Detecting Schistosoma mansoni infections among pre-school-aged children in southern Ghana: a diagnostic comparison of urine-CCA, real-time PCR and Kato-Katz assays

Background In Ghana, pre-school-aged children (PSAC) are at risk of intestinal schistosomiasis and are living in need of praziquantel treatment. To better assess the infection burden within this vulnerable demographic group, we have provided a comparative assessment of the prevalence of Schistosoma mansoni in pre-school-aged children by urine circulating cathodic antigen (CCA) dipsticks, real-time PCR Taqman® faecal assays and Kato-Katz coproscopy. Methods In all, 190 pre-school-aged children were sampled from three endemic communities (viz. Tomefa, Torgahkope/Adakope, and Manheam) around Weija dam, Southern Ghana. Fresh stool and urine samples were collected from all participants for diagnosis. Results Among all the three communities, the urine-CCA assay recorded the highest prevalence values of 90.5% (95% CI 80.4–96.4), 87.9% (95% CI 76.7–95), and 81.2% (95% CI 69.9–89.6) in Tomefa, Torgahkope/Adakope, and Manheam respectively. Prevalence by real-time PCR was 50% (95% CI 35.5–64.5), 8% (95% CI 2.2–19.2) and 16.7% (95% CI 8.3–28.5), while by Kato-Katz was 55.6% (95% CI 42.5–68.1), 8.6% (95% CI 2.9–19) and 11.6% (95% CI 5.1–21.6) respectively. Children aged 1 year and over were found to be positive with the urine-CCA assay; by the ages of 3–4, over 50% were urine-CCA patent. The sensitivity and specificity of the POC-CCA dipsticks, when compared against the combined results of Kato-Katz/TaqMan results was found to be 84.1% (95% CI = 72.7–92.1) and 12.9% (95% CI = 6.6–22) respectively. Conclusions We propose that the urine-CCA dipstick may be a useful rapid diagnostic tool to estimate the prevalence of intestinal schistosomiasis in PSAC, particularly in rapid identification of at-risk areas. However, our assessment has shown that it possible to record false positives when compared to combined Kato-Katz and qPCR results. To guide PSAC praziquantel treatment needs, we propose the urine CCA assay should be included in routine surveillance of intestinal schistosomiasis alongside other diagnostics such as Kato-Katz and urine filtration

Dataset used in preparing article in SPSS format.

The impact of the Global Programme to Eliminate Lymphatic Filariasis (GPELF) (initiated in 2000 in Ghana and ran for 12 years) in mitigating soil-transmitted helminth (STH) infections in LF-endemic areas is unknown. During a 1-year hiatus which ensued between 2011 and 2012, a longitudinal study was conducted to determine GPELF effect on hookworm infections in selected communities involved in the programme since its inception, while measuring the effectiveness of biannual ALB treatments on schoolchildren living in such communities. A total of 399 school children aged 3 to 18 years were randomly selected from four communities in the Kpandai district of northern Ghana. Each presented a single stool sample at baseline, 21 days post-treatment, at the 3rd and 6th months, 21 days post-second intervention (i.e. following sample collection and treatment with ALB in the 6th month), and in the ninth month of the study period. Haemoglobin (hb) levels were also measured at all time points using finger prick blood samples and a URIT digital test kit. Each participant submitting a sample, was treated with a single-dose ALB (400mg) at baseline and in the sixth month. Stool samples were processed by preparing duplicate Kato-Katz slides per sample, and examined by microscopy. The Body Mass Index-for-age z-scores (BAZ) of participants were assessed following the determination of BMIs at each time point by measuring their height and weight with a stadiometer and weighing scale. Overall hookworm prevalences were 25.68% (95% CI = 20.51–31.75) at baseline, 11.18% (95% CI = 7.87–15.41) 21 days post-treatment, 11.78% (95% CI = 8.38–16.11) and 6.95% (95% CI = 4.41–10.43) in the 3rd and 6th months, 0.91% (95% CI = 0.19–2.65) 21 days post-second intervention, and 8.46% (95% CI = 5.62–12.23) in the ninth month. Observed overall faecal egg count reduction rates (ERRs) were 94.21% (95% CI = 81.50%– 100.00%) 21 days after baseline treatment, 97.70% (95% CI = 85.08–100.00) and 96.95% (95% CI = 84.18%– 100.00%) in the 3rd and 6th months, 99.98% (95% CI = 86.42%– 100.00%) 21 days post-second intervention, and 17.18% (95% CI = 14.07%– 20.67%) in the 9th month. Respective cure rates (CRs) were 62.35% (95% CI = 46.71–81.56%), 85.88% (95% CI = 67.32–100.00%), 87.06% (95% CI = 68.36%– 100.00%), 98.82% (95% CI = 78.83%– 100.00%), and 36.36% (95% CI = 9.91%– 93.11%). Additionally, increases in the percent frequency of ‘normal hb’ (p </div

Faecal egg count reduction (ERR) and cure rates (CR) with respect to hookworm infection over time.

Faecal and egg reduction rates over time for (A) Jagbengbendo, (B) Kojobone, (C) Takumdo, and (D) Wiae. (E) Overall ERR and CR for the four study communities over time. Error bars represent the 95% Confidence Intervals (CI) of prevalences.</p

Associations between hookworm infection status and potential risk factors.

Associations between hookworm infection status and potential risk factors.</p

A map of the Kpandai district indicating the locations of the study communities.

Map was developed by Elias K. Asuming-Brempong using the QGIS Girona version 3.0.3 (Boston, MA., USA). Shape files of the regions of Ghana were obtained online (URL: https://github.com/tierney/gis-sandbox/tree/master/data/GIS-Ghana/ghana.shapefiles). Also, GPS data were obtained from the field, using appropriate devices, and exported to Microsoft Office Excel version 2013, where conversions were made. The document was then exported to the QGIS Girona version 3.0.3 software as a delimited text file. (PDF)</p

Demographic information on study participants.

The impact of the Global Programme to Eliminate Lymphatic Filariasis (GPELF) (initiated in 2000 in Ghana and ran for 12 years) in mitigating soil-transmitted helminth (STH) infections in LF-endemic areas is unknown. During a 1-year hiatus which ensued between 2011 and 2012, a longitudinal study was conducted to determine GPELF effect on hookworm infections in selected communities involved in the programme since its inception, while measuring the effectiveness of biannual ALB treatments on schoolchildren living in such communities. A total of 399 school children aged 3 to 18 years were randomly selected from four communities in the Kpandai district of northern Ghana. Each presented a single stool sample at baseline, 21 days post-treatment, at the 3rd and 6th months, 21 days post-second intervention (i.e. following sample collection and treatment with ALB in the 6th month), and in the ninth month of the study period. Haemoglobin (hb) levels were also measured at all time points using finger prick blood samples and a URIT digital test kit. Each participant submitting a sample, was treated with a single-dose ALB (400mg) at baseline and in the sixth month. Stool samples were processed by preparing duplicate Kato-Katz slides per sample, and examined by microscopy. The Body Mass Index-for-age z-scores (BAZ) of participants were assessed following the determination of BMIs at each time point by measuring their height and weight with a stadiometer and weighing scale. Overall hookworm prevalences were 25.68% (95% CI = 20.51–31.75) at baseline, 11.18% (95% CI = 7.87–15.41) 21 days post-treatment, 11.78% (95% CI = 8.38–16.11) and 6.95% (95% CI = 4.41–10.43) in the 3rd and 6th months, 0.91% (95% CI = 0.19–2.65) 21 days post-second intervention, and 8.46% (95% CI = 5.62–12.23) in the ninth month. Observed overall faecal egg count reduction rates (ERRs) were 94.21% (95% CI = 81.50%– 100.00%) 21 days after baseline treatment, 97.70% (95% CI = 85.08–100.00) and 96.95% (95% CI = 84.18%– 100.00%) in the 3rd and 6th months, 99.98% (95% CI = 86.42%– 100.00%) 21 days post-second intervention, and 17.18% (95% CI = 14.07%– 20.67%) in the 9th month. Respective cure rates (CRs) were 62.35% (95% CI = 46.71–81.56%), 85.88% (95% CI = 67.32–100.00%), 87.06% (95% CI = 68.36%– 100.00%), 98.82% (95% CI = 78.83%– 100.00%), and 36.36% (95% CI = 9.91%– 93.11%). Additionally, increases in the percent frequency of ‘normal hb’ (p </div

Hookworm infection distribution by age groups over the study time points.

(A) Hookworm infection prevalence distribution by age groups for all study time points. (B) Hookworm infection intensity distribution by age groups for all study time points. Marker and error bars represent the arithmetic mean and standard error of mean (SEM) respectively. Red vertical dashed lines demarcate treatment intervention time points.</p

Fig 2 -

Impact of albendazole (ALB) treatment interventions on (A) the prevalences of hookworms and other Helminthes in the study cohort; and (B-C) on community-stratified hookworm infection intensities over the study period. Two ALB treatment interventions were administered to recruited school children at baseline (after parasitological screening) and in the 6th month (after parameters of interest had been collected and assessed). No A. lumbricoides was observed throughout the study. Vertical, red-dashed lines demarcate treatment intervention time points.</p

Association of risk factor-treatment interactions over time with anaemia status.

Association of risk factor-treatment interactions over time with anaemia status.</p

Dataset used in preparing article in MS Office Excel format.

Dataset used in preparing article in MS Office Excel format.</p