Vector borne and zoonotic diseases最新文献

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.

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.

Introduction: Lyme disease (LD) surveillance yields useful information to monitor the disease trends and spatial distribution. However, due to several factors, the Manitoba Health surveillance system, as with other systems, could be subject to underreporting. Objectives: To estimate the number and incidence of clinician-diagnosed LD over the study period in Manitoba, describe the epidemiology of clinician-diagnosed LD, and compare the findings with Manitoba Health LD surveillance data during the same period to estimate the extent of underreporting. Methods: A retrospective analysis of administrative health data was performed to calculate the number and incidence of clinician-diagnosed LD from 2009 to 2018 in Manitoba and describe the epidemiological characteristics using the International Classification of Diseases, Tenth and Ninth Revision (ICD-10-CA and ICD-9-CM) codes, and antimicrobial drug prescriptions. Conclusion: Of the 1,629,698 registrants within the Manitoba Health Insurance Registry followed over 10 years, 1658 LD events were identified. Most of the cases occurred from May to July and corresponded to the peak activity of the nymphal stage of the blacklegged tick in the province. LD events presented a bimodal distribution with a peak in children between 5 and 9 years of age for both sexes, and a peak in adults from 65 to 84 and from 50 to 74, respectively, for males and females. We estimated that an average of 165 LD events occurred annually in Manitoba (mean annual incidence of 10.17 per 100,000 population), compared with 30 cases per year reported in the surveillance system; therefore, the LD surveillance yields an important underreporting.