Canine infection with Dirofilaria immitis, Borrelia burgdorferi, Anaplasma spp., and Ehrlichia spp. in the United States, 2013-2019.

BACKGROUND: Dogs in the US are commonly infected with vector-borne pathogens, including heartworm and tick-borne disease agents. The geographic distribution of both arthropod vectors and the pathogens they transmit continues to expand. METHODS: To describe the current geographic distribution and prevalence of antigen of Dirofilaria immitis and antibody to Borrelia burgdorferi, Ehrlichia spp., and Anaplasma spp. in dogs, we summarized over 144 million test results from 2013 to 2019, inclusive, by county, state, and region. Canine seroprevalence by state was compared to population-adjusted human reports of tick-borne diseases. RESULTS: Results varied regionally, with D. immitis antigen and Ehrlichia spp. antibodies more frequently detected in the Southeast (2.6% and 5.2%, respectively) and antibody to B. burgdorferi and Anaplasma spp. most common in the Northeast (12.1% and 7.3%, respectively). Overall, percent positive test results to D. immitis decreased in the Southeast by 33.3% when compared to earlier summaries using the same strategy (from 3.9 to 2.6%). Geographic expansion of areas where dogs commonly test positive for Ehrlichia spp. was evident, likely because of a change in the test made in 2012 to allow detection of antibodies to E. ewingii concomitant with expansion of vector tick populations. Percent positive test results to Ehrlichia spp. increased in every region; this shift was particularly pronounced in the Southeast, where percent positive test results increased fourfold (from 1.3 to 5.2%). Continued geographic expansion of B. burgdorferi and A. phagocytophilum was apparent in the Northeast, Midwest, and Upper South, although canine seroprevalence of antibody to B. burgdorferi was much lower than prior surveys in many Lyme-endemic areas. Annual reports of human cases of Lyme disease, ehrlichiosis, and anaplasmosis were associated with percent positive canine results by state for the three tick-borne disease agents (R2 = 0.812, 0.521, and 0.546, respectively). Within endemic areas, percent positive test results for all three tick-borne agents demonstrated evidence of geographic expansion. CONCLUSIONS: Large scale analysis of results from screening dogs in practice for evidence of vector-borne infections, including those with zoonotic importance, continues to be a valuable strategy for understanding geographic trends in infection risk over time.

Changes in renal parameters and their association with subclinical vector-borne infections in Bernese Mountain dogs.

BACKGROUND: An increased risk for glomerulonephritis and a higher prevalence of antibodies to Borrelia (B.) burgdorferi sensu lato have been reported in Bernese mountain dogs (BMDs). The aim of the study was to determine the prevalence of laboratory abnormalities suggestive of kidney disease in clinically healthy BMDs compared to a control population and to investigate if there is a correlation with the occurrence of antibodies to B. burgdorferi sensu lato, Ehrlichia canis, and Anaplasma (A.) spp. and with the occurrence of Dirofilaria (D.) immitis antigen. A total of 197 BMDs and 57 control dogs were included in the study. Laboratory evidence of kidney disease was defined as renal azotemia and/or proteinuria with a urine protein creatinine ration of more than 0.5 in an inactive urine sediment. A SNAP®4Dx® ELISA (IDEXX, Laboratories, Inc., Westbrook, ME, USA) was used to detect antibodies to B. burgdorferi sensu lato, E. canis and Anaplasma spp. and antigen of D. immitis. RESULTS: Laboratory evidence of kidney disease was significantly more common in BMDs than in control dogs (17.8% versus 1.8%) (p = 0.005). The proportion of BMDs with anti-B. burgdorferi sensu latu antibodies and anti-A. phagocytophilum antibodies was significantly higher in BMDs (p <  0.001). However, an association between these findings could not be identified. CONCLUSION: BMDs are more often affected by kidney disease and have a higher prevalence of antibodies to bacterial pathogens transmitted by Ixodes ticks than control dogs. However, a causal relationship between these two variables could not be established due to a lack of association between these two findings.

Serosurvey of arthropod-borne diseases among shelter dogs in the Cumberland Gap Region of the United States.

BACKGROUND: The Cumberland Gap Region (CGR) of the United States is a natural corridor between the southeastern, northeastern, and midwestern regions of the country. CGR has also many species of ticks and mosquitos that serve as competent vectors for important animal and human pathogens. In this study, we tested dogs from six different animal shelters in the CGR for Rocky Mountain spotted fever (RMSF), anaplasmosis, Lyme disease, canine ehrlichiosis and canine heartworm disease. RESULTS: Sera from 157 shelter dogs were tested for antibodies to RMSF agent, Rickettsia rickettsii, using an indirect immunofluorescence assay. Sixty-six dogs (42.0%) were positive for either IgM or IgG, or both IgM and IgG antibodies to R. rickettsii. Moreover, the same set of sera (n = 157) plus an and additional sera (n = 75) from resident dogs at the same shelters were tested using the SNAP 4Dx Plus. Of 232 dogs tested, two (0.9%) were positive for antibodies to Anaplasma phagocytophilum/A. platys, nine (3.9%) were positive for antibodies to Borrelia burgdorferi, 23 (9.9%) for positive for antibodies to Ehrlichia canis/E. ewingii, and 13 (5.6%) were positive for Dirofilaria immitis antigen. Co-infection with two or more etiologic agents was detected in five animals. Three dogs had antibodies to both B. burgdorferi and E. canis/E. ewingii, and two dogs were positive for D. immitis antigen and antibodies to B. burgdorferi and E. canis/E. ewingii. CONCLUSIONS: Shelter dogs in the CGR are exposed to a number of important vector-borne pathogens. Further studies are required to ascertain the roles these animals play in maintenance and transmission of these pathogens.

Prevalence and Risk Factors of Antibodies to Anaplasma spp. in Chile: A Household-Based Cross-Sectional Study in Healthy Adults and Domestic Dogs.

Background: Pet-related tick-borne infections constitute an emerging problem in human and veterinary medicine worldwide. In Chile, two pathogens of the Anaplasmataceae family, Anaplasma platys and Ehrlichia canis, have been identified in recent years in dogs and vectors. This epidemiological survey aimed to determine the human and canine seroprevalence of Anaplasma spp. in urban and rural areas of different regions in Chile and to analyze the factors associated with seropositivity. Methods: We performed a cross-sectional household-based study in four regions, where healthy adults and their household dogs were included. Households were chosen by double stratified random sampling in urban areas and by convenience sampling in rural areas. Anaplasma seroreactivity was determined by a commercial microimmunofluorescence assay using Anaplasma phagocytophilum antigens. A questionnaire survey was applied to assess risk factors for Anaplasma seropositivity. Results: A total of 1105 persons and 905 dogs were included. The overall seroprevalence in humans was 9.4%, ranging from 5.6% in central Chile to 13.7% in the extreme north; in dogs the overall prevalence was 44.0% and ranged from 37.2% in the northern region to 61.1% in central Chile. Risk factors for human seropositivity were lower education and external deworming of dogs, whereas canine seropositivity was associated to urban site, mixed-breed, older animals, and tick infestation. Conclusions: This cross-sectional study suggests a broad exposure of both dogs and dog owners to Anaplasma or related agents in Chile. Further epidemiological and clinical studies are necessary to understand the complete spectrum and epidemiology of tick-borne zoonotic infections in the different ecoclimatic regions of Chile.

Balanced Th1/Th2 immune response induced by MSP1a functional motif coupled to multiwalled carbon nanotubes as anti-anaplasmosis vaccine in murine model.

Anaplasmosis is one of the most prevalent tick-borne diseases of cattle caused by Anaplasma marginale. MSP1a surface protein has been shown to be involved in eliciting immunity to infected cattle. Carbon nanotubes (CNTs) has been increasingly highlighted due to their needle like structure, which contain multiple attachment sites for biomolecules and may interact with or cross biological membranes, increasing antigen availability to immune system. Here, we have successfully designed a nanocomplex of a synthetic peptide noncovalently attached to multiwalled CNT (MWCNT). Peptide comprising the core motif of the MSP1a was efficiently adsorb onto the nanoparticle surface. The MWCNT-Am1 nanocomplex exhibited high stability and good dispersibility and in vivo immunization showed high levels of IgG1 and IgG2a, followed by increased expression of pro-inflammatory and anti-inflammatory cytokines. This is a proof-of-concept of a nanovaccine that was able to generate a strong immune response compared to the common antigen-adjuvant vaccine without the nanoparticles.

Development and evaluation of a double-antigen sandwich ELISA to identify Anaplasma marginale-infected and A. centrale-vaccinated cattle.

Bovine anaplasmosis is a worldwide infectious disease caused by the intraerythrocytic bacterium Anaplasma marginale, which is transmitted by ticks and fomites. A. centrale is a less virulent subspecies used as a live vaccine in cohorts of 8- to 10-mo-old calves that did not naturally reach enzootic stability. We developed 3 variants of a double-antigen sandwich ELISA (dasELISA) using a recombinant major surface protein 5 (MSP5) from A. marginale (dasELISAm) or from A. centrale (dasELISAc) or using MSP5 from both organisms (dasELISAmc). Each dasELISA was tested for the detection of antibodies against A. marginale and A. centrale. The tests were validated using serum samples from cattle not infected with Anaplasma spp. (n = 388), infected with A. marginale (n = 436), and vaccinated with A. centrale (n = 358), confirmed by nested PCR. A total of 462 samples were compared with a commercial competitive ELISA (cELISA). For dasELISAm, dasELISAc, and dasELISAmc, specificities were 98.7%, 98.7%, and 97.4%, and overall sensitivities were 92.6%, 85.7%, and 97.4%, respectively. For A. marginale-infected and A. centrale-vaccinated cattle, sensitivities were 97.7% and 86.3% for dasELISAm, and 77.7% and 95.5% for dasELISAc, respectively. Sensitivity of dasELISAmc was similar for both groups (>96%). The agreement rate between dasELISAmc and cELISA was 96.3% (κ = 0.92); the former test allowed earlier detection of seroconversion of vaccinated cattle than did cELISA. Based on these results, the test could be used to 1) determine the enzootic stability or instability of anaplasmosis in calves, 2) conduct epidemiologic studies, and 3) evaluate the immunogenicity of A. centrale live vaccine.

Molecular detection of vector-borne agents in cats in Southern Brazil / Detecção molecular de agentes transmitidos por vetores em felinos domésticos no Sul do Brasil

Abstract This study used serological and molecular methods to investigate the occurrence of vector-borne pathogens (VBP) with zoonotic potential in cats neutered at the University Veterinary Hospital in Canoinhas, Santa Catarina. The combined PCR and serological results revealed that 17 (56.6%) cats were positive for one or more pathogens. The sampled cats had antibodies to Ehrlichia spp. (7/30), Anaplasma phagocytophilum (3/30) and Leishmania infantum (2/30). The PCR assay detected DNA closely related to Ehrlichia canis in 6/30 cats, Mycoplasma haemofelis in 2/30 cats, A. phagocytophilum and Cytauxzoon sp. in one cat each. While Bartonella clarridgeiae and B. henselae were detected in two cats each, and B. koehlerae was detected in one cat.

Resumo Como os felinos podem ser parasitados por diversos patógenos transmitidos por vetores (PTV), alguns com caráter zoonótico, este estudo objetivou detectar por métodos sorológicos e moleculares, patógenos transmitidos por vetores hematófagos, em gatos atendidos em um Hospital Veterinário Universitário em Santa Catarina. Os resultados da PCR e da sorologia combinados, revelaram que 17 (56,6%) gatos foram positivos para um ou mais patógenos. Na sorologia, foram positivos 7/30 gatos para Ehrlichia, 3/30 para Anaplasma phagocytophilum e 2/30 para Leishmania infantum. Na PCR foi detectado DNA filogeneticamente associado a: Ehrlichia canis em 6/30 gatos; Mycoplasma haemofelis, em 2/30 gatos; A. phagocytophilum e Cytauxzoon sp. em 1/30 gatos cada. Enquanto Bartonella clarridgeiae e B. henselae foram detectadas, cada uma, em dois gatos, B. koehlerae foi detectada em um gato.

Trends in canine seroprevalence to Borrelia burgdorferi and Anaplasma spp. in the eastern USA, 2010-2017.

BACKGROUND: Borrelia burgdorferi and Anaplasma phagocytophilum are tick-borne infections transmitted by Ixodes scapularis in the eastern USA; both agents cause disease in dogs and people. To characterize changes in seroprevalence over time, Cochran Armitage trend tests were used to evaluate percent positive test results for antibodies to B. burgdorferi and Anaplasma spp. in approximately 20 million canine tests from 2010-2017 in 25 states and 905 counties in the eastern USA. RESULTS: A significant decreasing trend in seroprevalence to B. burgdorferi was evident in eight states along the mid-Atlantic coast from Virginia to New Hampshire, and in Wisconsin. In contrast, a continued increasing trend was evident in five northeastern and Midwestern states where Lyme borreliosis is endemic or emerging, as well as in three southern states where endemicity has not yet been widely established. Similarly, seroprevalence to Anaplasma spp. showed a significant, although smaller, decreasing trend in five states along the mid-Atlantic coast from Virginia to Connecticut and Rhode Island, as well as in Minnesota and Wisconsin in the Midwest; despite the fact that those trends were significant they were weak. However, a strong increasing trend was evident in Massachusetts and three states in northern New England as well as in Pennsylvania. CONCLUSIONS: As expected, seroprevalence continued to increase in regions where Lyme borreliosis and anaplasmosis are more newly endemic. However, the declining seroprevalence evident in other areas was not anticipated. Although the reasons for the decreasing trends are not clear, our finding may reflect shifting ecologic factors that have resulted in decreased infection risk or the combined positive influence of canine vaccination, tick control, and routine testing of dogs in regions where these infections have long been endemic. Analysis of trends in canine test results for tick-borne infections continues to be a valuable tool to understand relative geographical and temporal risk for these zoonotic agents.

Molecular detection of vector-borne agents in cats in Southern Brazil.

This study used serological and molecular methods to investigate the occurrence of vector-borne pathogens (VBP) with zoonotic potential in cats neutered at the University Veterinary Hospital in Canoinhas, Santa Catarina. The combined PCR and serological results revealed that 17 (56.6%) cats were positive for one or more pathogens. The sampled cats had antibodies to Ehrlichia spp. (7/30), Anaplasma phagocytophilum (3/30) and Leishmania infantum (2/30). The PCR assay detected DNA closely related to Ehrlichia canis in 6/30 cats, Mycoplasma haemofelis in 2/30 cats, A. phagocytophilum and Cytauxzoon sp. in one cat each. While Bartonella clarridgeiae and B. henselae were detected in two cats each, and B. koehlerae was detected in one cat.

Associations between clinical canine leishmaniosis and multiple vector-borne co-infections: a case-control serological study.

BACKGROUND: Dogs that have clinical leishmaniosis (ClinL), caused by the parasite Leishmania infantum, are commonly co-infected with other pathogens, especially vector-borne pathogens (VBP). A recent PCR-based study found that ClinL dogs are more likely to be additionally infected with the rickettsial bacteria Ehrlichia canis. Further information on co-infections in ClinL cases with VBP, as assessed by serology, is required. The research described in this report determined if dogs with ClinL are at higher risk of exposure to VBP than healthy control dogs using a case-control serology study. RESULTS: Of the 47 dogs with ClinL, anti-E. canis/ Ehrlichia ewingii antibodies were detected in 17 (36.2%), anti-Anaplasma phagocytophilum/Anaplasma platys antibodies in 5 (10.6%) and antigen for Dirofilaria immitis in 2 (4.3%). Of the 87 control dogs, anti-E. canis/E. ewingii antibodies were detected in 14 (16.1%) and anti-A. phagocytophilum/A. platys antibodies in 2 (2.3%). No anti-Borrelia burgdorferi antibody tests were positive. No statistical differences between the ClinL dogs and control dogs regarding lifestyle or use of ectoparasitic prevention, were identified. The ClinL was significantly associated with anti-E. canis/E. ewingii antibodies (odds ratio = 2.9, 95% confidence interval: 1.3-6.7, P = 0.010) compared to controls by both multivariable logistic regression and structural equation modelling. CONCLUSIONS: It was demonstrated that an increased risk for E. canis/E. ewingii seropositivity is present in dogs with ClinL compared to clinically healthy control dogs, despite similar ectoparasitic prevention use and lifestyle. Based on these findings it is suggested that dogs with ClinL should not only be tested for E. canis co-infection using PCR but also serologically for E. canis/E. ewingii.

Vector-borne bacteria in blood of camels in Iran: New data and literature review.

Despite close association between camels and humans, molecular based studies on vector-borne pathogens infecting camels are scarce compared to other animals in Iran. The current study was carried out to investigate the occurrence of vector-borne bacteria in the blood of dromedaries by molecular tools. A total of 200 peripheral blood samples were collected from apparently healthy animals. Microscopic examination was performed on Giemsa-stained blood smears, and drops of blood were spotted on Whatman FTA® cards for molecular analyses. Genomic DNA was extracted from the cards, and PCR amplification followed by sequencing of positive samples was carried out for the detection of Anaplasmataceae, spotted fever group (SFG) rickettsiae, Bartonella spp. and Borrelia spp. Intra-cytic forms of any blood pathogens could not be detected by light microscopy. PCR results revealed 30 animals (15%) to be infected with Anaplasmataceae bacteria. Analyses of sequences revealed a strain of Anaplasma sp. identical to Candidatus Anaplasma camelii isolated from camels, cattle and deer in Asia and Africa. Neither SFG rickettsiae, nor Borrelia or Bartonella species were found. Further studies for determining epidemiological role of camels and its zoonotic potential are recommended. This paper reviews the current knowledge on camels' tickborne bacteria including microscopy, serology and molecular studies.

Discrepancies between self-reported tick bites and evidence of tick-borne disease exposure among nomadic Mongolian herders.

Twenty-six per cent of Mongolians live pastoral lifestyles, increasing their likelihood of exposure to ticks and placing them at a higher risk for contracting tick-borne diseases (TBDs). Anaplasma spp. and Rickettsia spp. have been identified in ticks, livestock and humans in Mongolia, but no known qualitative research has been conducted investigating the association between nomadic herder characteristics, tick bite history and exposure to TBDs. To better understand the association between self-reported tick bites and symptoms versus actual exposure to TBDs, this study paired serological data with 335 surveys administered to Mongolian herders, ages 12-69, from 2014 to 2015. Logistic regression results identified no significant associations between reported tick bites or symptoms with serological evidence of Anaplasma spp. and Rickettsia spp. controlling for age, gender and aimag. Among the 335 respondents who were seropositive to either Anaplasma spp. or Rickettsia spp., 32.9% self-reported experiencing abnormal symptoms such as redness, inflammation, headache, arthritis or fever after being bitten. Alternatively, 17.3% (58/335) of individuals reported experiencing symptoms following a tick bite in instances where serological results indicated no exposure to Anaplasma spp. or Rickettsia spp. Results also identified inconsistencies in reporting and seroprevalence among different age groups, with children having the highest reporting and treatment seeking rates but low levels of exposure in comparison with other groups. While survey results showed that individuals were aware of peak tick seasons and tick species that inhabit specific areas, 58% of heads of households (49/84) were unaware that ticks can cause disease in livestock or dogs. This study suggests that herders are an at-risk population in Mongolia with gaps in awareness of TBD risk. Increased surveillance paired with focused outreach to prevent TBDs targeted to the herder population is encouraged.

Diversity of Anaplasma species in cattle in Mozambique.

Although species of Anaplasma are highly prevalent Rickettsiales agents in domestic and wild ruminants with a wide distribution worldwide, few studies have been conducted so far to detect and/or investigate the diversity of these agentsin cattle in Mozambique. In the present study, serological and molecular assays were used to investigate the occurrence of Anaplasma spp. in 219 bovines sampled in the districts of Boane, Magude, Matutuíne, Moamba and Namaacha in Maputo, Mozambique. In the iELISA test for detection ofIgG antibodies to A. marginale, 86.3% (189/219) of the samples were positive. In qPCR assays for the gene msp1ß for A. marginale and msp2 for A. phagocytophilum, 97.3% (213/219) and 2.7% (6/219) of the animals were positive, respectively. Two different cPCR protocols based on the 16S rRNA gene showed that 100% of the samples were positive for Anaplasma spp. The DNA sequences obtained were phylogenetically related to A. platys, A. phagocytophilum, Candidatus Anaplasma boleense, A. centrale, A. marginale and A. ovis. Phylogenetic inference based on the msp4 and msp5 genes positioned the obtained sequences in the clade of A. marginale, with evidence of occurrence of 8 and 5 different haplotypes for each gene, respectively. Anaplasma sp. phylogenetically associated with A. platys was evidenced in phylogenetic analyzes based on 16S rRNA and groEL genes. It is concluded that a high diversity of species of Anaplasma spp. occurs in cattle in Mozambique.

Recent Increase of Human Granulocytic Anaplasmosis and Co-Infection with Scrub Typhus or Korean Hemorrhagic Fever with Renal Syndrome in Korea.

We report 17 patients with human granulocytic anaplasmosis between January 2015 and September 2018 at two tertiary university hospitals in Korea. Monthly incidence peaked in May and June. Among these patients, we identified three who were co-infected with scrub typhus, and one patient with hemorrhagic fever with renal syndrome.

Prevalence of Borrelia burgdorferi, Anaplasma spp., Ehrlichia spp. and Dirofilaria immitis in Canadian dogs, 2008 to 2015: a repeat cross-sectional study.

BACKGROUND: Vector-borne pathogens are emerging concerns in multiple regions of Canada. Determining regional prevalence of canine vector-borne pathogens and documenting change will improve clinician awareness, enable targeted prevention, enhance diagnosis and ideally reduce the risk of disease. Study objectives were to: (i) estimate the prevalence of positive canine vector-borne test results from samples submitted in Canada; (ii) assess change in prevalence over time, from baseline (2008) to 2015; and (iii) estimate the prevalence of pathogen co-infections. METHODS: This repeat cross-sectional study evaluated 753,468 test results for D. immitis antigen and B. burgdorferi, Ehrlichia canis/ewingii/muris serology, and 753,208 test results for Anaplasma phagocytophilum/platys serology using the SNAP® 4Dx®Test and SNAP 4Dx® Plus Test. RESULTS: Based on all submitted samples from Canada (2008-2015), the period seroprevalence of B. burgdorferi, Ehrlichia spp., Anaplasma spp. and D. immitis antigen were 2.0%, 0.5%, 0.4% and 0.2%, respectively. Over the 7 years (2008 compared to 2015) we observed a significant increase in seroprevalence for B. burgdorferi (144.4%) and Ehrlichia spp. (150%). Co-infections (positive for two or more pathogens on a single 4 pathogen test kit) were estimated at 5.4% (1162/21,612) of total positive tests. CONCLUSIONS: The temporal rise and geographical differences in prevalence detected for these pathogens (notably B. burgdorferi) are consistent with anecdotal information on canine illness related to tick-borne pathogen exposure in multiple regions of Canada, particularly canine Lyme disease.

Seroprevalence of vector-borne pathogens in dogs from Croatia.

Canine vector-borne pathogens (VBPs) are a group of globally distributed and rapidly spreading microorganisms transmitted by arthropods. In the present survey, we investigated Anaplasma spp., Ehrlichia canis, Dirofilaria immitis and Borrelia burgdorferi sensu lato seroprevalence between three groups of dogs (asymptomatic, suspected and deceased) from continental and coastal regions of Croatia with the commercial point-of-care SNAP®4Dx®Plus for VBPs. The overall prevalence for tested pathogens in dogs was 6.1% with the highest prevalence detected for Anaplasma spp. (4.5%), while the remaining pathogens were found at a prevalence of less than 1% (E. canis 0.6%, B. burgdorferi s.l. 0.4%, D. immitis 0.6%). No statistically significant differences in VBP detection between dog cohorts could be found with the exception of D. immitis in the deceased group. Interestingly, no evidence of D. immitis could be found in the hearts of dogs in this group at necropsy, however. This study provides the first data on the seroprevalence of selected VBPs between dogs of different health statuses in Croatia. The results demonstrate that serological evidence of VBPs alone or in combination with co-infections were found just as frequently in asymptomatic dogs as those with suspected or confirmed evidence of VBP disease, raising questions about the pathogenic potential of these organisms in domesticated dogs.

Comparative Evaluation of 2 In-Clinic Assays for Vector-Borne Disease Testing in Dogs.

Vector-borne agents comprise medically important infections affecting dogs throughout much of the world. Sensitive detection of antibodies directed at tick-borne disease-causing organisms in dogs is diagnostically important for veterinarians, pets and their owners, and epidemiologically important for public health surveillance. The SNAP 4Dx Plus Test (IDEXX Laboratories, Inc., Westbrook, ME) identifies antibodies to or infection with multiple tick-borne pathogens and canine heartworm antigen in a single assay. Recently, VetScan FLEX4 Rapid Test (Abaxis, Inc., Union City, CA) was launched as a new assay to detect tick-borne pathogen antibodies and heartworm antigen. In the present study, we evaluated the comparative performance of SNAP 4Dx Plus (SNAP) and FLEX4 Rapid Test (FLEX4) using samples selected based on geographic distributions for canine vector borne diseases, including Borrelia burgdorferi (n = 105), Anaplasma phagocytophilum (160), Anaplasma platys (115), Ehrlichia canis (154), Ehrlichia ewingii (163), Ehrlichia chaffeensis (151) and Dirofilaria immitis (105). Canine vector borne diseases infection status was established for each sample by a combination of reference methods that included necropsy (D. immitis, heartworm disease), Western immunoblotting (B. burgdorferi), immunofluorescence assays (A. phagocytophilum and E. canis) and species-specific ELISAs (A. platys, E. canis, E. ewingii and E. chaffeensis). For comparisons among the 2 assays, samples were evaluated per the manufacturers' instructions for each test kit. By testing each same sample set compared to the defined reference results, sensitivities differed substantially between SNAP and FLEX4, at 95.5 vs. 40.9%, respectively for B. burgdorferi, 97.1% vs. 61.4% for E. canis, 98.2% vs. 59.3% for E. ewingii, 64.3% vs. 35.7% for E. chaffeensis, 84.5% vs. 12.7% for A. phagocytophilum, 83.3% vs. 33.3% for A. platys, and 94.1% vs. 88.2% for D. immitis. Specificities for both rapid assay tests ranged from 98% to 100%. Based upon the comparative results derived from this study, the SNAP test was more sensitive than the FLEX4 test for detection of antibodies to all tick-borne pathogens and heartworm disease (Dirofilaria immitis) antigen in dogs.

Seroprevalence and current infections of canine vector-borne diseases in Nicaragua.

BACKGROUND: Vector-borne diseases constitute a major problem for veterinary and public health, especially in tropical regions like Central America. Domestic dogs may be infected with several vector-borne pathogens of zoonotic relevance, which may also severely compromise canine health. METHODS: To assess the prevalence of canine vector-borne diseases in Nicaragua, 329 dogs from seven cities, which were presented to the veterinarian for various reasons, were included in this study. Dogs were examined clinically and diagnostic blood samples were taken for analysis of packed cell volume (PCV) and presence of microfilariae as well as antigen of Dirofilaria immitis and antibodies to Ehrlichia spp., Anaplasma spp. and Borrelia burgdorferi (sensu lato) by use of a commercially available rapid ELISA. To detect current infections, specific PCRs for the detection of E. canis, A. platys and A. phagocytophilum were carried out on blood samples of the respective seropositive dogs. Microfilaremic blood samples, as well as D. immitis antigen positive samples were further subjected to PCR and subsequent sequencing for filarial species identification. RESULTS: Antibodies against Ehrlichia spp. were present in 62.9% of dogs, while Anaplasma spp. seroprevalence was 28.6%. Antibodies against species of both genera were detected in 24.9% of dogs. Borrelia burgdorferi (s.l.) antibodies were not detected. Dirofilaria immitis antigen was present in six animals (1.8%), two of which also showed D. immitis microfilariae in buffy coat. In addition to D. immitis, Acanthocheilonema reconditum was identified by PCR and sequencing in two of four additional microfilaremic blood samples, which were tested negative for D. immitis antigen. Current E. canis infections as defined by DNA detection were present in 58.5% of Ehrlichia-seropositive dogs, while 5.3% of Anaplasma-seropositive dogs were PCR-positive for A. platys, 2.2% for A. phagocytophilum and 16.0% for both Anaplasma species. Current E. canis infection had a statistically significant negative impact on PCV, whereas no relationship between infection status and clinical signs of disease could be observed. CONCLUSIONS: These results indicate that canine vector-borne diseases are widespread in Nicaragua and that dogs may constitute a reservoir for human infection with E. canis, A. phagocytophilum and D. immitis. Thus, the use of repellents or acaricides to protect dogs from vector-borne diseases is strongly recommended.

Serological Detection of Antibodies against Anaplasma spp. in Cattle Reared in the Gyeongsangbuk-do, Korea.

Anaplasmosis is a tick-borne, non-contagious, zoonotic disease caused by Anaplasma spp., which include Anaplasma marginale, A. centrale, A. phagocytophilum, A. platys, A. ovis, and A. bovis. Recently, in Korea, the prevalence of Anaplasma spp. has been investigated in some animals, such as dogs, horses, goats, cats, and Korean water deer. In cattle, A. marginale is the most virulent species and regarded as the typical type of species. However, data on the seroprevalence of Anaplasma spp. in cattle in Korea during the last decade is limited. This study was designed to investigate the seroprevalence of bovine anaplasmosis in Korea. From 2010 to 2013, blood samples were collected from 568 cattle. Forty animals (7.0%) tested seropositive for Anaplasma spp. by cELISA. Despite that current bovine anaplasmosis seropositivity rate in the Gyeongsangbuk-do is lower than those in tropical countries, anaplasmosis needs to be regarded as a concerning disease. The identification of the specific Anaplasma species infecting cattle in this province requires additional molecular studies. Moreover, further monitoring and control programs for bovine anaplasmosis is required, and the information from this study will be beneficial to develop these programs.

Molecular and serological prevalence of Toxoplasma gondii and Anaplasma spp. infection in goats from Chongqing Municipality, China.

Toxoplasmosis and anaplasmosis are severe zoonotic diseases, the former caused by Toxoplasma gondii and the latter by Anaplasma spp. In the present study, 332 goat blood samples were randomly collected from Chongqing Municipality, China to screen for T. gondii and Anaplasma spp. We used a polymerase chain reaction (PCR) to detect DNA, and enzyme-linked immunosorbent assay (ELISA) to test for T. gondii antibodies. The prevalence of T. gondii and Anaplasma spp. was 38% and 35% respectively by PCR, and 42% for T. gondii antibodies by ELISA. The co-infection rate by T. gondii and Anaplasma was 13%, where the two predominant pathogens co-infecting were Anaplasma phagocytophilum + A. bovis (10%), followed by T. gondii + A. phagocytophilum (9.64%). While co-infection by three pathogens varied ranging from 1.81% to 5.72%, less than 1% of goats were found to be positive for four pathogens. This is the first investigation of T. gondii and Anaplasma spp. infection in goats from Chongqing.