Search Results (61)

Wild animals often serve as reservoirs for vector-borne zoonoses, which are on the rise worldwide but have not yet been sufficiently researched. Vector-borne zoonoses, such as those caused by Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato, and Dirofilaria immitis, are a growing public health concern due to their increasing incidence and broad host range. The aim of this study was to determine the prevalence and risk factors for vector-borne bacterial (borreliosis, anaplasmosis, ehrlichiosis) and parasitic (dirofilariasis) pathogens and to detect some of these pathogens in the red fox (Vulpes vulpes) population in Croatia. A total of 179 blood samples from foxes from nine districts were analysed. The SNAP ^® 4Dx ^® Plus rapid test was used to detect circulating D. immitis antigen and antibodies against B. burgdorferi, A. phagocytophilum/Anaplasma platys, and Ehrlichia canis/Ehrlichia ewingii. Circulating D. immitis antigen was detected in 6.70% of the samples (95% CI: 3.20–10.19%), while antibodies against A. phagocytophilum/A. platys were found in 10.06% (95% CI: 5.8–14.25%). Only one sample was positive for B. burgdorferi, while no antibodies were detected for E. canis/E. ewingii. Spatial analysis revealed statistically significant differences in prevalence by geographical region (district) and age, while no significant correlations were found. In the standard PCR analysis, DNA of D. immitis was not detected in any of the eight positive and eight negative SNAP ^® 4Dx ^® Plus samples. D. repens, A. reconditum, or co-infections were also not detected by PCR. Of the nine samples that tested positive for A. phagocytophilum/A. platys antibodies, four were confirmed to be positive for A. phagocytophilum by nested and semi-nested PCR targeting the 16S rRNA and GroEL genes. Phylogenetic analysis revealed similarities with various European strains, including zoonotic strains. This study is the first molecular detection of A. phagocytophilum from blood samples of red foxes in Croatia. The results show that red foxes are not free from infections such as anaplasmosis and dirofilariasis, emphasising their possible role in the maintenance and transmission of these pathogens in certain regions of Croatia. These results underline the need for further research to better understand the epidemiological importance of red foxes in the spread of vector-borne diseases. Full article

Tick-borne diseases (TBDs) are a growing public health concern in the United States. This study analyzed 261,630 weighted hospitalizations from the Healthcare Cost and Utilization Project (HCUP) Nationwide Inpatient Sample (NIS) database between 2002 and 2021 to evaluate trends, coinfections, demographic disparities, and financial impacts. Lyme disease was the most common cause, accounting for 65% of hospitalizations (171,328 admissions), followed by ehrlichiosis/anaplasmosis (46,446), babesiosis (18,057), rickettsial diseases (16,412), tularemia (2428), and other TBDs (19,435). Hospitalizations increased 2.5-fold over the study period, with the Northeast region bearing 52.9% of the burden and peaking in July. Males (53.9%), Caucasians (81.4%), and residents of higher-income zip codes were predominant, though rickettsial diseases showed elevated Hispanic representation (18.4%). Coinfections were common, with 35.8% of babesiosis and 15.6% of ehrlichiosis/anaplasmosis cases involving another TBD, suggesting that routine testing may be warranted. Median hospital charges rose from USD 9433 in 2002 to USD 35,161 in 2021, totaling USD 1.265 billion in 2021. In-hospital mortality was 1.1%, with the highest cause of mortality being babesiosis (2.06%). Future areas for research include characterizing the burden of disease in an outpatient setting, understanding the causes of racial disparities in hospitalizations, and testing strategies to identify coinfection. Full article

Rickettsia, Anaplasma, and Ehrlichia species are emerging tick-borne pathogens that cause zoonotic diseases, including rickettsiosis, anaplasmosis, and ehrlichiosis in both human and animal populations. This study aimed to investigate the prevalence of these pathogens in cattle-associated ticks from Ganzhou City, Jiangxi Province, China. Through molecular characterization using multilocus sequence analysis (16S rRNA, gltA, groEL, and ompA genes), we analyzed 392 Rhipicephalus microplus ticks collected from March to September in 2022. The PCR results showed that eight Rickettsiales bacteria were detected, including two species of Rickettsia (51/392, 13.0%), four species of Anaplasma (52/392, 13.3%), and two species of Ehrlichia (70/392, 17.9%). Notably, the circulation of multiple pathogen species within R. microplus populations demonstrates significant microbial diversity in this region. Further consideration and investigation should be given to the possible occurrence of rickettsiosis, ehrlichiosis, and anaplasmosis in humans and domestic animals. Our study provides critical baseline data for developing targeted surveillance strategies and informing public health interventions against tick-borne diseases in southeastern China. Full article

Canine monocytic ehrlichiosis (CME) is a highly infectious disease with zoonotic potential. Ehrlichia canis, the causative agent, is primarily transmitted by Rhipicephalus sanguineus. Tick infestation and tick-borne diseases (TBDs) are serious human and veterinary health problems due to the lack of efficient control measures. This review aims to provide information about CME, detailing epidemiology, pathogenesis, clinical manifestations, and current strategies for diagnosis, treatment, and prevention. The review delves into the biology of R. sanguineus, exploring its lifecycle, habitat, and mechanisms of E. canis transmission. Ehrlichia canis infection follows a three-phase transition: acute, subclinical, and chronic, with distinct clinical signs, from mild to severe and even life-threatening in some cases, with the potential for asymptomatic long-term carriers acting as reservoirs. Pathogenesis involves complex interactions between the pathogen and host immune responses, influencing disease severity and progression. Additionally, the review highlights challenges in controlling CME due to the widespread distribution of R. sanguineus. Genetic diversity within R. sanguineus populations and their varying vector competence further complicate control efforts. The role of environmental changes in tick distribution aligns the control of CME within the One Health concept, integrating approaches to improve outcomes for humans, animals, and the environment. Preventive measures on tick control and potential vaccine development are also reviewed. Full article

Canine monocytic ehrlichiosis (CME) is a globally prevalent disease transmitted by the tick Rhipicephalus sanguineus and caused by the Gram-negative bacterium Ehrlichia spp. Following an incubation period, the infection is categorized based on the progression of the disease into acute, subclinical, and chronic stages. Besides hematological alterations, the cardiovascular system is significantly impacted by the hemodynamic effects of the disease, as persistent anemia can lead to myocardial hypoxia and the activation of inflammatory processes, potentially causing myocarditis. It is known that in dogs infected with Ehrlichia canis, there is a higher occurrence of arrhythmias and a predominance of sympathetic activity. This study assessed arrhythmogenic parameters, including P wave dispersion (Pd), QT dispersion (QTd), and QT instability, along with heart rate variability (HRV) analysis from 24 h Holter monitoring in naturally infected dogs during the acute phase (n = 10) and chronic phase (n = 10) compared to a control group (n = 10). The Pd and QTd values were higher in the infect group, confirming the arrhythmogenic character. Instability parameters (TI, LTI, and STI) were higher in sick animals, but no worsening was observed in the chronic phase. All HRV metrics in the time domain were higher in the control group, indicating a balanced sympathovagal activity throughout the day in healthy dogs. Additionally, parameters linked to parasympathetic activity (rMSSD and pNN50) were reduced in the sick groups, confirming the dominance of sympathetic activity. These findings indicate a decrease in HRV in sick individuals and reinforce this useful marker for assessing the influence of the autonomic nervous system on the cardiovascular system. In conclusion, CME exhibits arrhythmogenic activity characterized by the deterioration of predictive parameters for ventricular arrhythmias and increased activity of the sympathetic autonomic nervous system in the heart. This is likely secondary to myocarditis, myocardial hypoxia, and structural damage to cardiomyocytes. Full article

A conventional PCR (cPCR) remains an effective molecular technique for the diagnosis of canine monocytic ehrlichiosis. However, agarose gel electrophoresis requires additional time after thermal cycling. In the present study, we developed a PCR-based lateral flow biosensor (PCR-LFB) to detect Ehrlichia canis (E. canis). Lateral flow strips allow for the simple and rapid detection of PCR products and provide an alternative to gel electrophoresis. The sensitivity, specificity, and detection limit of PCR-LFB were compared to those of TaqMan probe-based real-time PCRs (qPCRs). The PCR-LFB was performed with 5′ 6-FITC and biotin-labeled primers specific to E. canis, targeting the dsb gene. The detection limit of the PCR-LFB assay was 10⁻⁶ for the target DNA sequence in a 10-fold dilution of the recombinant plasmid, which is 10 times lower than that of qPCR. Among the confirmed qPCR results in the 30 dog samples, false-positive results were not detected by the PCR-LFB. Compared to qPCR, the sensitivity and specificity of PCR-LFB were 63.6% (95% CI; 42.9–80.2%) and 100% (95% CI; 67.5–100%), respectively. The Kappa value of the PCR-LFB is in moderate agreement with the qPCR (κ = 0.483). Perfect agreement (κ = 1) was observed between cPCR and PCR-LFB. Lower cost and shorter time consumption were demonstrated using PCR-LFB. Full article

Glomerulonephritis, caused by the deposition of immune complexes, can lead to kidney damage in dogs with canine monocytic ehrlichiosis (CME). The early diagnosis of renal insult is important to prevent severe kidney disease in infected dogs by Ehrlichia canis. This study aimed to investigate urinary biomarkers of renal function, neutrophil gelatinase (uNGAL), and kidney injury molecule-1 (uKIM-1) using the Luminex^® xMAP^® platform, and the proportion of mixed or high molecular weight proteinuria in dogs with CME. This study included blood samples of thirty dogs with clinical signs of CME and amplified DNA for E. canis (CME group) and six dogs of different breeds and both sexes, aged 3 to 7 years, that showed no clinical-laboratory alterations or tick parasitism and were tested negative for E. canis via PCR (control group). The total calcium, phosphorus (p < 0.05), urea (p < 0.001), creatinine (p < 0.05), urinary density (p < 0.05), urinary protein creatinine ratio (p < 0.001), uNGAL (p < 0.05), and uKIM-1 (p > 0.05), as well as the proportion of high molecular weight proteinuria and mixed proteinuria (p < 0.01), were measured. Elevated serum concentrations of creatinine, urea, and phosphorus combined with reduced urinary density, increased urinary creatinine–protein ratio, urinary NGAL, and mixed proteinuria detected renal damage in dogs with CME, while KIM -1 remained unchanged. uNGAL can detect early renal lesions, reflecting renal damage before a significant increase in serum creatinine occurs, and appears to be an early diagnostic biomarker in renal disease in dogs with CME. Full article

Ehrlichioses, caused by Ehrlichia species, are tick-borne diseases (TBDs) that affect animals and humans worldwide. This study aimed to investigate the molecular occurrence of Ehrlichia spp. in 530 animals (155 Dromedary camels, 199 goats, 131 cattle, and 45 sheep) in the Benadir and Lower Shabelle regions of Somalia. Blood DNA samples were tested for PCR targeting dsb and sodB genes of Ehrlichia spp. and PCS20 and map1 genes of E. ruminantium. The obtained sequences were submitted for phylogenetic analyses. Ehrlichia spp. were detected in 26.4% (140/530) of animals by dsb-PCR, with the highest prevalence in dromedary camels (54.8%), followed by cattle (29.8%), goats (7.0%), and sheep (4.4%). Dromedary camels, cattle, and goats had significantly higher infection odds compared to sheep (p < 0.05). Among dsb-PCR-positive samples, 76.9% (30/39) of cattle tested sodB-positive, while other species were negative. E. ruminantium was detected in 13.7% (18/131) of cattle by pCS20-PCR, but none were positive for the map1 gene. Phylogenetic analysis confirmed E. minasensis in camels, sheep, and goats and E. ruminantium in cattle, marking the first molecular evidence of E. minasensis in dromedary camels, sheep, and goats globally, and E. ruminantium in cattle from Somalia. These findings emphasize the need for further research on its economic and public health impact. Full article

Vector-borne diseases represent a serious threat to human and animal health, especially where environmental conditions favor pathogen-carrying vectors. Dogs serve as natural hosts for two tick-borne pathogens: Ehrlichia canis, which causes canine monocytic ehrlichiosis, and spotted fever group (SFG) Rickettsia spp., a zoonotic threat in the Mediterranean region. Rhipicephalus sanguineus is the primary vector for these pathogens. Shelter dogs, due to increased exposure to ticks and confined living conditions, facilitate the spread of vector-borne pathogens, raising the risk of zoonotic transmission. This study conducted a serological survey of 1287 dogs from two shelters, assessing exposure to Rickettsia spp. and E. canis and examining the influence of demographic and environmental factors. Seroprevalence rates were 41.8% for Rickettsia spp. and 24.5% for E. canis, with 14% of dogs positive for both pathogens. No significant association was found with sex or breed. A higher seroprevalence was observed in dogs older than 12 months and in those from the shelter on the Mediterranean coast compared to those from the Tyrrhenian coast, likely due to climatic differences. The study highlights the role of climate in disease spread and the need for public health interventions, supporting One Health initiatives to prevent zoonotic disease transmission. Full article

Canine monocytic ehrlichiosis (CME) is an infectious disease caused by Ehrlichia canis, a globally recognized obligate intracellular bacterium. In addition to dogs, other animals, including humans, may be affected. Despite its epidemiological importance and impact on public health, there is currently no commercial vaccine against E. canis. This study aimed to present relevant aspects of the challenges and advances encountered in the development of vaccines for CME and highlight perspectives for future investigations. High genetic variability, along with the various evasion mechanisms employed by E. canis, has hindered the identification of an antigen that targets Th1 cells and is immunogenic to most E. canis isolates, considering their genotypic and phenotypic characteristics. The vaccine must predominantly confer cellular and humoral immunity to achieve robust immune responses. Early production efforts have been challenging due to low immunogenicity, difficulties in establishing long-term protection, and limitations of the techniques used. However, with the refinement of bioinformatic tools, research in this area will be facilitated, thereby accelerating the development of effective vaccines for CME. According to these authors, this vaccine should consist of multiple epitopes. Full article

Vector-borne infections persist as a significant issue in both human and animal health. Many of the most common vector-borne infections in the USA, especially tick-borne infections, are known to be zoonotic, including Lyme disease, anaplasmosis, and ehrlichiosis, and these infections may also negatively impact the health of infected animals. Convenient patient-side assays for the detection of antibodies to Borrelia burgdorferi, Anaplasma spp., and Ehrlichia spp., and antigen of Dirofilaria immitis have allowed for the generation of robust and large-scale prevalence data in dogs. Data of similar scale and distribution are not available in cats, and most feline prevalence studies have evaluated a small sample size with limited geographic distribution. The objective of this study was to evaluate the prevalence of antibodies to B. burgdorferi, Anaplasma spp., and Ehrlichia spp., and D. immitis antigen among shelter cats across the USA, a population that is presumably at high risk for ectoparasitism and, consequently, exposure to vector-borne infections. In total, 2232 whole blood samples were collected from shelter cats across four regions of the USA—South, Northeast, Midwest, and West—and were evaluated using the Idexx SNAP^® 4Dx^® Test. Ectoparasites were also opportunistically collected from cats during blood collection and morphologically identified. The prevalence of at least one vector-borne infection was 2.60%, and the nationwide prevalence was 1.88% for B. burgdorferi, 0.54% for Anaplasma spp., 0.09% for Ehrlichia spp., and 0.55% for D. immitis. A total of 1120 ectoparasites were collected from 423 cats, including 27 ticks and 1093 fleas. Although the overall prevalence of the pathogens in this survey is relatively low, we observe that there is an increased exposure risk regionally for some agents, with geographic distributions in this study mostly coinciding with established human and canine distributions. Understanding these findings in an assumed non-protected population of cats allows us to extrapolate the risk to pet cats if they are not provided routine veterinary care, including a broad-spectrum parasite prevention program. Full article

The present study aimed to investigate pathological epidemiology and molecular confirmation of Ehrlichia canis among pet dogs in Bhubaneswar, Odisha, a state in eastern India. A total of 178 dogs were screened for Ehrlichiosis based on history, clinical signs, blood, and buffy coat smear examination, resulting in only 56 dogs (31.46%) screening positive. The epidemiological study recorded a non-significant (p ≥ 0.05) increase in incidences among male dogs (68%), German Shepherds (25%), dogs more than 20 kg body weight (75%), in the summer months (55%), and dogs housed in pukka houses with exposure to the outside (59%). The majority of the infected dogs had a history of tick infestation (79%) at some point in their lives. Clinical signs showed non-typical manifestations like fever, lethargy, diarrhoea, epistaxis, hind limb edema, and corneal opacity. Haematological studies revealed anaemia and thrombocytopenia along with neutrophilia with relative lymphopenia and monocytosis. A decreasing trend was observed in the levels of total protein and albumin, with an increase in the levels of globulin, alanine aminotransferase, alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, and creatinine. The ultrasonography studies revealed hepatosplenomegaly along with hyper-echogenicity in various organs. Proteinuria and haematuria were consistent, along with the presence of bile salts in the urine of affected dogs. Molecular confirmation from n-type PCR data using Ehrlichia-specific primers targeting the p28 gene (843 bp) was done, and the identified gene sequences submitted to NCBI databases have accession numbers OQ383671-OQ383674 and OP886674-OP886677. Ticks collected from dogs were identified morphologically through microscopy and scanning electron microscopy as Rhipicephalus sanguineus. Full article

National parks provide visitors access to hiking, camping, and the outdoors. These activities are associated with an increased risk of tick exposure. This brief report is observational, depicting case reports using raw data, and is not intended to analyze or establish risk but rather to examine geographic areas for potential future research and to identify disparities between canine and human disease reports within the same location. Locally vs. travel-acquired data are not provided by most public health departments in the U.S. Therefore, multimodal data analyses are needed for an improved understanding of disease risk. With data limitations in mind, observations from human and canine comparisons, in addition to tick presence, in this report include (1) tick-borne diseases are reported at most national park areas in the U.S., with the highest case reports in park areas located in Maine and Minnesota; (2) the average total tick-borne diseases combined (i.e., Lyme disease, ehrlichiosis, and anaplasmosis) for park areas allowing dogs is 15.34%. In comparison, the average for national parks without dogs is 8.7%, indicating the need for further study to assess human activity with pets, considering geography and ecology as potential explanatory factors; (3) canine data do not align with human data in many national park geographic areas; and (4) Ixodes scapularis presence overlaps with human and canine disease. Using multimodal data can assist with assessing risk when travel vs. local acquisition is unknown. Full article

Human monocytic ehrlichiosis, an emerging tick-borne disease, is caused by Ehrlichia chaffeensis. Infections with the pathogen are also common in the canine host. Our previous studies demonstrated that functional disruption within the E. chaffeensis phage head-to-tail connector protein gene results in bacterial attenuation, creating a modified live attenuated vaccine (MLAV). The MLAV confers protective immunity against intravenous and tick transmission challenges one month following vaccination. In this study, we evaluated the duration of MLAV protection. Dogs vaccinated with the MLAV were challenged with wild-type E. chaffeensis via intravenous infection at 4-, 8-, and 12-months post-vaccination. Immunized dogs rapidly cleared the wild-type pathogen infection and tested positive for bacteremia less frequently than unvaccinated controls. While immune responses varied among dogs, vaccinees consistently mounted IgG and CD4+ T-cell responses specific to E. chaffeensis throughout the assessment period. Our findings demonstrate that MLAV-mediated immune protection persists for at least one year against wild-type bacterial infection, marking a major advancement in combating this serious tick-borne disease. The data presented here serve as the foundation for further studies, elucidating the molecular mechanisms underlying virulence and vaccine development and aiding in preventing the diseases caused by E. chaffeensis and other tick-borne rickettsial pathogens. Full article