Humans ; Animals ; Culicidae ; Flavivirus ; Cell Line ; Spiramycin

Flavivirus ; Humans ; Immunity ; Vaccines ; Zika Virus ; Zika Virus Infection/prevention & control*

Zika virus (ZIKV) is a mosquito-borne flavivirus associated with severe neurological disorders including Guillain-Barré syndrome and microcephaly. The host innate immune responses against ZIKV infection are essential for protection; however, ZIKV has evolved strategies to evade and antagonize antiviral responses via its nonstructural (NS) proteins. Here, we demonstrated that ZIKV infection unexpectedly inhibits NLRP3-dependent inflammasome activation in bone marrow-derived macrophages and mixed glial cells from mouse brain. ZIKV infection led to increased transcript levels of proinflammatory cytokines such as IL-1β and IL-6 via activating NF-κB signaling. However, ZIKV infection failed to trigger the secretion of active caspase-1 and IL-1β from macrophages and glial cells even in the presence of LPS priming or ATP costimulation. Intriguingly, ZIKV infection significantly attenuated NLRP3-dependent, but not absent in melanoma 2-dependent caspase-1 activation and IL-1β secretion from both cells. ZIKV infection further blocked apoptosis-associated speck-like protein containing a caspase recruitment domain oligomerization in LPS/ATP-stimulated macrophages. Interestingly, expression of ZIKV NS3 protein reduced NLRP3-mediated caspase-1 activation and IL-1β secretion in macrophages, whereas NS1 and NS5 proteins showed no effects. Furthermore, NLRP3 was found to be degraded by the overexpression of ZIKV NS3 in 293T cells. Collectively, these results indicate that ZIKV evades host NLRP3 inflammasome-mediated innate immune responses in macrophages and glial cells; this may facilitate ZIKV's ability to enhance the replication and dissemination in these cells.
Adenosine Triphosphate ; Animals ; Brain ; Caspase 1 ; Cytokines ; Flavivirus ; Guillain-Barre Syndrome ; HEK293 Cells ; Immunity, Innate ; Inflammasomes ; Interleukin-6 ; Macrophages ; Melanoma ; Mice ; Microcephaly ; Nervous System Diseases ; Neuroglia ; Zika Virus

We developed a Rapid Diagnostic Test (RDT) kit for detecting IgG/IgM antibodies against Zika virus (ZIKV) using monoclonal antibodies to the envelope (E) and non-structural protein 1 (NS1) of ZIKV. These proteins were produced using baculovirus expression vector with Sf9 cells. Monoclonal antibodies J2G7 to NS1 and J5E1 to E protein were selected and conjugated with colloidal gold to produce the Zika IgG/IgM RDT kit (Zika RDT). Comparisons with ELISA, plaque reduction neutralization test (PRNT), and PCR were done to investigate the analytical sensitivity of Zika RDT, which resulted in 100% identical results. Sensitivity and specificity of Zika RDT in a field test was determined using positive and negative samples from Brazil and Korea. The diagnostic accuracy of Zika RDT was fairly high; sensitivity and specificity for IgG was 99.0 and 99.3%, respectively, while for IgM it was 96.7 and 98.7%, respectively. Cross reaction with dengue virus was evaluated using anti-Dengue Mixed Titer Performance Panel (PVD201), in which the Zika RDT showed cross-reactions with DENV in 16.7% and 5.6% in IgG and IgM, respectively. Cross reactions were not observed with West Nile, yellow fever, and hepatitis C virus infected sera. Zika RDT kit is very simple to use, rapid to assay, and very sensitive, and highly specific. Therefore, it would serve as a choice of method for point-of-care diagnosis and large scale surveys of ZIKV infection under clinical or field conditions worldwide in endemic areas.
Antibodies ; Antibodies, Monoclonal ; Baculoviridae ; Brazil ; Cross Reactions ; Dengue Virus ; Diagnosis ; Diagnostic Tests, Routine ; Enzyme-Linked Immunosorbent Assay ; Flavivirus ; Gold Colloid ; Hepacivirus ; Immunoglobulin G ; Immunoglobulin M ; Korea ; Methods ; Neutralization Tests ; Point-of-Care Systems ; Polymerase Chain Reaction ; Reagent Kits, Diagnostic ; Sensitivity and Specificity ; Sf9 Cells ; Yellow Fever ; Zika Virus

Japanese encephalitis virus (JEV) is a mosquito-borne, zoonotic flavivirus causing viral encephalitis in humans and reproductive disorder in swine. JEV is prevalent throughout China in human; however, spatiotemporal analysis of JEV in Chinese swine herds has not been reported previously. Herein, we present serological and molecular epidemiological results and estimates of prevalence of JEV infections among swine herds in various regions of China. The results suggest that JEV infections are widespread and genotype I and III strains co-exist in the same regions. Therefore, there is an urgent need to monitor JEV infection status among swine herds in China.
Asian Continental Ancestry Group ; China ; Encephalitis Virus, Japanese ; Encephalitis, Japanese ; Encephalitis, Viral ; Flavivirus ; Genotype ; Humans ; Molecular Epidemiology ; Prevalence ; Spatio-Temporal Analysis ; Swine

Dengue fever is an acute febrile disease that is caused by a mosquito-borne flavivirus. It has become a major infectious disease threat in tropical and subtropical areas. In Korea, travel-associated dengue fever is increasing. Thirty-five Koreans went to Sri Lanka to do volunteer activities. Eight of the volunteers developed fever, myalgia, and rash; they were diagnosed with dengue fever. Two patients had macular hemorrhages and edema with no ophthalmic symptoms. The maculopathy caused by the dengue fever improved without specific treatment.
Communicable Diseases ; Dengue* ; Edema ; Exanthema ; Eye Manifestations ; Fever ; Flavivirus ; Hemorrhage ; Humans ; Korea ; Myalgia ; Sri Lanka* ; Volunteers*

Zika virus (ZIKV) was spread to both eastward and westward from Uganda where the virus was identified approximately in 1947 by a group of arbovirus researchers. In 2015, ZIKV reached Americas with major outbreaks in Brazil. Most countries with mosquito transmitted ZIKV infection are located in tropical and subtropical areas, where ZIKV is endemic with other flaviviruses, including JEV, dengue and yellow fever virus. Approximately 40 countries in Central and South Americas and territories in South Pacific Islands and South East Asia show autochthonous ZIKV endemics. American lineage of ZIKV is known significantly to be mutated in susceptibility to host and in pathogenicity from Asian and Asian lineages approximately since 2014. Early and specific identification of ZIKV infection is very important for the effective management of patients. First of all, optimal collection of specimens for the laboratory diagnosis is required for both nucleic acid testing (NAT) and serological tests. Specimens for NAT tests and serological tests should be determined by the available laboratory resources, work-flow in each laboratory and the geographic areas of specimen collected in addition to days after showing symptoms. Testing strategy for specific differentiation among flaviviruses will vary depending on the prevalence of viruses known to be circulating in the area where the patients were exposed. NAT will be employed for the patients presenting with onset of symptoms less than 7 days. Advanced diagnostic technologies should be continuously developed for the increase of specificity and sensitivity of ZIKV diagnosis.
Americas ; Arboviruses ; Asian Continental Ancestry Group ; Biology* ; Brazil ; Clinical Laboratory Techniques* ; Culicidae ; Dengue ; Diagnosis ; Disease Outbreaks ; Epidemiology* ; Far East ; Flavivirus ; Humans ; Pacific Islands ; Prevalence ; Sensitivity and Specificity ; Serologic Tests ; South America ; Uganda ; Virulence ; Yellow fever virus ; Zika Virus*

Zika virus was first isolated in from nonhuman primate in 1947. It is in the genus Flavivirus, closely related to other flavivirus like Dengue, West Nile, Yellow fever and Japanese encephalitis virus. Since 2007 epidemic in Yap island, zika virus infections had spread to the countries in Micronesia and South Pacific. In 2015, Zika virus outbreak occurred in Brazil and now more than 40 countries in American continents reported autochthonous infection. The virus is transmitted mainly by Ae. aegypti mosquito with many other Aedes mosquito species known as vector. Recently, Zika virus infection is known to cause severe neurological complications and congenital malformation. In this paper, we will review current knowledge on Zika virus history, biology, clinical characteristics and preventive method.
Aedes ; Biology ; Brazil ; Culicidae ; Dengue ; Encephalitis Virus, Japanese ; Flavivirus ; Methods ; Microcephaly ; Micronesia ; Primates ; Yellow Fever ; Zika Virus Infection* ; Zika Virus*

Zika virus (ZIKV) is a vector-borne flavivirus. It was initially identified in Uganda in 1947, and the first human infection was reported in Nigeria in 1953. Since 2015, ZIKV has been spreading rapidly in Brazil and the Americas. Given its general symptoms, ZIKV is considered to be a mild, febrile illness, although it is associated with severe neurologic complications. On February 1, 2016, the World Health Organization (WHO) declared a Public Health Emergency of International Concern (PHEIC). We conducted a review of the literature on the epidemiology and transmission, clinical manifestations, and diagnosis of ZIKV. Additionally, we introduce original literature on the current ZIKV outbreak in this review.
Americas ; Brazil ; Diagnosis ; Emergencies ; Epidemiology ; Flavivirus ; Humans ; Nigeria ; Public Health ; Uganda ; World Health Organization ; Zika Virus*

The Zika virus, a flavivirus related to dengue and Japanese encephalitis was discovered in the Zika forest in Uganda, 1947. Since Zika virus was first reported in Brazil in May 2015, infections have occurred in at least 40 countries, especially in the Americas. Zika virus infection usually is asymptomatic or causes mild illness, but may be related to severe clinical manifestations, particularly microcephaly and Guillain-Barré syndrome. Although the possibility of autochthonous Zika virus transmission in South Korea is low, the imported cases and Zika virus-transmitting mosquito should be adequately monitored and promptly managed. In addition, enhancing preparedness for Zika virus infection are needed.
Americas ; Brazil ; Communicable Diseases* ; Culicidae ; Dengue ; Encephalitis, Japanese ; Flavivirus ; Guillain-Barre Syndrome ; Korea ; Microcephaly ; Specialization* ; Trees ; Uganda