LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 4 of total 4

Search options

  1. Article: Pooling of six respiratory samples for the detection of SARS-CoV-2: A validation and cost study in a cohort in Lima, Peru.

    Ochoa, Mayra / Peña, Bia / Flores, Omar / Gil, Ana I / Ecker, Lucie / Cornejo, Rubelio / Howard, Leigh M / Grijalva, Carlos G / Lanata, Claudio F

    Heliyon

    2023  Volume 9, Issue 8, Page(s) e18904

    Abstract: Background: The continuous evolution of the SARS-CoV-2 pandemic has led to a high demand for diagnostic testing and major shortages in testing materials, especially in low- and middle-income countries. As an alternative to testing individual samples, ... ...

    Abstract Background: The continuous evolution of the SARS-CoV-2 pandemic has led to a high demand for diagnostic testing and major shortages in testing materials, especially in low- and middle-income countries. As an alternative to testing individual samples, pooling of respiratory samples has been suggested. Previous studies have assessed performance of pooling, mainly using nasopharyngeal samples for the detection of SARS-CoV-2, but few studies have examined the performance of pooling the more practical nasal swabs or saliva samples.
    Objective: To evaluate the sensitivity, specificity, and potential cost reduction of pooling of nasal swab (NS) and saliva (SL) samples for detection of SARS-CoV-2 in a community-based cohort study in Lima, Peru.
    Study design: A prospective cohort study was conducted in a community setting in San Juan de Lurigancho, Lima-Peru. NS and SL samples were collected from 132 participants twice-a-week for a 2-month period. Pools of 2 to 12 samples of the same type, from participants of the same household, were tested by RT-PCR. After pooled testing, all individual samples from positive pools and all individual samples from randomly chosen negative pools were evaluated. For assessment of diagnostic performance, pool testing results were compared with results from individual testing, which served as reference, and concordance in pooled and individual test detections was evaluated. Laboratory costs for both types of samples and testing were compared.
    Results: A total of 2008 NS and 2002 SL samples were collected from 132 study participants. We tested 329 NS and 333 SL pools. The mean pool size for NS and SL pools was 6.22 (SD = 0.92) and 6.39 (SD = 1.71), respectively. Using individual testing as reference, NS pooling of 6 had a sensitivity and specificity of 94% and 100%, respectively, with kappa of 0.97 (CI 95%: 0.93-1.00). The corresponding values for SL pooling of 6 were 83%, 100%, and 0.90 (CI 95%: 0.83-0.97). Compared with individual testing, pooling resulted in a cost reduction of 74.8% for NS and 72.4% for SL samples.
    Conclusions: Pooling easy-to-collect respiratory samples, especially NS, demonstrated very high diagnostic performance for detection of SARS-CoV-2 with substantial cost savings. This approach could be considered in large population screening programs, especially in LMIC.
    Language English
    Publishing date 2023-08-03
    Publishing country England
    Document type Journal Article
    ZDB-ID 2835763-2
    ISSN 2405-8440
    ISSN 2405-8440
    DOI 10.1016/j.heliyon.2023.e18904
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article ; Online: Concordance in RT-PCR detection of SARS-CoV-2 between samples preserved in viral and bacterial transport medium.

    Peña, Bia / Ochoa, Mayra / Flores, Omar / Gil, Ana I / Ecker, Lucie / Cornejo, Rubelio / Lanata, Claudio F / Howard, Leigh M / Grijalva, Carlos G

    Journal of virological methods

    2022  Volume 304, Page(s) 114522

    Abstract: Background: While the detection of SARS-CoV-2 in samples preserved in viral transport medium (VTM) by RT-PCR is a standard diagnostic method, this may preclude the study of bacterial respiratory pathogens from the same specimen. It is unclear if the use ...

    Abstract Background: While the detection of SARS-CoV-2 in samples preserved in viral transport medium (VTM) by RT-PCR is a standard diagnostic method, this may preclude the study of bacterial respiratory pathogens from the same specimen. It is unclear if the use of skim milk, tryptone, glucose, and glycerin (STGG) transport media, used for study of respiratory bacteria, allows an efficient and concurrent study of SARS-CoV-2 infections.
    Objectives: To determine the concordance in SARS-CoV-2 detection by real time RT-PCR between paired nasopharyngeal (NP) swabs preserved in STGG and nasal (NS) swabs preserved in VTM.
    Study design: Paired samples of NP and NS swabs were collected between December 2020 and March 2021 from a prospective longitudinal cohort study of 44 households and 132 participants from a peri-urban community (Lima, Peru). NP and NS swabs were taken from all participants once and twice per week, respectively, independent of respiratory symptoms. STGG medium was used for NP samples and VTM for NS samples. Samples were analyzed for SARS-CoV-2 by RT-PCR for N, S and ORF1ab targets. We calculated the concordance in detections between sample types and compared the RT-PCR cycle thresholds (Ct).
    Results: Among the 148 paired samples, we observed a high concordance in detections between NP and NS samples (agreement = 94.59%; Kappa = 0.79). Median Ct values were statistically similar between sample types for each RT-PCR target: N, S and ORF1ab (p = 0.11, p = 0.71 and p = 0.11, respectively).
    Conclusions: NP swabs collected in STGG medium are reliable alternatives to nasal swabs collected in VTM for the study of SARS-CoV-2.
    MeSH term(s) COVID-19/diagnosis ; Humans ; Longitudinal Studies ; Nasopharynx/microbiology ; Prospective Studies ; Reverse Transcriptase Polymerase Chain Reaction ; SARS-CoV-2/genetics ; Sensitivity and Specificity ; Specimen Handling/methods
    Language English
    Publishing date 2022-03-09
    Publishing country Netherlands
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 8013-5
    ISSN 1879-0984 ; 0166-0934
    ISSN (online) 1879-0984
    ISSN 0166-0934
    DOI 10.1016/j.jviromet.2022.114522
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article: Concordance in RT-PCR detection of SARS-CoV-2 between samples preserved in viral and bacterial transport medium

    Peña, Bia / Ochoa, Mayra / Flores, Omar / Gil, Ana I. / Ecker, Lucie / Cornejo, Rubelio / Lanata, Claudio F. / Howard, Leigh M. / Grijalva, Carlos G.

    Journal of virological methods. 2022 June, v. 304

    2022  

    Abstract: While the detection of SARS-CoV-2 in samples preserved in viral transport medium (VTM) by RT-PCR is a standard diagnostic method, this may preclude the study of bacterial respiratory pathogens from the same specimen. It is unclear if the use of skim milk, ...

    Abstract While the detection of SARS-CoV-2 in samples preserved in viral transport medium (VTM) by RT-PCR is a standard diagnostic method, this may preclude the study of bacterial respiratory pathogens from the same specimen. It is unclear if the use of skim milk, tryptone, glucose, and glycerin (STGG) transport media, used for study of respiratory bacteria, allows an efficient and concurrent study of SARS-CoV-2 infections. To determine the concordance in SARS-CoV-2 detection by real time RT-PCR between paired nasopharyngeal (NP) swabs preserved in STGG and nasal (NS) swabs preserved in VTM. Paired samples of NP and NS swabs were collected between December 2020 and March 2021 from a prospective longitudinal cohort study of 44 households and 132 participants from a peri-urban community (Lima, Peru). NP and NS swabs were taken from all participants once and twice per week, respectively, independent of respiratory symptoms. STGG medium was used for NP samples and VTM for NS samples. Samples were analyzed for SARS-CoV-2 by RT-PCR for N, S and ORF1ab targets. We calculated the concordance in detections between sample types and compared the RT-PCR cycle thresholds (Ct). Among the 148 paired samples, we observed a high concordance in detections between NP and NS samples (agreement = 94.59%; Kappa = 0.79). Median Ct values were statistically similar between sample types for each RT-PCR target: N, S and ORF1ab (p = 0.11, p = 0.71 and p = 0.11, respectively). NP swabs collected in STGG medium are reliable alternatives to nasal swabs collected in VTM for the study of SARS-CoV-2.
    Keywords Severe acute respiratory syndrome coronavirus 2 ; cohort studies ; diagnostic techniques ; glucose ; glycerol ; nose ; skim milk ; tryptones ; Peru
    Language English
    Dates of publication 2022-06
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 8013-5
    ISSN 1879-0984 ; 0166-0934
    ISSN (online) 1879-0984
    ISSN 0166-0934
    DOI 10.1016/j.jviromet.2022.114522
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  4. Article ; Online: SARS-CoV-2 infections in households in a peri-urban community of Lima, Peru: A prospective cohort study.

    Lanata, Claudio F / Gil, Ana I / Ecker, Lucie / Cornejo, Rubelio / Rios, Stefano / Ochoa, Mayra / Peña, Bia / Flores, Omar / Howard, Leigh M / Grijalva, Carlos G

    Influenza and other respiratory viruses

    2021  Volume 16, Issue 3, Page(s) 386–394

    Abstract: Background: We assessed the prevalence and incidence of SARS-CoV-2 infections in a prospective study of households in Lima, Peru.: Methods: Households with a child, a young adult 18-50 years, and an adult age >50 years in peri-urban Lima were ... ...

    Abstract Background: We assessed the prevalence and incidence of SARS-CoV-2 infections in a prospective study of households in Lima, Peru.
    Methods: Households with a child, a young adult 18-50 years, and an adult age >50 years in peri-urban Lima were followed with twice-a-week household visits during a 2-month period. Nasal swabs and saliva specimens were collected twice weekly, and nasopharyngeal swabs were collected weekly from each participant, regardless of symptoms. Laboratory-confirmed SARS-CoV-2 infection was defined by two RT-PCR tests from any of the collected specimens within a week. Blood samples collected at enrollment and end of follow-up were tested with rapid serological tests. We calculated the prevalence and incidence of laboratory-confirmed SARS-CoV-2 infections.
    Results: We enrolled 132 participants from 44 households: 44 children, 44 young adults, and 44 older adults. A total of 13 SARS-CoV-2 infections were detected in eight households, for an overall period prevalence of 9.85% (95% confidence interval [CI]: 5.35-16.25). Most (61.54%) infections were symptomatic. Eight of 11 (72.73%) SARS-CoV-2 detections corresponded to the Lambda variant. During 218.79 person-months at risk of follow-up, there were six new SARS-CoV-2 infections detected (2.74 per 100 person-month, 95% CI: 1.25-6.04). At enrollment, 59 of 128 participants tested had positive SARS-CoV-2 IgG serology (46.09%, 95% CI: 37.25-55.12). Five of six new infections occurred among participants with negative baseline serology.
    Conclusions: We demonstrated high incidence of SARS-CoV-2 infections in households, especially among subjects without evidence of prior infection, most of them not detected by the Ministry of Health system.
    MeSH term(s) Aged ; COVID-19/diagnosis ; COVID-19/epidemiology ; Child ; Humans ; Middle Aged ; Peru/epidemiology ; Prospective Studies ; SARS-CoV-2 ; Young Adult
    Language English
    Publishing date 2021-12-27
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2274538-5
    ISSN 1750-2659 ; 1750-2640
    ISSN (online) 1750-2659
    ISSN 1750-2640
    DOI 10.1111/irv.12952
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top