Vector borne and zoonotic diseases最新文献

Background: Coxiella burnetii, an obligate intracellular bacterium, is the etiological agent of Q fever in humans and one of the causes of abortion in small ruminants. Although coxiellosis is considered an exotic disease, there are a few reports in Mexico. Methods: The objective of this work was to determine the presence of C. burnetii DNA in vaginal samples from sheep that presented abortion and ram semen. A total of 180 vaginal exudate samples and 20 semen samples were obtained from five Central and Southern States of Mexico. Total DNA was extracted from vaginal swabs and C. burnetii was identified by PCR amplification and sequencing of the IS1111 insertion sequence. Results and Conclusion: In total, 110 (110/180) vaginal samples and 12 (12/20) semen samples were positive for C. burnetii. This is the first report of C. burnetii in sheep that aborted and in ram semen in Mexico.

Background: Leptospira is a genus of bacteria that causes the zoonotic disease known as leptospirosis, which mainly affects countries with tropical and subtropical climates. Its prevalence may be underestimated because the initial stage of the infection is characterized by presenting a febrile condition that is easily confused with other diseases, such as dengue. This work reports the frequency of leptospirosis in the blood of patients with febrile symptoms of unknown origin. Materials and Methods: A total of 218 peripheral blood samples were analyzed from volunteer participants from Culiacan Sinaloa in June 2019, one half corresponded to patients with undiagnosed febrile symptoms and the other half to asymptomatic volunteers. Data collected included the age and sex of the participants. Leptospira was detected by qPCR using a fragment of the lipL32 gene from the bacteria's genome as a target. Fisher's exact test was used as a statistical method to estimate the relationship between the infection and the data collected. Results: The study group comprised 134 female and 84 male patients ranging from ages 1 to 92 years, averaging 41 years. In this study, Leptospira infection was identified in the blood of 22/218 participating volunteers (10.09%), of which 20/109 (18.34%) presented febrile symptoms, whereas 2/109 (1.83%) were asymptomatic. The most affected participants were women with ages between 27 and 59 years. However, the analysis of the relationship between infection and the variables studied did not show statistical significance. Conclusions: Leptospirosis was detected in blood samples from patients with undiagnosed febrile illness and asymptomatic symptoms in Sinaloa. The lipL32 gene is useful as a target in identifying Leptospira in human blood in the acute phase of the disease.

Background: Borrelia burgdorferi sensu stricto is the causative agent of Lyme disease (LD). Possible early symptoms include flu-like symptoms and erythema migrans and later, the risk of disruption of the nervous system, joints, and heart. A two-tiered testing method is employed for serological diagnostics. The Public Health Agency of Canada guidelines recommend that samples tested negative on first-tiered test need not be confirmed by second-tiered test. Due to the challenging nature of diagnosis leading to misconceptions among physicians about false negatives, confirmatory testing is requested despite the initial negative result. Methods: Hundred screen-negative Lyme patient samples from 2007 to 2016 were tested by Western blot (WB) second-tiered confirmatory test upon physician's request in British Columbia to study the first-tiered screening test sufficiency. Results: Those negative for first-tiered enzyme-linked immunosorbent assay were also negative by WB. Conclusion: Results demonstrate that confirmatory testing is not necessary on screen-negative samples. Hence, first-tiered test is sufficient to rule out LD.

Background: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne disease caused by Bandavirus dabieense. Initially identified in China, this disease has spread throughout Asian countries via tick bites and animal-to-human transmission. However, reports of the prevalence of SFTS virus (SFTSV) in cattle in Korea are lacking. This study aimed to investigate SFTSV infections in grazing cattle in the Republic of Korea (ROK). Materials and Methods: In total, 845 grazing cattle serum samples were collected over 2 years (2019 and 2020) in the ROK, and viral RNA was extracted using a kit. One-step RT-nested PCR was performed to amplify the S-segment of SFTSV. Positive serum samples were used to isolate SFTSV in Vero E6 cells, and the full sequences were analyzed. A phylogenetic tree was constructed using the maximum-likelihood method with MEGA X. In addition, immunoglobulin G antibodies against SFTSV were investigated using an enzyme-linked immunosorbent assay. Results: Here, 4.0% of serum samples (34/845) were positive for SFTSV S-segments, and one virus isolate was cultured in Vero E6 cells. Phylogenetic analysis based on the partial S-segment classified 4 SFTSV isolates as the B-2 genotype, 9 as the B-3 genotype, 18 as an unclassified B genotype, and 3 as the D genotype. One cultured virus was classified as the B-2 genotype based on SFTSV L-, M-, and S-segments. Antibody detection results showed that 21.1% of serum samples (161/763) were positive for SFTSV. Conclusion: To the best of our knowledge, this is the first study performed to identify the prevalence of SFTSV in grazing cattle in the ROK. Our findings indicate the necessity for more intensive and continuous SFTSV monitoring, not only in cattle but also in other animals, to comprehend the genetic diversity of the virus and its potential eco-epidemiological impact on human health.

Background: Tamdy Virus (TAMV) is a pathogenic nairovirus widely distributed in central Asia and northwestern China. However, the host range of TAMV remains unclear, which limits our understanding the transmission cycle and cross-species patterns of this virus. Materials and Methods: A total of 160 serum samples were collected from livestock animals of camels, cattle, and sheep in Xinjiang, China between 2018 and 2021. An indirect immunofluorescence assay for TAMV were developed in this study, and have been employed to test TAMV-specific antibodies in these serum samples. Results: TAMV IgG antibody was detectable in camel sera collected from Urumqi in 2018 (6/17, 35%) and also from the Alertai Region in 2021 (1/8, 12.5%). Conclusion: The serological results in this study provide the first evidence that TAMV is able to infect camels and that the pathogen is circulating in different regions of Xinjiang. These findings highlight the need to further increase clinical and epidemiological surveillance of TAMV in humans and livestock in northwestern China.

Introduction: The study presents renal manifestations in chronic filariasis, a substantial health concern in the eastern and north-eastern regions of India. Materials and Methods: The study is a retrospective analysis of a renal biopsy series of patients with chronic filariasis from a tertiary care hospital in Odisha. It involves eight cases of chronic filariasis. Results: Common indications of biopsy were nephrotic syndrome, chyluria, and unexplained renal failure. The mean duration from the diagnosis of filariasis to the onset of glomerular diseases was 15.75 years, SD ± 4.2 years. Patients were followed up for a minimum of 6 months. Renal histopathology revealed various patterns, including membranous nephropathy, minimal change disease, IGA nephropathy, and membranoproliferative glomerulonephritis. Conclusion: The study fills a critical gap in the literature by elucidating renal biopsy findings in chronic filariasis. The multifaceted nature of this disease underscores the need for continued research to understand kidney diseases due to filariasis, especially in endemic regions.

Background: Rickettsia spp. are obligate intracellular bacteria of utmost importance for public health and the economy since their presence can generate significant losses in livestock production, affecting the health of animals, the quality of the meat, milk, and other products derived from affected animals. Therefore, prevention of the transmission of these pathogens, their early identification and timely treatment are essential to mitigate their impact on public health and animal production. Materials and Methods: In the present work, hard ticks were collected from infested Bos indicus cattle in Aldama, Tamaulipas, Mexico. They were identified by morphology using dichotomous keys and by sequencing and analyzing of a fragment of the mitochondrial 16S. PCR was performed using specific primers targeting Rickettsia sp. gltA. Phylogenetic analyses were performed, aligning the amino acid sequences with Muscle, and a phylogenetic tree was generated using PhyML. Results and Conclusions: Amblyomma mixtum and Rhipicephalus microplus ticks infesting the cattle were identified. Using molecular techniques, the presence of Rickettsia amblyommatis was identified in the cohort of analyzed ticks, suggesting a circulation of this pathogen in livestock in this region and granting further research in this area.

Background: Highlighting the individual, host-vector interactions, and environmental risk factors for knowlesi malaria were consequential toward more focused and effective prevention and control strategies. This study aims to identify the individual, host-vector interactions, and environmental risk factors for Plasmodium knowlesi malaria among at-risk communities in Peninsular Malaysia. Materials and Methods: A case-control study was conducted involving laboratory-confirmed cases of P. knowlesi malaria, while a locality-matched individual with no history of fever and tested negative for malaria was taken as control. Univariate and multiple logistic regression were applied to evaluate the potential risk factors among respondents using IBM SPSS Statistics for Windows, Version 26.0. Results: Results showed higher cases among males as compared to females (76.1% vs. 23.9%). Multiple logistic regression analysis showed being male is 3.51 higher risk (p < 0.001) to become a case. Respondents whose place of work or study is near the forest edge have 44.0% lower risk (p = 0.030), while those living in the Orang Asli village were 56.0% lower risk as compared to the organized village to become a case (p = 0.035). Conclusion: These findings demonstrated that gender emerges as an independent individual risk factor while residing near a forest edge, in an Orang Asli village, or occupying workers' longhouses situated in hilly areas lowered the environmental risk among respondents. These findings attested that alternative directions must be considered in addressing the known risk factors associated with this type of malaria and the design of prevention and control programs should be tailored to the unique characteristics of each population.