We report a human case of severe fever with thrombocytopenia syndrome virus infection transmitted by a tick, confirmed by viral identification. Haemaphysalis aborensis, a tick species not native to Japan that has been observed to transmit the virus to humans, is now recognized as a potential vector of this virus in Japan.
View Article and Find Full Text PDFDengue is a viral infection caused by the dengue virus (DENV), transmitted to humans through the bite of infected mosquitoes. About half of the world's population is now at risk of dengue, which represents a global public health concern, especially in tropical and subtropical countries. Early detection of the viral infection is crucial to manage the disease; hence, effective rapid diagnostic tests are essential.
View Article and Find Full Text PDFDengue virus (DENV) is one of the most significant mosquito-borne diseases in Nepal. In 2023, DENV outbreaks began in Eastern Nepal, near the border with India, and rapidly spread nationwide. The study aims to describe the outbreak's epidemiological pattern, laboratory characteristics, DENV serotypes, and genotypes.
View Article and Find Full Text PDFSevere fever with thrombocytopenia syndrome (SFTS) is a potentially fatal tick-borne zoonosis caused by SFTS virus (SFTSV). In addition to tick bites, animal-to-human transmission of SFTSV has been reported, but little is known about feline SFTSV infection. In this study, we analyzed data on 187 cats with suspected SFTS to identify biomarkers for SFTS diagnosis and clinical outcome.
View Article and Find Full Text PDFDengue virus (DENV) poses a significant threat to global health, infecting approximately 390 million people annually. This virus comprises four serotypes capable of causing severe disease. Genetic analyses are crucial for understanding the epidemiology, evolution, and spread of DENV.
View Article and Find Full Text PDFBackground: Chikungunya virus (CHIKV) is an alphavirus (genus Alphavirus, family Togaviridae) that is primarily transmitted to humans by Aedes mosquitoes, and can be transmitted from mother to child. Little is known about CHIKV transmission in Vietnam, where dengue is endemic and Aedes mosquitoes are abundant. This study aimed to determine the prevalence and characteristics of vertical CHIKV infection in a birth cohort, and seroprevalence of anti-CHIKV antibodies with or without confirmation by neutralization tests among women bearing children in Vietnam.
View Article and Find Full Text PDFIn 2023, Nepal faced its second largest dengue outbreak ever, following a record-breaking number of dengue cases in 2022, characterized by the expansion of infections into areas of higher altitudes. However, the characteristics of the 2023 circulating dengue virus (DENV) and the vector density remain poorly understood. Therefore, we performed DENV serotyping, clinical and laboratory assessment, and entomological analysis of the 2023 outbreak in central Nepal.
View Article and Find Full Text PDFDengue virus (DENV) represents a significant global health burden, with 50% of the world's population at risk of infection, and there is an urgent need for next-generation vaccines. Virus-like particle (VLP)-based vaccines, which mimic the antigenic structure of the virus but lack the viral genome, are an attractive approach. Here, we describe a dengue VLP (DENVLP) vaccine which generates a neutralizing antibody response against all four DENV serotypes in 100% of immunized non-human primates for up to 1 year.
View Article and Find Full Text PDFIn search of a mouse model for use in evaluating dengue vaccines, we assessed A129 mice that lacked IFN-α/β receptors, rendering them susceptible to dengue virus (DENV) infection. To our knowledge, no reports have evaluated dengue vaccine efficiency using A129 mice. A129 mice were given a single intraperitoneal (IP) or subcutaneous (SC) injection of the vaccine, Dengvaxia.
View Article and Find Full Text PDFSaliva is a key component of mucosal immunity, which protects the oral cavity from viral infections. However, salivary immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in terms of immunoglobulin dynamics and recognition, have not been investigated sufficiently. In this study, saliva samples were collected from individuals that received SARS-CoV-2 vaccine, and immunoglobulin G (IgG), IgM, and IgA against whole spike protein and S1 protein were measured.
View Article and Find Full Text PDFObjective: The invasion of dengue virus (DENV)-2 Cosmopolitan genotype into the Philippines, where the Asian II genotype previously circulated challenges the principle of dengue serotype-specific immunity. Assessment of antibodies in this population may provide a mechanistic basis for how new genotypes emerge in dengue-endemic areas.
Methods: We evaluated the neutralizing antibody (nAb) and antibody-dependent enhancement (ADE) responses against the two genotypes using archived serum samples collected from 333 patients with confirmed dengue in Metro Manila, Philippines, before, during, and after the introduction of the Cosmopolitan genotype.
Background: A test-based strategy against coronavirus disease 2019 (COVID-19) is one of the measures to assess the need for isolation and prevention of infection. However, testing with high sensitivity methods, such as quantitative RT-PCR, leads to unnecessary isolation, whereas the lateral flow antigen test shows low sensitivity and false negative results. The purpose of this study was to evaluate the performance of the LumiraDx SARS-CoV-2 Ag test (Lumira Ag), a rapid microfluidic immunofluorescence method, in assessing infectivity.
View Article and Find Full Text PDFChikungunya fever is an acute febrile illness caused by the chikungunya virus (CHIKV), which is transmitted by mosquitoes. Since 1965, only a few studies with limited scope have been conducted on CHIKV in Vietnam. Thus, this study aimed to determine the seroprevalence and molecular epidemiology of CHIKV infection among febrile patients in Vietnam from 2017 to 2019.
View Article and Find Full Text PDFDengue virus (DENV) is mainly found in the tropics and infects approximately 400 million people annually. However, no clinically available therapeutic agents specific to dengue have been developed. Here, we examined the potential antiviral effects of the French maritime pine extract Pycnogenol® (PYC) against DENV because we previously found that the extract exerts antiviral effects on hepatitis C virus, which belongs to the Flavivirus family.
View Article and Find Full Text PDFWe assessed the development, sensory status, and brain structure of children with congenital Zika virus (ZIKV) infection (CZI) at two years and preschool age. CZI was defined as either ZIKV RNA detection or positive ZIKV IgM and neutralization test in the cord or neonatal blood. Twelve children with CZI born in 2017-2018 in Vietnam, including one with Down syndrome, were assessed at 23-25.
View Article and Find Full Text PDFIn 2017, Sri Lanka experienced its largest dengue epidemic and reported severe and unusual presentations of dengue with high morbidity. This outbreak was associated with the reemergence of dengue virus-2 (DENV-2), with the responsible strain identified as a variant of the previously circulating DENV-2 cosmopolitan genotype. In this study, we characterized the DENV-2 cosmopolitan genotype from patients during this epidemic.
View Article and Find Full Text PDFChikungunya virus (CHIKV) infection is a re-emerging arboviral disease with no approved vaccine, although numerous options are in development. Before vaccine implementation, disease burden, affected age group, and hospitalization rate information should be documented. In 2019, a sizeable outbreak of the East Central South African genotype of CHIKV occurred in Myanmar, and during this period, a cross-sectional study was conducted in two regions, Mandalay and Yangon, to examine the molecular and seropositivity rate of the CHIKV infection.
View Article and Find Full Text PDFBackground: Zika Virus (ZIKV) is a re-emerging, arthropod-borne flavivirus transmitted by Aedes mosquitoes (Ae. aegypti and Ae. albopictus).
View Article and Find Full Text PDFLancet Reg Health West Pac
September 2023
Myanmar is an endemic country for arboviruses, and outbreaks occur frequently. A cross-sectional analytical study was conducted during the peak season of the chikungunya virus (CHIKV) outbreak in 2019. A total of 201 patients with acute febrile illness who were admitted to the 550-bedded Mandalay Children Hospital in Myanmar were enrolled in the study, and virus isolation, serological tests, and molecular tests for the dengue virus (DENV) and CHIKV were performed for all samples.
View Article and Find Full Text PDFThe largest dengue outbreak in the history of Nepal occurred in 2022, with a significant number of casualties. It affected all 77 districts, with the nation's capital, Kathmandu (altitude 1300 m), being the hardest hit. However, the molecular epidemiology of this outbreak, including the dengue virus (DENV) serotype(s) responsible for this epidemic, remain unknown.
View Article and Find Full Text PDFWe report the structural functionalization of the terminal amino group of N -(7-chloroquinolin-4-yl) butane-1,4-diamine, leading to a series of 7-chloro-4-aminoquinoline derivatives, and their evaluation as potent anti-malarial and anti-viral agents. Some compounds exhibited promising anti-malarial effects against the Plasmodium falciparum 3D7 (chloroquine-sensitive) and Dd2 (chloroquine-resistant) strains. In addition, these compounds were assayed in vitro against influenza A virus (IAV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
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