Publications by authors named "Pamela Chauvin"

Dientamoeba fragilis is a ubiquitous intestinal parasite with detection in the stools that has become increasingly frequent following the advent of PCR as a routine screening tool. However, the pathogenicity of this parasite is still much debated. In order to assess the potentially pathogenic nature of this protozoan, a retrospective case-control study was carried out between January and December 2020 on patients from Toulouse University Hospital, with the aim of evaluating the potential clinical effects and changes in laboratory parameters linked to the presence and load of D.

View Article and Find Full Text PDF

Dermatophytosis is a superficial fungal infection with an ever-increasing number of patients. Culture-based mycology remains the most commonly used diagnosis, but it takes around four weeks to identify the causative agent. Therefore, routine clinical laboratories need rapid, high throughput, and accurate species-specific analytical methods for diagnosis and therapeutic management.

View Article and Find Full Text PDF

Objectives: We aimed to assess the performance of the Novodiag Stool Parasites (NSP) assay in the diagnosis of the most common intestinal protozoan and microsporidia infections.

Methods: A panel of 167 selected stool samples was retrospectively analysed with the NSP assay and compared to routine microscopy and qPCR methods for the detection of pathogenic protozoa and microsporidia.

Results: Whereas specificity was high for all protozoa and microsporidia, NSP sensitivity was strongly dependent on the comparative method used as reference.

View Article and Find Full Text PDF

Invasive mould infections are life-threatening and mainly occur in immunocompromised patients. Whereas aspergillosis is described during haemophagocytic lymphohistiocytosis (HLH), only a few cases of concomitant mucormycosis with HLH have been reported. Here, we present an uncommon coinfection of mucormycosis and aspergillosis associated with HLH probably due to a varicella zoster virus (VZV) viraemia which was unresponsive to triple antifungal therapy (liposomal amphotericin B combined with isavuconazole and caspofungin).

View Article and Find Full Text PDF

While COVID-19-associated pulmonary aspergillosis is now well described in developed countries, COVID-19-associated mucormycosis (CAM) has seemed to remain quite rare in Europe. A retrospective study was performed between March 2020 to September 2021 among COVID-19 adult patients in the intensive care unit (ICU) at Toulouse Hospital (Southern France). PCR screening on respiratory samples, which target or Mucorales DNA, were performed, and the number of fungal detections was evaluated monthly during the study period.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates the immune response of different lymphocyte subpopulations in patients with pneumonia caused by Pneumocystis jirovecii (PCP) compared to uninfected immunosuppressed patients.
  • It finds that low B cell counts are more common in PCP patients and that certain T cell and NK cell populations differ significantly between survivors and those who died from the infection.
  • The research suggests that traditional lymphocyte analyses may not fully capture the prognosis of PCP, highlighting the need for a more comprehensive approach that includes B cells and specific lymphocyte subpopulations.
View Article and Find Full Text PDF
Article Synopsis
  • - A study in Djibouti found that a significant portion of malaria cases (20.9%) were confirmed through quantitative PCR but went undetected by rapid diagnostic tests (RDTs) based on the PfHRP2 antigen.
  • - Among the 79 positive samples, a whopping 86.5% were confirmed to be missing key genes targeted by these RDTs, indicating a potential issue with current diagnostic methods.
  • - Given these findings, the researchers suggest the need for alternative RDTs and a comprehensive surveillance system to prevent misdiagnosis of malaria in Djibouti and similar regions where HRP2-based tests are common.
View Article and Find Full Text PDF

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF MS) is routinely used in mycology laboratories to rapidly identify pathogenic yeasts. Various methods have been proposed to perform routine MS-based identification of clinically relevant species. In this study, we focused on Bruker technology and assessed the identification performance of three protocols: two pretreatment methods (rapid formic acid extraction directly performed on targets and full extraction using formic acid/acetonitrile in tubes) and a direct deposit protocol that omits the extraction step.

View Article and Find Full Text PDF
Article Synopsis
  • The study assessed the effectiveness of two real-time PCR methods for diagnosing schistosomiasis infections by analyzing urine, stool, biopsy, and serum samples from patients before treatment.
  • Results showed that PCR significantly improved sensitivity compared to standard microscopy, with PCR on serum samples achieving high sensitivity (72.7%) and excellent specificity (98.9%).
  • The research concluded that Schistosoma PCRs outperform traditional methods and could enhance diagnosis and treatment monitoring, especially after a year post-treatment.
View Article and Find Full Text PDF

Background: Immunocompromised patients are at high risk for the development of severe toxoplasmosis from tissue cyst reactivation, the most frequently, or from recently acquired acute infections. Knowledge of serologic status is therefore crucial. Screening for toxoplasmosis is sometimes performed while patients are already immunocompromised and have a low or even undetectable IgG titer by routine automated enzyme immunoassays.

View Article and Find Full Text PDF

We assessed the ability to early detect a toxoplasmic seroconversion between 1 immunoblot (LDBIO II®) and 6 automated assays (TGS TA®, Architect®, Vidas II®, Liaison II®, Platelia®, and Elecsys®), comparing the time before anti-Toxoplasma gondii IgG detection during infection in pregnant women. From 2007 to 2015, 620 sera of 269 women were included. The median durations before positive IgG detection with Vidas II®, Liaison II®, Platelia®, and Elecsys® were significantly longer than Architect® with differential times from 11 to 28days (P<0.

View Article and Find Full Text PDF

Objectives: To determine, 6 years after the adoption of intermittent preventive treatment of pregnant women with sulfadoxine/pyrimethamine (IPTp-SP) in Cameroon, (i) the polymorphism and prevalence of Plasmodium falciparum dihydrofolate reductase (pfdhfr) and dihydropteroate synthase (pfdhps) gene mutations associated with sulfadoxine/pyrimethamine resistance and (ii) the consequences of sulfadoxine/pyrimethamine use in the selection of pfdhfr/pfdhps alleles.

Methods: pfdhfr and pfdhps genes from P. falciparum isolates collected in Yaoundé (Cameroon) from pregnant women with symptomatic malaria before taking IPTp-SP [SP- group (control) (n = 51)] or afterwards [SP+ group (n = 49)] were sequenced.

View Article and Find Full Text PDF

In South America, disseminated histoplasmosis due to Histoplasma capsulatum var. capsulatum (H. capsulatum), is a severe and frequent opportunistic infection in AIDS patients.

View Article and Find Full Text PDF
Article Synopsis
  • A new extraction method using Vitek MS mass spectrometry has been tested for quicker identification of Candida species directly from positive blood cultures.
  • This new method achieved a 97% accuracy in identifying single Candida species and significantly sped up diagnosis, but subculturing is still necessary to check for drug resistance and mixed infections.
View Article and Find Full Text PDF