Occurrence and molecular diagnosis of Cryptosporidium serpentis in captive snakes in São Paulo, Brazil

Minimal zoonotic risk of cryptosporidiosis and giardiasis from frogs and reptiles

The zoonotic potential of the protist parasites Cryptosporidium spp. and Giardia duodenalis in amphibians and reptiles raises public health concerns due to their growing popularity as pets. This review examines the prevalence and diversity of these parasites in wild and captive amphibians and reptiles to better understand the zoonotic risk. Research on Giardia in both groups is limited, and zoonotic forms of Cryptosporidium or Giardia have not been reported in amphibians. Host-adapted Cryptosporidium species dominate in reptiles, albeit some reptiles have been found to carry zoonotic (C. hominis and C. parvum) and rodent-associated (C. tyzzeri, C. muris and C. andersoni) species, primarily through mechanical carriage. Similarly, the limited reports of Giardia duodenalis (assemblages A, B and E) in reptiles may also be due to mechanical carriage. Thus, the available evidence indicates minimal zoonotic risk associated with these organisms in wild and captive frogs and reptiles. The exact transmission routes for these infections within reptile populations remain poorly understood, particularly regarding the importance of mechanical carriage. Although the risk appears minimal, continued research and surveillance efforts are necessary to gain a more comprehensive understanding of the transmission dynamics and ultimately improve our ability to safeguard human and animal health.

Cryptosporidium species in non-human animal species in Latin America: Systematic review and meta-analysis

Cryptosporidiosis is an infection caused by a protozoon that inhabits the gastrointestinal tract. More than forty valid species have been described in the genus Cryptosporidium, infecting a broad range of hosts around the world, some with zoonotic transmission and others with predominant anthroponotic transmission. Prevalence studies conducted in Latin American countries have been specific, without consolidating information on species prevalences. Thus, the aim of this study was to perform a systematic review and meta-analysis addressing the prevalence of Cryptosporidium species in animals in Latin America. The estimated pooled prevalence rate for cryptosporidiosis in animals, by means of meta-analysis with a random-effects model, based on species identification, was 18.0% (95% CI 11.0%-27.0%) with high heterogeneity. The estimated overall prevalence was 20.3% (36/177) in pets, 19.9% (1309/6573) in livestock animals and 23.9% (954/3995) in exotic/captive animals. Evidence of circulation of 16 Cryptosporidium species was found in five Latin American countries: Brazil, Colombia, Chile, Argentina and Mexico. Through meta-analysis with a random-effects model, the pooled prevalence rate for Cryptosporidium parvum was 0.7% (95% CI 0.2%-2.4%). Cryptosporidium felis (8.5%) was the most prevalent species in pets, C. parvum (10.3%) in livestock animals and Cryptosporidium galli (17.6%) in exotic/captive animals. C. parvum was the species with the greatest geographical dispersion, which can be explained by its eurixenic and zoonotic potential. Few studies on cryptosporidiosis in animals in Latin America were found, which shows that there is a need for investment in and expansion of studies on this parasite. The pooled prevalence of C. parvum in Latin America and its wide circulation are similar to what has been observed in other developing regions, which reaffirms the importance of this species as the cause of a neglected, emerging and zoonotic parasitosis.

Detection of Cryptosporidium parvum in a Red-Eared Slider Turtle (Trachemys scripta elegans), a Noted Invasive Alien Species, Captured in a Rural Aquatic Ecosystem in Eastern Poland

Purpose

Little is known about cryptosporidiosis in turtles of invasive alien species (IAS) inhabiting European bodies of fresh water. In this article, we report an occurrence of Cryptosporidium parvum in a red-eared slider turtle (Trachemys scripta elegans) captured in a rural aquatic ecosystem in eastern Poland.

Methods

A pair of samples consisting of feces and scrapings of intestinal mucosa (taken during necropsy) were collected from 104 animals representing the four IAS turtle species red-eared slider, yellow-bellied slider, false map and Cumberland slider. The animals were trapped in running and standing freshwater ecosystems across the Lublin province. Parasite genomic DNA was extracted from samples using a modified alkali wash and a heat-lysis method and identification of the Cryptosporidium species was performed at the 18SSU rRNA and COWP loci.

Results

The presence of Cryptosporidium DNA was only detected in one sample of intestinal scraping collected from a red-eared slider. A phylogenetic analysis of a 18SSU rRNA gene fragment showed 100% sequence identity between the C. parvum strain isolated from the turtle and other C. parvum strains previously detected in cattle from the Lublin province.

Conclusions

There was no clinical evidence that the red-eared slider turtle was truly infected rather than being merely a mechanical parasite carrier. Sporadic detection of this protozoan parasite in the studied population of IAS turtles could be associated with low natural occurrence of Cryptosporidium infections in this animal species. The results provide evidence for possible transmission of zoonotic Cryptosporidium species by IAS turtles.

HEALTH AND NUTRITIONAL ASSESSMENT OF FREE-RANGING EASTERN INDIGO SNAKES (DRYMARCHON COUPERI) IN GEORGIA, UNITED STATES

Clinical pathology and nutritional parameters are useful in evaluating and monitoring threatened and endangered wildlife populations, but reference ranges for most snake species are lacking. From 2001 to 2005, health assessments were performed on 58 eastern indigo snakes (EIS) (Drymarchon couperi) captured in the wild in southeastern Georgia, United States. Health and nutritional assessments performed included hematology, serum biochemistry, fat-soluble vitamins, heavy metals, pesticide contaminants, parasitology, and surveys of other pathogens. Significant differences in total solids, packed cell volume, glucose, blood urea nitrogen, albumin : globulin ratio, amylase, triglycerides, and bile acids between males and females were observed. Additionally, there was a significant difference between liver and kidney concentrations for vitamins A and E. As previously noted in captive EIS, total Ca was elevated in comparison to concentrations reported in other snake species. Parasitism was a common finding in sampled EIS, but the overall health status of this free-ranging population appeared good. A winter-time dermatitis was found in most snakes, which resolved in the summer months. This study represents the first health and nutritional assessment of free-ranging EIS, and provides needed data to guide monitoring and conservation efforts.

Clinical, serological, and parasitological analysis of snakes naturally infected with Cryptosporidium serpentis

Infection by Cryptosporidium serpentis is one of the most important diseases in reptiles and is characterized by chronic clinical or subclinical infection and the presence of hypertrophic gastritis, food regurgitation, progressive weight loss, mortality, and intermittent or continuous shedding of oocysts in the feces. The objectives of this study were to standardize an indirect enzyme-linked immunosorbent assay (ELISA) to detect antibodies against C. serpentis and to evaluate the clinical, parasitological, and humoral immune response in snakes naturally infected with C. serpentis. Twenty-one snakes naturally infected with C. serpentis and housed at the Butantan Institute, São Paulo, Brazil, underwent clinical and parasitological analyses for C. serpentis infection through daily records of clinical signs and a monthly survey of fecal shedding of oocysts using the Kinyoun's acid-fast staining. The serological evaluation was performed monthly by indirect ELISA using crude total antigen from oocysts of C. serpentis to detect anti-C. serpentis antibodies. Clinical symptoms consisted of food regurgitation, inappetence, and progressive weight loss. The parasitological analysis revealed intermittent fecal shedding of a variable number of oocysts in all snakes, with positivity in 85.32% (157/184) of the samples. The indirect ELISA was positive in 68.25% (86/126) of the samples. A humoral immune response was observed in most animals; however, fluctuating antibodies levels, leading to alternating positive and negative results, were observed in most snakes.