Vector borne and zoonotic diseases最新文献

Background: The tick-borne pathogens, Bourbon virus (BRBV) and Heartland virus (HRTV) are the cause of febrile illnesses that may progress to severe and fatal diseases. Materials and Methods: As a preliminary effort to determine if these viruses were enzootic in Texas, ticks and blood samples were collected from feral swine (Sus scrofa) and white-tailed deer (Odocoileus virginianus) (WTD) killed by gunning as part of an abatement program during 2019-2021 in Travis County, Texas. Ticks were collected from these animals by hand and blood samples were obtained by cardiac puncture using 22-gauge needles and 5 mL syringes. Information was recorded for each animal, including date, sex, and location. The species of ticks were identified morphologically using a taxonomic key, and serum samples were tested for neutralizing antibodies to BRBV and HRTV. Results: A total of 83 Ixodes scapularis and 58 Amblyomma americanum ticks were collected from feral swine, and 196 I. scapularis and 11 Dermacentor albipictus from WTD. Although A. americanum, the implicated vector of both viruses was collected from feral swine, neutralizing antibody was not detected to BRBV, but 12% (9/75) had antibody to HRTV as evidence of a previous infection. Of the serum samples obtained from WTD, all were negative for BRBV neutralizing antibody, but 6.6%% (5/75) were positive for HRTV antibody. Conclusion: These preliminary results indicated that HRTV was enzootic in Travis, County, Texas and further studies are warranted to determine the specific tick vectors and the possible role of WTD and feral swine in the maintenance and transmission cycle of this virus.

Background: Enterocytozoon bieneusi is reported to be a common microsporidian of humans and animals in various countries. However, limited information on E. bieneusi has been recorded in cats (Felis catus) and dogs (Canis familiaris) in China. Here, we undertook molecular epidemiological investigation of E. bieneusi in cats and dogs in Shanghai, China. Methods: A total of 359 genomic DNAs were extracted from individual fecal samples from cats (n = 59) and dogs (n = 300), and then were tested using a nested PCR-based sequencing approach employing internal transcribed spacer (ITS) of nuclear ribosomal DNA as the genetic marker. Results: Enterocytozoon bieneusi was detected in 34 of 359 (9.5%) (95% confidence interval [6.7 - 13.0%]) fecal samples from cats (32.2%; 19/59) and dogs (5.0%; 15/300), including 24 stray cats and dogs (22.6%; 24/106), as well as 10 household/raised cats and dogs (4.0%; 10/253). Correlation analyses revealed that E. bieneusi positive rates were significantly associated with stray cats and dogs (p < 0.05). The analysis of ITS sequence data revealed the presence of five known genotypes, CD7, CHN-HD2, D, PtEb IX, and Type IV, and two novel genotypes, D-like1 and PtEb IX-like1. Zoonotic genotype D was the predominant type with percentage of 61.8% (21/34). Phylogenetic analysis of ITS sequence data sets showed that genotypes D, D-like1, and Type IV were clustered within Group 1, showing zoonotic potential. The others were assigned into Group 10 with host specificity. Conclusions: These findings suggested that cats and dogs in Shanghai harbor zoonotic genotype D of E. bieneusi and may have a significant risk for zoonotic transmission. Further insight into the epidemiology of E. bieneusi in other animals, water, and the environment from other areas in China will be important to have an informed position on the public health significance of microsporidiosis caused by this microbe.

Background: Bourbon virus (BRBV) is an emerging pathogen that can cause severe and fatal disease in humans. BRBV is vectored by Amblyomma americanum (lone star ticks), which are widely distributed across the central, southern, and eastern United States. Wildlife species are potentially important for the maintenance and transmission of BRBV, but little is known about which species are involved, and what other factors play a role in their exposure to BRBV. Methods: To assess the exposure risk to BRBV among wildlife in the St. Louis, Missouri, area, we collected sera from 98 individuals, representing 6 different mammalian species from two locations in St. Louis County: Tyson Research Center (TRC) and WildCare Park (WCP) from fall 2021 to spring 2023. The sera were used in a BRBV neutralization assay to detect neutralizing antibodies and RT-qPCR for viral RNA analysis. We also sampled and compared the abundance of A. americanum ticks at the two locations and modeled which factors influenced BRBV seropositivity across species. Results: In TRC, we observed a high rate of seropositivity in raccoons (Procyon lotor, 23/25), and white-tailed deer (Odocoileus virginianus, 18/27), but a low rate in opossums (Didelphis virginiana, 1/18). Neutralizing antibodies were also detected in sampled TRC bobcats (Lynx rufus, 4/4), coyotes (Canis latrans, 3/3), and a red fox (Vulpes vulpes, 1/1). The virological analysis did not detect BRBV RNA in any serum samples. In contrast to TRC, all sera screened from WCP were negative for BRBV-specific neutralizing antibodies, and significantly fewer ticks were collected at WCP (31) compared with TRC (2316). Conclusions: Collectively, these findings suggest that BRBV circulates in multiple wildlife species in the St. Louis area and that tick density and host community composition may be important factors in BRBV ecology.

Background: Surveillance is important in addressing the significant public health concerns posed by tick-borne diseases. However, the southwestern U.S. presents particular challenges due to diverse tick fauna and varied ecologies. Methods: From 2021 to 2022, we conducted a partner-based tick surveillance program in Arizona and California to assess the presence of Rickettsia spp. pathogens and species composition of tick vectors. Results: A total of 913 ticks was collected, comprising in descending abundance Rhipicephalus sanguineus, Dermacentor similis, Ixodes pacificus (I. pacificus), Argas sp., Otobius megnini, and Haemaphysalis leporispalustris. Arizona submitted predominantly brown dog ticks (90.05% of all ticks from Arizona), while California showed greater tick species richness with five species identified. No Rickettsia rickettsii was detected, but a variety of other Rickettsia spp. was found in ticks from both Arizona and California and included Rickettsia rhipicephali (R. rhipicephali), Rickettsia massiliae, and Rickettsia monacensis-like rickettsial agents of I. pacificus, and two rickettsial organisms that were not identified to species: one Rickettsia montanensis or Rickettsia raoultii-like, and the other most similar to Candidatus Rickettsia tarasevichiae (R. tarasevichiae). Conclusion: This research contributes to our understanding of tickborne diseases in the southwestern U.S., and emphasizes the need for targeted surveillance and intervention initiatives in a region with complex relationships among ticks, hosts, and Rickettsia species. In particular, the finding of an apparently novel pairing of an unknown Argas sp. tick and R. tarasevichiae-like organism suggests that argasid species are an important target for future research. In addition, the results-both tick species submitted and resulting Rickettsia spp. identified-highlights the strengths and potential biases associated with a partner-based sampling method for tick surveillance.

Background: Getah virus (GETV) is a vector-borne virus that can proliferate in mosquitoes and be transmitted to host animals through bites. Clinical infection with the virus mainly causes diarrhea and reproductive disorders in pigs and fever, rash, and edema in horses. This caused huge losses to the pig industry and also affected the level of competition for horses. GETV has proliferated across over 20 regions within China, recently resulting in miscarriages and fatalities among the pig population, Guangdong province. Currently, there are no highly effective preventative or therapeutic strategies for diseases induced by GETV. Understanding the infection pathways, inclusive of GETV transmission vectors, is of paramount importance for the prevention and management of the disease. Results: To clarify the main transmission vectors and genotypes of GETV in this area, 3600 mosquitoes of different species were collected and GETV was detected using quantitative reverse transcription PCR. The minimum infection rate was 1.36 for Culex tritaeniorhynchus and 0.83 for Anopheles sinensis. The GETV GD2202 strain was successfully isolated from C. tritaeniorhynchus using mouse neuroblastoma (N2a) cells, and its complete genome was sequenced by PCR. This represents the first identification and isolation of GETV from mosquitoes in Guangdong Province of Southern China. Comparison with GenBank data showed 99.3% identity with the E2 gene of the GDFS2-2018 and GDFS9-2018 strains causing disease in local pig populations, and a nucleotide similarity of 99.8% with the E2 gene of the HNNY-1, HNPDS-1, and HNPDS-2 strains isolated from pigs in Henan, and the highest identity with the JL1708 strain isolated from mosquitoes in Jilin Province, with a nucleotide similarity in the E2 gene of 99.9%. Phylogenetic analysis showed that it had the closest genetic evolutionary relationship with the Culex-derived JL1708 strain and was on the same evolutionary branch as the pig-derived HNNY-1, HNPDS-1, and HNPDS-2 strains. Conclusion: A comprehensive investigation was undertaken to examine the prevalence of GETV infection among various mosquito species in Foshan, Guangdong Province, China. The findings indicated that C. tritaeniorhynchus acted as the principal vector for transmission, predominantly infected with GETV genotype III. This genotype was consistent with that identified in deceased pig populations and demonstrated significant homology. This study provides a robust scientific basis for understanding the propagation of GETV, thereby offering vital insights for the formulation of disease prevention and control strategies.

Introduction: Hepatitis E virus (HEV) infection is caused by viruses belonging to the Hepeviridae family. HEV infection can be self-limiting; however, extrahepatic manifestations may be present. The purpose of the current study was to establish the seroprevalence of HEV among Bulgarian liver transplant recipients (LTRs) and to identify associated risk factors. Materials & Methods: The present study was conducted between April 1, 2023, and October 30, 2023, at the Military Medical Academy, Sofia, Bulgaria. All serum samples were tested for anti-HEV IgG/IgM using HEV IgG/IgM enzyme-linked immunosorbent assay on Dia.Pro (Milan, Italy). Each participating LTR completed a detailed paper-based closed-ended questionnaire regarding the associated risk factors for HEV infection. Results: The study included 73 LTRs with a mean age of 47.0 ± 14.0 years. Anti-HEV IgG antibodies were detected in 25 LTRs (34.2%), including 20 males (37.7%) and 5 females (25%). All participants were HEV-IgM negative. HEV seropositivity rates were higher but not statistically significant in LTRs aged >60 years than in those aged <60 years (40% vs. 32.7%). A significant factor by logistic regression was "high level of education" (odds ratio [OR] = 2.917; p = 0.038). Conclusion: To the best of our knowledge, this is the first seroepidemiological HEV study among LTRs from Bulgaria that found a high seroprevalence (34.2%).

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: Dengue virus (DENV) infection, caused by serotypes DENV 1-4, represents a significant global public health challenge, with no antiviral drugs currently available for treatment. The host Protein kinase B (AKT) signaling pathway is crucial for DENV infection, presenting a potential target for antiviral drug development. Objective: This study aimed to evaluate the antiviral activity of kinase inhibitors that target the AKT pathway, focusing on the compound AT13148. Methods: A mini-screening was conducted to identify kinase inhibitors with antiviral properties against DENV-2. The effects of AT13148 on viral RNA replication and translation were assessed in a dose- and time-dependent manner following DENV-2 entry. The mechanism of action was further investigated by evaluating the impact of AT13148 on AKT kinase activity and phosphorylation status. Results: AT13148 exhibited potent antiviral activity against DENV-2, significantly inhibiting viral RNA replication and translation post-entry. The compound was found to inhibit AKT kinase activity through hyperphosphorylation. Conclusion: The findings indicate that AT13148 effectively targets the AKT pathway, demonstrating potential as an antiviral therapeutic against DENV-2 by interfering with the virus's post-entry processes. Further in vivo studies are warranted to assess the efficacy of AT13148 in controlling DENV infection.

Background: Acute encephalitis syndrome (AES) is a significant public health issue in India, attributed to various etiologies. In eastern Uttar Pradesh, Japanese encephalitis (JE) was the leading cause of AES (10-14% of total AES) until scrub typhus (ST), caused by Orientia tsutsugamushi, was identified in cerebrospinal fluid and blood samples of AES patients contributing more than 60% of AES cases. This study investigates the prevalence of JE-ST coinfection and compares clinical outcomes among JE mono-infection, ST mono-infection, and JE-ST coinfection. Materials and Methods: AES cases admitted to BRD Medical College, Gorakhpur, Uttar Pradesh, India, from January 1, 2017, to December 31, 2017, were included. JE and ST diagnosis was confirmed by serological (IgM) and molecular (PCR) tests. Statistical analysis was done to correlate clinical outcomes and infection group. Results: Total 1180 cases were tested positive for JE and/or ST. The prevalence of JE-ST coinfection was 8.9% among AES cases. JE mono-infection showed a mortality rate of 34.5%, ST mono-infection 13.4%, and JE-ST coinfection 9.5%. JE-ST co-infected cases experienced less severe clinical outcomes compared to mono-infected cases. Conclusion: JE-ST coinfection in AES cases is relatively common, with better clinical outcomes and lower mortality rates compared to JE or ST mono-infections.

Background: Between January 1, 2011, and December 31, 2017, over 12,000 case reports of Lyme disease (LD) were submitted to the California Reportable Disease Information Exchange for further investigation. The number of case reports has tripled compared to previous years, emphasizing the need for efficient estimation and classification methods. We evaluated whether estimation procedures can be implemented in a low-incidence state such as California to correctly classify a case of LD, similar to those procedures used in high-incidence states. Objective: The purpose of this study was to identify whether a minimum number of variables was sufficient to reliably classify cases in California and potentially reduce workload while maintaining the ability to track LD trends in California. Methods: To determine the relative value of diagnostic information, we compared five candidate logistic regression models that were used to classify cases based on information that varied in its degree of difficulty for collection. Results: Our results using California's surveillance data showed that automatically reported data were not sufficient, additional information such as, a patient's clinical presentation and travel history were necessary in a low-incidence state to improve the overall sensitivity of the models. Conclusion: This study may help inform public health surveillance efforts by demonstrating that both clinical and travel information are required to accurately classify a case of LD in a low-incidence state.