Journal of Vector Borne Diseases最新文献

The current systematic review and meta-analysis aims to estimate the prevalence of West Nile Virus (WNV) among humans in Iran. A comprehensive search was conducted in national databases, including SID, Magiran, and Barekat knowledge network and international databases, including Web of Science, MEDLINE, Embase, and Scopus, to identify the articles on the prevalence of human WNV in Iran. A random-effects model was used to assess the pooled prevalence. A meta-regression method was applied to determine the factors affecting the heterogeneity among the studied population. An analysis was performed on 11 studies with a total sample size of 3747. The total pooled estimate for the prevalence of human WNV was 14.92% (95% CI: 9.13 to 20.71). The highest pooled prevalence was in Khuzestan (southwest Iran) (58.31%; 95% CI: 21.12 to 90.82), and the lowest were in East Azerbaijan (Central Iran) (0.0%; 95% CI: 0.0 to 7.11) and Mazandaran (north Iran) (0.0%; 95% CI: 0.0 to 1.69), respectively. Based on the results of the univariate meta-regression, province (b: 0.35; p < 0.001) showed a significant direct association with the prevalence of human WNV, but other variables, including detection method, study population, publication year, and sample size, had no association with the prevalence of human WNV. The percentage of positive cases in serum samples shows that the WNV spreads in Iran.

Background objectives: Japanese Encephalitis (JE) is a re-emerging vector-borne zoonotic disease with a significant public health impact in India. JE is endemic in several Indian states, including Assam, which consistently reports the high burden of human JE cases in the country. Pigs, as amplifier hosts for the JE virus plays a critical role in JE transmission cycle and serves as suitable sentinels for predicting human JE outbreaks. Although several studies have assessed the JE prevalence in pigs across different districts of Assam, there is no prior report of occurrence of JE in pigs from Southern region of Assam. The present study was undertaken to determine the occurrence of JEV infection in pigs from Cachar, a Southern district of Assam through serological and molecular testing.

Methods: A total of 100 pig serum samples collected from backyard farms across eight villages in the Cachar district were screened using indirect ELISA(s) to detect JEV-specific IgM and IgG antibodies. Samples were further subjected to nested RT-PCR for viral RNA detection followed by phylogenetic analysis to identify the circulating JEV genotype in the region.

Results: Of the 100 pig serum samples tested, 59% were positive for JEV specific IgM antibodies whereas 53% samples were positive for IgG antibodies. The overall seropositivity of JEV among pigs from Cachar district was 66%. JEV RNA was detected in 12 samples and phylogenetic analysis confirmed the presence of genotype III of JEV circulating among pigs from Cachar district of Assam.

Interpretation conclusion: This is the first study to report the presence of JEV infection in pigs from the Cachar district of Assam, underscoring the need to initiate JEV surveillance in the pig population of the region.

Background objectives: The increasing prevalence of life-threatening viral diseases like dengue fever necessitates comprehensive research into their causes, recovery, and preventive measures. Dengue outbreak data often suffers from irregularities, underreporting, delays, and missing information, which challenge the development of reliable prediction models.

Methods: To overcome these issues, the study proposes an innovative framework that combines Evolutionary Sampling with Prediction (ESP) to handle temporal and stochastic dynamics, along with a Minimax K-nearest neighbour imputer to correct missing data biases. Additionally, a novel Firefly Dynamic Evolution (FDE) approach optimizes model parameters, while a Random Forest classifier captures complex, nonlinear relationships in the data. The model was evaluated using 10-fold cross-validation on two datasets: the Local Epidemics Dengue Fever dataset (San Juan and Iquitos) and the Brazil dengue dataset.

Results: The proposed model achieved a low Mean Absolute Error (MAE) of 22.1 and Root Mean Squared Error (RMSE) of 46.37 on the local dataset, and an MAE of 48.36 and RMSE of 86.76 on the Brazil dataset, demonstrating improved accuracy and robustness.

Interpretation conclusion: These findings highlight the model's potential for early warning systems and broader applications in forecasting other infectious diseases.

Background objectives: Rodents and arthropod vectors transmit zoonotic pathogens like Yersinia pestis, Rickettsia typhi etc. posing a threat to both veterinary and public health. The primary aim of this study was to record the incidence of rat fleas, a vector for plague and murine typhus on synanthropic rodents, their epidemiology and molecular characterization.

Methods: A comprehensive survey of synanthropic rodents viz. Bandicota bengalensis (190), Rattus rattus (201), and Tatera indica (180) across various habitats, including crop fields, poultry farms, fish markets, residential areas, shops, and railway stations in different seasons, was conducted to record the incidence of rat fleas. Fleas collected were identified morphologically, followed by molecular confirmation through PCR amplification of 28S rRNA gene and phylogenetic analysis.

Results: Morphological and molecular analyses confirmed the flea species as Xenopsylla cheopis. The nucleotide sequence obtained was submitted to GenBank (LC626773). The infestation rate varied among rodent species, with R. rattus exhibiting the highest prevalence (55.72%), followed by B. bengalensis (37.36%) and T. indica (6.67%). Adult male rodents were more frequently infested. Seasonal variations revealed peak infestations during winter (36.41%), particularly among rodents from poultry farms (63.33%). R. rattus posed the highest risk for disease transmission (8.35), followed by B. bengalensis (5.60).

Interpretation conclusion: This study highlights the critical role of R. rattus and B. bengalensis in spreading pathogens as primary hosts for X. cheopis. These findings emphasize the need for integrated vector surveillance and targeted control measures to reduce the risk of flea-borne zoonoses in urban and peri-urban areas.

Background objectives: In 2021, a Yellow Fever (YF) outbreak occurred in rural and mostly nomadic communities within the Savannah region of Ghana, leading to over 40 deaths. Following this outbreak, we determined the knowledge, attitude, and practice (KAP) of YF in these hotspot communities.

Methods: A cross-sectional study was conducted using a random sampling technique and a standard questionnaire involving face-to-face interviews from June 2022 to July 2022. Four districts were selected among the hotspot areas of the 2021 YF outbreak. The participants targeted were residents aged 15 years and above.

Results: The majority (80.8%) had heard about YF through healthcare personnel in all four districts. Most of them associated the cause with poor sanitation, but 14% specifically associated it with mosquito bites (N=869). The level of education was associated with awareness of YF (P = 0.008), however, a pairwise analysis did not show any association between those with no formal education and the highest education (P = 0.903). Vaccination rates were high (average 78%), and the distance to health facility influenced the vaccination status (P < 0.0001). Preventive measures employed included vaccination, sleeping under insecticide-treated bed nets, clearing bushes and getting rid of stagnant water.

Interpretation conclusion: There was high awareness of YF and vaccination rates among the participants. The emergency mass YF vaccination conducted in 2021 in response to the outbreak increased community awareness. Preventive practices employed may be associated with participants' knowledge of mosquito-borne diseases such as malaria. YF education should be integrated with routine health service delivery.

Background objectives: Dengue virus, a mosquito-borne flavivirus, is a serious worldwide health risk that can be fatal. Its replication is dependent on the NS2B/NS3 protease. Given the critical need for effective antivirals and the documented medicinal properties of Nigella sativa bioactive compounds, this study used molecular docking and ADMET analysis to assess the potential of N. sativa bioactive compounds as NS2B/NS3 protease inhibitors.

Methods: A total of 151 bioactive compounds from N. sativa were retrieved from the PubChem database. Molecular docking analyses were carried out using AutoDock Vina in conjunction with PyRx (v. 0.8) virtual screening tools. Physiochemical and ADMET properties of the top four compounds were evaluated using SwissADME and Deep-PK tools.

Results: The screening resulted 19 compounds with higher binding affinity values than the control compound Lopinavir. This study focused on the top four compounds (PubChem IDs: 11277543, 118717506, 101257318, and 102575929) that were found to form multiple hydrogen bonds and hydrophobic interactions with the NS2B/NS3 protease active site. Importantly, these compounds interacted with the catalytic triad of His51, Asp75, and Ser135 residues of NS2B/NS3 protease. Furthermore, these compounds had favourable druglikeness, pharmacokinetic, and toxicity profiles.

Interpretation conclusion: The compounds (PubChem IDs: 11277543, 118717506, 101257318, and 102575929) can be used as potential NS2B/NS3 protease inhibitors for further experimental validation and development in dengue management.

Background objectives: Molecular tests play crucial role in diagnosis, however, acquiring appropriate controls is challenging owing to strict biosafety and biosecurity regulations. Herein, we suggest an alternative to live virus for inclusion as positive controls in molecular testing.

Methods: We used inactivated antigens provided with ELISA kits, both as they are and after spiking the vector samples. The extracted RNA/DNA was used as a positive control in RT- PCR/PCR reactions.

Results: The PCR product of expected size and sequencing results confirmed that the inactivated antigens can be used as positive controls for Dengue, Chikungunya, Japanese Encephalitis and Lymphatic Filariasis in molecular tests.

Interpretation conclusion: We demonstrate that the inactivated antigens supplied with ELISA kits or obtained from microscopic slide can be used as positive controls in molecular tests while testing human and vector samples. This will be a useful technique for laboratories in resource constrained settings or during emergency situations.

Background objectives: Dengue represents a high economic and health burden, particularly in low, and middle-income countries, as in Brazil. This study aimed to evaluate the impact of demographic, clinical and laboratory characteristics on dengue-related hospital stay in Bauru, Brazil.

Methods: This was a retrospective, cross-sectional, observational study that evaluated the impact of demographic characteristics (age, sex, and self-reported ethnicity), of chronic diseases (diabetes mellitus, systemic arterial hypertension, chronic kidney disease, dyslipidemia, cancer, cardiomyopathy, and heart failure), clinical signs (hematemesis, hepatomegaly, and edema), and symptoms (anemia), alone or in combination, in the length of hospitalization. All patients admitted for dengue in a public tertiary-level referral hospital in Bauru, São Paulo, Brazil, 2019, were included. A survival analysis was performed for statistical purposes.

Results: Overall, 234 patients were evaluated, whose mean age was 35.35±1.80 years with an average length of hospitalization of 6.38±0.44 days. The final model presented higher ages, the presence of chronic diseases and clinical alterations as significant variables in determining the length of hospitalization.

Interpretation conclusion: Patients with dengue presented long hospitalization lengths at discharge, mainly those with higher ages, chronic diseases (diabetes mellitus, systemic arterial hypertension, chronic kidney disease, heart failure) and clinical signs (edema) and symptoms (anemia) alone or in combination. Sex, self-reported ethnicity, cancer, cardiomyopathy, dyslipidemia, hematemesis, and hepatomegaly had no significant impact on the length of hospitalization. Prevention of the disease through continuous education and immunization of the general population, mainly those belonging to high-risk groups, is urgently needed.

This review explores the structural dynamics of Dengue virus (DENV) during human-to-human transmission mediated by mosquito vectors, primarily Aedes aegypti. DENV remains a global health concern, with increasing cases due to climate change, urbanization, and mosquito adaptation. The structural biology of DENV, including its envelope (E), membrane (M), capsid (C) proteins, and RNA genome, plays a critical role in transmission and infectivity. The transmission cycle begins when mosquitoes ingest the virus from an infected human and later transmit it to others after viral replication within their salivary glands. Structural adaptations occur both in the mosquito host and human cells, enhancing viral stability and infectivity. Host-virus interactions, such as immune evasion and cellular entry mechanisms, further complicate disease progression. This review highlights the impact of structural changes on viral replication, pathogenesis, and resistance, while emphasizing recent research advancements and future challenges. Understanding these molecular mechanisms is crucial for developing effective therapeutics and controlling DENV spread.

Background objectives: This study aimed to assess chest computed tomography (CT) scans and laboratory parameters of patients with Crimean-Congo hemorrhagic fever (CCHF) and compare results between survivors and non-survivors.

Methods: Patients diagnosed with CCHF between July 2012 and July 2021 were examined retrospectively. Patient data, thorax CT findings, laboratory results, and demographic characteristics were evaluated. Survivors and non-survivors were compared for ground-glass opacity (GGO), pleural effusion, atelectasis, lung consolidation, pulmonary nodules, bronchiectasis, pericardial effusion, and enlarged mediastinal lymph nodes. Laboratory findings and respiratory complaints were recorded regarding survival status.

Results: A total of 112 patients were included, with a mean age of 54.2 years and 56.3% male predominance. The most common CT findings were GGO (46.3%), pleural effusion (40%), and atelectasis (36.3%). GGO, pleural effusion, atelectasis, lung consolidation, and pericardial effusion were more frequent in non-survivors than survivors (p<0.05).Non-survivors demonstrated significantly altered laboratory parameters including elevated WBC counts (p<0.01), reduced platelet counts (p<0.001), decreased fibrinogen (p<0.01), and prolonged coagulation times (PT and aPTT, both p<0.001). Pleural effusion and GGO showed significantly higher mortality risk (11.23-fold and 5.89-fold adjusted, respectively).

Interpretation conclusion: GGO, lung consolidation, pleural effusion, pericardial effusion, and atelectasis may serve as poor prognostic indicators, necessitating close monitoring for patients with these potentially life-threatening findings.