Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 10 de 10
Filter
1.
Nature ; 604(7905): 330-336, 2022 04.
Article in English | MEDLINE | ID: covidwho-1692583

ABSTRACT

The animal reservoir of SARS-CoV-2 is unknown despite reports of SARS-CoV-2-related viruses in Asian Rhinolophus bats1-4, including the closest virus from R. affinis, RaTG13 (refs. 5,6), and pangolins7-9. SARS-CoV-2 has a mosaic genome, to which different progenitors contribute. The spike sequence determines the binding affinity and accessibility of its receptor-binding domain to the cellular angiotensin-converting enzyme 2 (ACE2) receptor and is responsible for host range10-12. SARS-CoV-2 progenitor bat viruses genetically close to SARS-CoV-2 and able to enter human cells through a human ACE2 (hACE2) pathway have not yet been identified, although they would be key in understanding the origin of the epidemic. Here we show that such viruses circulate in cave bats living in the limestone karstic terrain in northern Laos, in the Indochinese peninsula. We found that the receptor-binding domains of these viruses differ from that of SARS-CoV-2 by only one or two residues at the interface with ACE2, bind more efficiently to the hACE2 protein than that of the SARS-CoV-2 strain isolated in Wuhan from early human cases, and mediate hACE2-dependent entry and replication in human cells, which is inhibited by antibodies that neutralize SARS-CoV-2. None of these bat viruses contains a furin cleavage site in the spike protein. Our findings therefore indicate that bat-borne SARS-CoV-2-like viruses that are potentially infectious for humans circulate in Rhinolophus spp. in the Indochinese peninsula.


Subject(s)
COVID-19 , Chiroptera , Angiotensin-Converting Enzyme 2 , Animals , Asia , Caves , Chiroptera/virology , Disease Reservoirs , Humans , Protein Binding , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/chemistry
2.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-323389

ABSTRACT

Background: Lao PDR has low reported COVID-19 cases but it is unclear whether this masks silent transmission. A nationwide seroprevalence study was done between August and September 2020 to determine SARS-CoV-2 exposure.Methods: Participants were from the general community/healthcare workers in five provinces. Bat/wildlife contacts were from Vientiane province. ELISAs detected anti-Nucleoprotein (N;n=3173 tested) and anti-Spike (S;n=1417 tested) SARS-CoV-2 antibodies. Double-positive samples were checked by IgM/IgG rapid tests. Positive controls were confirmed COVID-19 cases and negative controls were pre-COVID-19 samples.Findings: In pre-COVID-19 samples, 14/265 (5·3%, [95% CI=3·1-8·7%]) were anti-N antibody single-positive and 3/265 (1·1% [0·3-3·5%]) were anti-S antibody single positive. None were anti-N and anti-S antibody double positive. Anti-N and anti-S antibodies were detected in 131/2417 (5·4% [4·5-6·3%]) and 19/1061 (1·8% [1·1-2·8%]) of the general population, 13/666 (2·0% [1·1-3·3%]) and 4/282 (1·4% [0·5-3·7%]) of healthcare workers and 15/74 (20·3% [12·6-31·0%]) and 5/74 (6·8% [2·8-15·3%]) of bat/wildlife contacts. Only 2/3173 (0·1% [0·02-0·3%]) were double positive for anti-N and anti-S antibodies (rapid test negative).Interpretation: We find no evidence for significant circulation of SARS-CoV-2 in Lao PDR during or before September 2020. This likely results from decisive measures taken by the government early in the pandemic, social behavior, and low population density. High anti-N antibodies/low anti-S antibodies in bat/wildlife contacts may indicate exposure to cross-reactive animal coronaviruses with threat of emerging novel viruses.Funding: Core;Agence Française de Développement. Additional support;Institut Pasteur du Laos, Institute Pasteur, Paris and Luxembourg Ministry of Foreign and European Affairs (“PaReCIDS II”). Declaration of Interests: The authors have no conflict of interest to declare.Ethics Approval Statement: The study protocol was approved by all participating institutes and by the Lao National Ethics Committee for Health Research (NECHR) (Ref #052/2020).

3.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-322622

ABSTRACT

The animal reservoir of SARS-CoV-2 is unknown despite reports of various SARS-CoV-2-related viruses in Asian Rhinolophus bats, including the closest virus from R. affinis, RaTG13. Several studies have suggested the involvement of pangolin coronaviruses in SARS-CoV-2 emergence. SARS-CoV-2 presents a mosaic genome, to which different progenitors contribute. The spike sequence determines the binding affinity and accessibility of its receptor-binding domain (RBD) to the cellular angiotensin-converting enzyme 2 (ACE2) receptor and is responsible for host range. SARS-CoV-2 progenitor bat viruses genetically close to SARS-CoV-2 and able to enter human cells through a human ACE2 pathway have not yet been identified, though they would be key in understanding the origin of the epidemics. Here we show that such viruses indeed circulate in cave bats living in the limestone karstic terrain in North Laos, within the Indochinese peninsula. We found that the RBDs of these viruses differ from that of SARS-CoV-2 by only one or two residues, bind as efficiently to the hACE2 protein as the SARS-CoV-2 Wuhan strain isolated in early human cases, and mediate hACE2-dependent entry into human cells, which is inhibited by antibodies neutralizing SARS-CoV-2. None of these bat viruses harbors a furin cleavage site in the spike. Our findings therefore indicate that bat-borne SARS-CoV-2-like viruses potentially infectious for humans circulate in Rhinolophus spp. in the Indochinese peninsula.

4.
Lancet Reg Health West Pac ; 13: 100197, 2021 Aug.
Article in English | MEDLINE | ID: covidwho-1309327

ABSTRACT

BACKGROUND: In 2020 Lao PDR had low reported COVID-19 cases but it was unclear whether this masked silent transmission. A seroprevalence study was done August - September 2020 to determine SARS-CoV-2 exposure. METHODS: Participants were from the general community (n=2433) or healthcare workers (n=666) in five provinces and bat/wildlife contacts (n=74) were from Vientiane province. ELISAs detected anti- SARS-CoV-2 Nucleoprotein (N; n=3173 tested) and Spike (S; n=1417 tested) antibodies. Double-positive samples were checked by IgM/IgG rapid tests. Controls were confirmed COVID-19 cases (n=15) and pre-COVID-19 samples (n=265). Seroprevalence for the general community was weighted to account for complex survey sample design, age and sex. FINDINGS: In pre-COVID-19 samples, 5·3%, [95% CI=3·1-8·7%] were anti-N antibody single-positive and 1·1% [0·3-3·5%] were anti-S antibody single positive. None were double positive. Anti-N and anti-S antibodies were detected in 5·2% [4·2-6·5%] and 2·1% [1·1-3·9%] of the general community, 2·0% [1·1-3·3%] and 1·4% [0·5-3·7%] of healthcare workers and 20·3% [12·6-31·0%] and 6·8% [2·8-15·3%] of bat/wildlife contacts. 0·1% [0·02-0·3%] were double positive for anti-N and anti-S antibodies (rapid test negative). INTERPRETATION: We find no evidence for significant SARS-CoV-2 circulation in Lao PDR before September 2020. This likely results from early decisive measures taken by the government, social behavior, and low population density. High anti-N /low anti-S seroprevalence in bat/wildlife contacts may indicate exposure to cross-reactive animal coronaviruses with threat of emerging novel viruses. FUNDING: Agence Française de Développement. Additional; Institut Pasteur du Laos, Institute Pasteur, Paris and Luxembourg Ministry of Foreign and European Affairs ("PaReCIDS II").

5.
Euro Surveill ; 26(15)2021 04.
Article in English | MEDLINE | ID: covidwho-1190261

ABSTRACT

BackgroundChildren's role in SARS-CoV-2 epidemiology remains unclear. We investigated an initially unnoticed SARS-CoV-2 outbreak linked to schools in northern France, beginning as early as mid-January 2020.AimsThis retrospective observational study documents the extent of SARS-CoV-2 transmission, linked to an affected high school (n = 664 participants) and primary schools (n = 1,340 study participants), in the context of unsuspected SARS-CoV-2 circulation and limited control measures.MethodsBetween 30 March and 30 April 2020, all school staff, as well as pupils and their parents and relatives were invited for SARS-CoV-2 antibody testing and to complete a questionnaire covering symptom history since 13 January 2020.ResultsIn the high school, infection attack rates were 38.1% (91/239), 43.4% (23/53), and 59.3% (16/27), in pupils, teachers, and non-teaching staff respectively vs 10.1% (23/228) and 12.0% (14/117) in the pupils' parents and relatives (p < 0.001). Among the six primary schools, three children attending separate schools at the outbreak start, while symptomatic, might have introduced SARS-CoV-2 there, but symptomatic secondary cases related to them could not be definitely identified. In the primary schools overall, antibody prevalence in pupils sharing classes with symptomatic cases was higher than in pupils from other classes: 15/65 (23.1%) vs 30/445 (6.7%) (p < 0.001). Among 46 SARS-CoV-2 seropositive pupils < 12 years old, 20 were asymptomatic. Whether past HKU1 and OC43 seasonal coronavirus infection protected against SARS-CoV-2 infection in 6-11 year olds could not be inferred.ConclusionsViral circulation can occur in high and primary schools so keeping them open requires consideration of appropriate control measures and enhanced surveillance.


Subject(s)
COVID-19 , Child , Cohort Studies , France/epidemiology , Humans , Retrospective Studies , SARS-CoV-2 , Schools
6.
Euro Surveill ; 26(13)2021 04.
Article in English | MEDLINE | ID: covidwho-1167263

ABSTRACT

BackgroundChildren have a low rate of COVID-19 and secondary severe multisystem inflammatory syndrome (MIS) but present a high prevalence of symptomatic seasonal coronavirus infections.AimWe tested if prior infections by seasonal coronaviruses (HCoV) NL63, HKU1, 229E or OC43 as assessed by serology, provide cross-protective immunity against SARS-CoV-2 infection.MethodsWe set a cross-sectional observational multicentric study in pauci- or asymptomatic children hospitalised in Paris during the first wave for reasons other than COVID (hospitalised children (HOS), n = 739) plus children presenting with MIS (n = 36). SARS-CoV-2 antibodies directed against the nucleoprotein (N) and S1 and S2 domains of the spike (S) proteins were monitored by an in-house luciferase immunoprecipitation system assay. We randomly selected 69 SARS-CoV-2-seropositive patients (including 15 with MIS) and 115 matched SARS-CoV-2-seronegative patients (controls (CTL)). We measured antibodies against SARS-CoV-2 and HCoV as evidence for prior corresponding infections and assessed if SARS-CoV-2 prevalence of infection and levels of antibody responses were shaped by prior seasonal coronavirus infections.ResultsPrevalence of HCoV infections were similar in HOS, MIS and CTL groups. Antibody levels against HCoV were not significantly different in the three groups and were not related to the level of SARS-CoV-2 antibodies in the HOS and MIS groups. SARS-CoV-2 antibody profiles were different between HOS and MIS children.ConclusionPrior infection by seasonal coronaviruses, as assessed by serology, does not interfere with SARS-CoV-2 infection and related MIS in children.


Subject(s)
Antibodies, Viral/immunology , COVID-19/immunology , Coronavirus OC43, Human , SARS-CoV-2/immunology , Systemic Inflammatory Response Syndrome , Adolescent , Antibodies, Viral/blood , COVID-19/blood , COVID-19/diagnosis , Child , Child, Preschool , Cross-Sectional Studies , Female , France/epidemiology , Humans , Infant , Infant, Newborn , Male , Paris , Seasons , Serologic Tests/methods , Spike Glycoprotein, Coronavirus
7.
Am J Transplant ; 21(5): 1937-1943, 2021 05.
Article in English | MEDLINE | ID: covidwho-991160

ABSTRACT

Graft artery stenosis can have a significant short- and long-term negative impact on renal graft function. From the beginning of the COVID-19 pandemic, we noticed an unusual number of graft arterial anomalies following kidney transplant (KTx) in children. Nine children received a KTx at our center between February and July 2020, eight boys and one girl, of median age of 10 years. Seven presented Doppler features suggesting arterial stenosis, with an unusual extensive pattern. For comparison, over the previous 5-year period, persistent spectral Doppler arterial anomalies (focal anastomotic stenoses) following KTx were seen in 5% of children at our center. We retrospectively evidenced severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in five of seven children with arterial stenosis. The remaining two patients had received a graft from a deceased adolescent donor with a positive serology at D0. These data led us to suspect immune postviral graft vasculitis, triggered by SARS-CoV-2. Because the diagnosis of COVID-19 is challenging in children, we recommend pretransplant monitoring of graft recipients and their parents by monthly RT-PCR and serology. We suggest balancing the risk of postviral graft vasculitis against the risk of prolonged dialysis when considering transplantation in a child during the pandemic.


Subject(s)
Arteries/pathology , COVID-19/complications , Kidney Transplantation , Kidney/blood supply , Pandemics , Adolescent , Child , Constriction, Pathologic/pathology , Female , Humans , Male , Retrospective Studies
8.
One Health ; 10: 100164, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-733676

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which originated in Wuhan, China, in 2019, is responsible for the COVID-19 pandemic. It is now accepted that the wild fauna, probably bats, constitute the initial reservoir of the virus, but little is known about the role pets can play in the spread of the disease in human communities, knowing the ability of SARS-CoV-2 to infect some domestic animals. In this cross-sectional study, we tested the antibody response in a cluster of 21 domestic pets (9 cats and 12 dogs) living in close contact with their owners (belonging to a veterinary community of 20 students) in which two students tested positive for COVID-19 and several others (n = 11/18) consecutively showed clinical signs (fever, cough, anosmia, etc.) compatible with COVID-19 infection. Although a few pets presented many clinical signs indicative for a coronavirus infection, no antibodies against SARS-CoV-2 were detectable in their blood one month after the index case was reported, using an immunoprecipitation assay. These original data can serve a better evaluation of the host range of SARS-CoV-2 in natural environment exposure conditions.

9.
Emerg Infect Dis ; 26(12): 3069-3071, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-713381

ABSTRACT

In March 2020, a severe respiratory syndrome developed in a cat, 1 week after its owner received positive test results for severe acute respiratory syndrome coronavirus 2. Viral RNA was detected in the cat's nasopharyngeal swab samples and vomitus or feces; immunoglobulin against the virus was found in convalescent-phase serum. Human-to-cat transmission is suspected.


Subject(s)
COVID-19/veterinary , Cats , Animals , Belgium , COVID-19/diagnosis , COVID-19/transmission , Female , Humans , Viral Zoonoses
10.
Lancet Infect Dis ; 20(10): e251-e260, 2020 10.
Article in English | MEDLINE | ID: covidwho-693775

ABSTRACT

The term metagenomics refers to the use of sequencing methods to simultaneously identify genomic material from all organisms present in a sample, with the advantage of greater taxonomic resolution than culture or other methods. Applications include pathogen detection and discovery, species characterisation, antimicrobial resistance detection, virulence profiling, and study of the microbiome and microecological factors affecting health. However, metagenomics involves complex and multistep processes and there are important technical and methodological challenges that require careful consideration to support valid inference. We co-ordinated a multidisciplinary, international expert group to establish reporting guidelines that address specimen processing, nucleic acid extraction, sequencing platforms, bioinformatics considerations, quality assurance, limits of detection, power and sample size, confirmatory testing, causality criteria, cost, and ethical issues. The guidance recognises that metagenomics research requires pragmatism and caution in interpretation, and that this field is rapidly evolving.


Subject(s)
Metagenomics/methods , Metagenomics/statistics & numerical data , Computational Biology , Humans , Molecular Epidemiology , Research Design/standards
SELECTION OF CITATIONS
SEARCH DETAIL