Efficacy of Lactobacillus taiwanensis S29 and Lactiplantibacillus plantarum S27 against tapeworm infection in Swiss Albino rats.

Hymenolepis diminuta a zoonotic tapeworm infection in human remains an important cestode model for anthelmintic study as it display common clinical symptoms like other adult human tapeworms during heavy infestation. The use of Lactobacillus as a probiotic is an alternative to drugs which have increased in research and usage considerably during the last decade. The present study aims to determine the anthelmintic efficacy of two probiotics, L. taiwanensis strain S29 and L. plantarum strain S27 against H. diminuta in infected rat. Four groups of animals, each with six numbers were randomly chosen as the negative control (Group I), positive control (infected) (Group II) and the infected treated with two probiotics Group III and Group IV respectively. Another four groups (Group V-VIII) were selected and further subdivided into four sub-groups to investigate the development of larvae to adult during probiotics treatment. Worm burden, egg per gram were determined after treatment with these two probiotics. Furthermore, hematological assays and levels of biochemical markers were estimated, tissue damage was assayed through histological study and intestinal mitochondria detection was done. Worm sustainability reduced about 70-90% and EPG count decreased by 81-94% in probiotics treated groups. A significant level of unsuccessful establishment of larvae was observed in the developmental phase. Improvement in hematological parameter along with some biochemical parameters in the host were significantly observed after treatment with probiotics. The architecture damaged caused in the intestine and mitochondria density due to parasite infection improved significantly as that of control after probiotics treatment.

Dipylidium caninum in the twenty-first century: epidemiological studies and reported cases in companion animals and humans.

BACKGROUND: Dipilidiosis is a parasitic disease caused by the tapeworm Dipylidium caninum. Fleas and, less frequently, lice act as an intermediate host, and their ingestion is required for infection to occur. While the disease mainly affects domestic and wild carnivores, it is also considered a zoonotic disease, with most human cases reported in children. Dipylidium caninum is considered to be the most common tapeworm infesting companion animals, but dipilidosis in humans is rare. The aims of this review were to improve current understanding of the epidemiology of this parasitosis and its management by the medical and veterinary community. METHODS: A comprehensive review of the published literature during the last 21 years (2000-2021) on the epidemiology, clinical features, diagnosis, treatment and prevention measures of D. caninum infection and dipilidiosis in companion animals and humans was conducted. RESULTS: Using predefined eligibility criteria for a search of the published literature, we retrieved and screened 280 publications. Of these, 161 (141 epidemiological studies, 20 case reports [16 human cases]) were considered for inclusion in this review. This parasitosis is present worldwide; however, despite being the most frequent cestode infection in animals, it is often underdiagnosed using common coprological techniques. Its diagnosis in humans has also proved challenging, being frequently confused with pinworm infection, leading to inappropriate treatment and to the persistence of the disease over time. Prevention measures include control of ectoparasites in animals and the environment, as well as regular deworming of animals, most commonly with praziquantel. CONCLUSIONS: The diagnosis of dipilidiosis remains challenging in both animals and humans, primarily due to the low sensitivity of the diagnostic methods currently available and a lack of knowledge of the morphological characteristics of the parasite. Although treatment with the appropriate anti-cestode compounds is well tolerated and results in resolution of the infection, indiscriminate use of these compounds may predispose to an increase in resistance. Given the worldwide distribution of this parasite, it is essential to act on several fronts, with a focus on health education for children and animal owners and the control of intermediate hosts, both in animals and in the surrounding environment.

Tapeworms as pathogens of fish: A review.

Tapeworms (Cestoda) represents a species rich (about 5000 species) group of flatworms (Neodermata) parasitizing all groups of vertebrates including humans, with about 1000 species parasitizing elasmobranchs and almost 500 occurring in teleosts as adults. They are common parasites of cultured fish, both as adults and larvae (metacestodes), but only few adult tapeworms are actually pathogenic for their fish hosts. In contrast, cestode larvae can be harmful for fish, especially plerocercoids migrating throughout their tissue and internal organs. Current knowledge of host-parasite relationships, including immune response of fish infected with tapeworms, is still insufficient to enable adequate control of cestodoses, and most data available were obtained several decades ago. Treatment of fish infected with adult tapeworms is effective, especially with praziquantel, whereas the treatment of metacestodes is problematic. Control measures include interruption of the complex life cycle and prevention of transport of uninspected fish to new region.

The forgotten exotic tapeworms: a review of uncommon zoonotic Cyclophyllidea.

As training in helminthology has declined in the medical microbiology curriculum, many rare species of zoonotic cestodes have fallen into obscurity. Even among specialist practitioners, knowledge of human intestinal cestode infections is often limited to three genera, Taenia, Hymenolepis and Dibothriocephalus. However, five genera of uncommonly encountered zoonotic Cyclophyllidea (Bertiella, Dipylidium, Raillietina, Inermicapsifer and Mesocestoides) may also cause patent intestinal infections in humans worldwide. Due to the limited availability of summarized and taxonomically accurate data, such cases may present a diagnostic dilemma to clinicians and laboratories alike. In this review, historical literature on these cestodes is synthesized and knowledge gaps are highlighted. Clinically relevant taxonomy, nomenclature, life cycles, morphology of human-infecting species are discussed and clarified, along with the clinical presentation, diagnostic features and molecular advances, where available. Due to the limited awareness of these agents and identifying features, it is difficult to assess the true incidence of these 'forgotten' cestodiases as clinical misidentifications are likely to occur. Also, the taxonomic status of many of the human-infecting species of these tapeworms is unclear, hampering accurate species identification. Further studies combining molecular data and morphological observations are necessary to resolve these long-standing taxonomic issues and to elucidate other unknown aspects of transmission and ecology.

Topical or oral fluralaner efficacy against flea (Ctenocephalides felis) transmission of Dipylidium caninum infection to dogs.

BACKGROUND: Dipylidium caninum is a common tapeworm of dogs contracted from ingestion of fleas containing the infective cysticercoid stage. Fluralaner is a systemically distributed isoxazoline class insecticide that delivers highly effective activity against fleas and ticks for up to 12 weeks after a single oral or topical treatment. This study evaluated the impact of this flea insecticidal efficacy on the transmission of D. caninum to dogs. METHODS: Dogs were weighed and treated with a cestocide and then randomly assigned to 3 groups of 8. Fluralaner was administered topically (at the commercial dose) to one group and orally to another group while the third received topically administered sterile water. All dogs were subsequently infested with about 100 D. caninum infected Ctenocephalides felis at 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77 and 83 days after treatment. Visual proglottid inspections and counts were conducted daily from 35 to 113 days post-treatment. Post-treatment D. caninum incidence was calculated for each group and compared between treated and untreated groups. RESULTS: All 8 dogs in the placebo-treated group became infected with D. caninum while no shed proglottids were observed at any point during the post-treatment period from any dog in either fluralaner treated group. CONCLUSIONS: The insecticidal efficacy of a single treatment of either orally or topically administered fluralaner prevented D. caninum transmission from infected fleas to susceptible dogs for up to 12 weeks following administration.

Clinical characteristics and epidemiology of intestinal tapeworm infections over the last decade in Tokyo, Japan: A retrospective review.

BACKGROUND: Tapeworm (cestode) infections occur worldwide even in developed countries and globalization has further complicated the epidemiology of such infections. Nonetheless, recent epidemiological data on cestode infections are limited. Our objectives were to elucidate the clinical characteristics and epidemiology of diphyllobothriosis and taeniosis in Tokyo, Japan. METHODOLOGY/PRINCIPAL FINDINGS: We retrospectively reviewed 24 cases of human intestinal cestode infection from January 2006 to December 2015 at a tertiary referral hospital in Tokyo, Japan. The patients included were diagnosed with cestode infection based on morphological and/or molecular identification of expelled proglottids and/or eggs and treated in our hospital. Fifteen and 9 patients were diagnosed with diphyllobothriosis and taeniosis, respectively. The median patient age was 31 years (interquartile range [IQR]: 26-42 years), and 13 (54%) were male. Most of the patients (91.7%) were Japanese. All patients were successfully treated with praziquantel without recurrence. Diphyllobothriosis was caused by Diphyllobothrium nihonkaiense in all patients. Taeniosis was due to infection of Taenia saginata in 8 [88.9%] patients and T. asiatica in 1 [11.1%] patient. All patients with taeniosis were infected outside Japan, as opposed to those with diphyllobothriosis, which were domestic. The source locations of taeniosis were mostly in developing regions. The median duration of the stay of the patients with taeniosis at the respective source location was 1 month (IQR: 1-8). CONCLUSIONS/SIGNIFICANCE: The cestode infection, especially with D. nihonkaiense, has frequently occurred, even in Japanese cities, thereby implicating the probable increase in the prevalence of diphyllobothriosis among travelers, as the number of travelers is expected to increase owing to the Tokyo Olympics/Paralympics in 2020. In addition, medical practitioners should be aware of the importance of providing advice to travelers to endemic countries of taeniosis, including the potential risks of infection and preventive methods for these infections.

Monogenean parasites infect ornamental fish imported to Australia.

The ornamental fish trade provides a pathway for the global translocation of aquatic parasites. We examined a total of 1020 fish imported from Singapore, Malaysia, Thailand, or Sri Lanka to Australia (including freshwater and marine fish species) for monogenean ectoparasites. Fish were received following veterinary certification that they showed no clinical signs of pests and diseases from the exporting country and visual inspection at Australian border control. Australian import conditions require mandatory treatment for goldfish with parasiticides (e.g. trichlorfon, formaldehyde, sodium chloride) for the presence of gill flukes (Dactylogyrus vastator Nybelin, 1924 and Dactylogyrus extensus Mueller and Van Cleave, 1932) prior to export. Over 950 individual parasites were detected in five imported fish species, representing 14 monogenean species. Seven Dactylogyrus spp. including D. vastator and three Gyrodactylus spp. infected goldfish, Carassius auratus Linnaeus, 1758, from Malaysia, Singapore, and Thailand. Dactylogyrus ostraviensis Rehulka, 1988, infected rosy barb, Pethia conchonius Hamilton, 1822, from Singapore, Sri Lanka, and Thailand while two Trianchoratus spp. infected three spot gourami, Trichopodus trichopterus Pallas, 1970 and pearl gourami Trichopodus leerii Bleeker, 1852, from Sri Lanka. Urocleidoides reticulatus Mizelle & Price, 1964, infected guppy, Poecilia reticulata Peters, 1859, from Sri Lanka. The discovery of D. vastator in goldfish, as well as 13 other monogenean species, shows that pre-export health requirements, which include chemical treatment of goldfish, and inspection of all ornamental fish species did not prevent infection by monogeneans. Inspection prior to exportation and at border control must account for the highly cryptic nature of monogenean parasites and consider alternatives to current pre-export conditions and visual inspection at border control.

Preventive efficacy of NexGard Spectra® against Dipylidium caninum infection in dogs using a natural flea (Ctenocephalides felis) infestation model.

The efficacy of a monthly oral endectocide product, NexGard Spectra® (Merial), a combination of afoxolaner and milbemycin oxime, was evaluated in a flea (Ctenocephalides felis) challenge model for the prevention of Dipylidium caninum tapeworm infection in dogs. The efficacy of treatment with NexGard Spectra® was assessed in 10 dogs following weekly flea infestation with metacestode naturally infected fleas and compared with that in 10 untreated control dogs. The 100 fleas deposited weekly on each dog were not removed until Day 35, allowing enough time for their ingestion. The microscopical analysis of 30 fleas from the flea batches before each weekly challenge demonstrated that 10-33% of the fleas were infected by D. caninum cysticercoid larvae. The arithmetic mean flea count recorded was 47.7 for the 10 untreated dogs and 0 for the 10 treated dogs at Day 35. Based on the daily collection of expelled D. caninum proglottids by dogs during the 70 days of the study, 70% (7/10) of the control dogs and 0% (0/10) of the treated dogs were infected with D. caninum (p < 0.0031). Through its efficacy against fleas, NexGard Spectra® treatment provided indirect prevention of D. caninum infestation. No treatment-related adverse events were observed in dogs during this study.

Praziquantel induced oxidative stress and apoptosis-like cell death in Raillietina echinobothrida.

Praziquantel (PZQ) is an anthelmintic drug used against trematode and cestode parasites of humans and veterinary animals. Since praziquantel was introduced as a broadspectrum anthelmintic, numerous studies described its successful use against helminth parasites, but its exact mechanism of action is feebly understood. Therefore, the present study was carried out to evaluate the possible role of PZQ induced oxidative stress in apoptosis-like cell death in the poultry tapeworm Raillietina echinobothrida. Parasite viability assay revealed a time-dependent reduction in the worm viability compared to the control. Transmission electron microscopy showed typical apoptotic features like condensed nucleus, damaged nuclear envelope and altered mitochondrial membrane in PZQ exposed parasites. Results revealed chromatin condensation and DNA fragmentation in PZQ exposed parasites. There was a notable decline in the level of glutathione and glutathione-s-transferase activity leading to the augmented generation of reactive oxygen species. This led to the alterations in the mitochondrial membrane potential with increased active caspase-3/7, confirms the involvement of mitochondria in the event. The present study suggests that PZQ exerts oxidative stress leading to apoptosis-like events in the parasites resulting their death.

Helminths and helminthoses in Central Europe: diseases caused by cestodes (tapeworms).

The second part of the overview "Helminths and helminthoses in Central Europe" is dedicated to the cestodes (tapeworms) and the diseases caused by cestodes. The overview comprises the spectrum of the most relevant species, describes their incidence, geographic distribution and the most important clinical symptoms and highlights the possibilities of diagnosis, treatment and prophylaxis of cestode-caused diseases.

Culinary delights and travel? A review of zoonotic cestodiases and metacestodiases.

Due to increased globalization, food-borne parasitic infections are becoming more prevalent worldwide, including in countries where these parasites and parasitic diseases had previously been well controlled or eradicated. Improved sanitation, health education, and establishment of appropriate food safety mechanisms can go a long way towards the control of many these infections. However, food-borne parasitic infections are still common diseases in developing countries, especially in rural areas. As many of today's travelers are looking to explore more distant locations and partake in the local cuisine, they may be at greater risk of acquiring a food-borne parasitic infection, including those caused by a number of adult and larval tapeworms. This review discusses fish and meat-borne tapeworms and zoonotic metacestodiases of public health importance to both developing and developed countries, with a focus on infection prevention in travelers.

Spirometra (Pseudophyllidea, Diphyllobothriidae) severely infecting wild-caught snakes from food markets in Guangzhou and Shenzhen, Guangdong, China: implications for public health.

Sparganosis is a zoonotic disease caused by the spargana of Spirometra, and snake is one of the important intermediate hosts of spargana. In some areas of China, snake is regarded as popular delicious food, and such a food habit potentially increases the prevalence of human sparganosis. To understand the prevalence of Spirometra in snakes in food markets, we conducted a study in two representative cities (Guangzhou and Shenzhen), during January-August 2013. A total of 456 snakes of 13 species were examined and 251 individuals of 10 species were infected by Spirometra, accounting for 55.0% of the total samples. The worm burden per infected snake ranged from 1 to 213, and the prevalence in the 13 species was 0∼96.2%. More than half (58.1%) of the spargana were located in muscular tissue, 25.6% in subcutaneous tissue, and 16.3% in coelomic cavity. The results indicated that Spirometra severely infected snakes in food markets in Guangzhou and Shenzhen, implying that eating snakes has great health risk and improper cooking methods may increase the risk of Spirometra infection in humans in China. Additional steps should be considered by the governments and public health agencies to prevent the risk of snake-associated Spirometra infections in humans.

Prophylactic treatment of flea-infested dogs with an imidacloprid / flumethrin collar (Seresto®, Bayer) to preempt infection with Dipylidium caninum.

The objective of the study was to determine the sustained effectiveness of 10 % imidacloprid and 4.5 % flumethrin, incorporated in a slow-release matrix collar, in preventing Dipylidium caninum infection in dogs after repeated laboratory infestations with fleas infected with metacestodes of this tapeworm. Efficacy against infection with D. caninum was evaluated by infesting 16 dogs with cat fleas (Ctenocephalides felis) on study days 7, 14, 21, 28, 35 and 42, from batches suitably infected with D. caninum metacestodes. Prior to each post-treatment infestation the D. caninum infection rate for the fleas was determined by microscopically examining 100 fleas for D. caninum metacestodes. The D. caninum prevalence in the fleas used for infestations ranged from 23 % to 52 %. Medicated collars were fitted to 8 of the dogs on study day 0. The weight of the IVP collars varied between 35.48 g and 38.48 g (average 37.16 g), whilst animal weight varied between 12.20 kg and 17.98 kg (treated group, n = 8, average 14.79 kg). Seven days later infestation of each of the 16 dogs with 250 fleas commenced. Infestations continued at weekly intervals until Day 42 with efficacy against fleas evaluated 24 hours after each infestation. From Days 21 to 74, infection of the dogs with D. caninum was verified (daily examination of faeces and cages for the presence of expelled proglottids). Calculation of prophylactic effectiveness of the collars in preventing infection with D. caninum was based on the difference in geometric mean numbers of scoleces between groups at necropsy on Day 75. Effective prevention of infection with D. caninum was found to be 96.6 %. Efficacy of the collars against fleas was ≥ 99.9 % for the duration of the assessment period. Newly acquired infestations of fleas are rapidly eliminated by the insecticidal components of the medicated collars over a period of several months. In the event of fleas being infected with metacestodes, with D. caninum can be prevented in collared dogs, concurrently reducing the likelihood of transmission to humans.

In vitro ovicidal and cestocidal effects of toxins from Bacillus thuringiensis on the canine and human parasite Dipylidium caninum.

Bacillus thuringiensis is a gram-positive soil-dwelling bacterium that is commonly used as a biological pesticide. This bacterium may also be used for biological control of helminth parasites in domestic animals. In this study, we evaluated the possible ovicidal and cestocidal effects of a total protein extract of B. thuringiensis native strains on the zoonotic cestode parasite of dogs, Dipylidium caninum (D. caninum). Dose and time response curves were determined by coincubating B. thuringiensis proteins at concentration ranging from 100 to 1000 µ g/mL along with 4000 egg capsules of D. caninum. Egg viability was evaluated using the trypan blue exclusion test. The lethal concentration of toxins on eggs was 600 µ g/ml, and the best incubation time to produce this effect was 3 h. In the adult stage, the motility and the thickness of the tegument were used as indicators of damage. The motility was inhibited by 100% after 8 hours of culture compared to the control group, while the thickness of the cestode was reduced by 34%. Conclusively, proteins of the strain GP526 of B. thuringiensis directly act upon D. caninum showing ovicidal and cestocidal effects. Thus, B. thuringiensis is proposed as a potential biological control agent against this zoonosis.

Preventive efficacy of Frontline® Combo and Certifect® against Dipylidium caninum infestation of cats and dogs using a natural flea (Ctenocephalides felis) infestation model.

Two studies were performed to evaluate the effectiveness of two monthly topical anti-flea products for the prevention of Dipylidium caninum infestations in cats and dogs. A single treatment with Frontline(®) Combo spot-on for cats (fipronil-(S)-methoprene) and two successive monthly treatments of Certifect(®) for dogs (fipronil-amitraz-(S)-methoprene) were assessed for the prevention of D. caninum infestations following weekly challenges of treated cats or dogs with metacestode naturally-infected fleas. The rate of infestations using the model in cats versus dogs explains the choice of a 1-month trial in cats and a 2-month trial in dogs. The experimental flea-infection model resulted in a range of 22-53% of the fleas being infected by Dipylidium cysticercoids. The arithmetic mean flea counts recorded for the untreated cats ranged from 51.2 to 68. The geometric mean flea counts recorded for the Frontline Combo treated cats differed significantly (p < 0.05) from those of the untreated control cats on all assessment days. The arithmetic mean flea counts recorded for the untreated dogs ranged from 166.6 to 238.6. The geometric mean flea counts recorded for the Certifect treated dogs differed significantly (p < 0.001) from those of the untreated group on all assessment days. Frontline Combo treatment on cats provided ≥99.8% persistent anti-flea efficacy throughout the 30-day treatment period. In the dog study, the two Certifect treatments provided ≥97% persistent efficacy throughout the 60-day study. Based on the collection of expelled D. caninum proglottids by cats, 100% (6/6) of the control cats and 0% (0/6) of Frontline Combo treated cats were infested with D. caninum. Frontline Combo spot-on for cats was therefore 100% effective in preventing infection with D. caninum. In dogs, 7 out of the 8 control group dogs (87.5%) produced proglottids following infestation of infected fleas, whereas 0 out of 8 dogs (0%) in the treated group were infected. The infection rates of the two groups were significantly different. The percent effectiveness for the Certifect treatment group for the prevention of D. caninum infection was 100% during this 2-month trial. No treatment-related adverse events were observed in either cats or dogs during these studies.

Prophylactic treatment of flea-infested cats with an imidacloprid/flumethrin collar to forestall infection with Dipylidium caninum.

BACKGROUND: The objective of the study was to determine the sustained effectiveness of 10% imidacloprid (w/w) and 4.5% flumethrin (w/w) incorporated in a slow-release matrix collar in preventing Dipylidium caninum infection in cats following repeated laboratory-infestations with fleas infected with metacestodes. METHODS: Efficacy against infection with D. caninum was evaluated by infesting 16 cats with the flea Ctenocephalides felis felis infected with metacestodes of the tapeworm. Medicated collars were fitted to 8 of the cats and infestation of each cat with 200 fleas from a suitably infected batch commenced 7 days later and continued at weekly intervals until Day 28. Efficacy against fleas was evaluated 24 h after each infestation. Infection of the cats with D. caninum was verified by daily examination of the cats' faeces and immediate surroundings for proglottids from Day 21 to Day 60. Calculation of the prophylactic effectiveness of the collars in preventing infection of the cats with D. caninum was based on the difference in the geometric mean number of scoleces recovered from the gastrointestinal tracts of collared compared to untreated cats at necropsy on Day 61. RESULTS: Efficacy of the collars against infestation of the cats with fleas was 99.9% on Day 7 and 100% at each subsequent weekly assessment. Infection of the fleas with metacestodes was ≥40% in 7 to 13 day old fleas, but progressively decreased thereafter. At necropsy all the control cats were infected with D. caninum and harboured between 19 and 346 scoleces with a geometric mean of 58.3. A single treated cat was infected and harboured 2 scoleces. Effective prevention of infection with D. caninum, based on a comparison of the geometric mean numbers of scoleces recovered from control and treated cats, was 99.7%. CONCLUSION: The insecticidal components of the medicated collars are capable of rapidly eliminating newly-acquired infestations of fleas that are infected with the metacestodes of D. caninum, thus preventing infection with the cestode in collared cats.

Diagnosis and treatment of coenurosis in sheep.

Coenurosis is a disease of the central nervous system in sheep, caused by Coenurus cerebralis, the larval stage of Taenia multiceps, a tapeworm, which infests the small intestine of carnivores. In 80-90% of cases, the cyst is located in one cerebral hemisphere, whilst in 5-10% of cases, it is localised in the cerebellum; rarely it involves two sites in the brain of the affected animal. Listeriosis, louping-ill, sarcocystosis and polioencephalomalacia and brain abscessation should be considered when formulating a diagnosis of acute coenurosis. In all cases, it is essential to carefully examine the animal and not simply rely on results of ancillary tests (mainly of cerebrospinal fluid examination), as disorders other than coenurosis can be responsible for changes in the results of these tests. Treatment is based on surgical removal of the coenurus cyst after general anaesthesia of the animal; the approach has a very good success rate, especially after accurate localisation of the lesion. Despite that, many farmers may choose to slaughter those sheep fit for marketing for economic reasons and euthanise those in poor condition.