Prevalence Of Giardia Duodenalis Research Articles

Preliminary investigation of the prevalence and genotype distribution of Cryptosporidium spp., and Giardia duodenalis in cats in Siirt, Turkey

Abstract Cryptosporidium spp. and Giardia duodenalis are protozoan parasites found in humans and many animal species worldwide. The aim of this study was to determine the prevalence and genotypes of Cryptosporidium spp. and Giardia duodenalis in cats and to evaluate the zoonotic potential of these agents. The animal material of the study consisted of a total of 40 cats brought to the Veterinary Faculty. Fresh fecal samples taken from the cats were placed in individual sample containers. All samples were examined under the microscope by Kinyoun Acid Fast staining for Cryptosporidium spp. and by the native-Lugol method for Giardia duodenalis. Nested PCR and sequence analyses were then performed. As a result of microscopic and nested PCR analyses for Cryptosporidium spp., no positivity was found in any sample. The prevalence of Giardia duodenalis was 2.5% in both microscopic examination and nested PCR analyses. When the DNA sequences of the β-Giardin gene obtained in the study were compared with the database in NCBI Basic Local Alignment Search Tool, it was determined that one sample overlapped with Assemblage B samples. As a result of this study, the prevalence of Cryptosporidium spp. and Giardia duodenalis in cats was determined and the presence of Assemblage B was revealed. It is recommended that repetitive studies should be carried out as much as possible to determine the possible role of these parasites in the transmission of these parasites to humans.

Prevalence, Risk Factors and Genotypes of Giardia duodenalis in Sheltered Dogs in Tuscany (Central Italy).

In sheltered dogs, the prevalence of Giardia duodenalis is frequently high and may include potential zoonotic genotypes. The prevalence, genotypes and potential risk factors of G. duodenalis were assessed in 168 dogs from four kennels (Pistoia, Prato, Florence, Valdarno) in Tuscany, central Italy and compared with data from previous Italian studies. The prevalence of other intestinal parasites was also investigated. Individual dog faecal samples collected from each kennel were examined by parasitological techniques and a rapid immunoassay for the detection of G. duodenalis and Cryptosporidium faecal antigens. On Giardia-positive samples, molecular analysis was performed for genotype identification. Overall, 69 dogs scored positive for G. duodenalis (41%), but significant differences (p ≤ 0.05) were found among the four kennels and sampling seasons. The potentially zoonotic assemblages A and B and the canine-specific assemblage C (Pistoia: A-AII, B, C; Prato: A-AII, B; Florence: A-AII; Valdarno: A and C) were identified. Toxocara canis (8.9%), Trichuris vulpis (3.6%), hookworms (1.19%) and Cryptosporidium sp. (0.6%) were also identified. The high prevalence of G. duodenalis and the identification of potentially zoonotic genotypes in all examined kennels underline the need to improve routine parasite monitoring and control measures and to provide insights into the zoonotic potential of G. duodenalis.

Prevalence of intestinal parasites in children from public preschool in the Triple Border Brazil, Argentina, and Paraguay

Introduction: The prevalence of parasitosis in children from Brazilian border cities is unknown. Objective: To identify the prevalence of intestinal parasites in children from public pre-school on the Brazilian border and their socioeconomic and health profile. Methods: Fecal samples were obtained from 178 children from public early childhood educational center (CMEI) in Brazilian border municipalities in Foz do Iguaçu, Brazil. Samples were processed by Hoffman sedimentation and zinc sulfate centrifugation and flotation methods. A questionnaire was administered to children´s parents or guardians regarding parasitic diseases, socioeconomic status, and sanitary habits. Results: The prevalence of intestinal parasites was 26.9% (n=48). A high prevalence of Giardia duodenalis was found (16.3%), followed by Endolimax nana (8.4%), Enterobius vermiculares (1.7%), Ascaris lumbricoides, and Entamoeba coli (0.5%). Forty-seven children (26.4%) presented monoparasitism. The percentage of parasitosis was significantly higher among male children (33.7% - p<0.036) who exhibited weight loss (50.0%), were from low-income families (35.4%- p=0.05), and had mothers with a low education (54.0%-p=0.0001). The highest percentage of Giardia was in children who exhibited weight loss (42.9% - p<0.05) and had mothers with low education (35.0%- p=0.0001). Multivariate analysis indicated that in the variable gender (male gender), weight loss and low maternal education contributed to the variability of parasitosis in children from the surveyed MCEC. Conclusion: The higher prevalence of Giardia was due to child and family variables. The detection of Enterobius vermiculares and Ascaris lumbricoides, despite the low frequency, indicates the need for better basic sanitation policies. Keywords: child; parasites; prevalence; border areas; giardiasis.

Prevalencia de la Giardia duodenalis en el centro de bienestar animal “CEIBA”, Rionegro, Colombia (2017)

Determinar la prevalencia de parasitismo de Giardia duodenalis, en el centro de bienestar “CEIBA”, del municipio de Rionegro, Colombia durante junio 2017. Se realizó un estudio descriptivo transversal, no experimental, aleatorio, fueron evaluados 112 coprológicos de caninos del centro de bienestar “CEIBA”, de ambos sexos, todas las edades y alimentación comercial. Fueron sometidos a evaluación coprológica, por extracción directa de ampolla rectal y evaluada en el Laboratorio Clínico de la Corporación Universitaria Lasallista “Hermano Marco Antonio Serna f.s.c”, fueron realizados dos métodos diagnósticos, flotación con solución salina saturada (Willys Molloy) y frotis directo. La presencia de Giardia duodenalis fue categorizado en escala de cruces de 0-3. Se encontraron 60 (55%) muestras con presencia de parásitos, de los cuales 10 (8,92%) estaban infestados por Giardia duodenalis, representando 16,66% de la parasitosis total, para una cruz 2 (20%), con dos cruces 5 (50%) y con tres 3 (30%). La prevalencia de Giardia duodenalis en el centro de bienestar CEIBA, es baja con respecto a datos de prevalencia en otros albergues o centros caninos, lo cual puede estar influenciado por las medidas de prevención y control de la enfermedad.

Giardia Infection in Recently Acclimatized Kalahari Red Goats in Nigeria

Prevalence of Giardia duodenalis in recently acquired and acclimatized Kalahari Red goats in Nigeria was determined using a commercially produced enzyme-linked immunosorbent assay (ELISA) kit. Giardia duodenalis coproantigens were detected in 46.9% of the faecal samples collected from 98 Kalahari Red goats. The highest (58.1%) and lowest rates (38.2%) were recorded in pre-weaned goat kids up to three months of age and adults goats over one year of age respectively. Infection was higher in females (56.8%) and diarrhoeic goats (75.0%) than males (38.9%) and non-diarrhoeic goats (45.7%) respectively. No significant difference (p>0.05) was observed in the infection rates among age categories, sexes and stool consistencies of the goats. The results of this study showed a high prevalence of Giardia infection in the Kalahari Red goat herd which may imply that they are susceptible to giardiasis if managed under conditions that may facilitate transmission from infected indigenous animals. Key words: ELISA, Giardia , goat, Kalahari Red, Nigeria.

Prevalence and risk factors associated with Giardia duodenalis infection in dairy cattle of Chitwan, Nepal

Livestock farming has been an integral part of Nepalese agriculture systems since time immemorial. Giardia duodenalis is a cosmopolitan intestinal parasite present in a wide range of hosts. Very little or no information is reported on the prevalence of giardiasis in livestock of Nepal. This study was done during Jan 18 to July 19, 2014 to determine the prevalence and associated risk factors of Giardia duodenalis infection in dairy cattle of Chitwan, Nepal. A total of 96 fresh fecal samples were collected from various dairy pocket areas and were transferred to collection bottles with 10% formalin. Wet smears of the samples were prepared, stained with lugol's iodine and then viewed under microscope at 400× magnification. The overall prevalence was found to be 44.79% (43/96). Based on the risk factors assessment survey, age was found to be significantly associated with the prevalence of Giardia duodenalis. The prevalence was found significantly (P<0.05) higher in 1-6 months age group compared to>3 years. Similarly, higher prevalence was found in diarrheic animals compared to their counterparts (P<0.05). Though higher prevalence was recorded in unhygienically housed animals, it was statistically non-significant (P<0.05). Giardiasis should be considered as an important cause of diarrhea and further advanced diagnostic approaches should be employed for the confirmation of giardiasis in dairy cattle.

Comparison of ELISA, nested PCR and sequencing and a novel qPCR for detection of Giardia isolates from Jordan

Little is known about the prevalence of Giardia duodenalis in human patients in Jordan and all previous studies have used direct microscopy, which lacks sensitivity. The present study developed a novel quantitative PCR (qPCR) assay at the β-giardin (bg) locus and evaluated its use as a frontline test for the diagnosis of giardiasis in comparison with a commercially available ELISA using nested PCR and sequencing of the glutamate dehydrogenase (gdh) locus (gdh nPCR) as the gold standard. A total of 96 human faecal samples were collected from 96 patients suffering from diarrhoea from 5 regions of Jordan and were screened using the ELISA and qPCR. The analytical specificity of the bg qPCR assay revealed no cross-reactions with other genera and detected all the Giardia isolates tested. Analytical sensitivity was 1 Giardia cyst per μl of DNA extract. The overall prevalence of Giardia was 64.6%. The clinical sensitivity and specificity of the bg qPCR was 89.9% and 82.9% respectively compared to 76.5 and 68.0% for the ELISA. This study is the first to compare three different methods (ELISA, bg qPCR, nested PCR and sequencing at the gdh locus) to diagnose Jordanian patients suffering from giardiasis and to analyze their demographic data.

Goats in the city: prevalence of Giardia duodenalis and Cryptosporidium spp. in extensively reared goats in northern India

BackgroundVarious characteristics of goats mean they are highly suitable livestock for backyard rearing by people with limited resources. They are a popular livestock choice in India, where they are often kept to supplement an already scarce income. In these settings, hygiene and sanitation standards tend to be low, and weakens the interface between humans and animals, thus reducing the barrier between them and thereby increasing the likelihood that zoonotic and anthroponotic infections will occur.ResultsThis study reports an investigation of the occurrence of Cryptosporidium spp. and Giardia duodenalis in goats being reared in different settings in urban and peri-urban areas in northern India, and addressed the zoonotic potential of these important protozoan parasites shed from goats living close to humans. The overall prevalence of G. duodenalis was 33.8 and 0.5% for Cryptosporidium spp.; the relatively low prevalence of cryptosporidiosis may reflect that most samples were derived from adult animals. The prevalence of G. duodenalis excretion was found to be similar to that reported in other studies. However, although other studies have reported a predominance of non-zoonotic Assemblage E in goats, in this study potentially zoonotic Assemblages predominated [Assemblage A (36%) and Assemblage B (32%)].ConclusionsThe results of this study indicate that in this area where goats and humans are living in close proximity, there may be sharing of intestinal parasites, which can be detrimental for both host species.

Detection of Giardia duodenalis assemblage E infections at the Tibetan Plateau Area: Yaks are suitable hosts

The prevalence of Giardia duodenalis (G. duodenalis) assemblages in yaks is poorly known. The present study examined 297 fecal samples from weaned yak, 4–7 months of age, from 3 different farms, in Tibetan Plateau Area (TPA) of the Qinghai Province in Western China. The prevalence of infection was determined by light and immunofluorescence microscopy, and nested-PCR. PCR was performed for the small subunit ribosomal RNA (SSU) amplified 16 positive for G. duodenalis products. The prevalence of Giardia species was 5.0% (15/297) on light microscopic analysis, 6.1% (18/297) on immunofluorescence test (IFT) and 5.4% (16/297) on nested-PCR. The overall prevalence with the three methods was 5.5%. Ten of the 16 PCR products have been successfully sequenced. Sequence results and phylogenetic analysis of the 18S rRNA sequence data using MEGA5.0 and DNAstar7.0 identified all samples of interest as G. duodenalis assemblage E. This study revealed for the first time the presence of G. duodenalis in yaks from the Qinghai province in China and confirmed that yak is a suitable host for Giardia parasites. The results provide useful information about G. duodenalis prevalence and the epidemiological significance of yak a suitable host to harbor Giardia infections.

Prevalence of Giardiaduodenalis among children from a central region of Cuba: molecular characterization and associated risk factors.

Giardia duodenalis is one of the most frequent intestinal parasitic infections in children worldwide. To date, eight main assemblages of G. duodenalis have been described, but only A and B genetic groups are known to infect humans. A cross-sectional study was conducted to determine the prevalence and risk factors of Giardia duodenalis infection in 417 preschool children from the Fomento municipality in the central region of Cuba between January and June 2013. The overall prevalence of Giardia infection was 10.79%. Assemblage identification was carried out by the amplification of a fragment of the triose phosphate isomerase (tpi) gene. DNA from 36 of 45 (80%) samples was successfully amplified by PCR-tpi. Assemblage B and mixed assemblages A+B represented 52.78 and 36.11% respectively, of genotyped samples. Assemblage A accounts for only 11.11%. Children who were cared for at home were associated with diarrhea caused by assemblage B. No associations were found between other clinical variables with infecting assemblage of Giardia. Univariate analysis identified the use of unsafe water resources (OR 2.9; CI 1.2-6.8) and-even more interestingly-keeping dogs indoor (OR 2.5; CI 1.2-5.4) were significant risk factors associated with Giardia infection among children. Multivariate analysis using introduction test logistic regression ratified the association of these two risk factors: kept dogs indoor (OR 2.8, CI 1.1-5.3), and untreated water (OR 1.4, CI 1.4-4.9) with Giardia infection. This information may be useful for an effective prevention and control programme of giardiasis in this population.

Multilocus genotyping of Giardia duodenalis isolates from calves in Oromia Special Zone, Central Ethiopia

Giardia duodenalis is a widespread protozoan parasite that infects human and other mammals. Assessing the zoonotic transmission of the infection requires molecular characterization as there is considerable genetic variation within the species. This study was conducted to identify assemblages of Giardia duodenalis in dairy calves; and to assess the potential role of cattle isolates in zoonotic transmission in central Ethiopia. A total of 449 fecal samples were collected and screened using microscopy and PCR targeting the small-subunit (ssu) rRNA, triose phosphate isomerase (tpi), β-giardin (bg) and glutamate dehydrogenase (gdh) genes. The overall prevalence of Giardia duodenalis in dairy calves was found to be 9.6% (43/449). The prevalence of infection based on sex, age and breed difference was statistically not significant (p>0.05). Genotyping results revealed the presence of assemblage E and assemblage A (AI). The genotypic frequency reported was 95.3% (41/43) for assemblage E and 4.7% (2/43) for assemblage A. There was one mixed infection with assemblages AI and E. Sequence analyses showed the existence of 10 genotypes within assemblage E. One genotype that showed novel nucleotide substitution was identified at the ssu rRNA locus. The other 9 genotypes, 3 at each locus, were identified at the tpi, the bg and the gdh loci with two of the gdh genotypes were novel. Findings of the current study indicate the occurrence of the livestock-specific assemblage E and the potentially zoonotic assemblage A, with the former being more prevalent. Although the zoonotic assemblage was less prevalent, there is a possibility of zoonotic human infection as AI is reported from both animals and humans.

Multilocus genotyping of Giardia duodenalis isolates from children in Oromia Special Zone, central Ethiopia

BackgroundGiardia duodenalis is the etiologic agent of giardiasis in humans and other mammals worldwide. The burden of disease is high among children in developing countries where sanitation is inadequate. However, the epidemiology and genetic diversity of this parasite is poorly understood in Ethiopia. This study aimed to determine the prevalence and genetic diversity of G. duodenalis in asymptomatic children in Oromia Special Zone, central Ethiopia.ResultsA total of 286 fresh fecal specimens were collected from children and screened using microscopy and PCR. The prevalence of Giardia duodenalis was 10.8 % (31/286) and 16.8 % (48/286) as detected by microscopy and nested PCR, respectively. The infection rate by the study area, sex and age group difference was not significant (P > 0.05). Genotyping results showed that 22.9 % (11/48) of the isolates belonged to assemblage A while 77.1 % (37/48) belonged to assemblage B. Although double peaks were observed at the chromatogram level, no mixed assemblage or sub-assemblage infections were demonstrated. Isolates of assemblage A mostly belonged to the sub-assemblage AII and showed similarity with previously described isolates. However, there was great genetic variability within assemblage B that showed heterogeneous nucleotide positions. Fifteen of them were new genotypes: 5 at the triose phosphate isomerase (tpi), 2 at the β-giardin (bg), and 8 at the glutamate dehydrogenase (gdh) genes.ConclusionsGiardia duodenalis mainly assemblage B infection was predominant among the asymptomatic children in the study area. The high polymorphism found in isolates of assemblage B warrants a more defining tool to discriminate assemblage B at the sub-assemblage level. The findings of the present study indicate that there is a need to carry out national screening programs aiming to detect asymptomatic infections to minimize the reservoir of the disease.Electronic supplementary materialThe online version of this article (doi:10.1186/s12866-016-0706-7) contains supplementary material, which is available to authorized users.

Molecular detection and prevalence of Giardia duodenalis and Cryptosporidium spp. among long-tailed macaques (Macaca fascicularis) in Thailand

Giardia duodenalis and Cryptosporidium spp. are divergent protozoal intestinal parasites that infect human beings and other animals, including non-human primates. Although long-tailed macaques (Macaca fascicularis) reside in human communities in Thailand, the prevalence of Giardia spp. and Cryptosporidium spp. in these primates has not been previously investigated. The objective of this study was to evaluate long-tailed macaques living near human communities as possible hosts of these intestinal parasites. In 2014, 200 fecal samples were randomly collected from long-tailed macaques living in different areas of Lopburi province, Thailand, and tested with a panel of PCR assays for Giardia spp. and Cryptosporidium spp. G. duodenalis assemblage B was most frequently detected (6%), while assemblage A and an inconclusive assemblage were detected in single samples, for a total G. duodenalis infection rate of 7%. Two samples (1%) tested positive for Cryptosporidium spp., which were both classified as monkey genotypes. No significant associations were found between G. duodenalis infection and sex or location of macaques. This study indicates that long-tailed macaques can carry G. duodenalis and, to a lesser extent, Cryptosporidium spp. monkey genotype. These results warrant education of residents and tourists to limit contact with long-tailed macaques and to take hygienic precautions to mitigate risk of zoonotic and anthroponotic transmission of these parasites between people and macaques.

The generation gap: Proteome changes and strain variation during encystation in Giardia duodenalis

The prevalence of Giardia duodenalis in humans is partly owed to its direct and simple life cycle, as well as the formation of the environmentally resistant and infective cysts. Proteomic and transcriptomic studies have previously analysed the encystation process using the well-characterised laboratory genomic strain, WB C6. This study presents the first quantitative study of encystation using pathogenically relevant and alternative assemblage A strains: the human-derived BRIS/82/HEPU/106 (H-106)and avian-derived BRIS/95/HEPU/2041 (B-2041). We utilised tandem MS/MS with a label-free quantitative approach to compare cysts and trophozoite life stages for strain variation, as well as confirm universal encystation markers of assemblage A. A total of 1061 non-redundant proteins were identified from both strains, including trophozoite- and cyst-specific proteomes and life-stage differentially expressed proteins. Additionally, 24 proteins previously classified in the literature as encystation-specific were confirmed as strain-independent markers of encystation. Functional cluster analysis of differentially expressed proteins saw significant overlap between strains, including protein trafficking and localisation in cysts, NEK kinase function, and carbohydrate metabolism in trophozoites. Two significant points of strain specific adaptations in cysts were also identified. B-2041 possessed major up-regulation of the ankyrin repeat protein 21.1 family compared to H-106. Furthermore, cysts of B-2041 retained near-complete VSP variant diversity between cysts and trophozoites, while H-106 lost 45% of its VSP variant diversity between life cycle stages, a constriction previously observed in studies of WB C6. This is the first report of strain variation in the cyst stage in G. duodenalis, and highlights cyst variation and its impacts on reinfection and life cycle success.

Zoonotic potential of Giardia duodenalis and Cryptosporidium spp. and prevalence of intestinal parasites in young dogs from different populations on Prince Edward Island, Canada

The prevalence of Giardia duodenalis, Cryptosporidium spp. and other intestinal parasites was determined in dogs <1 year old from Prince Edward Island, Canada. Fecal samples were collected from the local animal shelter (n=62), private veterinary clinics (n=78) and a pet store (n=69). Intestinal parasites isolated included G. duodenalis, Cryptosporidium spp., Toxocara canis, Isospora spp. and Uncinaria stenocephala. To estimate the zoonotic risk associated with these infections, genotypes of G. duodenalis and Cryptosporidium spp. were determined using 16S rRNA and Hsp70 gene sequencing, respectively.Dogs from the pet store had the highest prevalence of intestinal parasites (78%, 95% CI: 68–88%), followed by the private veterinary clinics (49%, 95% CI: 37–60%), and the local animal shelter (34%, 95% CI: 22–46%).The majority G. duodenalis belonged to host-adapted assemblages D (47%, 95% CI: 31–64%) and C (26%, 95% CI: 13–43%), respectively. Zoonotic assemblages A and B were isolated alone or in mixed infections from 16% (95% CI: 6–31%) of G. duodenalis-positive dogs. All Cryptosporidium spp. were the host-adapted C. canis. While host-adapted, non-zoonotic G. duodenalis genotypes were more common, the presence of G. duodenalis assemblages A and B, T. canis, and U. stenocephala suggests that these dogs may present a zoonotic risk. The zoonotic risk from Cryptosporidium-infected dogs was minimal.

Prevalence and genotypes of Giardia duodenalis from dogs in Spain: possible zoonotic transmission and public health importance

The prevalence of Giardia duodenalis was determinate in faecal samples from dogs and cats in Madrid, Spain and molecular characterisation of isolates. A total of 604 and 144 faecal samples from dogs and cats, respectively, were analysed by routine coprological methods. The prevalence of G. duodenalis was 16.4 % (99/604) in dogs and 4.2 % (6/144) in cats. Sixty-four G. duodenalis isolates (63 from dogs and 1 from a cat) were characterised using glutamate dehydrogenase and β-giardin genes by PCR-RFLP. The single cat sample showed a mixed infection by assemblages A + F. The assemblages found in the dog samples were A, B, C, D and E, both as single and as mixed infections. The zoonotic assemblages A and B were found in 56 (88.8 %) G. duodenalis-positive samples with 15.9 % of samples having assemblage A (10/63) and 73 % of samples with assemblage B (46/63), indicating high potential zoonotic risk and public health significance.

Genotype identification and prevalence of Giardia duodenalis in pet dogs of Guangzhou, Southern China

Giardia duodenalis is a flagellated parasite and is considered one of the most common causes of protozoal diarrhea in both humans and animals worldwide. This paper represents the first study of the prevalence of G. duodenalis in pet dogs in Guangzhou, China. Faecal samples (209 specimens) were obtained from young (<6 months old), adult (6 months to 3 years) and elder dogs (>3 years old). 8.61% (18/209) faecal samples were recorded positive using microscopy examination, and 11.00% (23/209) using PCR. The prevalence was significantly higher in diarrheic dogs (26.31%) compared with non-diarrheic dogs (5.10%), while it was higher in young (25.58%) than both adult (7.37%) and elder (7.04%) dogs and the difference was statistically significant (P<0.05). The prevalence in male dogs 11.30% (13/115) was higher than females 10.87% (10/92), and in suburban dogs (12.15%) higher than urban 9.80%, but the difference was not statistically significant (P>0.05). Sequence analysis of the 23 PCR-positive samples revealed the presence of Assemblage D (18/23), and zoonotic Assemblage A (5/23). The present investigation reported a high infection rate of G. duodenalis in pet dogs, especially in young dogs. Genotypic characterization demonstrated that the zoonotic Assemblage A was found, a fact that poses a potential risk of G. duodenalis transmission from pet dogs to humans. It is suggested that pet owners should take appropriate hygiene measures to prevent and control giardiasis in this region.

Giardia duodenalis and Cryptosporidium Spp. in the Intestinal Contents of Ringed Seals (Phoca hispida) and Bearded Seals (Erignathus barbatus) in Nunavik, Quebec, Canada

The prevalence of Giardia duodenalis and Cryptosporidium spp. was determined for ringed and bearded seals harvested for food in the Nunavik region in northern Quebec, Canada. Flow cytometric results demonstrated that G. duodenalis was present in the intestinal contents of 80% of the ringed seals and 75% of the bearded seals tested, while Cryptosporidium spp. were present in 9% of the ringed seals and none of the bearded seals. Prevalence of both parasites was highest in animals less than 1 yr of age. Giardia sp. isolates from ringed seals were identified as G. duodenalis Assemblage B, which is commonly identified in human infections. The high prevalence of G. duodenalis in ringed seals, and the presence of Assemblage B in these animals, highlights the potential for zoonotic transmission to the Inuit people, who consume dried seal intestines and uncooked seal meat.

Prevalence of Giardia duodenalis and Cryptosporidium spp. in dogs from different living conditions in Uberlândia, Brazil

Infection rates with Giardia duodenalis and Cryptosporidium spp. were compared among dogs living under different conditions. Stool samples ( n = 433) collected from dogs of different ages, gender, living conditions and origin were analyzed using three techniques, i.e., centrifugal flotation in zinc sulfate solution, centrifugal flotation in sucrose solution, and methylene blue gram safranin staining. Eighty-nine of the samples were from stay dogs living in shelters run by animal protection societies, 199 were from kennels and 122 from households. A total of 119 (29.0%) had G. duodenalis cysts and six (1.4%) were positive for Cryptosporidium spp. oocysts. Dogs from kennels were most frequently affected by G. duodenalis (49.7%) while those from shelters showed a higher prevalence of Cryptosporidium spp. (2.2%). A significant difference ( p ≤ 0.05) was observed between immature dogs and adults only with respect to Giardia infection. There was no significant difference between the gender with regard to the presence of either protozoan.

Estimation of diagnostic test characteristics and prevalence of Giardia duodenalis in dairy calves in Belgium using a Bayesian approach

A Bayesian approach was used to determine both the test properties of three diagnostic test procedures and the prevalence of Giardia duodenalis in dairy calves in Belgium. A cross-sectional survey was conducted in the province of East Flanders, Belgium. Between September 2001 and December 2003, a total of 100 farms were visited and faecal samples were obtained rectally from 499 calves aged from newborn to 70 days. Because there is no gold standard for the diagnosis of a G. duodenalis infection in dairy calves, a subset of 235 samples obtained on the first 50 farms, was examined using three different assays: microscopical examination, an immunofluorescence assay (IFA) and an antigen detecting Elisa (ELISA). Based on the results of these three tests, Bayesian analysis indicated that the prevalence of G. duodenalis in dairy calves was 0.19 (95% Confidence Interval: 0.11–0.28) and that ELISA (Sensitivity (Se) 0.89 and Specificity (Sp): 0.90) and IFA (Se: 0.77 and Sp: 0.95) were both sensitive and specific diagnostic techniques, whereas microscopical examination was less sensitive (Se: 0.56 and Sp: 0.87). The proportion of positive farms was estimated as 0.42 (0.24–0.62). The prevalence and the cyst excretion in calves from different age categories were based on data obtained by IFA on all 499 samples. The prevalence was highest among four to five week old calves and remained high among older calves up to 10 weeks, but was lower among calves before the age of two weeks. The number of excreted cysts was estimated by IFA and ranged from 100 to 1,040,000 cysts per gram faeces, with a mean of 3516 cysts per gram faeces. The intensity of excretion peaked among four-week-old calves and remained high among calves up to the age of eight weeks. This is the first known study to use Bayesian analysis to estimate the prevalence of G. duodenalis in the faeces of dairy calves and to estimate test characteristics of diagnostic assays used for the detection of G. duodenalis.