Performance of a rapid diagnostic test for the detection of Cryptosporidium spp. in African children admitted to hospital with diarrhea

Abstract

Background Cryptosporidium is a protozoan parasite that causes mild to severe diarrhoeal disease in humans. To date, several commercial companies have developed rapid immunoassays for the detection of Cryptosporidium infection. However, the challenge is to identify an accurate, simple and rapid diagnostic tool for the estimation of cryptosporidiosis burden. This study aims at evaluating the accuracy of CerTest Crypto, a commercialized rapid diagnostic test (RDT) for the detection of Cryptosporidium antigens in the stool of children presenting with diarrhoea. Methods A cross-sectional study was conducted in four study sites in Sub-Saharan Africa (Gabon, Ghana, Madagascar, and Tanzania), from May 2017 to April 2018. Stool samples were collected from children under 5 years with diarrhoea or a history of diarrhoea within the last 24 hours. All specimens were processed and analyzed using CerTest Crypto RDT against a composite diagnostic panel involving two polymerase chain reaction (PCR) tests (qPCR and RFLP-PCR,) as the gold standard.

Prevalence of Pathogens in Young Children Presenting to Hospital with Diarrhea from Lambaréné, Gabon

“…Enterotoxigenic Escherichia coli was identified in seven samples (4.7%), and EAEC was found in 57 samples (38%). 20 Whether this considerable difference between our respective findings is due to an emergence of new strains of E. coli in this region or a different testing protocol cannot be conclusively answered. Samples collected as part of the said study were analyzed in Austria and only submitted for molecular diagnostic testing when the growth of suspect E. coli had been shown in culture, whereas in this current study, PCR was conducted regardless of results attained by conventional microbiological culture in our study.…”

“…This could be due to the fact that most children younger than 6 months were usually breastfed, which has been shown to have a preventative effect on gastrointestinal illnesses. 20 The high number of patients with G. lamblia suggests considerable levels of contamination in the local water supply, because this pathogen has been mainly found to be transmitted by water in this demographic group. 31 It is, however, not clear whether this parasite actually always represents a cause of diarrhea or may just be an accompanying colonization as has been suggested by several other authors.…”

First Molecular Characterization of Cryptosporidium spp. in Patients Living with HIV in Honduras

“…A recent cross-sectional study conducted among children with diarrhea from four African countries compared this RDT with a diagnostic panel that included PCR and qPCR tests as gold standards. The authors concluded that the RDT had a very low sensitivity compared to molecular approaches [ 42 ]. On the other hand, other authors compared two RDTs against PCR as the reference method in patient samples from three hospitals in Madrid, finding 100% sensitivity and specificity in the RDT used in our study [ 43 ].…”

Evaluación de pruebas inmunológicas en el diagnóstico de Giardia duodenalis y Cryptosporidium spp., Honduras

“…Curiosamente, una misma prueba (CerTest Crypto) diseñada para identificar especies de Cryptosporidium dio resultados diferentes en cinco países africanos: la más alta sensibilidad fue observada en Madagascar (72.2%) comparado con Gabón y Ghana con 50% y 52% respectivamente y el más bajo en Tanzanía (35.2%); una sensibilidad general de 49.6%, especificidad de 92.5% y valor predictivo de 61.3%. 12 No hubo evidencia de que los resultados estuvieran influenciados por período de lluvia, período de evaluación, género o grupo etario y sí hubo concordancia de que la edad más parasitada por Cryptosporidium fue en los dos primeros años de vida.…”