Evaluation of portable microscopic devices for the diagnosis of Schistosoma and soil-transmitted helminth infection.
The diagnosis of parasitic worm (helminth) infections requires specialized laboratory settings, but most affected individuals reside in locations without access to such facilities. We tested two portable microscopic devices for the diagnosis of helminth infections in a cross-sectional survey in rural Côte d'Ivoire. We examined 164 stool samples under a light microscope and then re-examined with a commercial portable light microscope and an experimental mobile phone microscope for the diagnosis of Schistosoma mansoni and soil-transmitted helminths. Additionally, 180 filtered urine samples were examined by standard microscopy and compared with the portable light microscope for detection of Schistosoma haematobium eggs. Conventional microscopy was considered the diagnostic reference standard. For S. mansoni, S. haematobium and Trichuris trichiura, the portable light microscope showed sensitivities of 84.8%, 78.6% and 81.5%, respectively, and specificities of 85.7%, 91.0% and 93.0%, respectively. For S. mansoni and T. trichiura, we found sensitivities for the mobile phone microscope of 68.2% and 30.8%, respectively, and specificities of 64.3% and 71.0%, respectively. We conclude that the portable light microscope has sufficient diagnostic yield for Schistosoma and T. trichiura infections, while the mobile phone microscope has only modest sensitivity in its current experimental set-up. Development of portable diagnostic technologies that can be used at point-of-sample collection will enhance diagnostic coverage in clinical and epidemiological settings.
Divisions of Internal Medicine and Infectious Diseases,Toronto General Hospital,14EN-209, 200 Elizabeth Street, Toronto, ON, M5G 2C4,Canada.
Isaac I
II
Bogoch
Unité de Formation et de Recherche Biosciences,Université Félix Houphouët-Boigny,22 BP 770, Abidjan 22,Côte d'Ivoire.
Jean T
JT
Coulibaly
Division of Infectious Diseases and Geographic Medicine,Stanford University School of Medicine,Stanford, CA, 94305-5107,USA.
Jason R
JR
Andrews
Department of Medical Parasitology and Infection Biology,Swiss Tropical and Public Health Institute,P.O. Box, CH-4002 Basel,Switzerland.
Benjamin
B
Speich
Department of Medical Parasitology and Infection Biology,Swiss Tropical and Public Health Institute,P.O. Box, CH-4002 Basel,Switzerland.
Jennifer
J
Keiser
Parasitology Department,Liverpool School of Tropical Medicine,Liverpool L3 5QA,UK.
J Russell
JR
Stothard
Unité de Formation et de Recherche Biosciences,Université Félix Houphouët-Boigny,22 BP 770, Abidjan 22,Côte d'Ivoire.
Eliézer K
EK
N'goran
University of Basel,P.O. Box, CH-4003 Basel,Switzerland.
Jürg
J
Utzinger
D000818:Animals; D040421:Cell Phone; D007560:Cote d'Ivoire / Q000453:epidemiology; D003430:Cross-Sectional Studies; D003710:Demography; D005243:Feces / Q000469:parasitology; D005260:Female; D006373:Helminthiasis / Q000175:diagnosis* / Q000453:epidemiology; D006376:Helminths / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008853:Microscopy / Q000295:instrumentation*; D058069:Neglected Diseases / Q000175:diagnosis / Q000453:epidemiology; D012548:Schistosoma haematobium / Q000302:isolation & purification; D012550:Schistosoma mansoni / Q000302:isolation & purification; D012552:Schistosomiasis / Q000175:diagnosis* / Q000453:epidemiology; D012680:Sensitivity and Specificity; D012987:Soil / Q000469:parasitology; D014258:Trichuris / Q000302:isolation & purification
D012987:Soil