Tropical Diseases, Travel Medicine and Vaccines最新文献

Monkeypox virus (MPXV) is an enclosed, double-stranded DNA virus from the Orthopoxvirus genus, which also contains variola, vaccinia, and cowpox. MPXV, which was once confined to West and Central Africa, has recently had a rebound, spreading beyond its original range since 2017. The virus is distinguished by its unique morphology, which includes an oval or brick-shaped structure and a complex lipid and protein makeup. The current multi-country outbreak designated a public health emergency in 2022, has highlighted MPXV's shifting epidemiology and ability to spread rapidly over the globe. 'No one is safe until everyone is safe' is a slogan we often heard during the COVID-19 pandemic, which is now also required for the growing global and regional mpox outbreaks. The epidemic is divided into two clades: Clade I and Clade II, which have distinct pathogenic characteristics. Diagnostic approaches have developed with advances in molecular techniques, yet problems persist in resource-constrained situations. This overview summarizes the virus's history, epidemiology, morphology, and clinical characteristics, offering insights into its recent comeback and current global response efforts.

Oropouche fever is an increasingly significant health concern in tropical and subtropical areas of South and Central America, and is primarily spread by midge vectors. The Oropouche virus (OROV) was first identified in 1955 and has been responsible for numerous outbreaks, particularly in urban environments. Despite its prevalence, the disease is often under-reported, making it difficult to fully understand its impact. OROV typically causes febrile illness characterized by symptoms such as headaches, muscle pain, and, occasionally, neurological issues such as meningitis. The ability of the virus to thrive in both forested and urban areas has raised concerns regarding its potential spread to new regions, particularly in the context of climate change. This paper delves into the epidemiology, clinical features, and transmission patterns of OROV, shedding light on the difficulties in diagnosing and managing the disease. The absence of specific treatments and vaccines highlights the urgent need for continued research and development of targeted public health strategies. Advancements in molecular diagnostics and vector control strategies can mitigate Oropouche fever's impact. However, a comprehensive public health approach involving increased surveillance, public education, and cross-border collaboration is needed, especially as the global climate crisis may expand vector habitats, posing risks to previously unaffected regions.

Tuberculosis represents a significant menace to health, leading to millions of cases and fatalities each year. Traditional diagnostic methods, while effective, have limitations, necessitating improved tools. Aptamers possessing remarkable specificity single-stranded DNA or RNA molecules promising in TB diagnosis due to their adaptability and precise biomarker detection capabilities. In this study, we aimed to evaluate the research on aptamer applications in TB diagnosis, evaluating the efficacy, limitations, and future prospects. The present systematic review study followed PRISMA guidelines, including peer-reviewed studies on aptamer efficacy in TB diagnosis. Eligibility criteria covered experimental and human studies on TB diagnosis, prognosis, progression, and treatment response. Of 1165 identified studies, 35 met inclusion criteria. Aptamers were utilized for MTB and mycobacterial antigen detection, showcasing notable sensitivity and specificity. Targeted antigens included ESAT-6, HspX, MPT 64, and IFN-γ. Various aptamer-based assays, such as electrochemical, fluorescent, and immunosensors, demonstrated effectiveness. Multiplex assays, particularly for IFN-γ, showed enhanced diagnostic accuracy. Aptamer-based assays exhibited discrimination between active TB and other conditions, showcasing their diagnostic value. Aptamers, especially in conjunction with nanomaterials, show promise in developing advanced TB biosensors with superior detection capabilities. Cost-effective devices with heightened sensitivity for clinical and screening use are crucial for TB control, emphasizing the need for ongoing research in this field.

Background: Climate change in the upcoming years will raise the health burden of zoonotic parasites. As a liver fluke, Fasciola depends on certain climate conditions to complete its life cycle and is significantly influenced by climate changes. We aimed to investigate the relationship between the increasing prevalence of human fascioliasis and climate changes in Upper Egypt.

Methods: Records of Fasciola cases in Assiut Governorate in Upper Egypt were evaluated between September 2018 and March 2023. The annual and monthly climate parameters of the region's temperature and humidity acquired from ERA5 and FLDAS were investigated between 2000 and 2023.

Results: A total of 303 patients were included. The mean age was 33.9 ± 17.4 years; 57.1% were females, and the majority were rural residents. Positive correlations were found between temperature and the recorded cases in 2018, 2020, 2021, and 2022 (r = 0.92, 0.41, 0.61, and 0.60, respectively). In 2018 and 2022, humidity and Fasciola frequency had a significant positive correlation (r = 0.97 and 0.49, respectively). An outbreak of fascioliasis was recorded in September 2018, coinciding with the peak temperature and high humidity levels, exceeding the average climatology range from 2000 to 2017. The recorded cases exhibited a seasonal pattern, with peaks in hot, humid summer and autumn.

Conclusion: The rise of human fascioliasis in Upper Egypt is influenced by local climate characteristics. A climate-based map of Fasciola distribution using forecast risk models is needed to predict future outbreaks and for better control.

Dengue virus (DENV) is a mosquito-borne virus that causes dengue fever, a significant public health concern in many tropical and subtropical regions. Dengue is endemic in more than 100 countries, primarily in tropical and subtropical regions of the world. Each year, up to 400 million people get infected with dengue. Approximately 100 million people get sick from infection, and 40,000 die from severe dengue. Unfortunately, dengue vaccine development is also marred with various complicating factors, as the forefront candidate vaccine performed unsatisfactorily. Moreover, the only licensed vaccine (Dengvaxia) for children 9 through 16 years of age is available in just a few countries. The treatment difficulties are compounded by the absence of an effective antiviral agent. Exploring plant-based therapeutics for dengue from the laboratory to clinical application involves a multi-stage process, encompassing various scientific disciplines. Individual investigators have screened a wide range of plant extracts or compounds for potential antiviral activity against DENV. In vitro studies help identify candidates that exhibit inhibitory effects on viral replication. Some of the most promising medicinal plants showing in vitro activity against DENV include Andrographis paniculate, Acorus calamus, and Cladogynos orientalis. Further laboratory studies, both in vitro and in animal models (in vivo), elucidate the mechanisms of action by which the identified compounds exert antiviral effects. Medicinal plants such as Carica papaya, Cissampelos pareira, and Ipomea batata exhibited potent platelet-enhancing activities while Azadirachta indica and Curcuma longa showed promising effects in both in vitro and in vivo studies. Based on positive preclinical results, researchers design clinical trials. This involves careful planning of trial phases, patient recruitment criteria, ethical considerations, and endpoints. The most important medicinal plants showing efficacy and safety in clinical trials include Carica papaya and Cissampelos pareira. This review suggests that several promising medicinal plants exist that have the potential to be turned into clinical drugs to treat dengue infection. However, in addition to developing synthetic and plant-based therapies against dengue infection, vector management strategies should be made robust, emphasizing the need to focus on reducing disease incidence.

Dengue is the most rapidly spreading vector-borne disease worldwide, with over half the global population at risk for an infection. Antibody-dependent enhancement (ADE) is associated with increased disease severity and may also be attributable to the deterioration of disease in vaccinated people. Two dengue vaccines are approved momentarily, with more in development. The increasing use of vaccines against dengue, combined with the development of more, makes a thorough understanding of the processes behind ADE more important than ever. Above that, due to the lack of treatment options, this method of prevention is of great importance. This review aims to explore the impact of ADE in dengue vaccinations, with the goal of enhancing potential vaccination strategies in the fight against dengue.

Purpose: Nocardia is emerging as a common and easily neglected cause of both healthcare- and occupation-associated infections worldwide, however, human vaccines for Nocardia prevention are not yet available. In this study, we aimed to evaluate the immunoprotective effect of the NFA47630 protein, a secreted protein abundant in the N. farcinica IFM10152 supernatant.

Methods: Conservation and characteristics of nfa47630 were analyzed by PCR and bioinformatics. Then recombinant NFA47630 protein was cloned, expressed and purified for further antigenicity analysis. Subsequently, the ability to activate innate immunity was evaluated by examining the phosphorylation status of the MAPK signaling pathway and cytokine levels. Finally, the protective effect was evaluated on rNFA47630-immunized mice.

Results: nfa47630 was conserved in N. farcinica strains with good antigenicity. The rNFA47630 protein was expressed under the optimal conditions of 0.2 mM IPTG, 28 °C, and it can be recognized by anti-N. farcinica and anti-N. cyriacigeorgica sera, but not anti-N. asteroids, anti-N. brasiliensis, anti-N. nova and anti-Mycobacterium bovis sera. It can upregulate the phosphorylation status of ERK, JNK, P38 and the cytokine levels of TNF-α, IL-10, IL-12, and IFN-γ. In addition, mice immunized with rNFA47630 protein exhibited higher antibody titers, greater bacterial clearance ability, milder organ infection, and higher survival rates than PBS-immunized mice.

Conclusions: Our data demonstrate that NFA47630 is a potential vaccine candidate for defending against N. farcinica infection.

Background: Dengue virus remains a major public health problem with one of the hallmark pathologies is the vascular leakage caused by endothelial dysfunction which can lead to Dengue Hemorrhagic Fever (DHF) manifestation. In the status quo, no specific therapy has been discovered but rather heavily relies on judicious and frequent monitoring of intravenous fluids administration. The current guideline has discussed the roles of fluid therapy during the Dengue Shock Syndrome (DSS) stage, however, administration of early fluid intervention for DHF grade I and II remains uncharted territory. In addition, the choice and timing of colloid administration remains underexplored. As one of the widely available colloids, 5% albumin has known physiological properties that potentially minimize plasma leakage. Therefore, this study aimed to evaluate the benefit of early intervention of 5% albumin in adults with DHF in the hope of preventing the lethal progression to DSS and further, shorten the length of stay (LOS) for patients.

Methods: We conducted a multicenter, open-labeled, randomized controlled trial in Jakarta and Banten to compare the effect of early intervention with 5% albumin in adult patients with DHF compared to Ringer's Lactate (RL). Statistical analyses were conducted using unpaired t-test and Mann-Whitney for normally and abnormally distributed data respectively.

Results: Adult patients with a diagnosis of DHF grade I and II that being hospitalized to receive the early intervention of 5% albumin had significantly lower levels of hemoconcentration 4, 12, and 24 h (p = 0.002, 0.001, 0.003, respectively), higher platelet counts 4 h (p = 0.036), higher serum albumin levels 48 h (p = 0.036), lower proteinuria 24 and 48 h post-albumin administration (p < 0.001, < 0.001, respectively), and shorter LOS (p < 0.001) when compared to the RL group.

Conclusion: Early intervention of 5% albumin showed better control on vascular integrity and function compared to ringer lactate in hospitalized adults with grade I & II DHF, thus halting the progression of DHF into DSS and other related complications which leads to faster recovery and shorter length of stay.

Trial registration: The study was registered to www.

Clinicaltrial: gov with trial registration number NCT04076254, and registration date October 31st 2016.

Background: Influenza remains a global public health concern. Understanding the vaccination-induced response in an aging population, which is susceptible and at high risk, is essential for disease prevention and control. Here, we report findings on the safety and immunogenicity of a quadrivalent influenza split-virion vaccine (15 µg/subtype/0.5 ml/dose) (hereinafter referred to as the "quadrivalent influenza vaccine") in a population aged ≥ 60 years.

Methods: This open-label, pragmatic post-marketing trial enrolled 1399 older adults to receive one dose of an approved commercially available quadrivalent influenza vaccine manufactured by Hualan Biological Bacterin Inc. (hereinafter referred to as "Hualan Bio"). Participants with contraindications for the vaccine were excluded, while poor health condition was acceptable. All vaccinated subjects experienced adverse events collection within 30 days and serious adverse events within 180 days post-vaccination. 25% subjects, selected randomly, underwent venous blood sampling pre-vaccination and 30 days after post-vaccination, for detecting antibody titers against each subtype of influenza virus by hemagglutination inhibition assay. The incidences of adverse events and antibody titers against each subtype of influenza virus were statistically analyzed using SAS 9.4.

Results: No grade 3 adverse reactions occurred within 30 days post-vaccination. The incidences of overall adverse reactions, local adverse reactions and systemic adverse reactions were 3.79%, 2.86% and 1.00%, respectively. No serious adverse reactions occurred within 180 days post-vaccination. There were 350 subjects who completed venous blood sampling pre-vaccination, among whom 348 subjects completed venous blood sampling at 30 days post-vaccination for immunogenicity assessment. With respect to hemagglutination inhibition antibodies against influenza viruses H1N1, H3N2, BV and BY subtypes, at 30 days post-vaccination, the seroconversion rates were 87.64%, 75.57%, 73.28% and 78.74%, respectively; the seropositive rates were 93.97%, 98.56%, 79.31% and 95.40%, respectively; and the geometric mean increase (GMI) in post-immunization/pre-immunization antibodies was 24.80, 7.26, 10.39 and 7.39, respectively.

Conclusion: One 15 µg/subtype dose of the vaccine had a good safety profile and elicited favorable immunogenicity among subjects aged ≥ 60 years. The results of this study indicate that Hualan Bio quadrivalent influenza vaccine strike balance between safety and immunogenicity, supporting unnecessity to increase dosage or inoculation frequency for further enhancing immunogenicity.

Trial registration: Registered on ClinicalTrials.gov.

Registration number: NCT06334510. Registered on 28/03/2024 (retrospectively registered).

Background: Chagas disease (CD), triggered by the Trypanosoma cruzi parasite, is originally endemic across Latin America, affecting millions. While cardiac complications are widely recognized, the association between CD and stroke remains underexplored. This systematic review aims to elucidate the relationship between CD and stroke, highlighting the cardioembolic origins of stroke in CD patients and assessing the elevated stroke risk compared to non-infected individuals.

Methodology: Adhering to the PRISMA guidelines, we conducted a comprehensive search in PubMed and Scopus databases without date restrictions, including articles in both Spanish and English. This approach enabled the identification and analysis of relevant studies to understand the interplay between CD and stroke risk.

Results: Our analysis of 25 selected studies indicates that strokes in CD patients predominantly arise from cardioembolic sources. The data underscore a significant increase in stroke risk among individuals infected with T. cruzi compared to uninfected counterparts. Additionally, CD patients face a higher stroke and mortality risk than those with other heart failure etiologies, irrespective of disease severity.

Conclusion: The review establishes CD as a critical contributor to stroke incidence, emphasizing the need for heightened awareness and diagnosis of CD in stroke patients, particularly in regions with high CD prevalence. Recognizing the increased stroke risk associated with T. cruzi infection is crucial for developing targeted educational and preventive strategies in endemic areas.