Infection of man with Trichuris vulpis, the whipworm of dogs

Canine and Feline Parasitology: Analogies, Differences, and Relevance for Human Health

Cats and dogs are treated as family members by most pet owners. Therefore, a high quality of veterinary care and preventive medicine is imperative for animal health and welfare and for the protection of humans from zoonotic pathogens. There is a general perception of cats being treated as "small dogs," especially in the field of clinical parasitology. As a result, several important differences between the two animal species are not taken into proper consideration and are often overlooked. Dogs and cats are profoundly different under evolutionary, biological, ethological, behavioral, and immunological standpoints. These differences impact clinical features, diagnosis, and control of canine and feline parasites and transmission risk for humans. This review outlines the most common parasitoses and vector-borne diseases of dogs and cats, with a focus on major convergences and divergences, and discusses parasites that have (i) evolved based on different preys for dogs and cats, (ii) adapted due to different immunological or behavioral animal profiles, and (iii) developed more similarities than differences in canine and feline infections and associated diseases. Differences, similarities, and peculiarities of canine and feline parasitology are herein reviewed in three macrosections: (i) carnivorism, vegetarianism, anatomy, genetics, and parasites, (ii) evolutionary adaptation of nematodes, including veterinary reconsideration and zoonotic importance, and (iii) behavior and immune system driving ectoparasites and transmitted diseases. Emphasis is given to provide further steps toward a more accurate evaluation of canine and feline parasitology in a changing world in terms of public health relevance and One Health approach.

Morphobiological analysis of Trichuris vulpis (Nematoda, Trichuridae), obtained from domestic dogs

The parasitic nematode Trichuris vulpis Frölich, 1789 is the pathogen of trichuriasis in domestic and wild carnivores, and humans. This helminth species is distributed world-wide in populations of domestic dog (Canis lupus familiaris). The prevalence of T. vulpis in dogs depends to a large degree on the morphofunctional and biological adaptations of the parasite which support its high survivability in various environmental conditions. The present study considers the species-specific peculiarities of morphology, and metric parameters of the mature and embryonic stages of Trichuris nematodes parasitizing in C. lupus familiaris. We studied the periods of stages of development and infectious egg formation, and their survivability under optimal conditions for T. vulpis in laboratory culture. The differential characteristics of both female and male adult T. vulpis nematodes include the metric characteristics of cuticular protrusions at the surface of the anterior body part. The male T. vulpis nematodes can be distinguished from males of other species by the specifics of spicule sheath ornamentation, the shape and size of spicule, and the width of spicule sheath at different sections. In identification of the female nematodes of this species, it is necessary to consider the presence and size of papillary processes in the vulval area and metric parameters of vulva location. Nine metric characters of sexual dimorphism are described for T. vulpis nematodes. In laboratory conditions, five embryonic stages were observed for T. vulpis: protoplast, blastomere cleavage, and formation of bean-like embryo, larva and mobile larva. These stages are characterized by specific morphological features. The egg develops to the infectious stage at 27 °С in 18 days of culture, and their survivability is up to 76.6%. The egg development is associated with changes in their metric characters, such as decreasing egg length and width of egg shell, and increasing egg width and egg plug width.

Vaginal candidiasis among women of reproductive age in Dnipro city (Ukraine): Species spectrum of Candida and their susceptibility to antimycotics

Candidiasis is one of the most common pathological processes, especially among women of reproductive age, especially pregnant. It can be expressed as Candida carriage and as an active form of infection. Although candidiasis is caused by opportunistic microorganisms, its effects can be quite significant, so it is necessary to treat it with the use of antimycotic drugs. In view of the spread among these microorganisms of resistance to antimicrobial drugs, the determining factor for the success of therapeutic measures, it is important to make a preliminary assessment of the susceptibility to antimycotics of strains isolated from persons with Candida carriage or active candidiasis. The aim of the research was to study the species range of fungi of the genus Candida isolated from the reproductive tract in women with dysbiosis and to study their susceptibility to antimycotics. Total of 227 samples of biological material from women aged 16 to 56 years have been investigated. Microscopic and cultural methods of detecting of fungi in the primary material were used for research. For the identification of species of Candida fungi, a polymerase chain reaction method in real-time was used. It was determined that the frequency of detection of Candida fungi in the composition of vaginal microbiome during inflammatory pathological processes was 76.7%. It was shown that the incidence of Candida carriage – 51.7% – slightly exceeded the frequency of detection of the active form of infection – 48.3%. The species spectrum of pathogens included: C. albicans (57.1%), C. krusei (12.6%), C. glabrata (19.5%) and Candida spp. (16.1%). In the case of active form of infection, C. albicans was prevalent – 64 (76.2%) cases. In the case of Candida carriage, other species were prevalent – 58 (64.4%) cases. The most effective drug against all isolates was amphotericin B – more than 87% of isolates were susceptible. The least effective drug was nystatin: less than 60% of isolates were susceptible. There is a rather high level of resistance to certain antimycotic drugs among the Candida species, which requires a prior preliminary study of the susceptibility of isolated strains to antimycotics for the purpose of choosing a rational and effective treatment scheme.

Trichuris vulpis and T. trichiura infections among schoolchildren of a rural community in northwestern Thailand: the possible role of dogs in disease transmission

Background: Trichuriasis is an important soil-transmitted helminth infection caused by Trichuris trichiura. About one-tenth of the world population may be infected. Incidentally, T. vulpis or dog whipworm has been reported to infect humans based on the egg size. However, an overlapping egg dimension occurs between T. trichiura and T. vulpis leading to the potential for misdiagnosis. Objective: Develop a PCR method to differentiate T. trichiura and T. vulpis eggs in stool samples and to investigate the prevalence of both whipworms in humans and dogs in a rural community in Thailand. Materials and methods: We determined and compared the small subunit ribosomal RNA sequences of both species of whipworms for developing species-specific PCR diagnosis. After validation of the method, we conducted a cross-sectional survey at Ta Song Yang District in Tak Province, northwestern Thailand in 2008. Stool samples were randomly recruited from 80 schoolchildren (36 males, 44 females) and 79 dogs in this community. Results: Fifty-six individuals harbored Trichuris eggs in their stools. The PCR-based diagnosis revealed that 50 cases were infected with T. trichiura and six (10.7%) were co-infected with both T. trichiura and T. vulpis. Although the dimension of Trichuris eggs provided some diagnostic clues for species differentiation, a remarkable variation in the length of these whipworm eggs was observed among samples that could lead to misdiagnosis. Conclusion: Both T. trichiura and T. vulpis eggs were detected in stool samples of dogs that roamed around this community, highlighting the potential reservoir role of dogs in the transmission of both human and dog whipworms in this population.

Molecular species identification of Trichuris trichiura in African green monkey on St. Kitts, West Indies

The population of African green monkeys (AGM, Chlorocebus aethiops sabaeus) on St. Kitts, West Indies is believed to be as large as or greater than the human population. Interactions with humans are frequent and the pathogens carried by AGM, such as Trichuris spp., may pose a risk to humans. The objectives of this study were to assess the use of molecular methods for diagnosing Trichuris spp. in AGM and compare its DNA sequences to those of Trichuris spp. found in other non-human primates and humans. Fecal samples were collected from trapped and individually housed AGM between January and December 2015 and analysed using fecal flotation with Sheather's sugar flotation solution and PCR amplification and DNA sequencing of 18S rRNA and ITS2 fragments. Phylogenetic analysis was performed. 91% (81/89) and 55.4% (31/56) were Trichuris spp. positive by fecal flotation and PCR, respectively. Both AGM-NADH1 gene and T. trichiura-18S rRNA gene showed no variations in sequence and were 100% identical to corresponding sequences deposited in GenBank. Nevertheless Trichuris ITS2 showed some diversities among 12 sequences, which was <5%. Phylogenetic analysis of ITS2 put Trichuris spp. in Kittitian AGM into the same clades of T. trichiura found in human and other non-human primates in many other geographical regions. These data confirm that AGM are reservoirs for T. trichiura in humans. We suggest a one health approach to curtail enteric parasitic infections in human populations in the insular country.

Morphological diversity of Trichuris spp. eggs observed during an anthelminthic drug trial in Yunnan, China, and relative performance of parasitologic diagnostic tools

The presence of large Trichuris spp. eggs in human faecal samples is occasionally reported. Such eggs have been described as variant Trichuris trichiura or Trichuris vulpis eggs. Within the frame of a randomised controlled trial, faecal samples collected from 115 Bulang individuals from Yunnan, People's Republic of China were subjected to the Kato-Katz technique (fresh stool samples) and the FLOTAC and ether-concentration techniques (sodium acetate-acetic acid-formalin (SAF)-fixed stool samples). Large Trichuris spp. eggs were noted in faecal samples with a prevalence of 6.1% before and 21.7% after anthelminthic drug administration. The observed prevalence of standard-sized T. trichiura eggs was reduced from 93.0% to 87.0% after treatment. Considerably more cases of large Trichuris spp. eggs and slightly more cases with normal-sized T. trichiura eggs were identified by FLOTAC compared to the ether-concentration technique. No large Trichuris spp. eggs were observed on the Kato-Katz thick smears.

Trichuris vulpis (Froelich, 1789) infection in a child: a case report

We present a human infection with the canine whipworm, Trichuris vulpis, in a child suffering from rhinitis with a diagnosis of rhinitis. T. vulpis eggs resemble those of T. trichiura but they can be differentiated based on their morphological features and egg size, using micrometry with an ocular micrometer. T. vulpis eggs measured an average of 90 µm by 44 µm (range 86-99 µm by 38-47 µm). Prevalence of hookworms (28.1%), Toxocara canis (11.8%), and Trichuris vulpis (3.5%) was found in 292 fecal samples of dogs collected at the peri-domicile, which showed that the risk of infection was not only fortuitous. The treatment of canine whipworm infections is similar to that of T. trichiura infection. We recommend differentiation of the 2 species for their epidemiological and prevention implications.

Are we paying too much attention to cardio-pulmonary nematodes and neglecting old-fashioned worms like Trichuris vulpis?

Trichuris vulpis, the dog whipworm, causes an intestinal parasitosis of relevance in current canine veterinary practice. Its occurrence is well-known in pets, kennelled dogs and stray animals, and its eggs contaminate the ground in urban areas all over the world. Moreover, T. vulpis has been occasionally incriminated, though not convincingly substantiated, as a cause of zoonosis. This nematode is erroneously considered an "old-fashioned" pathogen with a consequent lack of up- to- date knowledge on several aspects of the infection. These, in turn, are still controversial and need to be studied in greater depth. This article reviews current knowledge of T. vulpis, together with a discussion of critical points in epidemiology, zoonotic hazard, diagnosis and treatment of canine trichurosis.

Infectious causes of appendicitis

The pathologic spectrum of the inflamed appendix encompasses a wide range of infectious entities, some with specific histologic findings, and others with nonspecific findings that may require an extensive diagnostic evaluation. The appendix is exclusively involved in some of these disorders, and in others may be involved through extension from other areas of the gastrointestinal tract. This review discusses the pathologic features of bacterial, viral, fungal, and parasitic infections affecting the appendix, including adenovirus; cytomegalovirus; Yersinia, Actinomyces, Mycobacterium, or Histoplasma species; Enterobius vermicularis; schistosomiasis; and Strongyloides stercoralis. Pertinent ancillary diagnostic techniques and the clinical context and significance of the various infections are also discussed.

Appendicitis and infections of the appendix

The pathologic spectrum of the acutely inflamed appendix encompasses a wide range of infectious and noninfectious entities. The appendix suffers alone in some of these disorders, and in others may be involved through extension from other areas of the gastrointestinal tract. Although the appendix is the most commonly resected and examined intraabdominal organ, the pathogenesis and etiology of acute nonspecific appendicitis (the most common diagnosis made in this organ) remains enigmatic. This review encompasses the pathology, pathogenesis, and bacteriology of acute appendicitis, as well as controversial issues such as the diagnosis of chronic appendicitis and the significance of a morphologically unremarkable appendectomy specimen in the clinical context of appendicitis. In addition, the pathologic features, pertinent diagnostic techniques, and clinical significance of several specific bacterial, viral, fungal, and parasitic infections affecting the appendix are presented, including adenovirus, cytomegalovirus, Yersinia species, actinomycosis, Mycobacteria species, histoplasmosis, pinworms, schistosomiasis, and Strongyloides stercoralis.

A survey of intestinal helminths of well-cared-for dogs in Jamaica, and their potential public health significance

This study investigates the level of helminthic infestation in better-cared-for dogs in a middle-class community in suburban Kingston. A canine zoographic study was conducted, and fresh faecal deposits were collected and analysed for helminth life-cycle stages. The survey indicated that 73% (n = 93) of households in the study area owned one dog or more (mean = 1.4). Resident's attitudes towards canine management suggested that the dog population was, in general, restricted to the residential estate, and most owners claimed to have dewormed their dogs at least as young animals. Of 141 faecal specimens, 58% contained eggs or larvae of one or more of eight helminths: Uncinaria stenocephala (26%), Ancylostoma sp. (23%), Trichuris vulpis (9%), Toxocara canis (8%), Spirocerca lupi (6%), Strongyloides sp. (6%), Apophallus sp. (4%) and taeniids (1%). There was a high level of multiple infection in the host animals, with approximately one fifth of the infected samples containing three or more helminth types. Infection intensity was apparently low, but some dogs harboured heavy worm loads.

Variations in egg size of Trichuris trichiura

In patients infected with Trichuris trichiura, large eggs as well as more typical eggs were frequently found in the feces; these large eggs have been attributed to human infection by T. vulpis. To clarify whether the female worms laying the large eggs were T. trichiura or T. vulpis, we examined the morphology of adult worms and the size of whipworm eggs obtained from a patient and from several domestic dogs. Adult female T. trichiura worms were easily and quickly distinguished from those of T. vulpis by their convoluted vaginal tracts and uteri. Eggs obtained from the uteri of T. trichiura were of two sizes, with approximately 80% being of the smaller variety (57 X 26 microns) and 20%, the larger (78 X 30 microns). These percentages were about equal to those found the feces of the patient. T. vulpis uterine eggs were slightly larger (82 X 39 microns) than the large eggs of T. trichiura. The distribution of the 2 populations of eggs in 30 adult female T. trichiura was as follows: 1 worm had only large eggs, 14 had only the typical smaller eggs, and 15 had both varieties in their uteri.

Whipworms and intestinal threadworms

Whipworms (genus Trichuris) parasitize the lower bowel of humans, domestic animals, and wild animals. The species of Trichuris that are important in small animal practice are T. vulpis in the dog and T. campanula and T. serrata in the cat. Intestinal threadworms (Strongyloides stercoralis in the dog and S. tumefaciens in the cat) parasitize the small intestine. The identification of whipworms and threadworms, their life cycles, and the diagnosis, treatment, and control of infection are discussed in this article.