Temporal and spatial dynamics of Cryptosporidium parvum infection on dairy farms in the New York City Watershed: a cluster analysis based on crude and Bayesian risk estimates.

BACKGROUND: Cryptosporidium parvum is one of the most important biological contaminants in drinking water that produces life threatening infection in people with compromised immune systems. Dairy calves are thought to be the primary source of C. parvum contamination in watersheds. Understanding the spatial and temporal variation in the risk of C. parvum infection in dairy cattle is essential for designing cost-effective watershed management strategies to protect drinking water sources. Crude and Bayesian seasonal risk estimates for Cryptosporidium in dairy calves were used to investigate the spatio-temporal dynamics of C. parvum infection on dairy farms in the New York City watershed. RESULTS: Both global (Global Moran's I) and specific (SaTScan) cluster analysis methods revealed a significant (p < 0.05) elliptical spatial cluster in the winter with a relative risk of 5.8, but not in other seasons. There was a two-fold increase in the risk of C. parvum infection in all herds in the summer (p = 0.002), compared to the rest of the year. Bayesian estimates did not show significant spatial autocorrelation in any season. CONCLUSIONS: Although we were not able to identify seasonal clusters using Bayesian approach, crude estimates highlighted both temporal and spatial clusters of C. parvum infection in dairy herds in a major watershed. We recommend that further studies focus on the factors that may lead to the presence of C. parvum clusters within the watershed, so that monitoring and prevention practices such as stream monitoring, riparian buffers, fencing and manure management can be prioritized and improved, to protect drinking water supplies and public health.

Seasonal variation in the prevalence and molecular epidemiology of Cryptosporidium infection in dairy cattle in the New York City Watershed.

We conducted cross-sectional studies in the New York City Watershed to ensure a valid estimate of the risk associated with Cryptosporidium infection in dairy herds. Our aims were to obtain species-specific estimates of the prevalence of Cryptosporidium in dairy cattle and to investigate seasonal variations in prevalence. We validated our empirical estimates using a Bayesian approach. Samples were collected on 32 study farms, once in each of 3 different seasons using an age-stratified sampling design. The overall prevalence of Cryptosporidium parvum-like species and Cryptosporidium andersoni among the 1911 animals tested by the flotation method was 5% and 1%, respectively. Among preweaned calves (<65 days of age), the prevalence of C. parvum-like species was twice as high in the summer (26%) compared with the winter (11%). Herd prevalence showed the same seasonal trend. Preweaned calves were also shedding C. andersoni at an average intensity of 20 oocysts per gram of feces. We did not detect C. parvum-like oocysts in cattle older than 5 months. Sequencing of a portion of the 18s rRNA gene revealed that in the summer, 42% of the C. parvum-like oocysts shed by preweaned calves were zoonotic, compared with >74% during the rest of the year. Both empirical and stochastic methods revealed a summer peak in the prevalence of C. parvum-like oocysts in preweaned calves. Determining whether seasonal variation in the prevalence and proportion of Cryptosporidium species shed by preweaned calves is due to management practices or ecological factors will have important implications for effective control of this parasite.

Eurytrema procyonis and pancreatitis in a cat.

A young adult male domestic shorthair cat was presented for physical examination, routine vaccinations, and a fecal examination. Physical examination revealed no significant abnormalities. Eggs of the raccoon pancreatic fluke Eurytrema procyonis were detected by fecal flotation. Results of a complete blood count and serum biochemistry panel were normal. Abdominal sonography revealed an enlarged hypoechoic pancreas with a hyperechoic rim, and a distended and thickened pancreatic duct. Serum pancreatic lipase immunoreactivity (PLI) was increased. These findings supported the possibility of fluke-associated pancreatitis. Treatment with praziquantel/pyrantel/febantel was associated with resolution of sonographic abnormalities and normalization of PLI.

A survey of parasites identified in the feces of eastern spotted skunks (Spilogale putorius) in western Arkansas.

The endoparasite community of the eastern spotted skunk (Spilogale putorius) is poorly known. We surveyed parasites found in the feces of 29 eastern spotted skunks captured between March 2005 and January 2007 from a population in west-central Arkansas as part of a broader study of the ecology of the species. We identified 13 species (nine nematodes, four protozoa) from 82 fecal samples. Mean (+/-SD) number of species per individual skunk was 4.1+/-2.1, although this is likely an underestimate because some individuals were sampled more intensively than others. Most of the identified parasite species were also found in other skunk species or in other small carnivore species.

Prevalence of Cryptosporidium species in wildlife populations within a watershed landscape in southeastern New York State.

A cross-sectional study was conducted to determine the prevalence of Cryptosporidium in wildlife in the New York City (NYC) Watershed in southeastern New York State. A total of 6227 fecal samples were collected and evaluated from 5892 mammals (38 species), 263 birds (14 species), 2 reptiles (2 species), 8 amphibians (4 species), and 62 fish (15 species). Cryptosporidium was detected in 30 species. Of the species found positive for Cryptosporidium, 16 represented new records for this parasite-Alosa pseudoharengus, Larus delawarensis, Blarina brevicauda, Sorex cinereus, Parascalops breweri, Myotis lucifugus, Peromyscus maniculatus, Microtus pennsylvanicus, Clethrionomys gapperi, Tamiasciurus hudsonicus, Marmota monax, Erethizon dorsatum, Canis latrans, Mustela erminea, Mustela vison, and Lynx rufus. Factors such as age, sex, season, and land use were evaluated to determine if there was any association with infection by this parasite. Animals were more likely to be positive for Cryptosporidium during spring and in agricultural land use.

Cryptosporidium spp. from small mammals in the New York City watershed.

The objective of this study was to assess the potential role that wildlife plays in environmental degradation of watersheds through the contamination of the water supply with zoonotic genotypes of Cryptosporidium. Cryptosporidium isolates recovered from wildlife in the New York City (NYC) watershed were examined to determine genotype using a polymerase chain reaction protocol targeting the 18-Small Subunit (SSU) rRNA locus. Seventy-seven DNA samples recovered from 12 wildlife host species captured in the NYC watershed were amplified and sequenced. Data on risk factors associated with the perpetuation of these genotypes also were collected and analyzed. Although many genotypes appeared to be host-specific, 38% of the samples examined were identified as Cryptosporidium parvum, indicating the presence of zoonotic Cryptosporidium. Adult animals were more likely to shed the zoonotic strains of Cryptosporidium spp. Animals captured in the fall and winter were more likely to be infected with C. parvum than those captured in spring and summer.

Evaluation of polymerase chain reaction diagnosis of Cryptosporidium spp in dairy cattle and wildlife.

This study investigated the utility of the polymerase chain reaction (PCR) protocol as a screening test for Cryptosporidium spp in 125 fecal samples from dairy cattle and wild rodents. Samples initially examined by fecal flotation and ELISA were evaluated using four PCR protocols (18S SSU rRNA, TRAP-C2, HSP70, and COWP), and the relative accuracy and agreement of PCR protocols was assessed. Although PCR can be both highly sensitive and accurate, the ability of these protocols to accurately detect DNA in samples can vary. A combination of techniques may be the best choice for to screen samples for this parasite.

Factors associated with shedding of Cryptosporidium parvum versus Cryptosporidium bovis among dairy cattle in New York State.

OBJECTIVE: To isolate and speciate Cryptosporidium DNA from fecal samples obtained from dairy cattle in New York State and identify factors associated with whether cattle were shedding Cryptosporidium parvum versus Cryptosporidium bovis. DESIGN: Cross-sectional study. SAMPLE POPULATION: 115 fecal samples positive for DNA coding for the Cryptosporidium 18S rRNA gene from dairy cattle in New York State. PROCEDURES: A PCR assay was used to amplify DNA from fecal samples; amplification products were submitted for bidirectional DNA sequencing. Logistic regression was used to test for associations between various host factors and Cryptosporidium spp. RESULTS: 70 of the 115 (61%) fecal samples were found to have C parvum DNA, 42 (37%) were determined to have C bovis DNA, and 3 (3%) were found to have C parvum deer-type DNA. The presence of diarrhea at the time of fecal sample collection, oocyst count, and breed were associated with whether cattle were infected with C parvum or C bovis, with animals more likely to be infected with C parvum if they had diarrhea, had a high oocyst count, or were Holsteins. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that C parvum and C bovis can be isolated from dairy cattle in New York State and that various factors affect whether cattle infected with Cryptosporidium spp are infected with C parvum or C bovis. Findings also lend credence to the theory that C bovis may be more host adapted and thus less pathogenic to dairy cattle than C parvum.

Parasites of free-ranging small canids and felids in the Bolivian Chaco.

Parasite surveys of free-ranging wildlife provide important information for monitoring population health. Between March 2001 and March 2003, we sampled 10 ocelots (Leopardus pardalis), eight Geoffroy's cats (Oncifelis geoffroyi), a jaguarundi (Herpailurus yaguarondi), five pampas foxes (Pseudalopex gymnocercus), and three crab-eating foxes (Cerdocyon thous) at three sites in the Bolivian Chaco. The objective of the study was to survey the parasite fauna of these carnivores and compare prevalence of parasites among the sites. The parasite community of these carnivores was diverse, with representatives from eight genera of nematodes, two families of cestodes, two protozoan species, and six arthropod species. Fecal parasites identified from 12 of the 13 felids and five of the six canids examined included Aelurostrongylus abstrusus, Ancylostoma tubaeforme, Uncinaria sp., Crenosoma sp., Toxocara cati, Spirurida, Capillaria aerophila, Spirometra sp., Taeniidae, and Cystoisospora sp. Four tick species, Amblyomma parvum, A. tigrinum, A. ovale, and A. cajennense, and two flea species, Pulex irritans and Delostichus phyllotis, were identified. Two crab-eating foxes had serologic evidence of heartworm disease (HWD). Antibodies against Toxoplasma gondii were found in 15 of 26 animals. Although HWD was found only in canids inside the national park, parasite prevalence did not appear to differ among sites, and no evidence was found of parasite spillover from domestic to wild carnivores.

Incidence of Cryptosporidium parvum in the dairy cattle population in a New York City Watershed.

A longitudinal study of 2-year duration was conducted to determine the risk, as measured by incidence rate, of Cryptosporidium parvum infection among dairy cattle in the Catskill/Delaware Watershed of New York City (NYC), and the factors that predispose animals to the likelihood of infection. A proportional sampling scheme with follow up at quarterly farm visits was employed for heifers and cows. Additionally, all calves born on the 39 study farms were sampled once during the first four weeks of life and at least once more before weaning. Samples were analyzed for the presence of C. parvum using a quantitative centrifugation concentration flotation technique and a C. parvum-specific enzyme-linked immunosorbent assay (ELISA). Of the 9914 fecal samples collected, 747 were found to contain C. parvum. The average number of oocysts detected was 1.3x10(5)/g (range: 1.0/g--8.2x10(6)/g). The average age at time of first detection of the organism was 15.0 days with a standard deviation of 6.59 days. The age range of animals infected with C. parvum in the study population was 3--60 days (inclusive). The unadjusted (crude) incidence rate of C. parvum among the entire study population was 2.05 per 1000 animal-days. The unadjusted incidence rate among pre-weaned calves was 15.55 per 1000 animal-days. After controlling for age and prior protozoal risk level, no seasonal impact on the incidence of C. parvum was detected among animals less than 61 days by negative binomial regression. A seasonal impact was identified among the oocyst counts of infected animals after controlling for age and prior protozoal risk level.

Risk of infection with Cryptosporidium parvum and Cryptosporidium hominis in dairy cattle in the New York City watershed.

OBJECTIVE: To determine the risk posed by Cryptosporidium parvum and Cryptosporidium hominis from dairy cattle in the New York City watershed (NYCW). SAMPLE POPULATION: Samples from cattle at risk for shedding Cryptosporidium organisms on randomly selected dairy farms in the NYCW. PROCEDURE: Feces were collected for 4 years from calves at risk for infection on 37 dairies. Oocysts were detected by use of centrifugation concentration-flotation microscopy. The DNA was directly isolated from fecal samples and used to amplify fragments of the small subunit ribosomal RNA and thrombospondin-related adhesion protein C-2 genes by use of nested polymerase chain reaction assays. Small subunit ribosomal RNA fragments were restriction digested by the enzyme Vspl and thrombospondin-related adhesion protein C-2 fragments were digested by Eco91l to distinguish between C hominis (formerly known as genotype 1) and C parvum (formerly known as genotype 2). RESULTS: Of 437 fecal samples examined, 214 contained oocysts. Amplicons were generated for 200 samples. We can be certain, with 95% confidence, that cattle in the NYCW did not harbor C hominis. CONCLUSIONS AND CLINICAL RELEVANCE: Cryptosporidium infections in cattle are under examination because of the potential contamination of public waters by manure. Although cattle may be the source of zoonotic infection via C parvum, they pose little risk for C hominis (the strain commonly isolated from humans in waterborne outbreaks of disease). Other sources of oocysts should be considered when investigating outbreaks attributable to contaminated urban drinking water because cattle pose only a small risk via shedding of C hominis.

A serological and fecal parasitologic survey of the critically endangered pygmy raccoon (Procyon pygmaeus).

The pygmy raccoon (Procyon pygmaeus) of Cozumel Island, Mexico, is among the most endangered carnivores in the world, and causes of its decline are unclear. During 2002 and 2003, we sampled approximately 10% of the remaining population to survey exposure to viral and parasitic pathogens that may have contributed to population decline. We found evidence of exposure to infectious canine hepatitis, canine distemper, feline panleukopenia virus, and Toxoplasma gondii. The latter is suggestive of spillover from domestic cats, which have only recently been introduced to the island. Additional parasites identified include Eimeria nutalli, Placoconus lotoris, Capillaria procyonis, Physaloptera sp., a mite in the family Listrophoridae, and a trematode in the family Heterophyidae. Several of these are typical of the parasite community of the common raccoon (Procyon lotor).

Gastrointestinal Parasites of Ecuadorian Mantled Howler Monkeys (Alouatta palliata aequatorialis) Based on Fecal Analysis.

An analysis of gastrointestinal parasites of Ecuadorian mantled howler monkeys, Alouatta palliata aequatorialis, was conducted based on examination of fecal smears, flotations, and sedimentations. At least 1 type of parasite was detected in 97% of the 96 fecal samples screened across 19 howler monkey groups using these techniques. Samples averaged 3.6 parasite species per individual (±1.4 SD). Parasites included species representing genera of 2 apicomplexans: Cyclospora sp. (18% of individual samples) and Isospora sp. (3%); 6 other protozoa: Balantidium sp. (9%), Blastocystis sp. (60%), Chilomastix sp. (4%), Dientamoeba sp. (3%), Entamoeba species (56%), Iodamoeba sp. (5%); 4 nematodes: Enterobius sp. (3%), Capillaria sp. (78%), Strongyloides spp. (88%) which included 2 morphotypes, Trypanoxyuris sp. (12%); and the platyhelminth Controrchis sp. (15%). A statistically significant positive correlation was found between group size and each of 3 different estimators of parasite species richness adjusted for sampling effort (ICE: r(2) = 0.24, P = 0.05; Chao2: r(2) = 0.25, P = 0.05, and Jackknife: r(2) = 0.31, P = 0.03). Two significant associations between co-infecting parasites were identified. Based on the prevalence data, individuals infected with Balantidium sp. were more likely to also be infected with Isospora sp. (χ(2) = 6.02, P = 0.01), while individuals harboring Chilomastix sp. were less likely to have Capillaria sp. present (χ(2) = 4.03, P = 0.04).

Microlichus americanus acariasis in saffron finches (Sicalis flaveola) with dermatitis and feather loss.

Over a 5-year period, 13 saffron finches (Sicalis flaveola) housed in mixed aviaries at the Bronx Zoo (Bronx, New York) were examined with feather loss and dermatitis, primarily affecting the nape, neck, and dorsum. Feather loss, hyperkeratosis, epidermal hyperplasia, and mixed granulocytic and mononuclear inflammation were identified in biopsies from live birds and tissue sections from postmortem specimens. In 10 of 13 cases, sections of arthropod parasites were seen histologically within feather follicles and along the surface of affected skin. Based on morphological characteristics, mites recovered from samples of formalin-fixed skin in 4 birds were identified as Microlichus americanus, an epidermoptid mite infrequently reported from wild birds and hippoboscid flies. Gross and histological lesions strongly implicate M. americanus as the cause of dermatitis affecting practically all saffron finches in the collection.

The sensitivity of PCR detection of Cryptosporidium oocysts in fecal samples using two DNA extraction methods.

BACKGROUND: The implementation of cost-effective intervention strategies for zoonotic protozoa relies on the development of sensitive and accurate diagnostic methods. We carried out a study to evaluate the accuracy of a PCR method for the detection of Cryptosporidium spp. oocysts in fecal samples from cattle. METHODS: Fecal samples were spiked with different numbers of oocysts and the limit of detection of the method was determined. Two methods of DNA extraction were assessed: glass beads and freeze-thawing using liquid nitrogen. A nested PCR approach was developed targeting the Cryptosporidium SSU rRNA and TRAP-C2 genes. Agreement between the diagnosis of Cryptosporidium spp. at the SSU rRNA and TRAP-C2 loci was quantified using the kappa-coefficient. RESULTS: Compared with the freeze-thawing method, the glass beads method was found to be a better way of extracting DNA from Cryptosporidium oocysts (sensitivities were 83 and 100%, respectively). The limits of detection for glass beads and freeze-thaw were low, 1 and 10 oocyst/g fecal samples, respectively. Forty-six percent of the field samples previously classified as negative for Cryptosporidium parvum by the flotation-concentration and enzyme-linked immunosorbent assay methods showed DNA with the PCR protocol. CONCLUSION: Primers for SSU rRNA are more successful in producing an amplification than primers for the TRAP-C2 gene which makes the former PCR protocol the approach of choice for detecting Cryptosporidium parvum oocysts in field samples.

A novel multiplex polymerase chain reaction approach for detection of four human infective Cryptosporidium isolates: Cryptosporidium parvum, types H and C, Cryptosporidium canis, and Cryptosporidium felis in fecal and soil samples.

A nested multiplex polymerase chain reaction (PCR) approach was adopted for the simultaneous detection of 4 human infective genotypes of the protozoan parasite Cryptosporidium. Specific PCR primers were designed for the heat shock protein 70 gene of 2 genotypes of Cryptosporidium parvum (human and bovine types), Cryptosporidium canis, and Cryptosporidium felis. These 4 genotypes have all been found in human fecal samples. The primers amplified DNA fragments of specific sizes, each representing a unique genotype. The limit of detection of the method was found to vary between 10 and 100 oocysts per 1 ml fecal material. There appeared to be no cross-reactivity with other organisms commonly present in feces and soil, and the approach has a high specificity. The rapid identification of various human infective Cryptosporidium isolates is a part of the authors' long-term aim of determining the routes of infection with oocysts and thereby increase their epidemiological understanding of Cryptosporidium infection in humans and animals.

A survey of the parasites of coyotes (Canis latrans) in New York based on fecal analysis.

Coyotes (Canis latrans) have colonized northeastern North America only within the past 10-80 yr. We examined feces of coyotes in 2000-01 at three sites in New York (USA) to survey parasites in the region. Two cestodes, nine nematodes, five protozoa, one trematode, and two arthropods were identified from 145 coyote fecal samples. Parasite component community diversity was higher (n = 16 species) in southern New York than in middle and northern sites (nine species each) and infracommunity species richness was greater in southern New York than at the other sites. These differences may reflect the variable diets of coyotes, as well as recent colonization of the region and the mixing of component communities from expanding coyote populations.

Udder cleft dermatitis and sarcoptic mange in a dairy herd.

OBJECTIVE: To determine prevalence of udder cleft dermatitis in a dairy herd that was experiencing an outbreak of sarcoptic mange. DESIGN: Clinical survey. ANIMALS: 1,597 Holstein cows and late-gestation heifers. PROCEDURE: Animals were examined for udder cleft dermatitis and for skin lesions consistent with sarcoptic or chorioptic mange. Skin scrapings were collected from 56 cows and examined for ectoparasites. The herd was revisited 1 year later, and prevalences of udder cleft dermatitis and lesions consistent with mange were determined in 506 cows. RESULTS: Of the 1,597 cattle examined, 280 (18%) had udder cleft dermatitis, and 1,397 (87.5%) had lesions consistent with mange. In 43 of 56 (77%) cows, skin scrapings revealed Sarcoptes mites. Udder cleft dermatitis was significantly more common in older than in younger cows. In first-lactation cows, udder cleft dermatitis was less common during the first 4 months of lactation than in the later stages of lactation, but udder cleft dermatitis was identified in cows in all stages of lactation and in cows that were not lactating. The herd was treated with eprinomectin to control mites, and prevalence of lesions consistent with mange 1 year later was only 2.8%. However, prevalence of udder cleft dermatitis was still 12%. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that cows in any stage of lactation and cows that are not lactating can have udder cleft dermatitis but that lesions are more common in older cows. Control of sarcoptic mange was accompanied by a moderate reduction in the prevalence of udder cleft dermatitis but did not eliminate the condition.

Prevalence of antibodies to Toxoplasma gondii in white-tailed deer (Odocoileus virginianus) in New York State, USA.

Sera collected from 299 white-tailed deer (Odocoileus virginianus) harvested in New York State by hunters in November 2010 were assayed for anti-Toxoplasma gondii IgG antibodies. White-tailed deer are a useful sentinel for risk of human and domestic animal exposure to Toxoplasma oocysts and pose a potential risk for infection to humans and other animals by ingestion of the meat. White-tailed deer share grazing space with domestic animals raised for meat and are likely to be exposed by horizontal transmission through oocyst consumption, similar to other grazing species of economic concern. Overall, 42.2% of samples were positive by enzyme-linked immunosorbent assay, indicating a true prevalence of 38.5%, with a significantly higher proportion of adult than immature deer antibody positive. No significant difference in prevalence was found between male and female deer nor was there a significant effect of local human population density on deer antibody prevalence. These results provide insight into the risk of environmental Toxoplasma exposure in New York State and support horizontal transmission through oocyst consumption as the most common mechanism of white-tailed deer infection.

Characterization of Giardia duodenalis infections in dogs in Trinidad and Tobago.

To our knowledge, the zoonotic potential of Giardia duodenalis has not been assessed in companion animals in Trinidad and Tobago. This report details the first attempt to evaluate the potential zoonotic risk of G. duodenalis in dogs and identify assemblages of G. duodenalis found in dog populations on both islands. Fecal samples were collected from free-roaming dogs and dogs at the Trinidad and Tobago Society for the Prevention of Cruelty to Animals from October 2010 to June 2011. A total of 168 samples were collected of which 104 samples were analyzed for the presence of G. duodenalis by PCR amplification of the ssu-rRNA gene with subsequent assemblage-typing. A subset of samples was also analyzed by ELISA. Twenty-six samples were positive for G. duodenalis by PCR for an overall prevalence of 25%. Four samples were identified as assemblage C (15.4%), 21 as assemblage D (80.8%), and one as assemblage E (3.8%). Puppies were four-times more likely to be infected with G. duodenalis than adult dogs (OR 4.61, 95% CI 1.73-12.2). There was a significant agreement between ELISA and PCR in the detection of the protozoa (κ=0.67). We infer from our results that while the prevalence of G. duodenalis is relatively high in Trinidad and Tobago, the zoonotic risk of infection in humans is low since neither assemblage A nor B was identified in the study population.