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1.
Clin Med Insights Circ Respir Pulm Med ; 17: 11795484231156755, 2023.
Article in English | MEDLINE | ID: covidwho-2287907

ABSTRACT

BACKGROUND: COVID-19 placed a significant burden on the global healthcare system. Strain in critical care capacity has been associated with increased COVID-19-related ICU mortality. This study evaluates the impact of an early warning system and response team implemented on medical floors to safely triage and care for critically ill patients on the floor and preserve ICU capacity. METHODS: We conducted a multicenter, retrospective cohort study, comparing outcomes between intervention and control hospitals within a US eight-hospital urban network. Patients hospitalized with COVID-19 pneumonia between April 13th, 2020 and June 19th, 2020 were included in the study, which was a time of a regional surge of COVID-19 admissions. An automated, electronic early warning protocol to identify patients with moderate-severe hypoxemia on the medical floors and implement early interventions was implemented at one of the eight hospitals ("the intervention hospital"). RESULTS: Among 1024 patients, 403 (39%) were admitted to the intervention hospital and 621 (61%) were admitted to one of the control hospitals. Adjusted for potential confounders, patients at the intervention hospital were less likely to be admitted to the ICU (HR = 0.73, 95% CI 0.53, 1.000, P = .0499) compared to the control hospitals. Patients admitted from the floors to the ICU at the intervention hospital had shorter ICU stay (HR for ICU discharge: 1.74; 95% CI 1.21, 2.51, P = .003). There was no significant difference between intervention and control hospitals in need for mechanical ventilation (OR = 0.93; 95% CI 0.38, 2.31; P = .88) or hospital mortality (OR = 0.79; 95% CI 0.52, 1.18; P = .25). CONCLUSION: A protocol to conserve ICU beds by implementing an early warning system with a dedicated response team to manage respiratory distress on the floors reduced ICU admission and was not associated with worse outcomes compared to hospitals that managed similar levels of respiratory distress in the ICU.

2.
Nature ; 612(7941): 758-763, 2022 12.
Article in English | MEDLINE | ID: covidwho-2160240

ABSTRACT

Coronavirus disease 2019 (COVID-19) is known to cause multi-organ dysfunction1-3 during acute infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with some patients experiencing prolonged symptoms, termed post-acute sequelae of SARS-CoV-2 (refs. 4,5). However, the burden of infection outside the respiratory tract and time to viral clearance are not well characterized, particularly in the brain3,6-14. Here we carried out complete autopsies on 44 patients who died with COVID-19, with extensive sampling of the central nervous system in 11 of these patients, to map and quantify the distribution, replication and cell-type specificity of SARS-CoV-2 across the human body, including the brain, from acute infection to more than seven months following symptom onset. We show that SARS-CoV-2 is widely distributed, predominantly among patients who died with severe COVID-19, and that virus replication is present in multiple respiratory and non-respiratory tissues, including the brain, early in infection. Further, we detected persistent SARS-CoV-2 RNA in multiple anatomic sites, including throughout the brain, as late as 230 days following symptom onset in one case. Despite extensive distribution of SARS-CoV-2 RNA throughout the body, we observed little evidence of inflammation or direct viral cytopathology outside the respiratory tract. Our data indicate that in some patients SARS-CoV-2 can cause systemic infection and persist in the body for months.


Subject(s)
Autopsy , Brain , COVID-19 , Organ Specificity , SARS-CoV-2 , Humans , Brain/virology , COVID-19/virology , RNA, Viral/analysis , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , SARS-CoV-2/pathogenicity , SARS-CoV-2/physiology , Virus Replication , Time Factors , Respiratory System/pathology , Respiratory System/virology
3.
Ann Intern Med ; 174(9): 1240-1251, 2021 09.
Article in English | MEDLINE | ID: covidwho-1789654

ABSTRACT

BACKGROUND: Several U.S. hospitals had surges in COVID-19 caseload, but their effect on COVID-19 survival rates remains unclear, especially independent of temporal changes in survival. OBJECTIVE: To determine the association between hospitals' severity-weighted COVID-19 caseload and COVID-19 mortality risk and identify effect modifiers of this relationship. DESIGN: Retrospective cohort study. (ClinicalTrials.gov: NCT04688372). SETTING: 558 U.S. hospitals in the Premier Healthcare Database. PARTICIPANTS: Adult COVID-19-coded inpatients admitted from March to August 2020 with discharge dispositions by October 2020. MEASUREMENTS: Each hospital-month was stratified by percentile rank on a surge index (a severity-weighted measure of COVID-19 caseload relative to pre-COVID-19 bed capacity). The effect of surge index on risk-adjusted odds ratio (aOR) of in-hospital mortality or discharge to hospice was calculated using hierarchical modeling; interaction by surge attributes was assessed. RESULTS: Of 144 116 inpatients with COVID-19 at 558 U.S. hospitals, 78 144 (54.2%) were admitted to hospitals in the top surge index decile. Overall, 25 344 (17.6%) died; crude COVID-19 mortality decreased over time across all surge index strata. However, compared with nonsurging (<50th surge index percentile) hospital-months, aORs in the 50th to 75th, 75th to 90th, 90th to 95th, 95th to 99th, and greater than 99th percentiles were 1.11 (95% CI, 1.01 to 1.23), 1.24 (CI, 1.12 to 1.38), 1.42 (CI, 1.27 to 1.60), 1.59 (CI, 1.41 to 1.80), and 2.00 (CI, 1.69 to 2.38), respectively. The surge index was associated with mortality across ward, intensive care unit, and intubated patients. The surge-mortality relationship was stronger in June to August than in March to May (slope difference, 0.10 [CI, 0.033 to 0.16]) despite greater corticosteroid use and more judicious intubation during later and higher-surging months. Nearly 1 in 4 COVID-19 deaths (5868 [CI, 3584 to 8171]; 23.2%) was potentially attributable to hospitals strained by surging caseload. LIMITATION: Residual confounding. CONCLUSION: Despite improvements in COVID-19 survival between March and August 2020, surges in hospital COVID-19 caseload remained detrimental to survival and potentially eroded benefits gained from emerging treatments. Bolstering preventive measures and supporting surging hospitals will save many lives. PRIMARY FUNDING SOURCE: Intramural Research Program of the National Institutes of Health Clinical Center, the National Institute of Allergy and Infectious Diseases, and the National Cancer Institute.


Subject(s)
COVID-19/mortality , Hospitalization/statistics & numerical data , Adrenal Cortex Hormones/therapeutic use , Adult , COVID-19/therapy , Critical Care/statistics & numerical data , Female , Hospital Bed Capacity/statistics & numerical data , Hospital Mortality , Humans , Male , Odds Ratio , Respiration, Artificial , Retrospective Studies , Risk Assessment , Risk Factors , SARS-CoV-2 , Survival Rate , United States/epidemiology
4.
Rev Med Virol ; 32(5): e2352, 2022 09.
Article in English | MEDLINE | ID: covidwho-1782691

ABSTRACT

BACKGROUND: Determining how prior immune checkpoint inhibitor (ICI) therapy influences outcomes in cancer patients presenting with COVID-19 is essential for patient management but must account for confounding variables. METHODS: We performed a systematic review and meta-analysis of studies reporting adjusted effects of ICIs on survival, severe events, or hospitalisation in cancer patients with COVID-19 based on variables including age, gender, diabetes mellitus, hypertension (HTN), chronic obstructive pulmonary disease, and other comorbidities. When adjusted effects were unavailable, unadjusted data were analysed. RESULTS: Of 42 observational studies (38 retrospective), 7 reported adjusted outcomes for ICIs and 2 provided sufficient individual patient data to calculate adjusted outcomes. In eight studies, adjusted outcomes were based on ≤7 variables. Over all studies, only one included >100 ICI patients while 26 included <10. ICIs did not alter the odds ratio (95%CI) (OR) of death significantly (random effects model), across adjusted (n = 8) [1.31 (0.58-2.95) p = 0.46; I2  = 42%, p = 0.10], unadjusted (n = 30) [1.06 (0.85-1.32) p = 0.58; I2  = 0%, p = 0.76] or combined [1.09 (0.88;1.36) p = 0.41; I2  = 0%, p = 0.5)] studies. Similarly, ICIs did not alter severe events significantly across adjusted (n = 5) [1.20 (0.30-4.74) p = 0.73; I2  = 52%, p = 0.08], unadjusted (n = 19) [(1.23 (0.87-1.75) p = 0.23; I2  = 16%, p = 0.26] or combined [1.26 (0.90-1.77) p = 0.16; I2  = 25%, p = 0.14] studies. Two studies provided adjusted hospitalisation data and when combined with 13 unadjusted studies, ICIs did not alter hospitalisation significantly [1.19 (0.85-1.68) p = 029; I2  = 5%, p = 0.40]. Results of sensitivity analyses examining ICI effects based on 5 variables were inconclusive. Certainty of evidence was very low. CONCLUSIONS: Across studies with adjusted and unadjusted results, ICIs did not alter outcomes significantly. But studies with comprehensive adjusted outcome data controlling for confounding variables are necessary to determine whether ICIs impact COVID-19 outcomes in cancer patients.


Subject(s)
COVID-19 Drug Treatment , Neoplasms , Humans , Immune Checkpoint Inhibitors/therapeutic use , Neoplasms/complications , Neoplasms/drug therapy , Retrospective Studies
6.
Clin Infect Dis ; 74(8): 1489-1492, 2022 04 28.
Article in English | MEDLINE | ID: covidwho-1704507

ABSTRACT

In a retrospective cohort study, among 131 773 patients with previous coronavirus disease 2019 (COVID-19), reinfection with severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) was suspected in 253 patients (0.2%) at 238 US healthcare facilities between 1 June 2020 and 28 February 2021. Women displayed a higher cumulative reinfection risk. Healthcare burden and illness severity were similar between index and reinfection encounters.


Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/epidemiology , Delivery of Health Care , Female , Humans , Incidence , Reinfection , Retrospective Studies
7.
MMWR Morb Mortal Wkly Rep ; 71(1): 19-25, 2022 Jan 07.
Article in English | MEDLINE | ID: covidwho-1608771

ABSTRACT

Vaccination against SARS-CoV-2, the virus that causes COVID-19, is highly effective at preventing COVID-19-associated hospitalization and death; however, some vaccinated persons might develop COVID-19 with severe outcomes† (1,2). Using data from 465 facilities in a large U.S. health care database, this study assessed the frequency of and risk factors for developing a severe COVID-19 outcome after completing a primary COVID-19 vaccination series (primary vaccination), defined as receipt of 2 doses of an mRNA vaccine (BNT162b2 [Pfizer-BioNTech] or mRNA-1273 [Moderna]) or a single dose of JNJ-78436735 [Janssen (Johnson & Johnson)] ≥14 days before illness onset. Severe COVID-19 outcomes were defined as hospitalization with a diagnosis of acute respiratory failure, need for noninvasive ventilation (NIV), admission to an intensive care unit (ICU) including all persons requiring invasive mechanical ventilation, or death (including discharge to hospice). Among 1,228,664 persons who completed primary vaccination during December 2020-October 2021, a total of 2,246 (18.0 per 10,000 vaccinated persons) developed COVID-19 and 189 (1.5 per 10,000) had a severe outcome, including 36 who died (0.3 deaths per 10,000). Risk for severe outcomes was higher among persons who were aged ≥65 years, were immunosuppressed, or had at least one of six other underlying conditions. All persons with severe outcomes had at least one of these risk factors, and 77.8% of those who died had four or more risk factors. Severe COVID-19 outcomes after primary vaccination are rare; however, vaccinated persons who are aged ≥65 years, are immunosuppressed, or have other underlying conditions might be at increased risk. These persons should receive targeted interventions including chronic disease management, precautions to reduce exposure, additional primary and booster vaccine doses, and effective pharmaceutical therapy as indicated to reduce risk for severe COVID-19 outcomes. Increasing COVID-19 vaccination coverage is a public health priority.


Subject(s)
COVID-19 Vaccines/administration & dosage , COVID-19/complications , COVID-19/prevention & control , Hospitalization/statistics & numerical data , Vaccination/statistics & numerical data , Adult , Aged , Critical Care/statistics & numerical data , Databases, Factual , Death , Female , Humans , Male , Middle Aged , Respiration, Artificial , Respiratory Insufficiency/complications , Risk Factors , SARS-CoV-2/immunology , United States/epidemiology , Young Adult
8.
J Heart Lung Transplant ; 41(4): 458-466, 2022 04.
Article in English | MEDLINE | ID: covidwho-1587721

ABSTRACT

BACKGROUND: As a marker of underlying lung allograft injury, donor-derived cell-free DNA (dd-cfDNA) may be used to identify episodes of acute allograft injury in lung transplant recipients. We investigated the utility of dd-cfDNA to monitor subjects at risk of acute rejection or infection in routine clinical practice. METHODS: This multicenter, retrospective cohort study collected data from lung transplant recipients within 3 years of transplant at 4 centers between March 24, 2020 and September 1, 2020. During this period, as part of routine care during the COVID-19 pandemic, these centers implemented a home-based surveillance program using plasma dd-cfDNA in preference to surveillance bronchoscopy. Dd-cfDNA was used to detect acute lung allograft dysfunction (ALAD) - a composite endpoint of acute rejection and infection. dd-cfDNA levels in patients with ALAD were compared to stable patients. The performance characteristics of dd-cfDNA ≥ 1.0% to detect ALAD were estimated. RESULTS: A total of 175 patients underwent 380 dd-cfDNA measurements, of which 290 were for routine surveillance purposes. dd-cfDNA was higher in patients with ALAD than stable patients (Median (IQR) 1.7% (0.63, 3.1) vs 0.35% (0.22, 0.79), p < 0.001). As an indication of underlying ALAD during surveillance testing, the estimated sensitivity of dd-cfDNA ≥1% was 73.9%, specificity of 87.7%, positive predictive value of 43.4% and negative predictive value of 96.5%. CONCLUSIONS: dd-cfDNA identified acute lung allograft dysfunction in asymptomatic lung transplant patients that may not have been identified by using a clinically indicated biopsy strategy alone. dd-cfDNA <1.0% may be useful in ruling out acute rejection and infection, supporting its use as a potential noninvasive marker for surveillance monitoring.


Subject(s)
COVID-19 , Cell-Free Nucleic Acids , Kidney Transplantation , Allografts , Graft Rejection/genetics , Humans , Lung , Pandemics , Retrospective Studies
9.
Poult Sci ; 99(11): 5440-5451, 2020 Nov.
Article in English | MEDLINE | ID: covidwho-916884

ABSTRACT

Four GI-1/Massachusetts-type (GI-1/Mass-type) infectious bronchitis virus (IBV) strains were isolated and the complete genomes of these isolates, coupled with the Mass-type live-attenuated vaccine H120 and the Mass-type pathogenic M41 strains, were sequenced in the present study. Our results show that isolates LJL/140820 and I0306/17 may be derived from the Ma5 (another Mass-type live-attenuated vaccine strain) and H120 vaccine strains, respectively. The I1124/16 strain was found to be a M41 variant that likely resulted from nucleotide accumulated mutations in the genome. Consistently, the results of the virus neutralization test showed that isolate I1124/16 was antigenically related but slight different from the M41. Our results from the protection experiments pointed out that chickens immunized with H120 failed to eliminate viral shedding after infection with the isolate I1124/16, which was different from that of M41; this result was consistent to the field observation and further implicated that the variant IBV isolate I1124/16 was antigenic different from the M41 strain. Furthermore, the I1124/16 was found to have comparable but slightly lower pathogenicity with the M41 strain. More studies based on the reverse genetic techniques are needed to elucidate the amino acids in the S1 subunit of spike protein contributing to the altered antigenicity of the isolate I1124/16. In addition, an IBV isolate, LJL/130609, was found to be originated from recombination events between the I1124/16- and Connecticut-like strains. Our results from the virus neutralization test also showed that isolates LJL/130609 and I1124/16 were antigenic closely related. Hence, there are at least 3 different genetic evolution patterns for the circulation of the GI-1/Mass-type IBV field strains in China. The differences of vaccines used, the field conditions and genetic pressures between different flocks, likely account for the emergence, evolution patterns, and characteristics of the Mass-type IBV strains.


Subject(s)
Antigens, Viral , Coronavirus Infections , Genetic Heterogeneity , Infectious bronchitis virus , Poultry Diseases , Animals , Antigens, Viral/genetics , Chickens , China , Coronavirus Infections/veterinary , Coronavirus Infections/virology , Infectious bronchitis virus/genetics , Poultry Diseases/virology
10.
Rev Med Virol ; 31(6): e2228, 2021 11.
Article in English | MEDLINE | ID: covidwho-1126517

ABSTRACT

Chloroquine (CQ) and hydroxychloroquine (HCQ) have been used as antiviral agents for the treatment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection. We performed a systematic review to examine whether prior clinical studies that compared the effects of CQ and HCQ to a control for the treatment of non-SARS-CoV2 infection supported the use of these agents in the present SARS-CoV2 outbreak. PubMed, EMBASE, Scopus and Web of Science (PROSPERO CRD42020183429) were searched from inception through 2 April 2020 without language restrictions. Of 1766 retrieved reports, 18 studies met our inclusion criteria, including 17 prospective controlled studies and one retrospective study. CQ or HCQ were compared to control for the treatment of infectious mononucleosis (EBV, n = 4), warts (human papillomavirus, n = 2), chronic HIV infection (n = 6), acute chikungunya infection (n = 1), acute dengue virus infection (n = 2), chronic HCV (n = 2), and as preventive measures for influenza infection (n = 1). Survival was not evaluated in any study. For HIV, the virus that was most investigated, while two early studies suggested HCQ reduced viral levels, four subsequent ones did not, and in two of these CQ or HCQ increased viral levels and reduced CD4 counts. Overall, three studies concluded CQ or HCQ were effective; four concluded further research was needed to assess the treatments' effectiveness; and 11 concluded that treatment was ineffective or potentially harmful. Prior controlled clinical trials with CQ and HCQ for non-SARS-CoV2 viral infections do not support these agents' use for the SARS-CoV2 outbreak.


Subject(s)
Chikungunya Fever/drug therapy , Chloroquine/therapeutic use , HIV Infections/drug therapy , Hepatitis C, Chronic/drug therapy , Hydroxychloroquine/therapeutic use , Infectious Mononucleosis/drug therapy , Severe Dengue/drug therapy , Warts/drug therapy , Alphapapillomavirus/drug effects , Alphapapillomavirus/immunology , Alphapapillomavirus/pathogenicity , Antiviral Agents/therapeutic use , COVID-19/virology , Chikungunya Fever/immunology , Chikungunya Fever/pathology , Chikungunya Fever/virology , Chikungunya virus/drug effects , Chikungunya virus/immunology , Chikungunya virus/pathogenicity , Dengue Virus/drug effects , Dengue Virus/immunology , Dengue Virus/pathogenicity , HIV/drug effects , HIV/immunology , HIV/pathogenicity , HIV Infections/immunology , HIV Infections/pathology , HIV Infections/virology , Hepacivirus/drug effects , Hepacivirus/immunology , Hepacivirus/pathogenicity , Hepatitis C, Chronic/immunology , Hepatitis C, Chronic/pathology , Hepatitis C, Chronic/virology , Herpesvirus 4, Human/drug effects , Herpesvirus 4, Human/immunology , Herpesvirus 4, Human/pathogenicity , Humans , Infectious Mononucleosis/immunology , Infectious Mononucleosis/pathology , Infectious Mononucleosis/virology , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Severe Dengue/immunology , Severe Dengue/pathology , Severe Dengue/virology , Treatment Outcome , Warts/immunology , Warts/pathology , Warts/virology , COVID-19 Drug Treatment
11.
Open Forum Infect Dis ; 8(2): ofaa616, 2021 Feb.
Article in English | MEDLINE | ID: covidwho-1069291

ABSTRACT

We report off-label use patterns for medications repurposed for coronavirus disease 2019 (COVID-19) at 318 US hospitals. Inpatient hydroxychloroquine use declined by 80%, whereas corticosteroids and tocilizumab were initiated 2 days earlier in May versus March 2020. Two thirds of ventilated COVID-19 patients were already receiving corticosteroids during March-May 2020, resembling pre-COVID use in mechanically ventilated influenza patients.

12.
Avian Dis ; 64(2): 183-196, 2020 06.
Article in English | MEDLINE | ID: covidwho-892407

ABSTRACT

Nine infectious bronchitis virus (IBV) strains belonging to the GI-7 lineage were isolated between 2009 and 2017 in China. Phylogenetic analysis and comparisons of full-length sequences of the S1 gene suggested that the GI-7 lineage should be further classified as Taiwan (TW)-I and TW-II sublineages, which correspond to the previous TW-I and TW-II genotypes. The nine IBV strains were clustered in the TW-II sublineage. Further investigation revealed that viruses in the TW-I and TW-II were not only genetically but also antigenically different. Moreover, the TW-II sublineage contained various clades and recombinants. A recombinant was found to originate from recombination events between field strains (TW-II ck/CH/LJL/090608- and GI-19 ck/ CH/LDL/091022-like viruses) in which the recombination in the S1 subunit coding sequences had led to changes in antigenicity of the viruses. A more in-depth investigation demonstrated that TW-II viruses appear to have undergone a significant evolution following introduction in mainland China, which resulted in the viruses diverging into different clades. The viruses between the different clades in TW-II sublineage exhibited a significant change in genetic and antigenic characteristics. In addition, the five TW-II viruses selected on the basis of the results of S1 nucleotide sequence phylogenetic trees showed different pathogenicity to specific-pathogen-free chickens, although they could induce nephritis in the infected chickens and thus were identified as nephropathogenic strains.


Características genéticas, antigénicas y patógenas del virus de la bronquitis infecciosa GI-7/TW-II en China. Nueve cepas del virus de la bronquitis infecciosa (IBV) que pertenecen al linaje GI-7 se aislaron entre 2009 y 2017 en China. El análisis filogenético y las comparaciones de las secuencias completas del gene S1 sugirieron que el linaje GI-7 debería ser clasificado además como sublinajes TW-I y TW-II, que corresponden a los anteriores genotipos TW-T y TW-II. Las nueve cepas del virus de la bronquitis infecciosa se agruparon en el sublinaje TW-II. La investigación adicional reveló que los virus en TW-I y TW-II no solo eran tanto genéticamente como antigénicamente diferentes. Además, el sublinaje TW-II contenía varios clados y recombinantes. Se descubrió que un recombinante se originaba a partir de eventos de recombinación entre cepas de campo (virus similares a las cepas TW-II ck/CH/LJL/090608 y GI-19 ck/CH/LDL/091022) en los que la recombinación en las secuencias de codificación de la subunidad de S1 condujo a cambios en la antigenicidad de los virus. Una investigación más profunda demostró que los virus TW-II parecen haber experimentado una evolución significativa después de su introducción en China continental, lo que resultó en la divergencia de los virus en diferentes clados. Los virus entre los diferentes clados en el sublinaje TW-II exhibieron un cambio significativo en las características genéticas y antigénicas. Además, los cinco virus TW-II seleccionados con base en los resultados de los árboles filogenéticos de las secuencias de nucleótidos de S1 mostraron patogenicidad diferente en los pollos libres de patógenos específicos, aunque pudieron inducir nefritis en los pollos infectados y, por lo tanto, se identificaron como cepas nefropatógenas.


Subject(s)
Chickens , Coronavirus Infections/veterinary , Infectious bronchitis virus , Poultry Diseases/virology , Spike Glycoprotein, Coronavirus/genetics , Amino Acid Sequence , Animals , Antigens, Viral/genetics , Antigens, Viral/metabolism , China , Coronavirus Infections/virology , Infectious bronchitis virus/genetics , Infectious bronchitis virus/immunology , Infectious bronchitis virus/pathogenicity , Phylogeny , Sequence Alignment , Specific Pathogen-Free Organisms , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism
13.
Poult Sci ; 99(4): 1928-1938, 2020 Apr.
Article in English | MEDLINE | ID: covidwho-830463

ABSTRACT

In this study, we isolated and identified 2 infectious bronchitis virus (IBV) strains from layer chickens soon after vaccination with the Massachusetts-Connecticut bivalent vaccine (Conn) and H120 and 4/91 booster vaccines in China in 2011. The results of cross-virus-neutralization tests and phylogenetic analysis of the S1 subunit of spike gene of these vaccine strains and other reference strains showed that strain LJL/110302 was of GI-19 lineage, whereas LLN/111169 was of the GI-1 lineage of the Conn serotype. Further comparative genomic analysis revealed that LLN/111169, an IBV strain with novel traits, originated from multiple recombination events (at least 3 recombination sites) between GI-19 and the Conn and 4/91 vaccine strains. LLN/111169 was pathogenic to specific pathogen-free (SPF) chickens. This is of prime importance because while IBV prevention measures worldwide are mainly dependent on modified live vaccine strains, our results showed that recombination between field and vaccine strains has produced a novel pathogenic IBV strain. In addition, LLN/111169 showed relatively broad tissue tropism (trachea, lungs, kidneys, and cecal tonsils) in infected SPF chickens. These results emphasize the importance of IBV surveillance in chicken flocks.


Subject(s)
Chickens , Coronavirus Infections/veterinary , Infectious bronchitis virus/physiology , Infectious bronchitis virus/pathogenicity , Poultry Diseases/virology , Virus Replication , Animals , Antigens, Viral/analysis , China , Coronavirus Infections/virology , Infectious bronchitis virus/genetics , Recombination, Genetic , Retrospective Studies , Serogroup , Specific Pathogen-Free Organisms , Vaccines, Attenuated/analysis , Viral Vaccines/analysis , Virulence
14.
Virus Res ; 285: 198002, 2020 08.
Article in English | MEDLINE | ID: covidwho-165136

ABSTRACT

In the present study, an IBV strain I0305/19 was isolated from a diseased commercial broiler flock in 2019 in China with high morbidity and mortality. The isolate I0305/19 was clustered together with viruses in sublineage D of GI-19 lineage on the basis of the complete S1 sequence analysis. Isolate I0305/19 and other GI-19 viruses isolated in China have the amino acid sequence MIA at positions 110-112 in the S protein. Further analysis based on the complete genomic sequence showed that the isolate emerged through at least four recombination events between GI-19 ck/CH/LJS/120848- and GI-13 4/91-like strains, in which the S gene was found to be similar to that of the GI-19 ck/CH/LJS/120848-like strain. Pathological assessment showed the isolate was a nephropathogenic IBV strain that caused high morbidity of 100 % and mortality of 80 % in 1-day-old specific-pathogen-free (SPF) chicks. The isolate I0305/19 exhibited broader tropisms in different tissues, including tracheas, lungs, bursa of Fabricius, spleen, liver, kidneys, proventriculus, small intestines, large intestines, cecum, and cecal tonsils. Furthermore, subpopulations of the virus were found in tissues of infected chickens; this finding is important in understanding how the virulent IBV strains can potentially replicate and evolve to cause disease. This information is also valuable for understanding the mechanisms of replication and evolution of other coronaviruses such as the newly emerged SARS-CoV-2.


Subject(s)
Chickens/virology , Coronavirus Infections/veterinary , Infectious bronchitis virus/genetics , Infectious bronchitis virus/pathogenicity , Poultry Diseases/virology , Recombination, Genetic , Viral Tropism , Animals , China , Coronavirus Infections/virology , Genome, Viral , Infectious bronchitis virus/classification , Infectious bronchitis virus/physiology , Phylogeny , Specific Pathogen-Free Organisms , Spike Glycoprotein, Coronavirus/genetics , Virus Replication
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