. This study provides an insight into distinct patterns of SARS-CoV-2 household transmission in case of pediatric and adult index cases as well as age-dependent susceptibility to SARS-CoV-2 infection. Immune analysis, medical interviewing, and contact tracing of 26 families with confirmed SARS-CoV-2 infection cases have been conducted. Blood samples were analyzed serologically with the use of a SARS-CoV-2-specific IgG assay and virus neutralization test (VNT). Uni- and multivariable linear regression and mixed effect logistic regression models were used to describe potential risk factors for higher contagiousness and susceptibility to SARS-CoV-2 infection. SARS-CoV-2 infection could be confirmed in 67 of 124 family members. Fourteen children and 11 adults could be defined as index cases in their households. Forty of 82 exposed family members were defined as secondarily infected. The mean secondary attack rate in households was 0.48 and was significantly higher in households with adult than with pediatric index cases (0.85 vs 0.19; p< 0.0001). The age (grouped into child and adult) of index case, severity of disease, and occurrence of lower respiratory symptoms in index cases were significantly associated with secondary transmission rates in households. Children seem to be equally susceptible to acquire a SARS-CoV-2 infection as adults, but they suffer milder courses of the disease or remain asymptomatic. SARS-CoV-2 transmission from infected children to other household members occurred rarely in the first wave of the pandemic, despite close physical contact and the lack of hygienic measures.

Household transmission of SARS-CoV-2 from unvaccinated asymptomatic and symptomatic household members with confirmed SARS-CoV-2 infection: an antibody-surveillance study.

Background:Household transmission contributes to SARS-CoV-2 spread, but the role of children in transmission is unclear. We conducted a study that included symptomatic and asymptomatic children and adults exposed to SARS-CoV-2 in their households with the objective of determining how SARS-CoV-2 is transmitted within households.Methods:In this case-ascertained antibody-surveillance study, we enrolled households in Ottawa, Ontario, in which at least 1 household member had tested positive for SARS-CoV-2 on reverse transcription polymerase chain reaction testing. The enrolment period was September 2020 to March 2021. Potentially eligible participants were identified if they had tested positive for SARS-CoV-2 at an academic emergency department or affiliated testing centre; people who learned about the study through the media could also self-identify for participation. At least 2 participants were required for a household to be eligible for study participation, and at least 1 enrolled participant per household had to be a child (age < 18 yr). Enzyme-linked immunosorbent assays were used to evaluate SARS-CoV-2-specific IgA, IgM and IgG against the spike-trimer and nucleocapsid protein. The primary outcome was household secondary attack rate, defined as the proportion of household contacts positive for SARS-CoV-2 antibody among the total number of household contacts participating in the study. We performed descriptive statistics at both the individual and household levels. To estimate and compare outcomes between patient subgroups, and to examine predictors of household transmission, we fitted a series of multivariable logistic regression with robust standard errors to account for clustering of individuals within households.Results:We enrolled 695 participants from 180 households: 180 index participants (74 children, 106 adults) and 515 of their household contacts (266 children, 249 adults). A total of 487 household contacts (94.6%) (246 children, 241 adults) had SARS-CoV-2 antibody testing, of whom 239 had a positive result (secondary attack rate 49.1%, 95% confidence interval [CI] 42.9%–55.3%). Eighty-eight (36.8%, 95% CI 29.3%–43.2%) of the 239 were asymptomatic; asymptomatic rates were similar for children (51/130 [39.2%, 95% CI 30.7%–48.5%]) and adults (37/115 [32.2%, 95% CI 24.2%–41.4%]) (odds ratio [OR] 1.3, 95% CI 0.8–2.1). Adults were more likely than children to transmit SARS-CoV-2 (OR 2.2, 95% CI 1.3–3.6). The odds of transmission from asymptomatic (OR 0.6, 95% CI 0.2–1.4) versus symptomatic (OR 0.9, 95% CI 0.6–1.4) index participants to household contacts was uncertain. Predictors of household transmission included household density (number of people per bedroom), relationship to index participant and number of cases in the household.Interpretation:The rate of SARS-CoV-2 transmission within households was nearly 50% during the study period, and children were an important source of spread. The findings suggest that children are an important driver of the COVID-19 pandemic; this should inform public health policy.

An Evaluation of Knowledge, Awareness, Attitudes, and Behaviors Regarding COVID-19 Among Parents of Pediatric Dental Patients

Children infected with COVID-19 have a critical part in community-based viral transmission. This study aimed to evaluate knowledge, awareness, attitudes, and behaviors of parents of pediatric dental patients on COVID-19 and to present required actions to prevent its spreading. A total of 524 parents took part in this cross-sectional study. A self-administered questionnaire was prepared for determining sociodemographic characteristics and socioeconomic status of parents, along with their COVID-19-related knowledge, awareness, attitudes, and behaviors. In total, 90.6% of parents were unaware that disease may show no symptoms; 61.1% and 32.6% did not know roles of "close contact with asymptomatic patients" and "dentistry practices" in transmission, respectively; 30.2% thought it could be transmitted to their children at dental clinics, and only 16.4% stated their children as carriers. Parents need to be informed on COVID-19 transmission through contact with asymptomatic individuals, risks associated with dentistry practices, and role of children in transmission.

The role of children in the spread of COVID-19: Using household data from Bnei Brak, Israel, to estimate the relative susceptibility and infectivity of children.

One of the significant unanswered questions about COVID-19 epidemiology relates to the role of children in transmission. This study uses data on infections within households in order to estimate the susceptibility and infectivity of children compared to those of adults. The data were collected from households in the city of Bnei Brak, Israel, in which all household members were tested for COVID-19 using PCR (637 households, average household size of 5.3). In addition, serological tests were performed on a subset of the individuals in the study. Inspection of the PCR data shows that children are less likely to be tested positive compared to adults (25% of children positive over all households, 44% of adults positive over all households, excluding index cases), and the chance of being positive increases with age. Analysis of joint PCR/serological data shows that there is under-detection of infections in the PCR testing, which is more substantial in children. However, the differences in detection rates are not sufficient to account for the differences in PCR positive rates in the two age groups. To estimate relative transmission parameters, we employ a discrete stochastic model of the spread of infection within a household, allowing for susceptibility and infectivity parameters to differ among children and adults. The model is fitted to the household data using a simulated maximum likelihood approach. To adjust parameter estimates for under-detection of infections in the PCR results, we employ a multiple imputation procedure using estimates of under-detection in children and adults, based on the available serological data. We estimate that the susceptibility of children (under 20 years old) is 43% (95% CI: [31%, 55%]) of the susceptibility of adults. The infectivity of children was estimated to be 63% (95% CI: [37%, 88%]) relative to that of adults.

Comprehensive Contact Tracing, Testing and Sequencing Show Limited Transmission of SARS-CoV-2 Between Children in Schools in Norway, August 2020 to May 2021

Background: The role of children in the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in schools has been a topic of controversy. We investigated transmission from children in comprehensive school contact-investigations and assessed whether these differed by age of the children and by viral variants.Methods: We prospectively followed school contacts of children with laboratory confirmed SARS-CoV-2 infection in Norway from August 2020 to May 2021. All participants were tested for SARS-CoV-2 twice during the 7–10 days follow-up period, using PCR on home-sampled saliva. Positive samples were whole genome sequenced to determine possible transmission.Findings: In 43 contact-investigations, 559 child contacts were tested, of which eight tested positive (1·4%, 95% CI 0·62–2·80). We found no significant difference between primary (1·0%, 95% CI 0·27–2·53) and secondary schools (2·6%, 95% CI 0·70–6·39), p=0·229, or between the period before (1·4%, 95% CI 0·50–2·94) and after (1·7%, 95% CI 0·21–5·99) the Alpha variant (B.1.1.7) was established in the study area (March 2021), p=0·665. Only one adult contact (1/100, 1·0%) tested positive. In 34 indexes, we detected 13 different SARS-CoV-2 Pango lineage variants with the B.1.1.7 (Alpha) being the most frequent. In the eight contact-investigations with SARS-CoV-2 positive contacts, four had the same SARS-CoV-2 sequence identity as the index, one had no relation, and three were inconclusive. Interpretation: We found limited spread of SARS-CoV-2 from children in schools even after rigorous contact tracing and testing of school contacts, including the more transmissible Alpha variant. Whole genome sequencing revealed high consistency in SARS-CoV-2 Pango lineages, but ruled out transmission in one contact-investigation. By excluding contact-investigations with adult cases known at the time of enrollment, our data provide a valid estimate on the role of children in transmission of SARS-CoV-2 in schools. Funding Information: Norwegian Institute of Public Health.Declaration of Interests: None of the authors declare competing interests.Ethics Approval Statement: The Regional Committees for Medical and Health Research Ethics in Norway approved the study (reference 151649). The study complies with the EU general data protection regulation (GDPR) requirements. Consent was obtained from all participants of 16 years or above, or from both parents for participants <16 years. In case of sole parental responsibility, a single consent was sufficient.

Coronavirus Disease Pandemic: A Public Health Perspective

The new novel coronavirus was discovered by a Scottish virologist in London in 1964. As is usual with new discoveries, it seems the article she wrote about this discovery, was rejected by a peer reviewed journal. Dr Almeida wrote to the prestigious journal Nature (Nature 220, 1968), outlining her findings and proposed the name “coronavirus” for the new family of viruses. The name referred to the “crown like” appearance, she first observed on these viruses by electron microscopy. While SARS CoV-2 infection seems to be in control in China (less than 100,000 for a population of over billion), where it originated, the epidemic has moved briskly to the rest of the world. What seemed to be impossible to achieve, - imposing and enforcing strict quarantine of people, -is now a reality in majority of the countries. Success of preventive efforts is related, to how best the key principles of prevention strategies are followed; testing for infection, contact tracing, social distancing, wearing masks, and containment of the infected individuals. In December of 2019, several people in Wuhan, China, developed pneumonia and respiratory failure, like what happened during SARS epidemic of 2003. This virus is easily transmissible by symptomatic as well as asymptomatic individuals. As early as January 2020, SARS CoV-2 virus was found to spread during workshops, company meetings. Hospitals seem to provide a favorable environment for the propagation of coronavirus disease(Covid-19). Long-term care facilities are high-risk settings for infections of respiratory diseases. In the long-term care facilities, majority of the senior citizens, seem to have pre-existing conditions, such as hypertension, obesity, type-2 diabetes or cardiovascular diseases, which puts them at high-risk associated with Covid-19 severity. Several mass gatherings have been associated with explosive outbreaks of Covid-19, including political rallies, protests, sports and entertainment events. The possible role of children in transmission of the coronavirus is still not clear. Several individuals who had recovered from the COVID-19 have tested positive again at a later date, suggesting that the infection has been reactivated. These observations raise question about immunity in covid-19 patients for future infections, as well as the ‘herd immunity’ that we all are hoping for. In the absence of an evidence-based cure, the only choice we have of preventing infection is social distancing, wearing masks where needed, hand washing, contact tracing, and containment. SARS CoV-2 virus spreads through a receptor called angiotensin(ACE 2), which is expressed on many cells including the nasopharyngeal epithelial cells, by attaching to these receptors via its spike like external projections.In view of this observation, there is considerable interest in interventions, that may prevent these interactions including vaccines. The mRNA-1273 Group members have published their preliminary report in NEJM (July 14, 2020) about the successful completion of a phase-1 study of 45 healthy adults, who received two vaccines containing stabilized perfusion of SARS CoV-2 spike protein. The vaccines seem to have induced the SARS CoV-2 immune response in all participants. These preliminary findings, support and encourage the development of such novel vaccines, as well as drugs that interfere with the host receptor and virus interaction

COVID-19 Symptoms and SARS-CoV-2 Transmission in Children

The role of children in transmission of SARS-CoV-2 and the scope of pediatric illness has been examined since the start of the pandemic (NEJM JW Gen

COVID-19 in children: current evidence and key questions.

SARS-CoV-2 infection in children has been less well characterized than in adults, primarily due to a significantly milder clinical phenotype meaning many cases have gone undocumented by health professionals or researchers. This review outlines the current evidence of the epidemiology of infection in children, the clinical manifestations of disease, the role of children in transmission of the virus and the recently described hyperinflammatory syndrome observed later during the first phase of the pandemic. International seroprevalence studies have found younger children to have lower prevalence of antibodies to SARS-CoV-2, indicating they have not been infected as much as adults. This may be due to shielding by school closures, or by a reduced susceptibility to infection, as indicated by a significantly lower attack rate in children than adults in household contact tracing studies. The most well recognized symptoms in adults of cough, fever, anosmia and ageusia are less frequent in children, who may often present with mild and nonspecific symptoms, or with gastrointestinal symptoms alone. Risk factors for severe disease in children include chronic lung, cardiac or neurological disease, and malignancy. However, the absolute risk still appears very low for these cohorts. A new hyperinflammatory syndrome has emerged with an apparent immune cause. Important questions remain unanswered regarding why children have mild disease compared with adults; how children of different ages contribute to asymptomatic community transmission of the virus; and the pathophysiology of and most appropriate investigation and treatment strategies for the novel hyperinflammatory syndrome.

Epidemiology of paediatric Middle East respiratory syndrome coronavirus and implications for the control of coronavirus virus disease 2019.

AimTo compare the clinical features of Middle East respiratory syndrome coronavirus (MERS‐CoV) infection between paediatric and adult cases.MethodsUsing multiple public data sources, we created an enhanced open‐source surveillance dataset of all MERS‐CoV cases between 20 September 2012 and 31 December 2018 in Saudi Arabia including available risk factor data.ResultsOf the 1791 cases of MERS‐CoV identified, 30 cases (1.7%) were aged under 18 years and 1725 cases (96.3%) were aged 18 years and over. Three paediatric cases were fatal, aged 0, 2 and 15 years. The odds of asymptomatic MERS‐CoV infection among cases under 18 years (n = 10/23; 44%) was significantly higher (odds ratio (OR) = 4.98; 95% confidence interval (CI): 2.15–11.51; P = 0.001) compared to adults (n = 199/1487; 13%). The odds of hospitalisation were significantly lower (OR = 0.17; 95% CI: 0.08–0.39; P < 0.001) among cases under 18 years (n = 12/24; 50%) compared to adults (n = 1231/1443; 85%). Children were more likely to have a known source of exposure compared to adults (OR = 2.68; 95% CI: 1.29–5.56; P = 0.008).ConclusionsClinically severe illness is less common in children, although death can occur, and the proportion of paediatric cases (1.7%) is similar to that reported for COVID‐19. Age‐specific differences in the clinical presentation of MERS‐CoV cases could have implications for transmission for other betacoronaviruses including severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). Children may be at risk within the household with an infected adult. More studies are required on the role of children in transmission of betacoronaviruses.

The role of children in transmission of SARS-CoV-2: A rapid review.

BackgroundUnderstanding the role of children in the transmission of SARS-CoV-2 is urgently required given its policy implications in relation to the reopening of schools and intergenerational contacts.MethodsWe conducted a rapid review of studies that investigated the role of children in the transmission of SARS-CoV-2. We synthesized evidence for four categories: 1) studies reporting documented cases of SARS-CoV-2 transmission by infected children; 2) studies presenting indirect evidence on the potential of SARS-CoV-2 transmission by (both symptomatic and asymptomatic) children; 3) studies reporting cluster outbreaks of COVID-19 in schools; 4) studies estimating the proportions of children infected by SARS-CoV-2, and reported results narratively.ResultsA total of 16 unique studies were included for narrative synthesis. There is limited evidence detailing transmission of SARS-CoV-2 from infected children. We found two studies that reported a 3-month-old whose parents developed symptomatic COVID-19 seven days after caring for the infant and two children who may have contracted COVID-19 from the initial cases at a school in New South Wales. In addition, we identified six studies presenting indirect evidence on the potential for SARS-CoV-2 transmission by children, three of which found prolonged virus shedding in stools. There is little data on the transmission of SARS-CoV-2 in schools. We identified only two studies reporting outbreaks of COVID-19 in school settings and one case report of a child attending classes but not infecting any other pupils or staff. Lastly, we identified six studies estimating the proportion of children infected; data from population-based studies in Iceland, Italy, South Korea, Netherlands, California and a hospital-based study in the UK suggest children may be less likely to be infected.ConclusionsPreliminary results from population-based and school-based studies suggest that children may be less frequently infected or infect others, however current evidence is limited. Prolonged faecal shedding observed in studies highlights the potentially increased risk of faeco-oral transmission in children. Further seroprevalence studies (powered adequately for the paediatric population) are urgently required to establish whether children are in fact less likely to be infected compared to adults.NoteWe plan to update this rapid review as new data becomes available. These updates are available at https://www.ed.ac.uk/usher/uncover/completed-uncover-reviews.

Universal Influenza Vaccination in the United States: Are We Ready? Report of a Meeting

Universal influenza vaccination has been proposed as one strategy to improve vaccination coverage and disease prevention. In October 2005, influenza and vaccination experts, public health practitioners, representatives from medical professional societies, influenza vaccine manufacturers, and managed care organizations met to assess whether current data were sufficient to support an expansion of universal influenza vaccination and to define information gaps and potential barriers to implementation. Presenters at the meeting documented the substantial burden of influenza disease among all age groups, the major role of children in transmission, and the effectiveness of vaccine, especially in healthy children and adults. Observational studies and a mathematical model suggested that indirect protection, or "herd immunity," resulting from vaccination of school-age children would substantially reduce the incidence of disease in other age groups. Economic analyses generally showed that vaccination of healthy children and adults is cost-effective and is sensitive to vaccine cost, population group, and season. Influenza vaccination received annually over several years is safe and effective, but data on long-term use are limited. Challenges to expanded recommendations include maintenance of the vaccine supply, implementation of a feasible and effective strategy for vaccine delivery, the burden on the public health infrastructure, public acceptability, and financing. Overall, meeting attendees favored incremental expansion of recommendations, potentially toward universal influenza vaccination. They preferred to expand recommendations among children first, because children have a higher risk of illness, compared with healthy adults; because there is greater feasibility of implementation of the recommendations among children; and because of the potential for herd immunity decreasing morbidity and mortality among adults.