Abstract
BackgroundUrine microscopy is the standard diagnostic method for urogenital S. haematobium infection. However, this may lead to under-diagnosis of urogenital schistosomiasis, as the disease may present itself with genital symptoms in the absence of ova in the urine. Currently there is no single reliable and affordable diagnostic method to diagnose the full spectrum of urogenital S. haematobium infection. In this study we explore the classic indicators in the diagnosis of urogenital S. haematobium infection, with focus on young women.MethodsIn a cross-sectional study of 1237 sexually active young women in rural South Africa, we assessed four diagnostic indicators of urogenital S. haematobium infection: microscopy of urine, polymerase chain reaction (PCR) of cervicovaginal lavage (CVL), urogenital symptoms, and sandy patches detected clinically in combination with computerised image analysis of photocolposcopic images. We estimated the accuracy of these diagnostic indicators through the following analyses: 1) cross tabulation (assumed empirical gold standard) of the tests against the combined findings of sandy patches and/or computerized image analysis and 2) a latent class model of the four indicators without assuming any gold standard.ResultsThe empirical approach showed that urine microscopy had a sensitivity of 34.7% and specificity of 75.2% while the latent class analysis approach (LCA) suggested a sensitivity of 81.0% and specificity of 85.6%. The empirical approach and LCA showed that Schistosoma PCR in CVL had low sensitivity (14.1% and 52.4%, respectively) and high specificity (93.0% and 98.0, respectively). Using LCA, the presence of sandy patches showed a sensitivity of 81.6 and specificity of 42.4%. The empirical approach and LCA showed that urogenital symptoms had a high sensitivity (89.4% and 100.0%, respectively), whereas specificity was low (10.6% and 12.3%, respectively).ConclusionAll the diagnostic indicators used in the study had limited accuracy. Using urine microscopy or Schistosoma PCR in CVL would only confirm a fraction of the sandy patches found by colposcopic examination.
Highlights
Pathological changes caused by Schistosoma haematobium infection are found mainly in the urinary tract but are nearly as common in the gynaecological tract [1]
The empirical approach showed that urine microscopy had a sensitivity of 34.7% and specificity of 75.2% while the latent class analysis approach (LCA) suggested a sensitivity of 81.0% and specificity of 85.6%
The empirical approach and LCA showed that Schistosoma polymerase chain reaction (PCR) in cervico-vaginal lavage (CVL) had low sensitivity (14.1% and 52.4%, respectively) and high specificity (93.0% and 98.0, respectively)
Summary
Pathological changes caused by Schistosoma haematobium infection are found mainly in the urinary tract but are nearly as common in the gynaecological tract [1]. Urine microscopy is the most commonly used diagnostic method for S. haematobium [2] This may lead to under-diagnosis of urogenital schistosomiasis in young women, as genital lesions may be present in the absence of ova in the urine [3, 4]. After the parasites enter the human host, the adult male and female worms couple and settle within veins surrounding the pelvic organs, including the urinary and genital systems [4, 9] They lay ova that are either released into the environment by proteolytic migration through the urogenital mucosa or they get lodged in the urogenital organs, causing chronic inflammation [4, 10,11,12]. Urine microscopy is the standard diagnostic method for urogenital S. haematobium infection This may lead to under-diagnosis of urogenital schistosomiasis, as the disease may present itself with genital symptoms in the absence of ova in the urine. In this study we explore the classic indicators in the diagnosis of urogenital S. haematobium infection, with focus on young women
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
