Diagnosing Urogenital Schistosomiasis: Dealing with Diminishing Returns

Le, Liu; Hsieh, Michael H.

doi:10.1016/j.pt.2016.12.009

Cited by 47 publications

(63 citation statements)

References 106 publications

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“…Over the last five years, the case to incorporate praziquantel MDA into HIV/AIDS treatment programs has advanced even further due to new and important developments. They include the successful testing of a new prodispersable formulation of praziquantel suitable for use in treating young (preschool age) children to prevent the onset of the genital lesions leading to FGS, together with expanded treatment programs for young children and pregnant women [20,[22][23][24], improved FGS diagnostic technologies and algorithms [25][26][27][28][29][30][31], and expanded surveillance for FGS [23,24]. Also, there are now better basic science tools available, including a new mouse model and the applications of genomics, proteomics, metabolomics, and gene editing technologies and an expanded array of immunological reagents, to understand the pathogenesis of FGS [32][33][34][35].…”

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confidence: 99%

Female genital schistosomiasis and HIV/AIDS: Reversing the neglect of girls and women

et al. 2019

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confidence: 99%

Female genital schistosomiasis and HIV/AIDS: Reversing the neglect of girls and women

et al. 2019

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“…Urine samples were originally provided by school children aged 9–12 years from Pemba island, Zanzibar, as part of the Zanzibar Elimination of Schistosomiasis Transmission (ZEST) project (2011–2017), in 2016 and 2017 [ 49 , 50 , 51 ]. All urine samples were produced between 10:00 am and 14:00 pm to coincide with optimum egg output [ 18 ]. All urine samples had been previously screened for S. haematobium infection by urine filtration (10 mL) and egg microscopy during ZEST parasitological surveys according to a standard protocol outlined previously [ 39 , 49 ].…”

Section: Methodsmentioning

confidence: 99%

“…In adopting this strategy, significant gains have been made in reducing the overall burden of disease throughout many areas of sub-Saharan Africa [ 16 , 17 ]. As the number of individuals infected, as well as the intensity of infection within those infected individuals, is diminished, however, a sharp decline in transurinal egg output causes great difficulty in reliably detecting individuals with low levels of infection using standard diagnostic methods—urine-egg microscopy and haematuria-detecting lateral-flow strips [ 18 , 19 , 20 , 21 ].…”

Section: Introductionmentioning

confidence: 99%

Analytical and Clinical Assessment of a Portable, Isothermal Recombinase Polymerase Amplification (RPA) Assay for the Molecular Diagnosis of Urogenital Schistosomiasis

et al. 2020

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Accurate diagnosis of urogenital schistosomiasis is crucial for disease surveillance and control. Routine diagnostic methods, however, lack sensitivity when assessing patients with low levels of infection still able to maintain pathogen transmission. Therefore, there is a need for highly sensitive diagnostic tools that can be used at the point-of-care in endemic areas. Recombinase polymerase amplification (RPA) is a rapid and sensitive diagnostic tool that has been used to diagnose several pathogens at the point-of-care. Here, the analytical performance of a previously developed RPA assay (RT-ShDra1-RPA) targeting the Schistosoma haematobium Dra1 genomic region was assessed using commercially synthesised S. haematobium Dra1 copies and laboratory-prepared samples spiked with S. haematobium eggs. Clinical performance was also assessed by comparing diagnostic outcomes with that of a reference diagnostic standard, urine-egg microscopy. The RT-ShDra1-RPA was able to detect 1 × 101 copies of commercially synthesised Dra1 DNA as well as one S. haematobium egg within laboratory-spiked ddH2O samples. When compared with urine-egg microscopy, the overall sensitivity and specificity of the RT-ShDra1-RPA assay was 93.7% (±88.7–96.9) and 100% (±69.1–100), respectively. Positive and negative predictive values were 100% (±97.5–100) and 50% (±27.2–72.8), respectively. The RT-ShDra1-RPA therefore shows promise as a rapid and highly sensitive diagnostic tool able to diagnose urogenital schistosomiasis at the point-of-care.

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“…Some studies have shown that in very low prevalence settings, microhaematuria can be an unstable proxy for urogenital schistosomiasis [29][30]. On the other hand, the sensitivity of microscopic egg detection can vary according to intensity of infection, day-to-day variation in egg secretion, time the sample was collected, and number of examined samples [31][32][33][34][35]. Another potential reason for the difference in dipstick and microscopic examination could be the fact that the eligibility was carried out in 13-to-14-year olds and the parasitology survey among 9-to-12-year olds.…”

Section: Discussionmentioning

confidence: 99%

Evaluating the Impact of Biannual School-Based and Community-Wide Treatment on Urogenital Schistosomiasis in Niger

Phillips

Tohon²,

Dhanani³

et al. 2020

Preprint

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Abstract Background The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) coordinated a five-year study implemented in several countries, including Niger, to provide an evidence-base for programmatic decisions regarding cost-effective approaches to preventive chemotherapy for schistosomiasis control. Methods This was a cluster-randomised trial investigating six possible combinations of annual or biannual community-wide treatment (CWT), school-based treatment (SBT), and holidays from mass treatment over four years. The most intense arm involved two years of annual CWT followed by two years of biannual CWT, while the least intensive arm involved one year of annual SBT followed by a year without treatment and two more years of annual SBT. The primary outcome of interest was prevalence and intensity of S. haematobium among 100 children aged 9-to-12-years sampled each year. In addition, 100 children aged 5-to-8 years in their first year of school and 50 adults (aged 20-to-55 years) were tested in the first and final fifth year of the study. Results In total, data was collected from 167,500 individuals across 225 villages in nine districts within the Niger River valley, Western Niger. Overall, prevalence of S. haematobium decreased from baseline to Year 5 across all study arms. The relative reduction of prevalence was greater in biannual compared with annual treatment across all arms, however, the only significant difference was seen in areas with a high starting prevalence. Although adults were not targeted for treatment in SBT arms, a statistically significant decrease in prevalence among adults was seen in moderate prevalence areas receiving biannual (10.7% to 4.8%) SBT (p<0.001). Adults tested in the annual SBT group also showed a decrease in prevalence between Year 1 and Year 5 (12.2% to 11.0%), but this difference was not significant.Conclusions These findings are an important consideration for schistosomiasis control programs that are considering elimination and support the idea that scaling up the frequency of treatment rounds, particularly in areas of low prevalence, will not eliminate schistosomiasis. Interestingly, the finding that prevalence decreased among adults in SBT arms suggests that transmission in the community can be reduced, even where only school children are being treated, which could have logistical and cost-saving implications for the national control programmes.

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Diagnosing Urogenital Schistosomiasis: Dealing with Diminishing Returns

Cited by 47 publications

References 106 publications

Female genital schistosomiasis and HIV/AIDS: Reversing the neglect of girls and women

Female genital schistosomiasis and HIV/AIDS: Reversing the neglect of girls and women

Analytical and Clinical Assessment of a Portable, Isothermal Recombinase Polymerase Amplification (RPA) Assay for the Molecular Diagnosis of Urogenital Schistosomiasis

Evaluating the Impact of Biannual School-Based and Community-Wide Treatment on Urogenital Schistosomiasis in Niger

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