Human social conditions predict the risk of exposure to zoonotic parasites in companion animals in East and Southeast Asia.

BACKGROUND: A recent dramatic surge in pet ownership has been observed across metropolitan areas in Asia. To date, there is a dearth of information on the risk associated with pet ownership for the transmission of parasites on a large scale in Asia, despite this continent giving rise to the largest burden of zoonotic infections worldwide. METHODS: We explored the nature and extent of zoonotic internal (endo-) and external (ecto-) parasites and arthropod-borne pathogens in 2381 client-owned dogs and cats living in metropolitan areas of eight countries in East and Southeast Asia using reliable diagnostic tests and then undertook extensive statistical analyses to define predictors of exposure to zoonotic pathogens. RESULTS: The estimated ORs for overall parasite infections are 1.35 [95% CIs 1.07;1.71] in young animals and 4.10 [1.50;11.2] in the animal group older than 15 years as compared with adult animals, 0.61 [0.48;0.77] in neutered animals as compared to unneutered animals, 0.36 [0.26;0.50] in animals living in urban areas as compared with rural areas, 1.14 [1.08;1.21] for each 1 °C increase of annual mean temperature which varies from 12.0 to 28.0 °C, and 0.86 [0.78;0.95] for each year of life expectancy which varies from 70.9 to 83.3 years. CONCLUSIONS: Here we highlight the influence of human life expectancy and the neutering status of the animals, which reflect increased living standards through access to education and human and veterinary health care, to be both strongly associated with exposure to zoonotic parasites. An integrated approach of local and international authorities to implement and manage educational programs will be crucial for the control of zoonotic infections of companion animals in Asia.

Parasites live on or inside animals or humans and can cause disease. Companion animals (pets) with parasites present a potential risk to the health of their owners, as certain kinds of parasites (known as zoonotic parasites) can affect both animal and human health. Here, we investigated whether human social conditions are associated with zoonotic parasite infections in companion animals in East and Southeast Asia. We found that higher human life expectancy and neutering of the companion animals were associated with fewer zoonotic parasite infections in the animals. These findings highlight the need for an enhanced commitment of local authorities to establish prevention campaigns, including education programs, against zoonotic pathogens. These measures will play a crucial role in alleviating the impact of these diseases in companion animals and humans in Asia.

Molecular detection of pathogens in ticks and fleas collected from companion dogs and cats in East and Southeast Asia.

BACKGROUND: Ticks and fleas are considered amongst the most important arthropod vectors of medical and veterinary concern due to their ability to transmit pathogens to a range of animal species including dogs, cats and humans. By sharing a common environment with humans, companion animal-associated parasitic arthropods may potentially transmit zoonotic vector-borne pathogens (VBPs). This study aimed to molecularly detect pathogens from ticks and fleas from companion dogs and cats in East and Southeast Asia. METHODS: A total of 392 ticks and 248 fleas were collected from 401 infested animals (i.e. 271 dogs and 130 cats) from China, Taiwan, Indonesia, Malaysia, Singapore, Thailand, the Philippines and Vietnam, and molecularly screened for the presence of pathogens. Ticks were tested for Rickettsia spp., Anaplasma spp., Ehrlichia spp., Babesia spp. and Hepatozoon spp. while fleas were screened for the presence of Rickettsia spp. and Bartonella spp. RESULT: Of the 392 ticks tested, 37 (9.4%) scored positive for at least one pathogen with Hepatozoon canis being the most prevalent (5.4%), followed by Ehrlichia canis (1.8%), Babesia vogeli (1%), Anaplasma platys (0.8%) and Rickettsia spp. (1%) [including Rickettsia sp. (0.5%), Rickettsia asembonensis (0.3%) and Rickettsia felis (0.3%)]. Out of 248 fleas tested, 106 (42.7%) were harboring at least one pathogen with R. felis being the most common (19.4%), followed by Bartonella spp. (16.5%), Rickettsia asembonensis (10.9%) and "Candidatus Rickettsia senegalensis" (0.4%). Furthermore, 35 Rhipicephalus sanguineus ticks were subjected to phylogenetic analysis, of which 34 ticks belonged to the tropical and only one belonged to the temperate lineage (Rh. sanguineus (sensu stricto)). CONCLUSION: Our data reveals the circulation of different VBPs in ticks and fleas of dogs and cats from Asia, including zoonotic agents, which may represent a potential risk to animal and human health.

Zoonotic Vectorborne Pathogens and Ectoparasites of Dogs and Cats in Eastern and Southeast Asia.

To provide data that can be used to inform treatment and prevention strategies for zoonotic pathogens in animal and human populations, we assessed the occurrence of zoonotic pathogens and their vectors on 2,381 client-owned dogs and cats living in metropolitan areas of 8 countries in eastern and Southeast Asia during 2017-2018. Overall exposure to ectoparasites was 42.4% in dogs and 31.3% in cats. Our data cover a wide geographic distribution of several pathogens, including Leishmania infantum and zoonotic species of filariae, and of animals infested with arthropods known to be vectors of zoonotic pathogens. Because dogs and cats share a common environment with humans, they are likely to be key reservoirs of pathogens that infect persons in the same environment. These results will help epidemiologists and policy makers provide tailored recommendations for future surveillance and prevention strategies.

Molecular characterization of MHC II DRB3 gene of swamp- and riverine-type water buffaloes.

OBJECTIVE: Major histocompatibility complex (MHC) is a set of molecular proteins on the surface of antigen presenting cells encoded by a large gene family which are important parts of the immune system. This study was conducted to convey information on the genetic characteristics of the MHC II DRB3 gene in riverine and swamp buffaloes. MATERIALS AND METHODS: Characterization of MHC II DRB3 gene was carried out using polymerase chain reaction (PCR)-based assay. Thirty-milliliter milk samples were collected from 10 swamp-type and 10 riverine-type buffaloes. RNA from milk samples were extracted using Trizol and then followed by reverse transcription-PCR (RT-PCR). RESULTS: The phylogenetic analysis with 1,000 bootstrap replications clearly showed complex parsimony in MHC II DRB3 gene between 10 riverine- and 10 swamp-type but also confirmed that the samples are similar to Bubalus bubalis. Aligned sequences of the 20 water buffaloes were compared with three other ruminants (Bos taurus, Ovis aries, and Capra hircus) and non-ruminant (Sus scrofa) that serve as an outgroup. MHC sequences from GenBank show that there was an average of 705 identical pairs, with 22 transitional pairs and 30 transversional pairs with a ratio of 0.7. CONCLUSION: Based on the molecular data, the current study conforms to other works of literature that this gene is highly polymorphic which can be due to its function in the immune responsiveness and disease resistance. Further study on the immunological response of MHC II DRB3 to infection may elucidate its underlying function and role in the protection against specific disease of animals.

Evidence of Fasciola spp. resistance to albendazole, triclabendazole and bromofenofos in water buffaloes (Bubalus bubalis).

Fasciolosis caused by Fasciola spp. is considered the most important helminth infection of ruminants in tropical countries. Anthelmintic resistance has become a global concern. This study compared the efficacy of the commonly used anthelmintics, determined the toxicity level and any indication of resistance. Thirty two water buffaloes naturally-infected with Fasciola spp. were used to determine the efficacy of triclabendazole (TBZ), albendazole (ABZ), and bromofenofos (BRO) using Fecal Egg Count Reduction Test (FECRT). To test the toxicity of the drugs given, serum glutamic-pyruvic transaminase (SGPT) was evaluated before and within one week after treatment. One dose administration of ABZ registered an efficacy of 79.17%, 73.33% for TBZ and 70.83% for BRO. Efficacy in two dose- treatment group was 83.33% for both BRO and ABZ, and 90.00% for TBZ. Two dose-treatment was effective for TBZ (90%), ineffective for BRO and ABZ. SGPT levels were not significantly different between pre-treatment and post- treatment across all treatments. Giving one or two doses of anthelmintics, at one month interval, does not increase the efficacy of the three drugs tested. The study also implies that anthelmintic resistance may have developed in the animals.

The prevalence of Ehrlichia canis, Anaplasma platys and Babesia spp. in dogs in Nueva Ecija, Philippines based on multiplex polymerase chain reaction (mPCR) assay.

The aim of the study was to determine the prevalence of Ehrlichia canis, Anaplasma platys and Babesia spp. in dogs. It describes the practice of veterinarians in detecting tick-borne diseases in Nueva Ecija, Philippines. Seventy blood samples were collected and were subjected to multiplex PCR for the detection of E. canis, Babesia spp. and A. platys. The prevalence of babesiosis is the highest in Cabanatuan City (2/10), while a 10% prevalence (1/10) was observed in Science City of Muñoz, Talavera and Sta. Rosa. E. canis were only detected in Cabanatuan City. However, no anaplasmosis was detected in any area. The prevalence of babesiosis and ehrlichiosis in Nueva Ecija is 7.14% (5/70) and 2.85% (2/70) respectively. In addition, 70% (7/10) of the Nueva Ecija veterinary practitioners encountered cases of suspected ehrlichiosis in their practice. The diagnosis of ehrlichiosis is based primarily on presented clinical signs and complete blood counts, which include a platelet count. Of the 10 respondents, half utilized test kits while 90% interpreted blood samples. Meanwhile, only 60% of the respondents used an ELISA test kit for ehrlichiosis. For some practitioners, the main reason for not utilizing a kit is the high cost. None of the respondents had previously attended cases of suspected anaplasmosis. Only one respondent diagnosed a case of babesiosis by blood smear microscopy.

The immunology and genetics of resistance of sheep to Teladorsagia circumcincta.

Teladorsagia circumcincta is one of the most economically important gastrointestinal nematode parasites of sheep in cool temperate regions, to which sheep show genetically-varying resistance to infection. This is a very common parasite and viable sheep production requires the extensive use of anthelmintic drugs. However, the emergence of drug-resistant parasites has stimulated the search for alternative control strategies to curb production losses. Lambs become infected soon after weaning and begin to control parasite burden within 8-10 weeks of continual infection. This control is an acquired characteristic mediated by the development of parasite-specific antibodies. This paper describes the immunology associated with resistance and susceptibility, focussing on differential T cell activation that regulates the production of specific effector mechanisms. It continues by summarizing the methods used to identify genes that could be exploited as molecular markers of selection for resistance. In particular it focusses on the link between understanding the molecular immunology of infection and the identification of candidate genes for selection.

Expression of sheep interleukin 23 (IL23A, alpha subunit p19) in two distinct gastrointestinal diseases.

This paper reports the sequence of sheep interleukin 23A (p19), and shows that it shares 98% identity with bovine IL23A, 85% with human and 76% with mouse IL23A. It also reports the existence of two allelic variants that differ largely within the region encoding the amino terminal polypeptide signal sequence. An optimized RT-qPCR assay was used to quantify IL23A transcripts in sheep infected with two common gastrointestinal pathogens, the intracellular bacterium Mycobacterium avium subspecies paratuberculosis and the parasitic nematode Teladorsagia circumcincta. No differential expression of IL23A was detected in the mesenteric lymph node of sheep with the different pathogenic forms of paratuberculosis, however significantly high levels of IL23A were detected in the ileal mucosa of the paucibacillary form in comparison with the asymptomatic or multibacillary forms. Similarly, significantly high levels were present in the gastric lymph node draining T. circumcincta-infected abomasum in susceptible sheep. High levels of IL23A seem to be associated with lymphocytic infiltration and inflammation in both diseases but not with the macrophage infiltrate of multibacillary paratuberculosis.

Relationship between susceptibility of Blackface sheep to Teladorsagia circumcincta infection and an inflammatory mucosal T cell response.

Teladorsagia circumcincta is the most economically important gastrointestinal (abomasal) nematode parasite of sheep in cool temperate regions, to which sheep show genetically-varying resistance to infection. Lambs, from parents with genetic variation for resistance, were trickle infected with L3 larvae over 12 weeks. 45 lambs were identified with a range of susceptibilities as assessed by: adult worm count at post mortem, faecal egg count (FEC) and IgA antibody levels. This project investigated the correlation of T cell cytokine expression and resistance to infection at the mature stage of response, when the resistant lambs had excluded all parasites.Histopathology showed only minor changes in resistant animals with a low level lymphocyte infiltration; but in susceptible lambs, major pathological changes were associated with extensive infiltration of lymphocytes, eosinophils and neutrophils.Absolute quantitative RT-qPCR assays on the abomasal lymph node (ALN) revealed a significant positive correlation between IL6, IL21 and IL23A transcript levels with adult worm count and FEC. IL23A was also negatively correlated with IgA antibody levels. Significantly positive correlation of TGFB1 levels with adult worm count and FEC were also seen in the abomasal mucosa. These data are consistent with the hypothesis that the inability to control L3 larval colonization, adult worm infection and egg production is due to the activation of the inflammatory Th17 T cell subset.

Expressed gene sequences of two variants of sheep interleukin-25.

This report describes the cloning and characterization of sheep interleukin-25 (IL25) expressed gene sequences and shows that, like humans, sheep express two transcript variants of IL25. Transcript variant 1 (IL25v1) has a 510 bp open reading frame encoding a 169 amino acid polypeptide with a calculated M(r) 19,200. The 498 bp IL25v2 encodes a 165 amino acid polypeptide with a calculated M(r) 18,710; both with an isoelectric point equal to 8.0307. The additional 12 bp of IL-25 isoform 1 are at the 5' end and encode an MYQA peptide, otherwise their sequences are identical. Phylogenetic analysis shows that both sheep IL-25 isoforms are most closely related to cattle and pig IL-25.