E Dopico1,2, Y Rando-Matos3,4, L Solsona3,4, J Almeda4,5,6, F L N Santos7, T Vinuesa2,8. 1. Laboratori Clínic Territorial Metropolitana Sud, Catalan Institute of Health, Hospitalet de Llobregat, Spain. 2. Institut d'Investigació Biomèdica de Bellvitge, Hospitalet de Llobregat, Spain. 3. Primary Care Center Florida Nord, Catalan Institute of Health, Hospitalet de Llobregat, Spain. 4. Fundació Institut Universitari per a la Recerca a l'Atenció Primària de Salut Jordi Gol i Gurina, Barcelona, Spain. 5. Costa de Ponent Research Support Unit, South Metropolitan Primary Care Area Management, Catalan Institute of Health, Cornellà de Llobregat, Spain. 6. Autonoma University of Barcelona, Bellaterra, Cerdanyola del Vallès, Spain. 7. Advanced Public Health Laboratory, Gonçalo Moniz Institute, Oswaldo Cruz Foundation, Salvador, Brazil. 8. Department of Pathology and Experimental Therapeutics, University of Barcelona, Spain.
Abstract
OBJECTIVES: To evaluate co-infection of Strongyloides stercoralis and Trypanosoma cruzi and to assess eosinophilia as a screening test for the detection of S. stercoralis infection in patients with Chagas disease (CD). METHODS: A retrospective diagnostic validation study was performed on serum samples from primary care patients diagnosed with CD in the southern Barcelona metropolitan area. All samples with eosinophilia (n = 87) and a random sample of non-eosinophilic sera (n = 180) were selected. Diagnosis of CD was based on positive serology by means of two tests: ORTHO® T. cruzi ELISA test, and BIO-FLASH® Chagas or Bioelisa CHAGAS. SCIMEDX ELISA STRONGY-96 was used to diagnose strongyloidiasis. RESULTS: Strongyloides stercoralis serology was positive in 15% of patients of whom 95% showed eosinophilia, vs. 21% of those with negative serology (P < 0.001), with differences in the mean eosinophil count (0.49 vs. 0.27 × 109 /l). Only 1.1% of patients with CD but without eosinophilia presented positive serology for S. stercoralis, whereas 44% of patients with CD and eosinophilia did (P < 0.001). Sensitivity and specificity values for eosinophilia were thus 95% and 79%, respectively. PPV was 42.5% and NPV, 98.9%. CONCLUSIONS: The prevalence of co-infection by T. cruzi and S. stercoralis is not negligible and has probably been underestimated for years in many areas, due to frequently subclinical infections. Therefore, serology seems mandatory for these patients and the use of eosinophilia as initial screening could facilitate the task, decreasing the number of analyses to be performed.
OBJECTIVES: To evaluate co-infection of Strongyloides stercoralis and Trypanosoma cruzi and to assess eosinophilia as a screening test for the detection of S. stercoralisinfection in patients with Chagas disease (CD). METHODS: A retrospective diagnostic validation study was performed on serum samples from primary care patients diagnosed with CD in the southern Barcelona metropolitan area. All samples with eosinophilia (n = 87) and a random sample of non-eosinophilic sera (n = 180) were selected. Diagnosis of CD was based on positive serology by means of two tests: ORTHO® T. cruzi ELISA test, and BIO-FLASH® Chagas or Bioelisa CHAGAS. SCIMEDX ELISA STRONGY-96 was used to diagnose strongyloidiasis. RESULTS:Strongyloides stercoralis serology was positive in 15% of patients of whom 95% showed eosinophilia, vs. 21% of those with negative serology (P < 0.001), with differences in the mean eosinophil count (0.49 vs. 0.27 × 109 /l). Only 1.1% of patients with CD but without eosinophilia presented positive serology for S. stercoralis, whereas 44% of patients with CD and eosinophilia did (P < 0.001). Sensitivity and specificity values for eosinophilia were thus 95% and 79%, respectively. PPV was 42.5% and NPV, 98.9%. CONCLUSIONS: The prevalence of co-infection by T. cruzi and S. stercoralis is not negligible and has probably been underestimated for years in many areas, due to frequently subclinical infections. Therefore, serology seems mandatory for these patients and the use of eosinophilia as initial screening could facilitate the task, decreasing the number of analyses to be performed.
Authors: Melissa S Nolan; Kristy O Murray; Rojelio Mejia; Peter J Hotez; Maria Jose Villar Mondragon; Stanley Rodriguez; Jose Ricardo Palacios; William Ernesto Murcia Contreras; M Katie Lynn; Myriam E Torres; Maria Carlota Monroy Escobar Journal: Trop Med Infect Dis Date: 2021-05-07