Publications by authors named "Sarah E Gwyn"
Article Synopsis
- - Baseline mapping revealed trachoma as a significant public health issue in Kiribati, prompting the government to implement two rounds of mass drug administration (MDA) of antibiotics.
- - An impact survey conducted in 2019 on Kiritimati Island and Tarawa found that while there was a 40% decrease in trachomatous inflammation (TF) in children aged 1-9 years, prevalence still surpassed the threshold required to stop MDA.
- - Despite some reductions in infection indicators, trachomatous trichiasis rates remained constant and above elimination targets, indicating that trachoma continues to be a public health challenge in Kiribati even after intervention efforts.
Article Synopsis
- The study aimed to assess the effectiveness of different SARS-CoV-2 IgG assays in Nigeria, where malaria is common, to get a better estimate of COVID-19 prevalence.
- Researchers tested four assays on plasma samples from COVID-19 positive and pre-pandemic individuals, finding that multi-antigen assays had higher sensitivity compared to a single-antigen assay.
- The findings suggest that multi-antigen tests can accurately measure COVID-19 seroprevalence in regions affected by malaria, potentially improving understanding of vaccine effectiveness.
Background: Chlamydia trachomatis causes pelvic inflammatory disease (PID) and tubal infertility. Plasmid gene protein 3 antibody (Pgp3Ab) detects prior chlamydial infections. We evaluated for an association of high chlamydial seropositivity with sequelae using a Pgp3Ab multiplex bead array (Pgp3AbMBA).
View Article and Find Full Text PDFRobust surveillance methods are needed for trachoma control and recrudescence monitoring, but existing methods have limitations. Here, we analyse data from nine trachoma-endemic populations and provide operational thresholds for interpretation of serological data in low-transmission and post-elimination settings. Analyses with sero-catalytic and antibody acquisition models provide insights into transmission history within each population.
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- * A study in four villages in Nepal observed significant changes in seroprevalence of antibodies to the trachoma-causing bacteria before and after mass drug administration (MDA).
- * After MDA, the rates of trachomatous inflammation-follicular (TF) in children decreased from 17.6% to 0%, and antibody responses in the entire population dropped from 82.1% to 35.8%, indicating that antibody levels could be effective indicators for future surveillance.
Background: The WHO seeks to control trachoma as a public health problem in endemic areas. Achham District in western Nepal was found to have TF (trachoma follicular) above 20% in a 2006 government survey, triggering 3 annual mass drug administrations finishing in 2010. Here we assess the level of control that has been achieved using surveillance for clinical disease, ocular chlamydia trachomatis infection, and serology for antibodies against chlamydia trachomatis protein antigens.
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- The study examines how HIV and SIV can use the CCR5 coreceptor independently of CD4, specifically in cases where CD4 levels are low or absent, leading to greater macrophage infection risk and increased neutralization sensitivity.
- It finds that CD4-independent SIV variants, emerging from a CD4+ T cell-depleted rhesus macaque model, show less flexibility in using coreceptors and require higher CCR5 levels for infection compared to CD4-dependent variants.
- The findings indicate that while being CD4-independent allows the virus to infect certain cells, it may limit its overall ability to target a wider range of cells that express low CCR5 levels or utilize alternative coreceptors like GPR15 and CXCR6 effectively.
CD4(+) T cells rather than macrophages are the principal cells infected by human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV) in vivo. Macrophage tropism has been linked to the ability to enter cells through CCR5 in conjunction with limiting CD4 levels, which are much lower on macrophages than on T cells. We recently reported that rhesus macaques (RM) experimentally depleted of CD4(+) T cells before SIV infection exhibit extensive macrophage infection as well as high chronic viral loads and rapid progression to AIDS.
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