Vector borne and zoonotic diseases最新文献

Background: Crimean-Congo hemorrhagic fever (CCHF) is a highly fatal, tick-borne zoonosis in humans for which no licensed vaccines exist. Camels are important hosts of Hyalomma ticks, yet data on their role in CCHF epidemiology in Nigeria are limited. This study assessed seroprevalence and risk factors of the CCHF virus (CCHFV) in camels from major livestock markets in northern Nigeria.

Materials and methods: From June 2023 to July 2024, 812 camels were sampled during 54 weekly visits to Maiduguri (Borno), Maigatari (Jigawa), and Illela (Sokoto) livestock markets. Epidemiological data (sex, age, origin, and tick infestation) were recorded for each sampled camel. Serum samples were tested using ID Screen CCHF double antigen Enzyme-linked immunosorbent assay (ELISA) kits. Descriptive statistics and logistic regression were applied to identify predictors of seropositivity (p < 0.05).

Results: CCHFV antibodies were detected in 89.4% of camels (95% CI: 87.1-91.4%). Prevalence was highest in Maiduguri (94.2%), followed by Maigatari (92.0%) and Illela (80.4%). Females (94.1%) had higher seropositivity than males (84.9%), and adults (>48 months) exceeded younger camels (94.3% vs. 81.7%). Tick infestation was strongly associated with seropositivity. Multivariable analysis showed younger age (OR = 0.35, 95% confidence intervals [CI]: 0.19-0.66), male sex (OR = 0.33, 95% CI: 0.18-0.60), and absence of ticks (OR = 0.45, 95% CI: 0.26-0.81) were significantly linked to reduced odds of seropositivity.

Conclusion: The very high seroprevalence observed in camels suggests that they may contribute to the epidemiology of CCHF in northern Nigeria. Although cultural practices such as consumption of raw camel milk and urine are common, their role in CCHFV transmission remains uncertain; therefore, further studies are recommended to investigate their potential epidemiological significance. Strengthening One Health-based surveillance, vector control, and public education is critical to reducing zoonotic transmission and protecting human and animal health.

Background: Chikungunya virus (CHIKV) outbreaks have affected the global population and demand effective antiviral strategies. Exploring the molecular mechanisms associated with its pathogenesis through modulation of host response is essential for the development of efficient antiviral interventions. Although CHIKV-encoded kinases are not perceived, the phosphorylation of CHIKV proteins in hosts is reported. Hence, elucidating the signaling cross-talks between host kinases and viral proteins provides opportunities for targeted therapeutic strategies.

Methods: Toward this, we predicted the phosphosites in CHIKV proteins and their potential host kinases using multiple prediction tools, followed by a human kinase substrate phosphomotif pattern analysis to identify putative kinase interactions. The phosphoproteome of CHIKV and CHIKV-infected host cells and further the host-viral interactome were analyzed in conjunction with kinase inhibition assays to identify host kinases associated with their infection. Subsequently, in silico protein-protein docking was performed between the selected kinases and viral proteins to identify potential interactions.

Results and conclusion: In silico analysis revealed Mitogen-activated protein kinase 1 (MAPK1), Protein kinase C alpha (PRKCA), and Eukaryotic elongation factor 2 kinase (EEF2K) as major host kinases of specific phosphosites in CHIKV proteins. Putative kinases were also predicted for the reported phosphorylation sites in the CHIKV phosphoproteome. This study reveals that host kinases may phosphorylate substrates critical to CHIKV persistence and pathogenesis and emphasizes the potential of targeting host kinases as an adjunct to antiviral strategies. Our approach demonstrates the utility of kinase substrate specificity modeling to identify host kinases that can interact with viral proteins for their selection as drug-repurposable targets, particularly for variants and viruses without efficient/approved vaccines.

Introduction: Borrelia bavariensis, a causative agent of Lyme disease, was first reported in South Korea in 2018, yet no complete genome sequence has been described. Here, we present the first whole-genome characterization of B. bavariensis strain KW3, isolated from Ixodes granulatus in the Kangwon region of South Korea. Methods: Genome assembly was achieved using a hybrid approach combining PacBio and Illumina sequencing. Results: The KW3 genome consists of a linear chromosome and 12 plasmids, totaling 1.33 Mbp comprising 1,310 annotated genes. Comparative analyses revealed that strain KW3 is most closely related to Japanese strains NT24 and JAASAAF1029. In multiple phylogenetic trees, strain KW3 consistently clustered within the Japanese clade but formed a distinct subbranch, suggesting regional diversification. Several plasmids showed evidence of fusion or divergence, including lp32-10_lp28-4, lp32-10_lp36, and cp32-6_cp32-12, which displayed partial similarity to plasmids of European Borrelia garinii strains PBes (Germany) and 20047 (France). Key plasmid-borne virulence genes (ospA, ospB, ospC, dbpA, dbpB) were fully conserved in strain KW3 and closely matched those of Japanese strains. In contrast, the vlsE locus, typically located on lp28-8 in B. bavariensis, was absent, possibly due to plasmid loss during in vitro culture. Conclusions: This study provides the first complete genome sequence of B. bavariensis isolate from South Korea and highlights its close relationship to Japanese isolates while revealing unique plasmid features and virulence gene profiles. These findings underscore the importance of continued genomic surveillance to monitor the circulation, evolution, and pathogenic potential of this tick-borne pathogen across East Asia.

Introduction: Coxiella burnetii, the causative agent of Q fever, remains poorly understood in Pakistan, despite its clinical relevance in both humans and ruminants. This study aimed to determine the seroprevalence of C. burnetii in rodents. Methods: Rodents were captured in urban settings across three districts of Punjab, Pakistan. A total of 300 serum samples were collected from rodents belonging to the Muridae family (n = 268) and the Sciuridae family (n = 32). Samples were screened for C. burnetii antibodies using an indirect enzyme-linked immunosorbent assay. Results: An overall seroprevalence of 12.7% (38/300) was observed, with a higher prevalence in males compared with females (p < 0.05). Using multiple logistic regression, age was identified as a potential risk factor for C. burnetii in rodents, with 14.1% (37/262) of adult rodents testing positive for C. burnetii antibodies, compared with a 2.6% (1/38) detection rate in juvenile rodents. Coxiella burnetii antibodies were detected in five rodent species, Tatera indica, Mus musculus, Millaria meltada, Rattus rattus, and Rattus norvegicus with seroprevalence ranging from 7.8% to 23.3%, depending on the species. Conclusion: This detection of C. burnetii in rodents residing in populated regions of Punjab, Pakistan indicates pathogen exposure. Additional studies, including molecular testing are needed to confirm their role as pathogen reservoirs.

Background: Campylobacter jejuni typically causes gastrointestinal illness but may lead to severe systemic infection in immunocompromised hosts. Resistance to macrolides, fluoroquinolones, and tetracyclines is increasingly reported. Case Presentation: A 27-year-old male with X-linked agammaglobulinemia developed recurrent right foot cellulitis after local trauma. Following application of a non-sterile herbal ointment and sheepskin, the lesion progressed, and the patient developed fever and chills. Blood cultures repeatedly yielded multidrug-resistant C. jejuni, while wound culture grew Citrobacter braakii. The C. jejuni isolates showed high MICs to macrolides, fluoroquinolones, and tetracycline. Given persistent bacteremia despite broad-spectrum therapy, meropenem was initiated, resulting in rapid defervescence and clinical improvement. Conclusion: This case highlights the potential for transdermal acquisition of C. jejuni in immunodeficient patients, the clinical challenges posed by multidrug-resistant strains, and the need for education regarding traditional practices that may increase infection risk.

Reactive arthritis is defined as a sterile inflammation of the joint space, following a remote infection, which can be bacterial or viral in origin. Although leptospirosis is not a frequent cause, it has been reported as a potential trigger. We herein report an 11-year-old boy who presented with fever, jaundice, and acute onset of right hip pain with restricted movement. Laboratory investigations were done to evaluate for infectious causes. IgM antibodies for Leptospira were equivocal, suggesting the possibility of an acute infection. This case highlights that reactive arthritis can develop early in the course of leptospiral infection, as early as within 3 days of symptom onset, and may coincide with active systemic illness. Early recognition of this rare association is essential for the diagnosis and management.

Background: Mosquitoes in the genus Culex are vectors of multiple arboviruses, including West Nile virus, St. Louis Encephalitis virus, and Western equine encephalitis virus. In the United States, West Nile (WN) is the leading cause of mosquito-borne diseases, including the El Paso, Texas, and surrounding communities. While Cx. quinquefasciatus, Cx. tarsalis, and Cx. erythrothorax are well documented in the El Paso region, the meteorological effects on the overall abundance and virus transmission risk are not well understood. Our study objective was to estimate temporal population abundance in two urban communities: Sparks, El Paso, Texas, and Anapra, Ciudad Juárez, Chihuahua, Mexico. Materials and Methods: Population abundance was estimated through collections of Cx. quinquefasciatus, Cx. tarsalis, and Cx. erythrothorax from June to December across years 2016-2018 using confirmed human case gravid traps. Mosquitoes were collected inside and outside 108 and 101 participating homes in Sparks and Anapra, respectively. Results: Generally, the results indicated that the abundance of these mosquito species was highest in June, followed by a slight decrease and then an increase in abundance during August, followed by a slight decrease until their near absence in December with colder winter season. The high abundance early in the year could be attributed to overwintering behavior which allowed these species to become dormant and/or diapause until ideal favorable environmental conditions return year after year during the spring season. Conclusion: Interestingly, the overall abundance of Cx. spp. was greater in Anapra, where no WN human cases have been reported. Our study provided a better understanding of the seasonal abundance and risk of arbovirus transmission by these medically important mosquitoes and the need to implement vector control measures early in the year.

Background: Brucellosis is a widespread zoonotic bacterial infection that affects over 500,000 people annually, with significant economic losses in the livestock industry, particularly in endemic regions such as the Middle East, Asia, and parts of Africa and Latin America. Despite standard antibiotic treatments, relapse rates remain as high as 10%-15%, highlighting the limitations of current therapeutic options. Objective: Phage therapy, which uses bacteriophages to selectively target and lyse Brucella spp. bacteria, offers a promising approach for managing brucellosis. Methods: This paper explores the current understanding of brucellosis, highlighting the impact on animal and human health, and reviews the mechanisms and efficacy of bacteriophages against Brucella spp.Results:Key factors, such as phage specificity, immune modulation, and recent advancements in phage encapsulation, are discussed as strategies to enhance treatment efficacy. Conclusion: This review aims to explore emerging alternative therapies beyond conventional antibiotics, focusing on approaches such as immunotherapy, bacteriophage therapy, and novel vaccine strategies to improve clinical outcomes and reduce disease burden.

Background: The Manuel Antonio National Park (MANP) and its surrounding areas in Costa Rica are home to endangered non-human primates (NHPs), including Saimiri oerstedii citrinellus and Cebus imitator, that coexist in close contact with humans and domestic animals. Such interactions may facilitate the transmission of vector-borne zoonotic diseases. This study aimed to investigate the presence of selected vector-transmitted pathogens of zoonotic relevance in NHPs from this region. Methods: Between 2021 and 2022, 40 free-ranging NHPs (19 C. imitator, 19 S. oerstedii citrinellus, 2 Alouatta palliata) were sampled in MANP and surrounding areas. Blood samples were tested for Trypanosoma spp., Plasmodium spp., Mycoplasma spp., and arboviruses including dengue virus (DENV), chikungunya virus (CHIKV), Zika virus (ZIKV), Venezuelan equine encephalitis virus (VEEV), and West Nile virus (WNV). Molecular analyses were conducted using PCR and RT-qPCR protocols, with sequencing for species confirmation. Results: Eight of 40 NHPs (20.0%) tested positive for at least one pathogen. Trypanosoma minasense was confirmed by sequencing in three C. imitator (16.7%). Plasmodium spp. was detected in one C. imitator and one A. palliata (5.0%), though species-level identification was unsuccessful. One C. imitator tested positive for CHIKV (Ct 36.8), representing the first PCR-confirmed case of CHIKV in NHPs in Central America. Two C. imitator were positive for Mycoplasma spp. (11.1%). No co-infections were observed. All animals were negative for DENV, ZIKV, VEEV, and WNV. Conclusions: This study provides the first molecular evidence of CHIKV infection in NHPs in Costa Rica and highlights the circulation of Trypanosoma spp., Plasmodium spp., and Mycoplasma spp. in wild primates from MANP. These findings emphasize the need for a One Health approach to surveillance, particularly in regions where human-wildlife interactions are frequent. Longitudinal and serological studies are recommended to assess the potential reservoir role of NHPs and their implications for public health and conservation.

Background: Hymenolepis diminuta, a rat tapeworm, is a rare zoonosis typically affecting children. We report the first confirmed human case in Yunnan Province, China, not able for its occurrence in an adult. Methods: A 42-year-old female farmer from Dali presented with unilateral painless vision loss. H. diminuta infection was diagnosed incidentally through routine stool microscopy during her ophthalmological workup. Results: Examination of fecal samples confirmed the presence of H. diminuta eggs. This identifies the first autochthonous human case in Yunnan Province and underscores infection in an atypical adult demographic. Conclusion: This case highlights the unexpected detection of a rat tapeworm in a new geographic region and age group, emphasizing the value of basic diagnostics in uncovering zoonotic diseases, even with unrelated clinical presentations.