Sylvia M. LaCourse

Dr. Sylvia M. LaCourse

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Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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2 January 2018 in AIDS
Verified
Journal Article
Closed access
SLSylvia M. LaCourse
Sylvia M. LaCourse
PPPatricia B. Pavlinac
Patricia B. Pavlinac
LCLisa M. Cranmer
Lisa M. Cranmer
INIrene N. Njuguna
Irene N. Njuguna
CMCyrus Mugo
Cyrus Mugo
LGLauren Gomez
Lauren Gomez
Background: Tuberculosis (TB) causes substantial morbidity and mortality in HIV-infected children. Sample collection and the paucibacillary nature of TB in children makes diagnosis challenging. Rapid diagnostic tools using easily obtained specimens are urgently needed. Methods: Hospitalized, HIV-infected children aged 12 years or less enrolled in a randomized controlled trial (NCT02063880) comparing urgent to post-stabilization antiretroviral therapy initiation in Kenya underwent TB evaluation. At enrollment, sputum or gastric aspirates were collected for TB culture and Xpert, stool for Xpert, and urine for lipoarabinomannan (LAM). When possible, a second sputum/gastric aspirate for culture was obtained. Stool Xpert and urine LAM performance were compared to reference sputum/gastric aspirate culture. Results: Among 165 HIV-infected children, median age was 24 months [interquartile range (IQR) 13–58], median CD4+% was 14.3 (IQR 8.9–22.0%), and 114 (69.5%) had severe immunosuppression. Thirteen (7.9%) children had confirmed TB (positive culture and/or Xpert). Sputum/gastric aspirate Xpert, stool Xpert, and urine LAM sensitivities were 60% [95% confidence interval (CI) 26–88%], 63% (95% CI 25–92%), and 43% (95% CI 10–82%), respectively. Specificity was 98% (95% CI 94–100%) for sputum/gastric aspirate Xpert, 99% (95% CI 95–100%) for stool Xpert, and 91% (95% CI 84–95%) for urine LAM. Stool Xpert and urine LAM sensitivity increased among children with severe immunosuppression [80% (95% CI 28–100) and 60% (95% Cl 15–95%)]. Conclusion: Stool Xpert had similar performance compared with sputum/gastric aspirate Xpert to detect TB. Urine LAM had lower sensitivity and specificity, but increased among children with severe immunosuppression. Stool Xpert and urine LAM can aid rapid detection of TB in HIV-infected children using easily accessible samples.

15 April 2020 in Clinical Infectious Diseases
Verified
Journal Article
Open access
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SLSylvia M. LaCourse
Sylvia M. LaCourse
GJGrace John-Stewart
Grace John-Stewart
KWKristina Adams Waldorf
Kristina Adams Waldorf
Investigators are employing unprecedented innovation in the design of clinical trials to rapidly and rigorously assess potentially promising therapies for coronavirus disease 2019 (COVID-19); this is in stark contrast to the continued near-universal regressive practice of exclusion of pregnant and breastfeeding women from these trials. The few trials that allow their inclusion focus on postexposure prophylaxis or outpatient treatment of milder disease, limiting the options available to pregnant women with severe COVID-19 to compassionate use of remdesivir, or off-label drug use of hydroxychloroquine or other therapies. These restrictions were put in place despite experience with these drugs in pregnant women. In this Viewpoint, we call attention to the need and urgency to engage pregnant women in COVID-19 treatment trials now in order to develop data-driven recommendations regarding the risks and benefits of therapies in this unique but not uncommon population.

9 April 2025 in Science Translational Medicine
Verified
Journal Article
Closed access
BYBrady M. Youngquist
Brady M. Youngquist
JSJulian Saliba
Julian Saliba
YKYelim Kim
Yelim Kim
TCThomas J. Cutro
Thomas J. Cutro
CLChristopher J. Lyon
Christopher J. Lyon
THTony Hu
Tony Hu
Rapid portable assays are needed to improve diagnosis, treatment, and reduce transmission of tuberculosis (TB), but current tests are not suitable for patients in resource-limited settings with high TB burden. Here we report a low complexity, lab-in-tube system that is read by an integrated handheld device that detects Mycobacterium tuberculosis ( Mtb ) DNA in blood and respiratory samples from a variety of clinical settings. This microprocessor-controlled device uses an LCD user interface to control assay performance, automate assay analysis, and provide results in a simple readout. This point-of-care single-tube assay uses a DNA enrichment membrane and a low-cost cellulose disc containing lyophilized recombinase polymerase amplification and CRISPR-Cas12a reagents to attain single-nucleotide specificity and high sensitivity within 1 hour of sample application, without a conventional DNA isolation procedure. Assay results obtained with serum cell–free DNA isolated from a cohort of children aged 1 to 16 years detected pulmonary and extrapulmonary TB with high sensitivity versus culture and GeneXpert MTB/RIF results (81% versus 55% and 68%) and good specificity (94%), meeting the World Health Organization target product profile criteria for new nonsputum TB diagnostics. Changes in assay results for serum isolated during treatment were also highly predictive of clinical response. Results obtained with noninvasive sputum and saliva specimens from adults with bacteriologically confirmed pulmonary TB were also comparable to those reported for reference methods. This rapid and inexpensive lab-in-tube assay approach thus represents one means to address the need for point-of-care TB diagnostics useable in low-resource settings.

1 February 2016 in JAIDS Journal of Acquired Immune Deficiency Syndromes
Verified
Journal Article
Closed access
SLSylvia M. LaCourse
Sylvia M. LaCourse
LCLisa M. Cranmer
Lisa M. Cranmer
DMDaniel Matemo
Daniel Matemo
JKJohn MBChB Kinuthia
John MBChB Kinuthia
BRBarbra A. Richardson
Barbra A. Richardson
DHDavid J. Horne
David J. Horne
Background: Tuberculosis (TB) during pregnancy in HIV-infected women is associated with poor maternal and infant outcomes. There are limited data on TB prevalence, optimal TB screening, and performance of rapid diagnostics in pregnant HIV-infected women. Methods: We conducted a cross-sectional study among HIV-infected pregnant women seeking antenatal care in western Kenya. After a standardized questionnaire, sputum smear microscopy for acid-fast bacilli, mycobacterial liquid culture, GeneXpert MTB/RIF (Xpert), urine lipoarabinomannan, and tuberculin skin testing were performed. We determined prevalence and correlates of culture-confirmed pulmonary TB, and compared diagnostic performance of World Health Organization (WHO) symptom screening and rapid diagnostic tests to sputum culture. Results: Between July 2013 and July 2014, we enrolled 306 women. Among 288 women with a valid sputum culture result, 54% were on antiretroviral treatment, median CD4 cell count was 437 cell per cubic millimeter (IQR 342–565), and prevalence of culture-confirmed pulmonary TB was 2.4% (confidence interval: 1.0% to 4.9%). Cough >2 weeks (P = 0.04) and positive tuberculin skin testing (≥5 mm, P = 0.03) were associated with pulmonary TB. Women with TB were 23-fold (95% confidence interval: 4.4 to 116.6) more likely to report a household member with TB symptoms (P = 0.002). WHO symptom screen (43%), acid-fast bacilli smear (0%), Xpert (43%), and lipoarabinomannan (0%) had low sensitivity but high specificity (81%, 99%, 99%, and 95%, respectively) for pulmonary TB. Conclusions: HIV-infected pregnant women had appreciable prevalence of pulmonary TB despite modest immunosuppression. Current TB screening and diagnostic tools perform poorly in pregnant HIV-infected women. Adapted TB screening tools that include household member TB symptoms may be useful in this population.

13 January 2022 in PLOS ONE
Verified
Journal Article
Open access
PDF file
SLSylvia M. LaCourse
Sylvia M. LaCourse
ESEvans Seko
Evans Seko
RWRachel Wood
Rachel Wood
WBWilfred Bundi
Wilfred Bundi
GOGregory S. Ouma
Gregory S. Ouma
GCGerard A. Cangelosi
Gerard A. Cangelosi
Objective: We evaluated diagnostic performance of oral swab analysis (OSA) for tuberculosis (TB) in a high HIV/TB burden setting in Kenya. Methods: In this cross-sectional study, buccal swabs and sputum were collected from 100 participants with suspected TB in outpatient clinics in Kenya at enrollment and subsequent morning visits. Buccal swabs underwent IS6110-targeted qPCR analysis. Sputum was evaluated by Xpert MTB/RIF (Xpert) and culture. Diagnostic performance of OSA for TB diagnosis was evaluated relative to a combined reference of sputum Xpert and culture. Results: Among 100 participants, 54% were living with HIV (PLHIV). Twenty percent (20/100) of participants had confirmed TB (19/20 [95%] culture-positive, 17/20 [85%] Xpert-positive). Overall buccal swab sensitivity was 65.0% (95% CI 40.8–84.6%) vs. sputum Xpert/culture and 76.5% (95% CI 50.1–93.2%) vs. sputum Xpert alone. Specificity was 81.3% (95% CI 71.0–89.1%) and 81.9% (95% CI 72.0–89.5%) compared to sputum Xpert/culture and Xpert alone, respectively. Sensitivity among PLHIV (n = 54) with suspected TB was 83.3% (95% CI 35.9–99.6%) vs. sputum Xpert/culture and 100% (95% CI 47.8–100.0%) vs. sputum Xpert alone. Among participants with TB, mean OSA threshold quantitation cycle (Cq) value was lower (stronger signal) at subsequent morning compared to enrolment visit (33.4 SD ± 3.7 vs. 35.2 SD ± 2.9, p = 0.009). Conclusions: In this pilot study, results confirm M. tuberculosis DNA is detectable in oral swabs including among PLHIV with fair diagnostic performance. Further work is needed to optimize OSA and evaluate its utility in diverse settings.

1 May 2017 in JAIDS Journal of Acquired Immune Deficiency Syndromes
Verified
Journal Article
Closed access
SLSylvia M. LaCourse
Sylvia M. LaCourse
LCLisa M. Cranmer
Lisa M. Cranmer
DMDaniel Matemo
Daniel Matemo
JKJohn MBChB Kinuthia
John MBChB Kinuthia
BRBarbra A. Richardson
Barbra A. Richardson
LGLauren Gomez
Lauren Gomez
Background: Peripartum immunologic changes may affect latent tuberculosis infection (LTBI) diagnostic performance among HIV-infected women. Methods: HIV-infected women were serially tested with tuberculin skin test (TST) and interferon gamma release assay [QuantiFERON TB Gold In-tube (QFT)] in pregnancy and 6 weeks postpartum in Kenya. Prevalence, sensitivity and agreement, and correlates of QFT/TST positivity were assessed. Quantitative QFT mitogen and Mycobacterium tuberculosis antigen (Mtb-Ag) responses were compared by peripartum stage. Incidence of test conversion at 6 weeks postpartum was evaluated in baseline TST−/QFT− women. Results: Among 100 HIV-infected women, median age was 26 years, median CD4 was 555 cells per cubic millimeter, and 88% were on antiretrovirals. More women were QFT+ than TST+ in both pregnancy (35.4% vs. 13.5%, P = 0.001) and postpartum (29.6% vs. 14.8%, P < 0.001). Among 18 consistently QFT+ women, 8 (44%) converted from TST− to TST+, with improved test agreement postpartum (56.9%, κ = 0.20 to 82.4%, κ = 0.60). Three initially QFT−/TST− women had test conversion (TST+ and/or QFT+), suggesting new infection (incidence 13.4/100 person-years). Mean QFT mitogen (4.46 vs. 7.64 IU/mL, P < 0.001) and Mtb-Ag (1.03 vs. 1.54 IU/mL, P = 0.03) responses were lower among all women retested in pregnancy vs. postpartum, and specifically among persistently QFT+ women (Mtb-Ag: 3.46 vs. 4.48 IU/mL, P = 0.007). QFT indeterminate rate was higher in pregnancy (16%) compared with postpartum (0%) because of lower mitogen response. Conclusions: QFT identified >2-fold more women with LTBI compared with TST in pregnancy and postpartum. Lower QFT Mtb-Ag and mitogen responses in pregnancy compared with postpartum suggest that pregnancy-associated immunologic changes may influence LTBI test performance.