TY - JOUR
T1 - Strongyloidiasis in humans
T2 - Diagnostic efficacy of four conventional methods and real-time polymerase chain reaction
AU - Campo-Polanco, Laura Francisca
AU - Sarmiento, José Mauricio Hernández
AU - Mesa, Miguel Antonio
AU - Franco, Carlos Jaime Velásquez
AU - López, Lucelly
AU - Botero, Luz Elena
AU - Builes, Lina Andrea Gutiérrez
N1 - Publisher Copyright:
© 2018, Sociedade Brasileira de Medicina Tropical. All rights reserved.
PY - 2018/7/1
Y1 - 2018/7/1
N2 - Introduction: Strongyloides stercoralis is an intestinal parasitic nematode that causes hyperinfection and/or a dissemination syndrome in hosts, which is often difficult to diagnose. This study aims to compare the diagnostic efficacy of four conventional methods used to diagnose strongyloidiasis with real-time polymerase chain reaction (qPCR) to detect S. stercoralis in fecal samples. Methods: We analyzed 143 fecal samples collected from Colombian regions with varying degrees of risk for intestinal infections caused by S. stercoralis to assess the validity, performance, overall efficiency, and concordance of the qPCR using a direct stool test, modified Ritchie concentration technique, agar plate culture, and Harada-Mori technique as reference tests. Results: While four fecal samples were positive for S. stercoralis using conventional methods, 32 were positive via qPCR. The diagnostic sensitivity of the qPCR was 75% [95% confidence interval (CI): 20.07-100%], whereas its specificity, negative predictive value, negative likelihood ratio, and Youden’s J index were 78.42% (95% CI: 71.22-85.62%), 99.09% (95% CI: 96.86-100%), 0.32 (95% CI: 0.06-1.74), and 0.53, respectively. In addition, the estimated kappa index between the qPCR and the conventional methods was 0.12 (95% CI: -0.020-0.26). Conclusions: The diagnostic sensitivity of qPCR to detect strongyloidiasis is analogous to that of conventional parasitology methods, with an additional advantage of being capable of identifying the parasite DNA at low sample concentrations.
AB - Introduction: Strongyloides stercoralis is an intestinal parasitic nematode that causes hyperinfection and/or a dissemination syndrome in hosts, which is often difficult to diagnose. This study aims to compare the diagnostic efficacy of four conventional methods used to diagnose strongyloidiasis with real-time polymerase chain reaction (qPCR) to detect S. stercoralis in fecal samples. Methods: We analyzed 143 fecal samples collected from Colombian regions with varying degrees of risk for intestinal infections caused by S. stercoralis to assess the validity, performance, overall efficiency, and concordance of the qPCR using a direct stool test, modified Ritchie concentration technique, agar plate culture, and Harada-Mori technique as reference tests. Results: While four fecal samples were positive for S. stercoralis using conventional methods, 32 were positive via qPCR. The diagnostic sensitivity of the qPCR was 75% [95% confidence interval (CI): 20.07-100%], whereas its specificity, negative predictive value, negative likelihood ratio, and Youden’s J index were 78.42% (95% CI: 71.22-85.62%), 99.09% (95% CI: 96.86-100%), 0.32 (95% CI: 0.06-1.74), and 0.53, respectively. In addition, the estimated kappa index between the qPCR and the conventional methods was 0.12 (95% CI: -0.020-0.26). Conclusions: The diagnostic sensitivity of qPCR to detect strongyloidiasis is analogous to that of conventional parasitology methods, with an additional advantage of being capable of identifying the parasite DNA at low sample concentrations.
KW - Helminthology
KW - Intestinal diseases
KW - Molecular diagnostic techniques
KW - Strongyloides stercoralis
UR - http://www.scopus.com/inward/record.url?scp=85052091760&partnerID=8YFLogxK
U2 - 10.1590/0037-8682-0055-2018
DO - 10.1590/0037-8682-0055-2018
M3 - Artículo
C2 - 30133633
AN - SCOPUS:85052091760
SN - 0037-8682
VL - 51
SP - 493
EP - 502
JO - Revista da Sociedade Brasileira de Medicina Tropical
JF - Revista da Sociedade Brasileira de Medicina Tropical
IS - 4
ER -