In many countries, urban areas are commonly contaminated with canine feces that spread parasites, a situation related to the natural and social environment. Dogs having free access to public areas therefore constitutes a health risk. Because in Patagonia there are no records of city comparisons that consider the number of free-roaming dogs and the local environmental and socioeconomic characteristics, in this study we analyse and compare canine parasitoses in two cities of Rio Negro province, Argentina. Canine feces were collected from public areas of El Bolsón and Cipolletti cities and examined using enrichment methods, Kinyoun stain and immunoassay (Copro-Elisa). The total percentage of positive feces in El Bolsón was 68.95% and 16 parasite taxa being identified, whereas in Cipolletti the total positive feces was 41.1%, with 11 taxa. Both cities presented more helminth species than protozoans. The variables that explained the occurrence of all parasites were rainfall and socioeconomic stratum with the highest values being found in low-income areas.

Soil moisture is conditioned by rainfall. This study highlights the presence of the zoonotic Echinococcus sp. in dogs in urban areas of the Rio Negro province. The occurrence of this parasite in Cipolletti is unexpected, given that this city is not considered an endemic zone for this disease, which is not included in local monitoring and control plans.

Interpretation errors may still represent a limiting factor for diagnosing Cryptosporidium spp. oocysts with the conventional staining techniques. Humans and machines can interact to solve this problem. We developed a new temporary staining protocol associated with a computer program for the diagnosis of Cryptosporidium spp. oocysts in fecal samples. We established 62 different temporary staining conditions by studying 20 experimental protocols. Cryptosporidium spp. oocysts were concentrated using the Three Fecal Test (TF-Test®) technique and confirmed by the Kinyoun method. Next, we built a bank with 299 images containing oocysts. We used segmentation in superpixels to cluster the patches in the images; then, we filtered the objects based on their typical size. Finally, we applied a convolutional neural network as a classifier. The trichrome modified by Melvin and Brooke, at a concentration use of 25%, was the most efficient dye for use in the computerized diagnosis. The algorithms of this new program showed a positive predictive value of 81.3 and 94.1% sensitivity for the detection of Cryptosporidium spp. oocysts. With the combination of the chosen staining protocol and the precision of the computational algorithm, we improved the Ova and Parasite exam (O&P) by contributing in advance toward the automated diagnosis.

Schistosoma mekongi, a blood-dwelling fluke, is a water-borne parasite that is found in communities along the lower Mekong River basin, i.e. Cambodia and Lao People's Democratic Republic. This study developed a real-time PCR assay combined with melting-curve analysis to detect S. mekongi in laboratory setting conditions, in experimentally infected snails, and in fecal samples of infected rats. The procedure is based on melting-curve analysis of a hybrid between an amplicon from S. mekongi mitochondrion sequence, the 260 bp sequence specific to S. mekongi, and specific fluorophore-labelled probes. This method could detect as little as a single cercaria artificially introduced into a pool of 10 non-infected snails, a single cercaria in filtered paper, and 2 eggs inoculated in 100 mg of non-infected rat feces. All S. mekongi-infected snails and fecal samples from infected rats were positive. Non-infected snails, non-infected rat feces, and genomic DNA of other parasites were negative. The method gave high sensitivity and specificity, and could be applied as a fast and reliable tool for cercarial location in water environments in endemic areas and for epidemiological studies and eradication programmes for intermediate hosts.

Parasites are increasingly recognized for their profound influences on individual, population and ecosystem health. We provide the first report of gastrointestinal parasites in gray wolves from the central and north coasts of British Columbia, Canada. Across 60 000 km2, wolf feces were collected from 34 packs in 2005–2008. At a smaller spatial scale (3300 km2), 8 packs were sampled in spring and autumn. Parasite eggs, larvae, and cysts were identified using standard flotation techniques and morphology. A subset of samples was analysed by PCR and sequencing to identify tapeworm eggs (n=9) and Giardia cysts (n=14). We detected ⩾14 parasite taxa in 1558 fecal samples. Sarcocystis sporocysts occurred most frequently in feces (43·7%), followed by taeniid eggs (23·9%), Diphyllobothrium eggs (9·1%), Giardia cysts (6·8%), Toxocara canis eggs (2·1%), and Cryptosporidium oocysts (1·7%). Other parasites occurred in ⩽1% of feces. Genetic analyses revealed Echinococcus canadensis strains G8 and G10, Taenia ovis krabbei, Diphyllobothrium nehonkaiense, and Giardia duodenalis assemblages A and B. Parasite prevalence differed between seasons and island/mainland sites. Patterns in parasite prevalence reflect seasonal and spatial resource use by wolves and wolf-salmon associations. These data provide a unique, extensive and solid baseline for monitoring parasite community structure in relation to environmental change.