Canine babesiosis among working dogs of organised kennels in India: A comprehensive haematological, biochemical, clinicopathological and molecular epidemiological multiregional study

Canine Babesiosis Caused by Large Babesia Species: Global Prevalence and Risk Factors-A Review

Canine babesiosis is a disease caused by protozoan pathogens belonging to the genus Babesia. Four species of large Babesia cause canine babesiosis (B. canis, B. rossi, B. vogeli, and the informally named B. coco). Although canine babesiosis has a worldwide distribution, different species occur in specific regions: B. rossi in sub-Saharan Africa, B. canis in Europe and Asia, and B. coco in the Eastern Atlantic United States, while B. vogeli occurs in Africa, southern parts of Europe and Asia, northern Australia, southern regions of North America, and in South America. B. vogeli is the most prevalent large Babesia species globally. This results from its wide range of monotropic vector species, the mild or subclinical nature of infections, and likely the longest evolutionary association with dogs. The most important risk factors for infection by large Babesia spp. include living in rural areas, kennels or animal shelters, or regions endemic for the infection, the season of the year (which is associated with increased tick activity), infestation with ticks, and lack of treatment with acaricides.

Advanced approaches for the diagnosis and chemoprevention of canine vector-borne pathogens and parasites-Implications for the Asia-Pacific region and beyond

Vector-borne pathogens (VBPs) of canines are a diverse range of infectious agents, including viruses, bacteria, protozoa and multicellular parasites, that are pernicious and potentially lethal to their hosts. Dogs across the globe are afflicted by canine VBPs, but the range of different ectoparasites and the VBPs that they transmit predominate in tropical regions. Countries within the Asia-Pacific have had limited prior research dedicated to exploring the epidemiology of canine VBPs, whilst the few studies that have been conducted show VBP prevalence to be high, with significant impacts on dog health. Moreover, such impacts are not restricted to dogs, as some canine VBPs are zoonotic. We reviewed the status of canine VBPs in the Asia-Pacific, with particular focus on nations in the tropics, whilst also investigating the history of VBP diagnosis and examining recent progress in the field, including advanced molecular methods, such as next-generation sequencing (NGS). These tools are rapidly changing the way parasites are detected and discovered, demonstrating a sensitivity equal to, or exceeding that of, conventional molecular diagnostics. We also provide a background to the armoury of chemopreventive products available for protecting dogs from VBP. Here, field-based research within high VBP pressure environments has underscored the importance of ectoparasiticide mode of action on their overall efficacy. The future of canine VBP diagnosis and prevention at a global level is also explored, highlighting how evolving portable sequencing technologies may permit diagnosis at point-of-care, whilst further research into chemopreventives will be essential if VBP transmission is to be effectively controlled.

Analysis of genetic diversity and population structure of Babesia gibsoni

Babesia gibsoni is a tick-borne apicomplexan protozoan causing canine babesiosis. This parasite has diploid sexual reproduction in ticks, during which genetic exchanges can occur leading to increased genetic diversity, which is an important factor in adapting to environmental changes. Exploring the genetic variation of B. gibsoni population can provide a foundation for understanding the patterns of disease transmission and developing babesiosis control strategies. Partial 18S rRNA fragment sequences were obtained from 11 B. gibsoni isolates collected from different regions in China and 117 publicly available sequences were from 12 geographical areas including China. The genetic variation, demographic expansion and population structure were examined. A total of 34 haplotypes were identified among B. gibsoni populations. Analysis of molecular variance, pairwise Fst and structure analysis showed that high genetic variation within populations, low genetic differentiation and obvious mixture haplotype were apparent in a single continent, but higher genetic differentiation was detected across different continents. Neutrality tests implied that B. gibsoni populations had experienced population extension. These findings will contribute to understand the genetics and evolution of B. gibsoni and will be useful for formulating effective management strategies to prevent and control this parasite.

Molecular survey and phylogenetic analysis of Babesia vogeli in dogs

Canine babesiosis is a life-threatening haemoparasitic disease in dogs that is prevalent worldwide. In this study, the prevalence of Babesia vogeli (B. vogeli) was investigated in dogs from Egypt by using Polymerase Chain Reaction (PCR) assay, and associated risk factors were evaluated. In addition, phylogenetic position of B. vogeli Egyptian isolate was determined by sequencing. A total of 275 blood samples were taken from dogs located in four governorates belonging to the north of Egypt. Samples were examined by PCR targeting the B. vogeli 18S rRNA gene and this species was also confirmed by sequencing. Overall, the prevalence of B. vogeli was 5.1% among the studied dogs and the highest prevalence rate was found in the Giza governorate. Univariate logistic regression was used to evaluate each variable individually. The results revealed a significant association between the prevalence of B. vogeli infection and whether or not dogs were infested with ticks and the type of floor used in dog shelters. Additionally, tick infestation (OR 6.1, 95% CI 1.2-31.4), and living in shelters with soil floors (OR 3.8, 95% CI 0.8-17.8) were identified as potential risk factors for B. vogeli infection. Phylogenetic analysis was performed using B. vogeli 18S rRNA partial sequences with the hypervariable V4 region from GenBank. The Egyptian isolate was assigned to second sub-cluster with B. vogeli isolates from Japan, Venezuela and Paraguay within the B. vogeli/B. canis cluster. The present data will be useful to improve the understanding of canine babesiosis epidemiology and ways to control the disease in companion dogs.

PCR detection and genetic characterization of piroplasms from dogs in Myanmar, and a possible role of dogs as reservoirs for Theileria parasites infecting cattle, water buffaloes, and goats

Canine vector-borne pathogens can act as zoonotic agents in humans; however, it poorly understood whether dogs play a role as reservoirs of vector-borne parasites in livestock animals. Here, we report the unexpected detection of 18S rRNA gene (rDNA) sequences of five ruminant Theileria species from the peripheral blood of dogs in Myanmar, in addition to those of two canine Babesia species. Using novel BTH primers capable of amplifying the 18S rDNA of Babesia, Theileria, and Hepatozoon spp., approximately 1,500 bp nested PCR products were detected in 19% (17/91) of local or imported dog breeds in different regions of Myanmar. Among the sequences of the 17 PCR products, ten were determined as Theileria 18S rDNA, including three as Theileria orientalis, three as Theileria buffeli, two as Theileria cf. velifera, one as Theileria luwenshuni, and one as Theileria sp. Most of these sequences showed higher identities with Theileria sequences determined in previous studies of cattle, water buffaloes, and goats in Myanmar. Six PCR products were identified as Babesia vogeli and one sample was determined as Babesia gibsoni. Furthermore, we obtained approximately 900 bp thrombospondin-related adhesive protein (TRAP) gene fragments from three dog blood DNA samples. Phylogenetic analysis of the TRAP gene showed that B. gibsoni parasites in Myanmar were considerably related to isolates from China, Korea, Japan, and Taiwan, but clearly separated from those from Bangladesh and India. These results provide new insights into a possible role of dogs in maintaining and spreading tick-borne pathogens among livestock and canine populations in Myanmar.

Prevalence, genetic, and biochemical evaluation of immune response of police dogs infected with Babesia vogeli

Background and Aim:

Babesia species are tick-borne protozoan parasites of apicomplexan type which infect the erythrocytes of dogs it ranges from subclinical to severe cases, depending on different factors such as immune status, age, and presence of other co-infections with the Babesia species. Hence, this study aimed to identify the protozoan parasites infecting police dogs of different breeds, ages, and both sexes in Egypt. Concerning molecular detection of Babesia vogeli using conventional polymerase chain reaction sequencing and phylogenetic analysis, followed by the assessment of immunological and biochemical status of infected dogs.

Materials and Methods:

The blood of 242 police K9 dogs was collected. The age, breed, sex, and health status with clinical signs of dogs were recorded. Hematological, biochemical, and oxidative stress analyses of the blood were performed together with gene expression analysis using two genes (gamma interferon [IFN-γ] and tumor necrosis factor-alpha [TNF-α]). The identification of the causative agent was performed using molecular analysis of the 18S ribosomal RNA (rRNA). The 18S rRNA region of canine Babesia spp. was successfully amplified, and sequencing data were deposited in GenBank (accession number: MT565474.1), which resembled those of B. vogeli.

Results:

The results of blood samples screening revealed that of the 242 blood samples, 62 were positive for B. vogeli infection. The infection rate in male dogs was higher than that in female dogs. The police dogs were classified into the following three groups of dogs: (1^st group) healthy, (2^nd infected with B. vogeli, and mixed infection of B. vogeli and Ehrlichia canis). The oxidative stress biomarkers levels in B. vogeli infected dogs were greater than that of healthy dogs. Likewise, IFN-γ and TNF-α level in B. vogeli infected dogs were elevated in infected dogs.

Conclusion:

Our findings demonstrated that B. vogeli had completely adverse effects on the health condition of the police dogs that may lead to death in some dogs.

Update on prevalence and distribution pattern of tick-borne diseases among humans in India: a review

In the present scenario, tick-borne diseases (TBDs) are well known for their negative impacts on humans as well as animal health in India. The reason lies in their increased incidences due to global warming, environmental and ecological changes, and availability of suitable habitats. On a global basis, they are now considered a serious threat to human as well as livestock health. The major tick-borne diseases in India include Kyasanur forest disease (KFD), Crimean-congo hemorrhagic fever (CCHF), Lyme disease (LD), Q fever (also known as coxiellosis), and Rickettsial infections. In recent years, other tick-borne diseases such as Babesiosis, Ganjam virus (GANV), and Bhanja virus (BHAV) infections have also been reported in India. The purpose of this paper is to review the history and the current state of knowledge of tick-borne diseases in the country. The conclusion of this review is extending the requirement of greater efforts in research and government management for the diagnosis and treatment and as well as prevention of these diseases so that tick-borne disease burden should be minimizing in India.

Survey and Molecular Study of Babesia gibsoni in Dogs of Baghdad Province, Iraq

This study aimed to detect Babesia gibsoni (B. gibsoni) in dogs of different ages, sex and breeds in Baghdad province by microscopic and molecular investigations using polymerase chain reaction (PCR), sequencing, and phylogenetic analyses. The present study was investigated B. gibsoni in 310 blood samples of dogs for the period from December 2018 to September 2019 in Baghdad province, Iraq. The molecular study was carried out by using universal primers of Babesia spp. (PIRO-A and PIRO-B) and specific primers of B. gibsoni (BAGIF and BAGIR) products size of 410 bp and 488 bp fragments of 18S rRNA gene respectively. The clinical signs revealed higher percentage and specific clinical signs of B. gibsoni as depression, anorexia, fever, pale mucus membrane, and ticks infestation, however icterus, and dead were low in which only occurred in two dogs out of infected dogs. The PCR assay and microscopic diagnosis revealed the infection rate of B. gibsoni 9 out of 310 (2.9%) in dogs. The sequence data analyses of nine DNA products were 98-100% similar to sequences of 18S rRNA gene of B. gibsoni data available in Gene bank. According to breed, age, and sex, the results revealed a significantly high-risk factor of infection in Husky dogs; B. gibsoni detected in females which was increased non-significantly than males; while the highest occurrence of disease was in young dogs aged three years or less in addition to the above, the infection rate of B. gibsoni was high in spring season. In conclusion, this study was considered the first molecular record of B. gibsoni in Baghdad, Iraq documented no differences in diagnosis by blood smear and conventional PCR to amplify of 18S rRNA gene and partial sequencing of B. gibsoni with low-cost method and easily done.