Performance of three rapid screening methods in the detection ofSchistosoma haematobiuminfection in school-age children in Southeastern Nigeria

Abstract

Background: A cross-sectional study of primary school children was conducted to evaluate and compare the performance of some rapid screening methods in the detection of Schistosoma haematobium infection in Nigeria Cement Factory (NigerCem) and Nike Lake areas of Southeastern Nigeria. Methods: Urine samples of school children were examined for macro-haematuria and tested for microhaematuria and proteinuria using reagent strips followed by egg microscopy. Self-reported haematuria was assessed using simple questionnaire. The performances of these rapid diagnoses singly and in combination were calculated using egg microscopy as gold standard. Results: The prevalence of the infection was 26.6% in NigerCem and 5.1% in Nike Lake area, classifying these areas as moderate-and low-prevalence areas (MPA and LPA); while in the subsample used for selfreported haematuria, the prevalence was 27.2 and 4.2% in MPA and LPA, respectively. The positive predictive value (PPV) of micro-haematuria was comparable in MPA (55.26%) and LPA (57.89%). Overall PPV of macro-haematuria was 87.50% in MPA and 66.70% in LPA while in the detection of heavy infection; PPV was higher in LPA (75%) than in MPA (66.67%). In LPA and MPA, combination of micro-haematuria and proteinuria, and concomitant presence of macro-haematuria, micro-haematuria, and proteinuria had PPV of 83.33 and 63.16%, and 100 versus 66.67%, respectively. Generally, the rapid screening tests had lower negative predictive values (NPVs) in MPA than in LPA. The use of simple questionnaire increased the PPV of heavy infection in MPA (77.78%). This was further increased to 80% when self-reported haematuria was combined with micro-haematuria. Conclusion: The result suggests that in MPA with chronic infections, combination of self-reported haematuria and micro-haematuria may reduce the chance of missing those who should be treated.

The usefulness of indirect diagnostic tests for Schistosoma haematobium infection after repeated rounds of mass treatment with praziquantel in Mpwapwa and Chakechake districts in Tanzania

“…This finding is similar to those of previous studies in low transmission settings (Lwambo et al, 1997a;Robinson et al, 2009). However, the high PPV of urine reagent strips in Uwandani Shehia area is similar to other moderate transmission areas in SSA (Bocanegra et al, 2015;Okeke and Ubachukwu, 2014;Robinson et al, 2009). Hence, these variations in performance of the urine reagent strips in low transmission settings will require confirmation of positive results with more sensitive diagnostic tests.…”

An update on non-invasive urine diagnostics for human-infecting parasitic helminths: what more could be done and how?

“…For these reasons, the diagnostic reliability of having trained and experienced personnel to identify the presence of macroscopic blood in the urine has also been assessed, again, comparing the method to urine-egg detection by microscopy (Okeke and Ubachukwu, 2014). Once more it was concluded that, unless used in conjunction with more taxing and costly methods, macrohematuria does not provide adequate sensitivity when compared to egg microscopy, and in using only this method low-, or even moderate-intensity, infections would likely be missed.…”

Evaluation of the Clinitek®, a point-of-care urinalysis system for the measurement of clinically significant urinary metabolites and detection of haematuria in Schistosoma haematobium infected children in southern Côte d’Ivoire

“…Haematuria is defined as the presence of red blood cells in urine. It can be detected by macroscopic urinalysis, where the presence of blood in urine is seen by naked eye, or via microscopic urinalysis, where the use of a microscope is needed [6]. Studies have shown that people shedding S. haematobium eggs also commonly have haematuria [1, 7–11].…”

“…In clinical settings, an automatic urinalysis reader is typically used as it eliminates bias due to subjective reading by naked eye and increases the throughput of read-outs (each read only requires one minute to process) [17]. Portable, battery-operated versions of these devices have been introduced which would, in theory, render them usable in more remote areas [6, 18].…”