Prevalence of Toxocara and Toxascaris infection among human and animals in Iran with meta-analysis approach.

BACKGROUND: Toxocariasis is a worldwide zoonotic parasitic disease caused by species of Toxocara and Toxascaris, common in dogs and cats. Herein, a meta-analysis was contrived to assess the prevalence of Toxocara/Toxascaris in carnivore and human hosts in different regions of Iran from April 1969 to June 2019. METHODS: The available online articles of English (PubMed, Science Direct, Scopus, and Ovid) and Persian (SID, Iran Medex, Magiran, and Iran Doc) databases and also the articles that presented in held parasitology congresses of Iran were involved. RESULTS: The weighted prevalence of Toxocara/Toxascaris in dogs (Canis familiaris) and cats (Felis catus) was 24.2% (95% CI: 18.0-31.0%) and 32.6% (95% CI: 22.6-43.4%), respectively. Also, pooled prevalence in jackal (Canis aureus) and red fox (Vulpes vulpes) was 23.3% (95% CI: 7.7-43.2%) and 69.4% (95% CI: 60.3-77.8%), correspondingly. Weighted mean prevalence of human cases with overall 28 records was 9.3% (95% CI: 6.3-13.1%). The weighted prevalence of Toxocara canis, Toxocara cati, and Toxascaris leonina was represented as 13.8% (95% CI: 9.8-18.3%), 28.5% (95% CI: 20-37.7%) and 14.3% (95% CI: 8.1-22.0%), respectively. CONCLUSION: Our meta-analysis results illustrate a considerable prevalence rate of Toxocara/Toxascaris, particularly in cats and dogs of northern parts of Iran. The presence of suitable animal hosts, optimum climate and close contact of humans and animals would have been the reason for higher seroprevalence rates of human cases in our region. Given the significance clinical outcomes of human Toxocara/Toxascaris, necessary measures should be taken.

Ascarid infection in wild Amur tigers (Panthera tigris altaica) in China.

BACKGROUND: Wild Amur tigers are a sparsely populated species, and the conservation of this species is of great concern worldwide, but as an important health risk factor, parasite infection in them is not fully understanding. RESULTS: In this study, sixty-two faecal samples were collected to investigate the frequency and infection intensity of Toxocara cati and Toxascaris leonina in wild Amur tigers. The T. cati and T. leonina eggs were preliminary identified by microscopy, and confirmed by molecular techniques. Infection intensity was determined by the modified McMaster technique. Phylogenetic trees demonstrated that T. cati of wild Amur tiger had a closer relationship with which of other wild felines than that of domestic cats. T. leonina of Amur tiger and other felines clustered into one clade, showing a closer relationship than canines. The average frequency of T. cati was 77.42% (48/62), and the frequency in 2016 (100%) were higher than those in 2013 (P = 0.051, < 0.1; 66.6%) and 2014 (P = 0.079, < 0.1; 72.2%). The infection intensity of T. cati ranged from 316.6 n/g to 1084.1 n/g. For T. leonina, only three samples presented eggs when the saturated sodium chloride floating method was performed, indicating that the frequency is 4.83% (3/62). Unfortunately, the egg number in faecal smears is lower than the detective limitation, so the infection intensity of T. leonina is missed. CONCLUSIONS: This study demonstrated that ascarids are broadly prevalent, and T. cati is a dominant parasite species in the wild Amur tiger population.

Ancient parasitic DNA reveals Toxascaris leonina presence in Final Pleistocene of South America.

Parasitological analysis of coprolites has allowed exploring ecological relationships in ancient times. Ancient DNA analysis contributes to the identification of coprolites and their parasites. Pleistocene mammalian carnivore coprolites were recovered from paleontological and archaeological site Peñas de las Trampas 1.1 in the southern Puna of Argentina. With the aim of exploring ancient ecological relationships, parasitological analysis was performed to one of them, dated to 16 573-17 002 calibrated years BP, with 95.4% probability. Parasite eggs attributed to Toxascaris sp. by morphological characters were isolated. DNA of coprolite and eggs was extracted to molecular identification. Ancient mitochondrial DNA analysis confirmed the zoological origin of the coprolite as Puma concolor and that of parasite eggs as Toxascaris leonina. This is the oldest molecular parasite record worldwide, and it supports the presence of this parasite since the Pleistocene in America. These findings have implications for the biogeographic history of parasites and for the natural history of the region.

Gastrointestinal Parasite Infection in Cats in Daegu, Republic of Korea, and Efficacy of Treatment Using Topical Emodepside/Praziquantel Formulation.

The purpose of this study was 2-fold: 1) to investigate the prevalence of gastrointestinal parasite infection in cats reared in Daegu, Republic of Korea and 2) to assess the efficacy and safety of a topical emodepside/praziquantel formulation for cats with parasitic infections. The gastrointestinal parasite infections were examined microscopically using the flotation method. Of 407 cats, 162 (39.8%) were infected by at least one gastrointestinal parasite, including Toxocara cati (63.0%), Toxascaris leonina (31.5%), Taenia taeniaeformis (3.7%), and Cystoisospora felis (1.9%). None of the infected animals had multiple infections. When the data were analyzed according to sex, age, and type of cat, stray cats showed statistically higher prevalence than companion cats (P<0.05). On the 5th day after treatment, no parasitic eggs were detected using microscopic examination. In addition, no adverse effects, such as abnormal behaviors and clinical symptoms, were observed in the cats treated with the drug. These results quantify the prevalence of gastrointestinal parasites in cats in Daegu, Republic of Korea, and show that topical emodepside/praziquantel is a safe and effective choice for treating the parasitic infections in cats.

Sequence Analysis of Mitochondrial Genome of Toxascaris leonina from a South China Tiger.

Toxascaris leonina is a common parasitic nematode of wild mammals and has significant impacts on the protection of rare wild animals. To analyze population genetic characteristics of T. leonina from South China tiger, its mitochondrial (mt) genome was sequenced. Its complete circular mt genome was 14,277 bp in length, including 12 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and 2 non-coding regions. The nucleotide composition was biased toward A and T. The most common start codon and stop codon were TTG and TAG, and 4 genes ended with an incomplete stop codon. There were 13 intergenic regions ranging 1 to 10 bp in size. Phylogenetically, T. leonina from a South China tiger was close to canine T. leonina. This study reports for the first time a complete mt genome sequence of T. leonina from the South China tiger, and provides a scientific basis for studying the genetic diversity of nematodes between different hosts.

Cross-reactivity of Toxocariasis with Crude Antigen of Toxascaris leonina Larvae by ELISA.

Roundworms of Toxocara canis and Toxascaris leonina are common gastrointestinal helminths of canids over the world. Humans are infected with T. canis larvae through ingestion of infective eggs in contaminated environments or larvae by consumption of raw or uncooked meat or livers. Recently, patients of clinically diagnosed toxocariasis are increasing and require correct diagnosis in Korea. The present study investigated serological cross-reactivity between crude antigens of T. canis (TCLA) and T. leonina (TLLA) larvae. We collected serum specimens from 177 toxocariasis patients who were clinically suspected in the Seoul National University Hospital and 115 healthy controls. An ELISA method for toxocariasis was used to evaluate diagnostic efficacy of TLLA for serodiagnosis of human toxocariasis. The IgG ELISA using TLLA gave 14 (14.3%) positives of 98 TCLA positive specimens among 177 suspected toxocariasis patients. Most of them showed high absorbances with TCLA. In conclusion, there is a partial cross reaction between serum specimens of toxocariasis and TLLA.

Intraspecific variation between the ITS sequences of Toxocara canis, Toxocara cati and Toxascaris leonina from different host species in south-western Poland.

Some parasitic nematodes can inhabit different definitive hosts, which raises the question of the intraspecific variability of the nematode genotype affecting their preferences to choose particular species as hosts. Additionally, the issue of a possible intraspecific DNA microheterogeneity in specimens from different parts of the world seems to be interesting, especially from the evolutionary point of view. The problem was analysed in three related species - Toxocara canis, Toxocara cati and Toxascaris leonina - specimens originating from Central Europe (Poland). Using specific primers for species identification, internal transcribed spacer (ITS)-1 and ITS-2 regions were amplified and then sequenced. The sequences obtained were compared with sequences previously described for specimens originating from other geographical locations. No differences in nucleotide sequences were established in T. canis isolated from two different hosts (dogs and foxes). A comparison of ITS sequences of T. canis from Poland with sequences deposited in GenBank showed that the scope of intraspecific variability of the species did not exceed 0.4%, while in T. cati the differences did not exceed 2%. Significant differences were found in T. leonina, where ITS-1 differed by 3% and ITS-2 by as much as 7.4% in specimens collected from foxes in Poland and dogs in Australia. Such scope of differences in the nucleotide sequence seems to exceed the intraspecific variation of the species.

A 3-year retrospective analysis of canine intestinal parasites: fecal testing positivity by age, U.S. geographical region and reason for veterinary visit.

BACKGROUND: Canine life stage is a key factor in parasite prevalence as clinical signs associated with parasitism are more common in pups. In adult dogs, health status and geographical region may also play a role in parasite prevalence. The purpose of this study was to evaluate fecal test results using zinc sulfate flotation by centrifugation combined with fecal antigen testing for hookworms (Ancylostoma spp. Uncinaria stenocephala), ascarids (Toxocara canis, Toxascaris spp., Baylisascaris spp.) and whipworms (Trichuris vulpis) sorted by age, geographical region and veterinary visit type. METHODS: A retrospective sample of intestinal parasite panels submitted to IDEXX Laboratories from 1,626,104 individual dogs were selected from the continental USA from 1 January 2017 to 31 December 2019. These data contain results from fecal exams performed using zinc sulfate flotation by centrifugation paired with coproantigen immunoassay results for hookworms, ascarids, whipworms and Giardia (Fecal Dx® with Giardia coproantigen immunoassay plate). For paired testing, if either the coproantigen assay or flotation test was positive, the sample was considered to be positive. Data were summarized by age category, U.S. Census Bureau geographical region (Northeast, South, Midwest, West) and veterinary visit type. Visit types were subdivided into Wellness Visits and Other Clinical Visits in which a fecal sample was submitted. RESULTS: In dogs presenting for either Wellness Visits or Other Clinical Visits in which Giardia testing was included, Giardia had the highest positivity (combined results for microscopy and coproantigen: 12.2 and 10.8%, respectively), followed by hookworms (combined microscopy and coproantigen: 4.1 and 4.2%, respectively), ascarids (combined microscopy and coproantigen: 2.5 and 1.7%, respectively) and whipworms (combined microscopy and coproantigen: 1.1 and 1.4%, respectively). When all test results were pooled together, pups aged 2-6 months were observed to have the highest proportion of positive results by either microscopy or coproantigen immunoassay regardless of clinical visit type. Parasite positivity varied by geographical region. Regardless of visit type, age or geographical region, the coproantigen method was observed to find a higher proportion of positive test results than microscopy in Giardia, ascarids, hookworms and whipworms. CONCLUSIONS: The Fecal Dx® coproantigen immunoassay combined with the zinc sulfate flotation by centrifugation method uncovers a higher number of positive hookworm, ascarid and whipworm infections than zinc sulfate flotation alone in both pups and adult dogs across all geographical regions of the USA regardless of visit type.

The role of dogs in transmission of Ascaris lumbricoides for humans.

The dog's role as a definitive host for a number of zoonotic parasites has been widely studied and recognized as being a significant public health problem worldwide. This study aimed to report, for the first time, our investigation into the role of dogs as a biological transmitter for Ascaris lumbricoides, via necropsy of a sample of rural stray dogs in a developing community in Giza governorate, Egypt, where promiscuous defecation by human was common, and examination for A. lumbricoides worms as well as other ascaridiod nematodes of dogs. The recovered worms were identified in the laboratory after observing cephalic alae and egg morphology under a microscope, as well as scanning electron microscopy of their anterior ends. Of the 25 dogs examined, 14 were infected with Toxocara canis (56.0%), two with Toxascaris leonina (8.0%), and two with A. lumbricoides (8.0%). One dog was co-infected with T. canis and T. leonina. A. lumbricoides eggs were shown to be viable and 75-80% of eggs embryonated following 3 weeks of incubation at 28 degrees C. The present study suggested that dogs could act as reservoir hosts of A. lumbricoides and environmental contaminators that increase risk of infection in humans.

Influence of parasitism on trace element contents in tissues of red fox (Vulpes vulpes) and its parasites Mesocestoides spp. (Cestoda) and Toxascaris leonina (Nematoda).

Bioaccumulation of cadmium, chromium, copper, manganese, nickel, lead, and zinc in 56 foxes (Vulpes vulpes) and their parasites Mesocestoides spp. (Cestoda) and Toxascaris leonina (Nematoda) was studied. The levels of heavy metals were determined in the livers and kidneys of the animals depending on parasitism in the following ranges: Pb, 0.029-3.556; Cd, 0.055-9.967; Cr, 0.001-0.304; Cu, 4.15-41.15; Mn, 1.81-19.94; Ni: 0.037-0.831; Zn, 52.0-212.9 microg/g dry weight (dw). Cd in parasites (0.038-3.678 microg/g dw) were comparable with those in the livers of the host and lower than in the kidneys (0.095-6.032 microg/g dw). Contents of Pb, Cr, Cu, Mn, Ni, and Zn in cestodes were predominantly higher than those in the kidney and liver of the host. Median lead levels in Mesocestoides spp. (45.6 microg/g dw) were 52-fold higher than in the kidney and liver of the red fox (Vulpes vulpes) infected by both parasites and median Pb values in T. leonina (8.98 microg/g dw) were 8-fold higher than in the tissues of the parasitized red fox. Bioaccumulation factors of copper, zinc, nickel, and manganese are lower than those of lead and mostly range from 1.9 to 24 for Mesocestoides spp. and from 1.5 to 6 for nematode T. leonina depending on the tissue of host and element. A significant decrease in the content of Pb was found in the kidney of animals infected by T. leonina (0.260 microg/g dw) as well as those infected by Mesocestoides spp. (0.457 microg/g dw) in comparison with the lead content (0.878 microg/g dw) in the kidneys of the nonparasitized red fox. Regardless of a bioaccumulation of copper and manganese in the parasites, a significant increase of the concentrations of Mn and Cu was observed in the host's livers infected predominantly by Mesocestoides spp.

Molecular characterization of ascaridoid parasites from captive wild carnivores in China using ribosomal and mitochondrial sequences.

BACKGROUND: Despite the public health importance of toxocariasis/toxascariasis, only a few species of these ascaridoid parasites from wild canine and feline carnivores have been studied at the molecular level so far. Poor understanding of diversity, host distribution and the potential (zoonotic) transmission of the ascaridoid species among wild animals negatively affects their surveillance and control in natural settings. In this study, we updated previous knowledge by profiling the genetic diversity and phylogenetic relationships of ascaridoid species among eleven wild canine and feline animals on the basis of a combined analysis of the ribosomal internal transcribed spacer region (ITS) gene and the partial mitochondrial cytochrome c oxidase subunit 2 (cox2) and NADH dehydrogenase subunit 1 (nad1) genes. RESULTS: In total, three genetically distinct ascaridoid lineages were determined to be present among these wild carnivores sampled, including Toxocara canis in Alopex lagopus and Vulpes vulpes, Toxocara cati in Felis chaus, Prionailurus bengalensis and Catopuma temmincki and Toxascaris leonina in Canis lupus, Panthera tigris altaica, Panthera tigris amoyensis, Panthera tigris tigris, Panthera leo and Lynx lynx. Furthermore, it was evident that T. leonina lineage split into three well-supported subclades depending on their host species, i.e. wild felids, dogs and wolves and foxes, based on integrated genetic and phylogenetic evidence, supporting that a complex of T. leonina other than one species infecting these hosts. CONCLUSIONS: These results provide new molecular insights into classification, phylogenetic relationships and epidemiological importance of ascaridoids from wild canids and felids and also highlight the complex of the taxonomy and genetics of Toxascaris in their wild and domestic carnivorous hosts.

Comparative analysis of mitochondrial DNA datasets indicates that Toxascaris leonina represents a species complex.

BACKGROUND: Toxascaris leonina is one of the most common intestinal parasites of canids and felids. In this study, we characterised the entire mitochondrial (mt) genome sequence of T. leonina from the cheetah and compared it with that of T. leonina from the dog. RESULTS: The entire mt genome sequence of T. leonina from the cheetah is 14,685 bp in size, which is 375 bp longer than that from the dog, and it is 408 bp longer than that from the South China tiger. The overall nucleotide sequence (except for the non-coding region) identity was 92.8% between the two mt genomes of T. leonina from the cheetah and the dog. For the 12 protein-coding genes, sequence difference between T. leonina from the cheetah and the dog was 5.0-9.7% at the nucleotide level and 1.0-7.2% at the amino acid level. Moreover, comparison of mt cox1 sequences among T. leonina isolates (n = 23) from different hosts revealed substantial nucleotide differences (10.6%). Phylogenetic analysis showed the separation of T. leonina from canid and felid hosts into three distinct clades. CONCLUSIONS: Taken together, these mtDNA datasets indicate that T. leonina from canid and felid hosts represents a species complex. Our results have implications for further studies of the molecular epidemiology, systematics and population genetics of this nematode.

Prevalence of Toxocara spp., Toxascaris leonina and ancylostomidae in public parks and beaches in different climate zones of Costa Rica.

This epidemiological study was conducted in different regions of Costa Rica to determine the prevalence of the developmental stages of potential zoonotic intestinal helminths of dogs and cats in public places. Samples were collected within three main climate zones including rural and urban areas during both the rainy and the dry season. Faecal and environmental samples were taken from 69 parks and beaches. Of the faecal samples 3% contained Toxascaris spp. eggs, 7% Toxocara spp. eggs and 55% contained ancylostomidae eggs. Of the soil samples, 2% contained ancylostomidae eggs and 0.8% contained ascarid eggs. Significant differences in the presence of parasites were found in faecal samples of dry, moist and wet climate zones and between the dry and rainy seasons. Significant differences in the presence of eggs and larvae were also found in the grass samples in the dry, the moist and the wet climate zones and between the different seasons. No significant differences were found between rural and urban areas.

Helminth Infections by Coprological Examination in Sheep-Dogs and Their Zoonotic Importance.

OBJECTIVE: This study was conducted to determine the prevalence of gastrointestinal helminths and diagnose the species of important zoonotic helminths in sheep dogs. METHODS: Firstly, fecal samples were macroscopically examined; subsequently, formalin-ethyl acetate sedimentation and ZnSO4 centrifugal floatation techniques were applied for the examination of helminth eggs. PCR technique was utilized to determine the species of E. granulosus and T. canis in dogs found positive for Taenia spp. and Toxocara spp. RESULTS: Helminth infection was detected in 35.26% of sheep dogs. Taenia spp. was the most common helminth (12.05%), followed by Toxocara spp. (9.38%), Toxascaris leonina (6.25%), and Trichuris spp. (4.2%). The positive results in the E. granulosus and T. canis-specific PCR-based molecular tests were obtained in 14 of the Taenia egg-positive samples and in 5 of the Toxocara egg-positive samples from dogs. This study has suggested that coprophagy and feed raw offal and meat to dogs may be responsible for finding atypical helminth eggs in fecal samples from dogs in the absence of an actual infection. CONCLUSION: To make the diagnosis of their owned parasites of dogs, E. granulosus and T. canis which have zoonotic importance, feces must be examined by both conventional and copro-PCR techniques. In addition to dogs' feeding habits, other related factors must be taken into account in the epidemiology of helminth infection; thus, precaution and control measures will be more reliable.

Parasitological investigation of children's sandboxes and dog faeces from public areas of housing development in Prague.

Two hundred sand samples from 50 children's sandboxes and 500 samples of dog faeces collected in 10 Prague housing developments were examined for the presence of parasites. Eggs of three helminth species were found in 28% of sandboxes and eggs and oocysts of 10 species of parasites were found in 10.4% of dog faeces. Toxocara canis occurred in 9 sandboxes and 3.2% of dog faeces, T. cati in 0.2% of dog faeces. The results from housing developments are compared with those from older estates.

Helminth eggs in the sludge from three sewage treatment plants in Czechoslovakia.

Developmental stages of 8 species of parasitic helminths were found during examination of sludge from 3 sewage treatment plants in Central Bohemia, Czechoslovakia. The eggs were comprised from Ascaris sp., Toxocara sp., Toxascaris leonina, Parascaris equorum, Enterobius vermicularis, Trichuris sp., Capillaria sp. and Hymenolepis spp. The quantity of these organisms in 100 g of dried sludge ranged between 24-105 eggs of Ascaris sp., 12-47 eggs of Toxocara sp., 0-8 eggs of Toxascaris leonina, 0-1 egg of Parascaris equorum, 2-33 eggs of Trichuris sp., 0-12 eggs of Capillaria sp., 0-46 eggs of Enterobius vermicularis and 0-49 eggs of Hymenolepis spp. Some eggs of Hymenolepis spp. and Enterobius vermicularis were structurally damaged, while some eggs of Ascaris sp. and Enterobius vermicularis contained developed larvae.

Prevalence of intestinal nematodes of dogs and cats in The Netherlands.

Faecal samples from 272 dogs and 236 cats from Dutch households were examined for nematode eggs. Toxocara eggs were found in 8 dogs (2.9%) and 11 cats (4.7%). Toxascaris eggs were found in 1 dog (0.4%) and Trichuris eggs in 2 dogs (0.7%). Examination of faeces from 56 stray cats revealed Toxocara in 12 cases (21%) and Toxascaris eggs in 3 cases (5.4%). No hookworm eggs were found. The percentage of positive samples was significantly higher in young animals than in older animals. Toxocara eggs were found significantly more frequently in stray cats than in cats kept in households.

Naturally infected dog droppings from public parks and playgrounds as a possible source of infections with Salmonellae and helminths.

In two periods (spring/summer and autumn/winter) investigations for salmonellae and helminths were made with 300 naturally infected dog droppings each. In the first period 10.33% of the collected fecal samples had been infected with salmonellae of 10 different serovars. Eggs of Taxascaris leonina were found in 3.33%, eggs of Toxocara canis in 4.33%, taeniid eggs in 1.67% and Ancylostomatides in 3.33% of examined droppings. The investigations in the autumn/winter period showed 9% fecal samples infected with salmonellae of 11 different serovars. 5% fecal specimens contained eggs of T. canis, 2% eggs of T. leonina, 0.33% eggs of Taenia spp. and Ancylostomatidae made up to 2%.

[Parasite-host relations in toxascariasis in Arctic foxes]. / Parazito-khoziainnye otnosheniia pri toksaskaridoze pestsov.

The effect of host infection doze (10, 100, 1000 eggs) and developmental stages of helminths (larvae, adult nematodes) on the relationships in the system "Toxascaris leonina-Alopex lagopus" was studied experimentally. It has been established that 100 eggs are the threshold dose for helminths and 1000 eggs for the host. More distinct changes in the indices are characteristic of the parasite. Dynamics of host-parasite relationships in the development of the parasitic process correspond to helminth developmental stage. Larvae of T. leonina are most pathogenic for the host.

[Helminth fauna of red foxes (Vulpes vulpes LINNE 1758) in southern Saxony--2: Nematodes]. / Zur Helminthenfauna des Rotfuchses (Vulpes vulpes LINNE 1758) im Süden Sachsen-Anhalts--Teil 2: Nematoden.

Between January 1993 and November 1994 a total of 1300 red foxes from the administrative districts Halle and Dessau were examined for the presence of nematodes in the stomach and the small intestine. The following nematodes were found: Toxocara canis (26.5%), Toxascaris leonina (10.5%), Uncinaria stenocephala (15.9%) Ancylostoma caninum (1.7%). The search for Trichinella spp. larvae was negative in all 780 examined foxes.