Rapid detection of Giardia intestinalis and Cryptosporidium spp. in stool samples using an antigen-

based detection approach : evaluation of a new commercial immunochromatographic strip test

Introduction & purpose

Materials & methods

Results

Acknowledgements We are grateful to CORIS BioConcept for providing the

reagents used in this study.

Microscopy is the gold standard for routine

laboratory diagnosis in faecal parasitology but

there is a growing interest for alternative methods

to overcome the limitations of microscopic

examination, which is time-consuming and

dependent on the operator’s skills and expertise

[1,2].

In this context, antigen-based detection using

rapid detection tests (RDTs) could represent

attractive alternatives.

Purpose

To evaluate a new immunochromatographic strip

test (Crypto-Giardia K-SeT®, Coris BioConcept,

Belgium) for the simultaneous detection of both

Giardia intestinalis and Cryptosporidium spp.

antigens from stool specimens.

ØEvaluation performed using a reference panel of

184 cryopreserved human stool samples [2]:

q 134 positive samples (Table 1)

q 50 negative samples

q Each sample previously determined by a

standardized protocol (microscopy+/-PCR) [2]

ØEach sample was tested blindly to the results

of microscopy

ØVisual reading performed after 15 min (Figure 1).

ØDiscrepancies with microscopy were investigated

by specific PCR assays

ØDetermination of sensitivity and specificity

Ø Correct agreement with microscopy (Table 2).

Ø Four false-negative samples.

Ø One false-positive (PCR/microscopy negative).

This RDT facilitates the detection of G. intestinalis

and Cryptosporidium spp. from stool samples, being

easy to use and time-saving compared to

microscopy (45 min for processing 15 samples).

A prospective evaluation of its performances in routine

diagnosis is currently undergoing.

Table 1: Diversity of the gastrointestinal

parasites included in the reference panel

(n= 134)

Genus/Species N=

Giardia intestinalis 37

Cryptosporidium spp. 30

C. parvum/C. hominis 28

C. felis 1

C. meleagridis 1

Other gastrointestinal parasites

Entamoeba coli 35

Endolimax nana 20

E. histolytica/E. dispar 16

Entamoeba hartmanni 4

Blastocystis sp. 15

Schistosoma mansoni 4

Iodamoeba bütschlii 3

Cystoisospora belli 2

Hookworms 2

Hymenolepis nana 1

Trichuris trichiura 1

Taenia sp. 1

Dientamoeba fragilis 1

Sarcocystis hominis 1

Chilomastix mesnili 1

Pentatrichomonas intestinalis 1

Enterocytozoon bieneusi 1

Table 2: Antigen detection findings for Giardia intestinalis

Conclusions

Gardia intestinalis Cryptosporidium spp.

Microscopy

+ -

Crypto-Giardia K-SeT® + 33 1

- 4 146

Se= 89.2%, Sp= 99.3% Microscopy

+ -

Crypto-Giardia K-SeT® + 26 0

- 4 154

Se = 86.7%, Sp = 100%

Ø Correct agreement with microscopy (Table 3).

Ø Four false-negative samples.

Ø Both C. meleagridis and C. felis detected (n=2).

Each sample was tested blindly. This test

appeared time-saving due to a reduced

turnaround time.

No cross-reactivity with other gastro-

intestinal parasites included in the reference

panel was observed.

Individual results for G. intestinalis and

Cryptosporidium spp. are presented below.

Table 3: Antigen detection findings for Cryptosporidium spp.

Figure 1: The Crypto-Giardia K-SeT diagnostic test (here positive for G. intestinalis)

C: Control-band, Cr: Crypto-specific band; Gi: Giardia-specific band

1Laboratoire de Parasitologie-Mycologie, CHU de Nantes ; 2Laboratoire de Parasitologie-Mycologie, CHU de Dijon ; 3Service de Parasitologie-Mycologie-Médecine Tropicale, CHU de Tours; 4Laboratoire de Parasitologie-Mycologie, AP-HP, Hôpital Bichat, Paris ; 5Laboratoire de

Parasitologie-Mycologie, CHU de Clermont-Ferrand ; 6Laboratoire de Parasitologie-Mycologie, CHU de Nice ; 7Laboratoire de Parasitologie-Mycologie, CHU de Nancy ; 8Laboratoire de Parasitologie-Mycologie, CHU d’Angers ; 9Laboratoire de Parasitologie-Mycologie, AP-HP Hôpital Henri

Mondor, Créteil ; 10Laboratoire de Parasitologie-Mycologie, CHU de Montpellier ; 11Laboratoire de Parasitologie-Mycologie, CHU de Poitiers ; 12Laboratoire de Microbiologie, CH de la Roche-sur-Yon.

For more information, please contact:

florent.morio@chu-nantes.fr

GOUDAL A.1, LAUDE A., VALOT S.2, DESOUBEAUX G.3, ARGY N.4, NOURRISSON C.5, POMARES C.6, MACHOUART M.7, LE GOVIC Y.8,

DALLE F.2, BOTTEREL F.9, BOURGEOIS N.10, CATEAU E.11, LETERRIER M.12, LAVERGNE RA.1, LE PAPE P. 1, MORIO F1.

References:

[1] Becker et al., Clin Microbiol Infect. 2015 Jun;21(6):591.e1-10.

[2] Laude et al., Clin Microbiol Infect. 2016 Feb;22(2):190.e1-8.