Browsing by Author "Adu‑Sarkodie Yaw"

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    Detection of Salmonella Typhi nucleic acid by RT-PCR and anti-HlyE, -CdtB, -PilL, and -Vi IgM by ELISA at sites in Ghana, Madagascar and Ethiopia
    (BioMed Central, 2022) Panzner Ursula; Mogeni Daniel Ondari; Owusu-Dabo Ellis; Adu‑Sarkodie Yaw; Toy Trevor...et al
    Background: We aimed to assess the prevalence of Salmonella Typhi through DNA and IgM-antibody detection methods as a prelude to extended surveillance activities at sites in Ghana, Madagascar, and Ethiopia. Methods: We performed species-specifc real-time polymerase reaction (RT-PCR) to identify bacterial nucleic acid, and enzyme-linked immunosorbent assay (ELISA) for detecting HlyE/STY1498-, CdtB/STY1886-, pilL/STY4539- and Vi-antigens in blood and biopsy specimens of febrile and non-febrile subjects. We generated antigen-specifc ELISA proxy cut-ofs by change-point analyses, and utilized cumulative sum as detection method coupled with 1000 repeti‑ tive bootstrap analyses. We computed prevalence rates in addition to odds ratios to assess correlations between ELISA outcomes and participant characteristics. Results: Defnitive positive RT-PCR results were obtained from samples of febrile subjects originating from Adama Zuria/Ethiopia (1.9%, 2/104), Wolayita Sodo/Ethiopia (1.0%, 1/100), Diego/Madagascar (1.0%, 1/100), and Kintampo/ Ghana (1.0%, 1/100), and from samples of non-febrile subjects from Wolayita Sodo/Ethiopia (1%, 2/201). While IgM antibodies against all antigens were identifed across all sites, prevalence rates were highest at all Ethiopian sites, albeit in non-febrile populations. Signifcant correlations in febrile subjects aged<15 years versus≥15 years were detected for Vi (Odds Ratio (OR): 8.00, p=0.034) in Adama Zuria/Ethiopia, STY1498 (OR: 3.21, p=0.008), STY1886 (OR: 2.31, p=0.054) and STY4539 (OR: 2.82, p=0.022) in Diego/Madagascar, and STY1498 (OR: 2.45, p=0.034) in Kintampo/Ghana. We found statistical signifcance in non-febrile male versus female subjects for STY1498 (OR: 1.96, p=0.020) in Adama Zuria/Ethiopia, Vi (OR: 2.84, p=0.048) in Diego/Madagascar, and STY4539 (OR: 0.46, p=0.009) in Kintampo/Ghana. Conclusions: Findings indicate non-discriminatory stages of acute infections, though with site-specifc diferences. Immune responses among non-febrile, presumably healthy participants may mask recall and/or reporting bias leading to misclassifcation, or asymptomatic, subclinical infection signs induced by suppression of infammatory