Diversity and prevalence of parasitic infestation with zoonotic potential in dromedary camel ( Camelus dromedarius ) and fat-tailed sheep (dhumba) in Bangladesh.

OBJECTIVE: Parasitic infestation is a major cause of losses in livestock production in tropical regions. A cross-sectional study was conducted to determine the prevalence of Gastro-intestinal (GI) parasites of dromedary camel (Camelus dromedarius) and fat-tailed sheep (dhumba), and the prevalence of hemoparasites in camel from Dhaka, Bangladesh. MATERIALS AND METHODS: A total of 87 fecal samples (32 dhumba and 55 camel) and 55 camel blood samples were collected during September-October 2015. Fecal samples were examined by direct smear, sedimentation method, flotation technique, and McMaster technique for GI parasite. Giemsa stained blood smears were examined under microscope for hemoparasite detection. RESULTS: 62% camel (n = 34; 95% confidence interval (CI): 47.7-74.6) were infected with at least one genus of parasite. 15% camel were harboring more than one genus of parasite. The prevalence of GI parasite and hemoparasite in camel were recorded as Trichuris spp. (n = 16; 29%; 95% CI: 17.6-42.9), Balantidium coli (n = 12; 22%; 95% CI: 11.8-35.0), Trichostrongylus spp. (n = 7; 13%; 95% CI: 5.3-24.5), Strongyloides spp. (n = 5; 9%; 95% CI: 3.0-20.0), Anaplasma spp. (n = 5; 9%; 95% CI: 3.02-20.0), Paragonimus spp. (n = 1; 2%; 95% CI: 0.05-9.7), Schistosoma spp. (n = 1; 2%; 95% CI: 0.05-9.7), Hymenolepis spp. (n = 1; 2%; 95% CI: 0.05-9.7), Moniezia spp. (n = 1; 2%; 95% CI: 0.05-9.7), and Babesia spp. (n = 1; 2%; 95% CI: 0.05-9.7). Mean EPG feces of camel was 291.76 ± 42.03 with a range of 0-1,400. Total 59.4% dhumba (n = 19; 95% CI: 41-76) were positive for GI parasite, including Trichostrongylus spp. (n = 10; 31.3%; 95% CI: 16.1-50), Strongyloides spp. (n = 9; 28%; 95% CI: 13.8-46.8), B. coli (n = 5; 15.6%; 95% CI: 5.3-32.8), and Trichuris spp. (n = 4; 12.5%; 95% CI: 3.5-28.9). CONCLUSIONS: High percentage of parasitic infestation in camel and dhumba in the present study refers to the necessity of use of anthelmintic for health and production improvement and to prevent zoonotic parasite transmission to animal handler and workers.

A clinical guideline on Dientamoeba fragilis infections.

Dientamoeba fragilis (D. fragilis) is an intestinal parasite frequently detected in humans with abdominal pain and diarrhoea, but it is also commonly found in asymptomatic subjects. Hence its clinical relevance is often disputed. The introduction of polymerase chain reaction (PCR) is a versatile and sensitive diagnostic technique for the detection of intestinal parasites, and in some Western world countries PCR has almost completely replaced microscopic diagnostics. PCR has however resulted in an increase in the number of D. fragilis-positive patients. The disputed pathogenic nature of this intestinal parasite and an apparent increase in the incidence of patients with positive PCR results have renewed the discussions between clinicians and microbiologists on how to deal with an infected patient. Moreover, treatment guidelines differ throughout the world which makes it difficult for clinicians to choose an optimal therapeutic regimen.AimTo summarize and discuss the current knowledge on the pathogenicity, best diagnostic approach, treatment and follow-up of children and adults infected with D. fragilis.

Diagnosis of Strongyloides stercoralis: Detection of parasite-derived DNA in urine.

Detecting infections of Strongyloides stercoralis is arduous and has low sensitivity. Clinically this is a major problem because chronic infections may disseminate in the host and lead to a life threatening condition. Epidemiologically, S. stercoralis is often missed in surveys as it is difficult to identify by standard stool examination procedures. We present, for the first time, evidence that the infection can be detected in filtered urine samples collected and processed in the field and subsequently assayed for the presence of parasite DNA. Urine specimens (∼40mL) were collected from 125 test and control individuals living in rural and peri-urban regions of Northern Argentina. From the same individuals, fresh stool specimens were processed using three different copropological methods. Urine specimens were filtered in the field through a 12.5cm Whatman No. 3 filter. The filters were dried and packed individually in sealable plastic bags with desiccant and shipped to a laboratory where DNA was recovered from the filter and PCR-amplified with primers specific to a dispersed repetitive sequence. Prevalence of S. stercoralis infection by stool culture and direct examination was 35/125 (28%), In contrast, PCR-based detection of parasite-specific trans-renal DNA in urine indicated that 56/125 (44.8%) carried the parasite. Of the patients that tested positive for urine-based parasite DNA, approximately half also tested positive in their stool specimens. There were 6.4% of cases where parasite larvae were seen in the stool but no DNA was amplified from the urine. As proof of principle, DNA amplification from urine residue reveals significantly more cases of S. stercoralis infection than the current standard stool examination techniques. Additional work is required to establish the relative utility, sensitivity and specificity of urine-based analysis compared to parasitological and nucleic acid detection from stool for clinical and epidemiological detection for S. stercoralis infection.

Genetic characterization of human-pathogenic Cyclospora cayetanensis parasites from three endemic regions at the 18S ribosomal RNA locus.

Cyclospora cayetanensis is an apicocomplexan parasite that infects the gastrointestinal tract and causes acute diarrheal disease in humans. In recent years, this human-pathogenic parasite has led to several foodborne outbreaks in the United States and Canada, mostly associated with imported produce. Understanding the biology and epidemiology of C. cayetanensis is difficult because little is known about its origin, possible zoonotic reservoirs, and genetic relationships with other coccidian parasites. Recently, we developed a 70kDa heat shock protein (HSP70) gene based nested PCR protocol for detection of C. cayetanensis parasite and sequenced the PCR products of 16 human isolates from Nepal, Mexico, and Peru. In this study, we have characterized the regions of 18S ribosomal RNA (rRNA) gene of 17 human C. cayetanensis isolates for molecular detection, and also to ascertain the genetic diversity of this parasite. The 18S rRNA primer sets were further tested by PCR amplification followed by nucleotide sequencing of the PCR amplified products of previously characterized C. cayetanensis isolates from three endemic regions at HSP70 locus. Although no genetic polymorphism was observed at the regions of HSP70 locus characterized in our previous study, the data analysis of this study revealed a minor genetic diversity at the 18S rRNA locus among the C. cayetanensis isolates. The 18S rRNA gene-based nested PCR protocol provides a useful genetic marker for the detection of C. cayetanensis parasite and confirms it as a genetically distinct species in genus Cyclospora. The results also supported lack of geographic segregation and existence of genetically homogeneous population for the C. cayetanensis parasites both at the HSP70 as well as at the18S rRNA loci.