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1.
J Gen Virol ; 102(11)2021 11.
Article in English | MEDLINE | ID: covidwho-1522470

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to spread worldwide as a severe pandemic, and a significant portion of the infected population may remain asymptomatic. Given this, five surveys were carried out between May and September 2020 with a total of 3585 volunteers in the municipality of Foz do Iguaçu, State of Paraná, a triple border region between Brazil/Argentina/Paraguay. Five months after the first infection, volunteers were re-analysed for the production of IgG anti-Spike and anti-RBD-Spike, in addition to analyses of cellular immunity. Seroconversion rates ranged from 4.4 % to a peak of 37.21 % followed by a reduction in seroconversion to 21.1 % in September, indicating that 25 % of the population lost their circulating anti-SARS-CoV-2 antibodies 3 months after infection. Analyses after 5 months of infection showed that only 17.2 % of people still had anti-RBD-Spike antibodies, however, most volunteers had some degree of cellular immune response. The strategy of letting people become naturally infected with SARS-CoV-2 to achieve herd immunity is flawed, and the first contact with the virus may not generate enough immunogenic stimulus to prevent a possible second infection.


Subject(s)
COVID-19/immunology , Carrier State/immunology , Immunity, Herd , SARS-CoV-2/immunology , Antibodies, Viral/immunology , Argentina/epidemiology , Brazil/epidemiology , COVID-19/epidemiology , COVID-19/virology , Carrier State/epidemiology , Carrier State/virology , Humans , Immunity, Cellular , SARS-CoV-2/genetics , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/immunology
2.
Nature ; 599(7883): 108-113, 2021 11.
Article in English | MEDLINE | ID: covidwho-1434121

ABSTRACT

Throughout the coronavirus disease 2019 (COVID-19) pandemic, countries have relied on a variety of ad hoc border control protocols to allow for non-essential travel while safeguarding public health, from quarantining all travellers to restricting entry from select nations on the basis of population-level epidemiological metrics such as cases, deaths or testing positivity rates1,2. Here we report the design and performance of a reinforcement learning system, nicknamed Eva. In the summer of 2020, Eva was deployed across all Greek borders to limit the influx of asymptomatic travellers infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and to inform border policies through real-time estimates of COVID-19 prevalence. In contrast to country-wide protocols, Eva allocated Greece's limited testing resources on the basis of incoming travellers' demographic information and testing results from previous travellers. By comparing Eva's performance against modelled counterfactual scenarios, we show that Eva identified 1.85 times as many asymptomatic, infected travellers as random surveillance testing, with up to 2-4 times as many during peak travel, and 1.25-1.45 times as many asymptomatic, infected travellers as testing policies that utilize only epidemiological metrics. We demonstrate that this latter benefit arises, at least partially, because population-level epidemiological metrics had limited predictive value for the actual prevalence of SARS-CoV-2 among asymptomatic travellers and exhibited strong country-specific idiosyncrasies in the summer of 2020. Our results raise serious concerns on the effectiveness of country-agnostic internationally proposed border control policies3 that are based on population-level epidemiological metrics. Instead, our work represents a successful example of the potential of reinforcement learning and real-time data for safeguarding public health.


Subject(s)
COVID-19/diagnosis , COVID-19/prevention & control , Carrier State/diagnosis , Carrier State/prevention & control , Machine Learning , Travel Medicine , Travel , COVID-19/epidemiology , COVID-19/transmission , Carrier State/epidemiology , Carrier State/transmission , Greece , Humans , Prevalence , Public Health
3.
Biomed Environ Sci ; 34(9): 743-749, 2021 Sep 20.
Article in English | MEDLINE | ID: covidwho-1417232

ABSTRACT

The aim of this study was to estimate the seroprevalence of immunoglobulin M (IgM) and G (IgG) antibodies against SARS-CoV-2 in asymptomatic people in Wuhan. This was a cross-sectional study, which enrolled 18,712 asymptomatic participants from 154 work units in Wuhan. Pearson Chi-square test, t-test, and Mann-Whitney test were used to compare the standardized seroprevalence of IgG and IgM for age and gender between different groups. The results indicated the standardized seroprevalence of IgG and IgM showed a downward trend and was significantly higher among females than males. Besides, different geographic areas and workplaces had different seroprevalence of IgG among asymptomatic people, and the number of abnormalities in CT imaging were higher in IgG antibody-positive cases than IgG-negative cases. We hope these findings can provide references for herd immunity investigation and provide basis for vaccine development.


Subject(s)
Antibodies, Viral/blood , COVID-19/epidemiology , Carrier State/epidemiology , Immunoglobulin G/blood , Immunoglobulin M/blood , SARS-CoV-2/immunology , Adolescent , Adult , Aged , Aged, 80 and over , COVID-19/immunology , Carrier State/immunology , Child , Child, Preschool , China/epidemiology , Coronavirus Nucleocapsid Proteins/immunology , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Occupations/classification , Phosphoproteins/immunology , Seroepidemiologic Studies , Spike Glycoprotein, Coronavirus/immunology , Young Adult
4.
PLoS One ; 16(5): e0251123, 2021.
Article in English | MEDLINE | ID: covidwho-1388912

ABSTRACT

BACKGROUND: There is a lack of population level data on risk factors, incidence and impact of SARS-CoV-2 infection in pregnant women and their babies. The primary aim of this study was to describe the incidence, characteristics and outcomes of hospitalized pregnant women with symptomatic and asymptomatic SARS-CoV-2 in the UK compared to pregnant women without SARS-CoV-2. METHODS AND FINDINGS: We conducted a national, prospective cohort study of all hospitalized pregnant women with confirmed SARS-CoV-2 from 01/03/2020 to 31/08/2020 using the UK Obstetric Surveillance System. Incidence rates were estimated using national maternity data. Overall, 1148 hospitalized women had confirmed SARS-CoV-2 in pregnancy, 63% of which were symptomatic. The estimated incidence of hospitalization with symptomatic SARS-CoV-2 was 2.0 per 1000 maternities (95% CI 1.9-2.2) and for asymptomatic SARS-CoV-2 was 1.2 per 1000 maternities (95% CI 1.1-1.4). Compared to pregnant women without SARS-CoV-2, women hospitalized with symptomatic SARS-CoV-2 were more likely to be overweight or obese (adjusted OR 1.86, (95% CI 1.39-2.48) and aOR 2.07 (1.53-2.29)), to be of Black, Asian or Other minority ethnic group (aOR 6.24, (3.93-9.90), aOR 4.36, (3.19-5.95) and aOR 12.95, (4.93-34.01)), and to have a relevant medical comorbidity (aOR 1.83 (1.32-2.54)). Hospitalized pregnant women with symptomatic SARS-CoV-2 were more likely to be admitted to intensive care (aOR 57.67, (7.80-426.70)) but the absolute risk of poor outcomes was low. Cesarean births and neonatal unit admission were increased regardless of symptom status (symptomatic aOR 2.60, (1.97-3.42) and aOR 3.08, (1.99-4.77); asymptomatic aOR 2.02, (1.52-2.70) and aOR 1.84, (1.12-3.03)). The risks of stillbirth or neonatal death were not significantly increased, regardless of symptom status. CONCLUSIONS: We have identified factors that increase the risk of symptomatic and asymptomatic SARS-CoV-2 in pregnancy. Clinicians can be reassured that the majority of women do not experience severe complications of SARS-CoV-2 in pregnancy.


Subject(s)
COVID-19/epidemiology , Carrier State/epidemiology , Pregnancy Outcome , Adult , COVID-19/complications , COVID-19/diagnosis , COVID-19/virology , Carrier State/diagnosis , Carrier State/virology , Cesarean Section , Cohort Studies , Databases, Factual , Female , Humans , Incidence , Intensive Care Units , Minority Groups/statistics & numerical data , Obesity/complications , Odds Ratio , Pregnancy , Pregnant Women , Prospective Studies , SARS-CoV-2/isolation & purification , United Kingdom/epidemiology , Young Adult
5.
Nihon Koshu Eisei Zasshi ; 68(8): 550-558, 2021 Aug 11.
Article in Japanese | MEDLINE | ID: covidwho-1352943

ABSTRACT

Objectives There is little evidence supporting the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from presymptomatic or asymptomatic SARS-CoV-2-infected individuals in Japan, where the incidence of SARS-CoV-2 infection is lower than that in other developed countries. This study aimed to determine whether SARS-CoV-2 transmission can occur from presymptomatic or asymptomatic SARS-CoV-2-infected individuals.Methods We surveyed all directors of Japanese public health centers for index cases and secondary patients who possibly contracted SARS-CoV-2 infection from a presymptomatic or asymptomatic SARS-CoV-2-infected individual who came under their care before June 20, 2020. The professional staff at the centers routinely perform contact tracing of infected persons based on the guidelines of the Infection Control Act. Four authors independently reviewed reports of 9 index cases of SARS-CoV-2-infected individuals with 17 secondary patients from 8 prefectures and examined the cases to determine whether transmission from a SARS-CoV-2-infected individual in the presymptomatic or asymptomatic state occurred.Results We reported 7 index cases with 13 secondary patients. 1) An elderly woman acquired SARS-CoV-2 infection from her sustained asymptomatic granddaughter at home, 2) 4 guests and 1 accompanying child waiting at a hair salon acquired infection from the presymptomatic female hair stylist, 3) 2 inpatients acquired infection from a presymptomatic nurse while providing nursing care in close contact, 4) an elderly couple acquired SARS-CoV-2 infection from their presymptomatic relative who was in the 50s during household care at their home, 5) a man acquired SARS-CoV-2 infection from a presymptomatic adult neighbor in an enclosed space with poor ventilation, 6) a presymptomatic man had transmitted infection to another man at a coffee shop while having a discussion on business, and 7) a man in his 50s acquired SARS-CoV-2 infection from a presymptomatic man during 50 minutes of close contact at their office and in a car. These secondary patients had no other likely routes of infection. The interval between the date of symptom onset in the presymptomatic index case and the secondary patient ranged from 2 to 6 days. The incidence rates at the time these infections occurred in the corresponding prefectures ranged from 0.00 to 6.56 cases/1 million person-days.Conclusion We report the first case of SARS-CoV-2 transmission from a sustained asymptomatic index case in Japan. All secondary patients came into close contact with presymptomatic index cases in areas with poor ventilation.


Subject(s)
Asymptomatic Diseases/epidemiology , COVID-19/epidemiology , COVID-19/transmission , Carrier State/epidemiology , Carrier State/transmission , Contact Tracing , SARS-CoV-2 , Adult , Aged , Female , Humans , Infectious Disease Incubation Period , Japan/epidemiology , Male , Middle Aged , Young Adult
6.
J Res Health Sci ; 21(2): e00512, 2021 May 26.
Article in English | MEDLINE | ID: covidwho-1326174

ABSTRACT

BACKGROUND: This study aimed to analyze the demographic and epidemiological features of identified COVID-19 cases in Kazakhstan. STUDY DESIGN: A cross-sectional study. METHODS: This cross-sectional study aimed to analyze COVID-19 cases (n=5116) collected from March 13 to June 6, 2020, in Kazakhstan. The data were obtained from a state official medical electronic database. The study investigated the geographic and demographic data of patients as well as the association of COVID-19 cases with gender and age. The prevalence of symptoms, the presence of comorbidities, complications, and COVID-19 mortality were determined for all patients. RESULTS: The mean±SD age of the patients in this study was 34.8±17.6 years, and the majority (55.7%) of COVID-19 cases were male and residents of cities (79.6%). In total, 80% of the cases had the asymptomatic/mild form of the disease. Cough (20.8 %) and sore throat (17.1%) were the most common symptoms among patients, and pneumonia was diagnosed in 1 out of 5 cases. Acute respiratory distress syndrome (ARDS) was recorded in 1.2% of the patients. The fatality rate was 1% in the study population and lethality was 2.6 times higher in males compared to females.  Each additional year in age increased the probability of COVID-19 infection by 1.06 times. The presence of cardiovascular, diabetes, respiratory, and kidney diseases affected the rate of mortality (P<0.05). CONCLUSION: The results demonstrated a high proportion (40%) of the asymptomatic type of coronavirus infection in the Kazakhstan population. The severity of COVID-19 symptoms and lethality were directly related to the age of patients and the presence of comorbidities.


Subject(s)
COVID-19 , Carrier State/virology , Cough/etiology , Pandemics , Pharyngitis/etiology , Adolescent , Adult , Age Factors , Aged , COVID-19/complications , COVID-19/epidemiology , COVID-19/mortality , COVID-19/virology , Carrier State/epidemiology , Child , Comorbidity , Cough/epidemiology , Cross-Sectional Studies , Female , Humans , Kazakhstan/epidemiology , Male , Middle Aged , Pharyngitis/epidemiology , Pneumonia/epidemiology , Pneumonia/etiology , Respiratory Distress Syndrome/epidemiology , Respiratory Distress Syndrome/etiology , Retrospective Studies , SARS-CoV-2 , Sex Factors , Young Adult
7.
Nat Med ; 27(3): 454-462, 2021 03.
Article in English | MEDLINE | ID: covidwho-1319036

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic continues to spread relentlessly, associated with a high frequency of respiratory failure and mortality. Children experience largely asymptomatic disease, with rare reports of multisystem inflammatory syndrome in children (MIS-C). Identifying immune mechanisms that result in these disparate clinical phenotypes in children could provide critical insights into coronavirus disease 2019 (COVID-19) pathogenesis. Using systems serology, in this study we observed in 25 children with acute mild COVID-19 a functional phagocyte and complement-activating IgG response to SARS-CoV-2, similar to the acute responses generated in adults with mild disease. Conversely, IgA and neutrophil responses were significantly expanded in adults with severe disease. Moreover, weeks after the resolution of SARS-CoV-2 infection, children who develop MIS-C maintained highly inflammatory monocyte-activating SARS-CoV-2 IgG antibodies, distinguishable from acute disease in children but with antibody levels similar to those in convalescent adults. Collectively, these data provide unique insights into the potential mechanisms of IgG and IgA that might underlie differential disease severity as well as unexpected complications in children infected with SARS-CoV-2.


Subject(s)
Antibodies, Viral/blood , COVID-19/epidemiology , SARS-CoV-2/immunology , Adolescent , Adult , Age of Onset , Aged , Antibodies, Neutralizing/analysis , Antibodies, Neutralizing/blood , Antibodies, Viral/analysis , Asymptomatic Infections , COVID-19/blood , COVID-19/pathology , Carrier State/blood , Carrier State/epidemiology , Child , Child, Preschool , Cohort Studies , Female , Humans , Immunity/physiology , Immunoglobulin A/blood , Immunoglobulin G/blood , Infant , Infant, Newborn , Male , Middle Aged , Pandemics , Severity of Illness Index , Systemic Inflammatory Response Syndrome/blood , Systemic Inflammatory Response Syndrome/epidemiology , Young Adult
8.
Rev Esp Anestesiol Reanim (Engl Ed) ; 68(6): 346-352, 2021.
Article in English | MEDLINE | ID: covidwho-1263366

ABSTRACT

INTRODUCTION: Due to its high transmissibility, measures aimed at reducing the spread of SARS CoV2 have become mandatory. Different organizations have recommended performing polymerase chain reaction tests (PCR) as part of the preoperative screening of surgical patients. We aimed to determine the performance of PCR testing to detect asymptomatic carriers. METHODS: Observational study carried out at a tertiary care center. We compared the results of preoperative real-time reverse-transcription-PCR test (RT-PCR) performed on a cohort of patients pending surgery with the results we would have expected assuming the epidemiological data released by government offices. RESULTS: We registered no positives in the 2,722 preoperative RT-PCR tests performed in our health care area between epidemiological Weeks 18 to 21, meaning a cumulative incidence trending to zero. Assuming public epidemiological data, the probabilistic projection of potential asymptomatic individuals ranged from 0.27 × 10e-4 (according to official data of new cases diagnosed by PCR) to 4.69 × 10e-4 if we assumed cases confirmed by IgG test in our province. Assuming a RT-PCR sensitivity of 95%, to obtain a positive result we should perform 38,461 and 2,028 tests respectively. CONCLUSIONS: In scenarios of very low prevalence and despite high sensitivity scores, indiscriminate preoperative RT-PCR screening is of a questionable effectiveness for detecting asymptomatic carriers. Our findings evidence the difficulty of establishing reliable predictive models for the episodic and rapidly evolving incidence of infections such as has characterized the SARS CoV2 pandemic.


Subject(s)
COVID-19 Nucleic Acid Testing , COVID-19/diagnosis , Carrier State/diagnosis , Pandemics , Preoperative Care , SARS-CoV-2 , COVID-19/epidemiology , COVID-19 Nucleic Acid Testing/statistics & numerical data , Carrier State/epidemiology , Humans , Incidence , Prevalence , Retrospective Studies , Spain/epidemiology
9.
Proc Natl Acad Sci U S A ; 118(21)2021 05 25.
Article in English | MEDLINE | ID: covidwho-1223146

ABSTRACT

We analyze data from the fall 2020 pandemic response efforts at the University of Colorado Boulder, where more than 72,500 saliva samples were tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using qRT-PCR. All samples were collected from individuals who reported no symptoms associated with COVID-19 on the day of collection. From these, 1,405 positive cases were identified. The distribution of viral loads within these asymptomatic individuals was indistinguishable from what has been previously observed in symptomatic individuals. Regardless of symptomatic status, ∼50% of individuals who test positive for SARS-CoV-2 seem to be in noninfectious phases of the disease, based on having low viral loads in a range from which live virus has rarely been isolated. We find that, at any given time, just 2% of individuals carry 90% of the virions circulating within communities, serving as viral "supercarriers" and possibly also superspreaders.


Subject(s)
COVID-19/virology , Carrier State/virology , SARS-CoV-2 , Asymptomatic Infections/epidemiology , COVID-19/diagnosis , COVID-19/epidemiology , COVID-19/transmission , Carrier State/diagnosis , Carrier State/epidemiology , Carrier State/transmission , Colorado/epidemiology , Hospitalization/statistics & numerical data , Humans , Mass Screening/statistics & numerical data , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , Saliva/virology , Universities , Viral Load , Virion
10.
Viruses ; 13(5)2021 04 30.
Article in English | MEDLINE | ID: covidwho-1217119

ABSTRACT

It is unclear whether universal PCR screening for SARS-CoV-2 in asymptomatic individuals prior to admission is useful. From April to December 2020, the positive rate of universal pre-admission screening was 0.005% (4/76,521) in a tertiary care hospital in Korea. The positive rates were not different between the periods (period 1 (daily new patients of <1 per million inhabitants) vs. period 2 (1-8.3 per million inhabitants) vs. period 3 (10.3 to 20 per million inhabitants); P = 0.45). Universal pre-admission screening for SARS-CoV-2 had a lower positive rate than that of symptom-based screening (0.005% vs. 0.049% (53/109,257), p < 0.001). In addition, seven patients with negative pre-admission test results had subsequent positive PCR during hospitalization, and four patients had secondary transmission. Universal pre-admission PCR screening may not be practical in settings of low prevalence of COVID-19, and negative PCR results at admission should not serve as a basis for underestimating the risk of nosocomial spread from asymptomatic patients.


Subject(s)
Asymptomatic Diseases/epidemiology , COVID-19 Nucleic Acid Testing/methods , COVID-19 , Carrier State , Nasopharynx/virology , SARS-CoV-2/isolation & purification , COVID-19/diagnosis , COVID-19/epidemiology , Carrier State/diagnosis , Carrier State/epidemiology , Humans , Prevalence , Republic of Korea/epidemiology , Tertiary Care Centers
11.
PLoS Biol ; 19(4): e3001216, 2021 04.
Article in English | MEDLINE | ID: covidwho-1207620

ABSTRACT

Lateral flow devices (LFDs) are quickly being implemented for use in large-scale population surveillance programs for SARS-CoV-2 infection in the United Kingdom. These programs have been piloted in city-wide screening in the city of Liverpool and are now being rolled out to support care home visits and the return home of University students for the Christmas break. Here, we present data on the performance of LFDs to test almost 8,000 students at the University of Birmingham between December 2 and December 9, 2020. The performance is validated against almost 800 samples using PCR performed in the University Pillar 2 testing lab and theoretically validated on thousands of Pillar 2 PCR testing results performed on low-prevalence care home testing samples. Our data show that LFDs do not detect infections presenting with PCR Ct values over 29 to 30 as determined using the Thermo Fisher TaqPath asssay. This may be of particular importance in detecting individuals that are either at the early, or late stages of infection, and reinforces the need for frequent, recurrent testing.


Subject(s)
COVID-19 Serological Testing , COVID-19/diagnosis , Carrier State/diagnosis , SARS-CoV-2/isolation & purification , COVID-19/epidemiology , COVID-19 Nucleic Acid Testing , Carrier State/epidemiology , Humans , Immunoassay , Mass Screening , Prevalence , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Sensitivity and Specificity , United Kingdom/epidemiology , Universities
12.
Infect Dis Poverty ; 10(1): 56, 2021 Apr 26.
Article in English | MEDLINE | ID: covidwho-1204112

ABSTRACT

BACKGROUND: As one of the non-pharmacological interventions to control the transmission of COVID-19, determining the quarantine duration is mainly based on the accurate estimates of the incubation period. However, patients with coarse information of the exposure date, as well as infections other than the symptomatic, were not taken into account in previously published studies. Thus, by using the statistical method dealing with the interval-censored data, we assessed the quarantine duration for both common and uncommon infections. The latter type includes the presymptomatic, the asymptomatic and the recurrent test positive patients. METHODS: As of 10 December 2020, information on cases have been collected from the English and Chinese databases, including Pubmed, Google scholar, CNKI (China National Knowledge Infrastructure) and Wanfang. Official websites and medias were also searched as data sources. All data were transformed into doubly interval-censored and the accelerated failure time model was applied. By estimating the incubation period and the time-to-event distribution of worldwide COVID-19 patients, we obtain the large percentiles for determining and suggesting the quarantine policies. For symptomatic and presymptomatic COVID-19 patients, the incubation time is the duration from exposure to symptom onset. For the asymptomatic, we substitute the date of first positive result of nucleic acid testing for that of symptom onset. Furthermore, the time from hospital discharge or getting negative test result to the positive recurrence has been calculated for recurrent positive patients. RESULTS: A total of 1920 laboratory confirmed COVID-19 cases were included. Among all uncommon infections, 34.1% (n = 55) of them developed symptoms or were identified beyond fourteen days. Based on all collected cases, the 95th and 99th percentiles were estimated to be 16.2 days (95% CI 15.5-17.0) and 22.9 days (21.7‒24.3) respectively. Besides, we got similar estimates based on merely symptomatic and presymptomatic infections as 15.1 days (14.4‒15.7) and 21.1 days (20.0‒22.2). CONCLUSIONS: There are a certain number of infected people who require longer quarantine duration. Our findings well support the current practice of the extended active monitoring. To further prevent possible transmissions induced and facilitated by such infectious outliers after the 14-days quarantine, properly prolonging the quarantine duration could be prudent for high-risk scenarios and in regions with insufficient test resources.


Subject(s)
COVID-19/prevention & control , Quarantine/methods , SARS-CoV-2/physiology , Adolescent , Adult , Aged , Asymptomatic Diseases/epidemiology , Asymptomatic Infections/epidemiology , Carrier State/epidemiology , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Infectious Disease Incubation Period , Male , Middle Aged , Models, Statistical , Time Factors , Young Adult
13.
BMC Pregnancy Childbirth ; 21(1): 326, 2021 Apr 26.
Article in English | MEDLINE | ID: covidwho-1204051

ABSTRACT

BACKGROUND: Knowledge about SARS-CoV-2 infection in pregnancy and newborns is scarce. The objective of this study is to analyse clinical and epidemiological characteristics of a cohort of women infected with SARS-CoV-2 during pregnancy and their newborns exposed to SARS-CoV-2 during gestation. METHODS: Multicentric observational study of Spanish hospitals from the GESNEO-COVD cohort, participants in RECLIP (Spanish Network of Paediatric Clinical Assays). Women with confirmed SARS-CoV-2 infection by PCR and/or serology during pregnancy, diagnosed and delivering during the period 15/03/2020-31/07/2020 were included. Epidemiological, clinical, and analytical data was collected. RESULTS: A total of 105 pregnant women with a median of 34.1 years old (IQR: 28.8-37.1) and 107 newborns were included. Globally, almost 65% of pregnant women had some COVID-19 symptoms and more than 43% were treated for SARS-COV-2. Overall, 30.8% of pregnant women had pneumonia and 5 (4.8%) women were admitted to the intensive care unit needing invasive mechanical ventilation. There was a rate of 36.2% of caesarean sections, which was associated with pneumonia during pregnancy (OR: 4.203, CI 95%: 1.473-11.995) and lower gestational age at delivery (OR: 0.724, CI 95%: 0.578-0.906). The prevalence of preterm birth was 20.6% and prematurity was associated with pneumonia during gestation (OR: 6.970, CI95%: 2.340-22.750) and having a positive SARS-CoV-2 PCR at delivery (OR: 6.520, CI95%: 1.840-31.790). All nasopharyngeal PCR in newborns were negative at birth and one positivized at 15 days of life. Two newborns died, one due to causes related to prematurity and another of unexpected sudden death during early skin-to-skin contact after delivery. CONCLUSIONS: Although vertical transmission has not been reported in this cohort, the prognosis of newborns could be worsened by SARS-CoV-2 infection during pregnancy as COVID-19 pneumonia increased the risk of caesarean section deliveries and preterm births.


Subject(s)
COVID-19/epidemiology , Carrier State/epidemiology , Pregnancy Complications, Infectious/epidemiology , Premature Birth/epidemiology , Adult , Anti-Bacterial Agents/therapeutic use , Antiviral Agents/therapeutic use , COVID-19/drug therapy , COVID-19/physiopathology , COVID-19/therapy , COVID-19 Nucleic Acid Testing , Cesarean Section/statistics & numerical data , Cohort Studies , Comorbidity , Cough/physiopathology , Diabetes, Gestational/epidemiology , Dyspnea/physiopathology , Female , Fever/physiopathology , Gestational Age , Humans , Hypertension/epidemiology , Hypothyroidism/epidemiology , Immunologic Factors/therapeutic use , Infant, Newborn , Infectious Disease Transmission, Vertical , Intensive Care Units/statistics & numerical data , Lung/diagnostic imaging , Male , Obesity, Maternal/epidemiology , Pneumonia, Viral/diagnostic imaging , Pneumonia, Viral/physiopathology , Pneumonia, Viral/therapy , Pregnancy , Pregnancy Complications/epidemiology , Pregnancy Complications, Infectious/physiopathology , Pregnancy Complications, Infectious/therapy , Pregnancy Trimester, Second , Pregnancy Trimester, Third , Radiography, Thoracic , Respiration, Artificial , Risk Factors , SARS-CoV-2 , Severity of Illness Index , Spain/epidemiology
14.
Elife ; 102021 04 26.
Article in English | MEDLINE | ID: covidwho-1201638

ABSTRACT

Background: Understanding changes in infectiousness during SARS-COV-2 infections is critical to assess the effectiveness of public health measures such as contact tracing. Methods: Here, we develop a novel mechanistic approach to infer the infectiousness profile of SARS-COV-2-infected individuals using data from known infector-infectee pairs. We compare estimates of key epidemiological quantities generated using our mechanistic method with analogous estimates generated using previous approaches. Results: The mechanistic method provides an improved fit to data from SARS-CoV-2 infector-infectee pairs compared to commonly used approaches. Our best-fitting model indicates a high proportion of presymptomatic transmissions, with many transmissions occurring shortly before the infector develops symptoms. Conclusions: High infectiousness immediately prior to symptom onset highlights the importance of continued contact tracing until effective vaccines have been distributed widely, even if contacts from a short time window before symptom onset alone are traced. Funding: Engineering and Physical Sciences Research Council (EPSRC).


Subject(s)
COVID-19/transmission , Contact Tracing/methods , COVID-19/epidemiology , Carrier State/epidemiology , Carrier State/transmission , Health Policy , Humans , Models, Theoretical , Public Health , Risk Factors , SARS-CoV-2
15.
Am J Perinatol ; 38(8): 857-868, 2021 07.
Article in English | MEDLINE | ID: covidwho-1193615

ABSTRACT

OBJECTIVE: This study was aimed to review 4 weeks of universal novel coronavirus disease 2019 (COVID-19) screening among delivery hospitalizations, at two hospitals in March and April 2020 in New York City, to compare outcomes between patients based on COVID-19 status and to determine whether demographic risk factors and symptoms predicted screening positive for COVID-19. STUDY DESIGN: This retrospective cohort study evaluated all patients admitted for delivery from March 22 to April 18, 2020, at two New York City hospitals. Obstetrical and neonatal outcomes were collected. The relationship between COVID-19 and demographic, clinical, and maternal and neonatal outcome data was evaluated. Demographic data included the number of COVID-19 cases ascertained by ZIP code of residence. Adjusted logistic regression models were performed to determine predictability of demographic risk factors for COVID-19. RESULTS: Of 454 women delivered, 79 (17%) had COVID-19. Of those, 27.9% (n = 22) had symptoms such as cough (13.9%), fever (10.1%), chest pain (5.1%), and myalgia (5.1%). While women with COVID-19 were more likely to live in the ZIP codes quartile with the most cases (47 vs. 41%) and less likely to live in the ZIP code quartile with the fewest cases (6 vs. 14%), these comparisons were not statistically significant (p = 0.18). Women with COVID-19 were less likely to have a vaginal delivery (55.2 vs. 51.9%, p = 0.04) and had a significantly longer postpartum length of stay with cesarean (2.00 vs. 2.67days, p < 0.01). COVID-19 was associated with higher risk for diagnoses of chorioamnionitis and pneumonia and fevers without a focal diagnosis. In adjusted analyses, including demographic factors, logistic regression demonstrated a c-statistic of 0.71 (95% confidence interval [CI]: 0.69, 0.80). CONCLUSION: COVID-19 symptoms were present in a minority of COVID-19-positive women admitted for delivery. Significant differences in obstetrical outcomes were found. While demographic risk factors demonstrated acceptable discrimination, risk prediction does not capture a significant portion of COVID-19-positive patients. KEY POINTS: · COVID-19 symptoms were present in a minority of COVID-19-positive women admitted.. · COVID-19 symptomatology did not appear to differ before or after the apex of infection in New York.. · Demographic risk factors are unlikely to capture a significant portion of COVID-19-positive patients..


Subject(s)
COVID-19/epidemiology , Pregnancy Complications, Infectious/epidemiology , Adult , Carrier State/epidemiology , Cesarean Section/statistics & numerical data , Chorioamnionitis/epidemiology , Cohort Studies , Delivery, Obstetric , Female , Fever/epidemiology , Hospitalization , Humans , Length of Stay/statistics & numerical data , Logistic Models , Maternal Age , New York City/epidemiology , Obesity, Maternal/epidemiology , Pneumonia/epidemiology , Pregnancy , Residence Characteristics , Retrospective Studies , Risk Factors , SARS-CoV-2 , Young Adult
16.
Epidemiol Infect ; 149: e91, 2021 04 14.
Article in English | MEDLINE | ID: covidwho-1182770

ABSTRACT

An outbreak of SARS-CoV2 infection in a Barcelona prison was studied. One hundred and forty-eight inmates and 36 prison staff were evaluated by rt-PCR, and 24.1% (40 prisoners, two health workers and four non-health workers) tested positive. In all, 94.8% of cases were asymptomatic. The inmates were isolated in prison module 4, which was converted into an emergency COVID unit. There were no deaths. Generalised screening and the isolation and evaluation of the people infected were key measures. Symptom-based surveillance must be supplemented by rapid contact-based monitoring in order to avoid asymptomatic spread among prisoners and the community at large.


Subject(s)
COVID-19/epidemiology , Carrier State/epidemiology , Infection Control , Prisons , Public Health , Quarantine , Adult , Aged , COVID-19/diagnosis , COVID-19/prevention & control , COVID-19 Nucleic Acid Testing , Carrier State/diagnosis , Carrier State/prevention & control , Disease Outbreaks , Health Personnel , Hospitalization , Humans , Male , Middle Aged , Prisoners , SARS-CoV-2 , Severity of Illness Index , Spain/epidemiology , Young Adult
17.
J Infect Dev Ctries ; 15(3): 389-397, 2021 03 31.
Article in English | MEDLINE | ID: covidwho-1175608

ABSTRACT

INTRODUCTION: At the end of 2019, the COVID-19 broke out, and spread to Guizhou province in January of 2020. METHODOLOGY: To acquire the epidemiologic characteristics of COVID-19 in Guizhou province, we collected data from 169 laboratory-confirmed COVID-19 related cases. We described the demographic characteristics of the cases and estimated the incubation period, serial interval and the effective reproduction number. We also presented two representative case studies in Guizhou province: Case Study 1 was an example of the asymptomatic carrier; while Case Study 2 was an example of a large and complex infection chain that involved four different regions, spanning three provinces and eight families. RESULTS: Two peaks in the incidence distribution associated with COVID-19 in Guizhou province were related to the 6.04 days (95% CI: 5.00 - 7.10) of incubation period and 6.14±2.21 days of serial interval. We also discussed the effectiveness of the control measures based on the instantaneous effective reproduction number that was a constantly declining curve. CONCLUSIONS: As of February 2, 2020, the estimated effective reproduction number was below 1, and no new cases were reported since February 26. These showed that Guizhou Province had achieved significant progress in preventing the spread of the epidemic. The medical isolation of close contacts was consequential. Meanwhile, the asymptomatic carriers and the super-spreaders must be isolated in time, who would cause a widespread infection.


Subject(s)
COVID-19/epidemiology , Carrier State/epidemiology , Adolescent , Adult , Aged , Aged, 80 and over , COVID-19/prevention & control , COVID-19/transmission , Carrier State/virology , Child , Child, Preschool , China/epidemiology , Female , Geography , Humans , Incidence , Infant , Infectious Disease Incubation Period , Male , Middle Aged , Young Adult
18.
A A Pract ; 15(3): e01419, 2021 Mar 08.
Article in English | MEDLINE | ID: covidwho-1150452

ABSTRACT

The risk of aerosol transmission has been a key factor for the rapid dissemination of the coronavirus pandemic. Transportation of coronavirus disease 2019 (COVID-19)-infected patients with active air leaks could expose unprotected health care personnel and other patients to aerosolized viral particles. We devised a way to avoid aerosolization while the chest tube drain is on water seal. It involves placing an Ultipor100 viral filter on the suction port of the drain system as well as sealing off the safety valve. This mechanism allows positive pressure from an air leak to escape while on water seal while trapping viral particles.


Subject(s)
COVID-19/therapy , Carrier State/prevention & control , Chest Tubes/adverse effects , Disease Management , Inventions/trends , Postoperative Care/trends , COVID-19/epidemiology , Carrier State/epidemiology , Humans , Postoperative Care/methods
19.
Emerg Infect Dis ; 27(4): 1249-1251, 2021 04.
Article in English | MEDLINE | ID: covidwho-1145546
20.
BMC Pregnancy Childbirth ; 21(1): 212, 2021 Mar 17.
Article in English | MEDLINE | ID: covidwho-1140481

ABSTRACT

BACKGROUND: Asymptomatic carriage of COVID-19 in pregnant women has been reported and could lead to outbreaks in maternity units. We sought to ascertain the impact of rapid isothernal nucleic acid based testing for COVID-19 in an unselected cohort of pregnant women attending our maternity unit. We also assessed the correlation between community prevalence and asymptomatic carriage. METHODS: Data for the retrospective cohort study were collected from a large UK tertiary maternity unit over a 4-week period using computerised hospital records. Literature searches were performed across multiple repositories. COVID-19 prevalence was extracted from online repositories. RESULTS: Nasopharyngeal and oropharyngeal swabs were obtained from 457/465 (98%) women during the study period. The median turnaround time for results was 5.3 h (interquartile range (IQR) 2.6-8.9 h), with 92% of the results returned within 24 h. In our cohort, only one woman tested positive, giving a screen positive rate of 0.22% (1/457; 95% CI: 0.04-1.23%). One woman who tested negative developed a fever postnatally following discharge but was lost to follow-up. From our literature review, we did not find any correlation between asymptomatic carriage in pregnant women and the reported regional prevalence of COVID-19. CONCLUSIONS: Testing using the SAMBA-II machine was acceptable to the vast majority of pregnant women requiring admission and had a low turnaround time. Asymptomatic carriage is low, but not correlated to community prevalence rates. Screening pregnant women on admission will remain an important component in order to minimise nosocomial infection.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , Carrier State/diagnosis , Cross Infection/prevention & control , Pregnancy Complications, Infectious/diagnosis , COVID-19/epidemiology , Carrier State/epidemiology , Cohort Studies , Female , Hospitals, Maternity , Humans , Mass Screening , Point-of-Care Testing , Pregnancy , Pregnancy Complications, Infectious/epidemiology , Retrospective Studies , SARS-CoV-2 , Time Factors , United Kingdom/epidemiology
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