Cryptosporidium and Giardia
The Cryptosporidium and Giardia research started in 2002.
Background
Cryptosporidium is one of the most common enteropathogens causing diarrhea in neonatal calves, while Giardia is more prevalent in calves older than 1 month, and is also known to cause diarrhea in calves. High prevalences of both protozoa have been reported worldwide, but differed significantly between countries, which can partially be attributed to the diagnostic methods employed. Furthermore, both parasites are potential zoonotic infections, and transmission of infection from animal to human hosts has previously been described.
For the treatment of bovine giardiosis, no chemotherapeutic compounds are registered, although previous studies indicated that several benzimidazole compounds effectively reduce cyst excretion, especially in well-managed environments.
Past research
A large scale molecular epidemiological study was conducted to estimate parasite prevalence and the occurence of zoonotic species and (sub)genotypes in calves younger than 10 weeks. To evaluate different diagnostic assays for use in epidemiological studies and to estimate parasite prevalence, a Bayesian approach was used. Both Cryptosporidium and Giardia were found to be highly prevalent in subsequent cross-sectional studies on 100 dairy and 50 beef farms in the province of East Flanders, Belgium. Furthermore, the prevalence of Cryptosporidium and Giardia is estimated in several additional hosts, including small ruminants, dogs and human patients. Since both parasites have zoonotic potential, molecular tools were used and developed for species determination and subgenotyping.
For the treatment and control of a Giardia infection in calves, paromomycin and fenbendazole were tested in experimental conditions. The use of fenbendazole was also evaluated in natural conditions. Furthermore, the effect of giardiasis on production in calves was evaluated in an experimental infection trial.
Ongoing projects
1 - The study of the dynamics between human and animal transmission cycles in endemic foci, using subgenotyping tools and GIS (www.avia-gis.com)
The main objective of the project is to study to what extent surface water and purified tap water produced from surface water is contaminated with C. parvum and G. duodenalis, and which factors contribute to contamination. The specific objectives are:
(1) optimisation and evaluation of the detection and molecular characterisation (to subgenotype level) of C. parvum and G. duodenalis in water samples
(2) monitoring the presence of C. parvum and G. duodenalis in surface and drinking water in different water catchment areas in Belgium and identifying the source of infection (human or animal) using multilocus sub-genotyping
(3) monitoring the presence of C. parvum and G. duodenalis in surface and drinking water in different water catchment areas in Bangladesh and identifying the source of infection (human or animal) using multilocus sub-genotyping
(4) the development of a GIS (Geographic Information System) risk assessment model for the identification of geological, hydrological, climate and other risk factors which might contribute to the contamination and spread of infection in surface water
2 - The immunity against Giardia infections in ruminant models, with focus on dendritic cells
The main objective of the project is to study the role of dendritic cells (DCs) and pattern-recognition receptors (PRRs) in the initialisation and polarisation of the adaptive immune response against Giardia in calves. The project comprises 2 phases:
(1) The effect of Giardia on the maturation of DCs, both in vitro and in vivo, and the potential of these DCs to activate naive T-cells
(2) The identification of the TLRs involved in DC maturation and of the TLR ligands
Contact
Prof. Dr. E. Claerebout 
In collaboration with:
Prof. Dirk Berkvens 
(Institute for Tropical Medicine, Antwerp)
Cindy Martens 
(VIB)
Prof Andrew Thompson (Murdoch University, Perth)
Publications since 2002
Geurden, T., Claerebout, E ., Vercruysse, J., Berkvens, D., 2004. Estimation of test characteristics and prevalence of Giardia duodenalis in dairy calves in Belgium using a Bayesian approach. Int J Parasitol 34, 1121-1127.
Geurden, T., Claerebout, E ., Dursin L., Deflandre, A., Bernay, F., Kaltsatos, V., Vercruysse, J., 2005. The efficacy of an oral treatment with paromomycin against an experimental infection with Giardia in calves. Vet Parasitol 135, 241-247.
Geurden, T., Goma, F.Y., Siwila, J., Phiri, I.G.K., Mwanza, A.M., Gabriel, S., Claerebout, E ., Vercruysse, J., 2006. Prevalence and genotyping of Cryptosporidium in three cattle husbandry systems in Zambia. Vet Parasitol 138, 217-222.
Geurden, T., Berkvens, D., Geldhof, P., Vercruysse, J., Claerebout, E ., 2006. A Bayesian approach for the evaluation of six diagnostic assays and the estimation of Cryptosporidium prevalence in dairy calves. Vet Res 37, 671-682.
Geurden, T., Vercruysse, J., Claerebout, E., 2006. Field testing of a fenbendazole treatment combined with hygienic and management measures against a natural Giardia infection in calves. Vet Parasitol 142, 367-371.
Hellebuyck T., Vancraynest D., Geurden T., Claerebout E., Pasmans F., 2007. Cryptosporidiosis in snakes. Vlaams Diergeneeskundig Tijdschrift 76, 26-30.
Hellebuyck T., Vancraynest D., Geurden T., Claerebout E., Pasmans F., 2007. The prevalence of cryptosporidiosis in Belgian snake collections. Vlaams Diergeneeskundig Tijdschrift 76, 31-34.
Goma, F.Y., Geurden, T., Siwila, J. , Phiri, I.G.K., Gabriel, S., Claerebout, E. , Vercruysse, J., 2007. The prevalence and molecular characterisation of Cryptosporidium spp. in small ruminants in Zambia. Small Ruminant Res, 72, 77-80
Siwila, J., Phiri, I.G.K.,Vercruysse, J., Goma, F., Gabriel, S., Claerebout, E., Geurden T., 2007. Asymptomatic cryptosporidiosis in Zambian dairy farm workers and their household members. T Roy Soc Trop Med H 101, 733-734.
Geurden, T., Berkvens D., Martens C., Casaert, S., Vercruysse, J., Claerebout, E., 2007. Molecular epidemiology with subtype analysis of Cryptosporidium in calves in Belgium. Parasitology 134, 1981-1987
Geurden, T., Geldhof, P., Levecke, B., Martens, C., Berkvens, D., Casaert, S., Vercruysse, J., Claerebout, E., 2007. Mixed Giardia duodenalis assemblage A and E infections in calves. Int J Parasitol, 38, 259-264
Geurden T., Claerebout E., Vercruysse J., Berkvens D., 2007. A Bayesian evaluation of four immunological assays for the diagnosis of clinical cryptosporidiosis in calves. Vet J 176, 400-402
Geurden T., Thomas P., Casaert S., Vercruysse J., Claerebout E., 2008. Prevalence and molecular characterisation of Cryptosporidium and Giardia in lambs and goat kids in Belgium. Vet Parasitol 155, 142-145
Geurden T., Berkvens D., Casaert S., Vercruysse J., Claerebout E., 2008. A Bayesian evaluation of three diagnostic assays for the detection of Giardia duodenalis in symptomatic and asymptomatic dogs. Vet Parasitol, 157, 14-20.
Claerebout E., Casaert S., Dalemans A.-C., De Wilde N., Levecke B., Vercruysse J., Geurden T. 2009. Giardia and other intestinal parasites in different dog populations in Northern Belgium. Vet Parasitol 161, 41-46.
Geurden T., Goossens E., Levecke B., Vercammen F., Vercruysse J., Claerebout E., 2009. Occurence and molecular characterisation of Cryptosporidium and Giardia in captive wild ruminants in Belgium. J Zoo Wildl Med 40, 126-30.
Geurden T., Levecke B., Cacció S. M., Visser A., De Groote G., Casaert S., Vercruysse J., Claerebout E., 2009. Multilocus genotyping of Cryptosporidium and Giardia in non-outbreak related cases of diarrhea in human patients in Belgium. Parasitology 136, 1161-1168.
Geurden T., Vercruysse J., Claerebout E., 2009. Is Giardia a significant pathogen in production animals? Exp Parasitol 124, 98-106
Sprong H., Cacciò S.M., van der Giessen J.W. and ZOOPNET network and partners, 2009. Identification of zoonotic genotypes of Giardia duodenalis. PLoS Neglected Tropical Diseases 3(12): e558.
Geurden T., Vandenhoute E., Pohle H., Casaert S., De Wilde N., Vercruysse J., Claerebout E., 2010. The effect of a fenbendazole treatment on cyst excretion and weight gain in calves experimentally infected with Giardia duodenalis. Veterinary Parasitology 169, 18-23
Geurden T., Levecke B., Pohle H., De Wilde N., Vercruysse J., Claerebout E., 2010. A Bayesian evaluation of two dip-stick assays for the on-site diagnosis of clinical giardiasis in calves. Veterinary Parasitology 172, 337-340
Upjohn M., Cobb C., Monger J., Geurden T., Claerebout E., Fox M., 2010. Prevalence, molecular typing and risk factor analysis for Giardia duodenalis infections in dogs in a central London rescue shelter. Veterinary Parasitology 172, 341-346.
Bénéré E., Geurden T., Robertson L., Cos P., Maes L., 2010. Infectivity of different Giardia duodenalis assemblages for the gerbil and in vitro axenisation of trophozoites. Parasitology International, accepted