In light of global climate change, the seasonal and geographical distribution of vector species, especially mosquitoes, chigger mites, and ticks, are of great importance for human beings residing in rural and urban environments. A total of 12 species belonging to 4 genera have been identified as vector mosquitoes in the Republic of Korea. The most common of the 56 mosquito species in this country from 2013 through 2015 was found to be a malaria vector, Anopheles sinensis s.l. (species ratio [SR] 52%); followed by a potential vector of West Nile virus, Aedes vexans nipponii (SR 38%); a Japanese encephalitis vector, Culex tritaeniorhynchus (SR 6%); a West Nile virus vector, Culex pipiens (SR 3%); and a dengue and Zika virus vector, Ae. albopictus (SR 0.3%). Of the scrub typhus vectors, Leptotrombidium scutellare is the predominant chigger mite in Gyongnam province and Jeju island, whereas L. pallidum is the predominant species in other areas of Korea. Ticks were found to be prevalent in most environmental conditions, and high levels of their activity were consistently observed from May to September. Haemaphysalis species of ticks were mostly collected in grasslands, whereas Ixodes species were frequently found in coniferous forests. Haemaphysalis longicornis, known as the main vector of severe fever with thrombocytopenia syndrome, was the predominant species and was widely distributed throughout the country.
Aedes ; Anopheles ; Climate Change ; Communicable Diseases* ; Coniferophyta ; Culex ; Culicidae ; Dengue ; Disease Vectors* ; Encephalitis, Japanese ; Fever ; Forests ; Globus Pallidus ; Grassland ; Humans ; Ixodes ; Korea* ; Malaria ; Mites ; Republic of Korea ; Scrub Typhus ; Seasons ; Thrombocytopenia ; Ticks ; Trombiculidae ; West Nile virus ; Zika Virus

West Nile virus (WNV) is a mosquito-borne zoonotic pathogen that has spread throughout Europe and the United States. Recently, WNV spread to East and Southeast Asia, and great efforts have been made in South Korea to prevent the spread of WNV from neighboring countries. In this study, we diagnosed the first case of WNV in pigeons (Columba livia domestica) residing in cities using a competitive enzyme-linked immunosorbent assay and confirmed it with nested reverse transcription polymerase chain reaction analysis and sequencing. This is the first report to provide convincing evidence that WNV is present within South Korea.
Asia, Southeastern ; Columbidae* ; Enzyme-Linked Immunosorbent Assay ; Europe ; Korea* ; Polymerase Chain Reaction ; Reverse Transcription ; United States ; West Nile virus*

Recently, the emergency of Middle East Respiratory Syndrome in Korea raised public concern regarding emerging infectious disease (EID) and affected the strategy for blood safety. Although some cases of EID such as West Nile virus in the United States and hepatitis E virus in Japan emerged in a restricted area, the emergence can rapidly affect the situation in other countries in a globalized society with advancements in transportation and international exchange. Because the risk of transfusion-mediated infection may occur by the agent of EID which can be transmitted through blood, the strategy for safety must be considered for agents that were not tested in the stage of blood donor screening. We reviewed the characteristics of transfusion-transmissible EIDs raising concerns worldwide and the strategies which had been adopted.
Blood Donors ; Blood Safety ; Communicable Diseases, Emerging* ; Emergencies ; Hepatitis E virus ; Humans ; Japan ; Korea ; Mass Screening ; Middle East ; Transportation ; United States ; West Nile virus

West Nile encephalitis was first identified in 1937, but until now, it was never diagnosed in Korea. A 58-yr-old Korean man was admitted with headache and cognitive dysfunction. The patient had been on a business trip in Guinea. Cerebrospinal fluid (CSF) showed pleocytosis. The patient complained of both leg weakness,and arachnoiditis and myelitis were observed on lumbar magnetic resonance imaging (MRI). A specific neutralizing antibody for West Nile virus was positive in serum. After a treatment with interferon-alpha 3mu, follow up CSF findings recovered completely after 3 months later. The first case of West Nile encephalitis in Korea was imported from Guinea, and was cured successfully.
Antibodies, Viral/*blood ; Headache/complications ; Humans ; Interferon-alpha/*therapeutic use ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Republic of Korea ; West Nile Fever/*diagnosis/*drug therapy ; West Nile virus/immunology

West Nile encephalitis was first identified in 1937, but until now, it was never diagnosed in Korea. A 58-yr-old Korean man was admitted with headache and cognitive dysfunction. The patient had been on a business trip in Guinea. Cerebrospinal fluid (CSF) showed pleocytosis. The patient complained of both leg weakness,and arachnoiditis and myelitis were observed on lumbar magnetic resonance imaging (MRI). A specific neutralizing antibody for West Nile virus was positive in serum. After a treatment with interferon-alpha 3mu, follow up CSF findings recovered completely after 3 months later. The first case of West Nile encephalitis in Korea was imported from Guinea, and was cured successfully.
Antibodies, Viral/*blood ; Headache/complications ; Humans ; Interferon-alpha/*therapeutic use ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Republic of Korea ; West Nile Fever/*diagnosis/*drug therapy ; West Nile virus/immunology

West Nile virus (WNV) is the most widespread arbovirus in the world. It can cause serious or fatal central nervous system (CNS) infection. We present a case of 58-year-old man who developed neuropsychologic and psychiatric impairment such as cognitive impairment, depressive symptoms, health concerns and thought disorder after West Nile virus encephalitis. This is the first imported case of West Nile virus infection in Korean.
Arboviruses ; Central Nervous System ; Depression ; Encephalitis* ; Humans ; Middle Aged ; Neuropsychological Tests ; West Nile virus*

In view of that there is no report of west Nile virus infection cases in our country, evaluation the self-prepared anti-WNV-IgG diagnostic ELISA kit should be employed with the establishment of the serum sample panel collected from the entry personnel. All individuals of entry personnel were traveled from epidemic area of infectious west Nile disease. In our study, the serum samples were both detected by self-prepared anti-WNV-IgG diagnostic ELISA kit and the FDA certified kits ,which are FOCUS West Nile Virus IgG Dxselect and Panbio Dengue IgG Capture ELISA kits. The self-prepared kit and FDA certified kits were compared and assessed simultaneously. Furthermore, the specificity, repeatability and stability of the kits were also evaluated. The results indicated that no significant difference of detective rates (35. 6% for self-prepared kit vs. 32.5% for FOCUS kit, χ2 = 3. 05, P > 0.05) and good consistency (Kappa = 0.8372) between the self-prepared kit and FDA certified kits. Also, the positive coincidence rate, the negative coincidence rate and the total coincidence rate were calculated as 91.18%, 95.34% and 92.66%, respectively. The laboratory self-developed kit presented similar quality as the counterpart kits with FDA certificate. The development of our self-prepared anti-WNV-IgG diagnostic ELISA kit will provide technical support for the prevention and control of west Nile virus entry.
Endemic Diseases ; Enzyme-Linked Immunosorbent Assay ; Humans ; Immunoglobulin G ; blood ; Reagent Kits, Diagnostic ; West Nile Fever ; epidemiology ; West Nile virus ; immunology

Understanding mechanisms by which genetic variants predispose to complications of infectious diseases can lead to important benefits including the development of biomarkers to prioritize vaccination or prophylactic therapy. Family studies, candidate genes in animal models, and the absence of well-defined risks where the complications are rare all can point to genetic predisposition. The most common approach to assessing genetic risk is to conduct an association study, which is a case control study using either a candidate gene approach or a genome wide approach. Although candidate gene variants may focus on potentially causal variants, because other variants across the genome are not tested these studies frequently cannot be replicated. Genome wide association studies need a sizable sample and usually do not identify causal variants but variants which may be in linkage disequilibrium to the actual causal variant. There are many pitfalls that can lead to bias in such studies, including misclassification of cases and controls, use of improper phenotypes, and genotyping errors. These studies have been limited to common genes and rare variants may not be detected. As the use of next generation sequencing becomes more common, it can be anticipated that more variants will be confirmed. The purpose of this review article is to address the issue of genomics in infectious diseases with an emphasis on the host. Although there are a plentitude of studies that focus on the molecular characteristics of pathogens, there are far fewer studies that address the role of human genetics in the predisposition to infection or more commonly its complications. This paper will review both the approaches used to study host genetics in humans and the pitfalls associated with some of these methods. The focus will be on human disease and therefore discussion of the use of animal models will be limited to those where there are genes that have been replicated in humans. The paper will focus on common genetic variants that account for complex traits such as infectious diseases using examples from flaviviruses.
Bias (Epidemiology) ; Biomarkers ; Case-Control Studies ; Communicable Diseases ; Encephalitis ; Flavivirus ; Genetic Predisposition to Disease ; Genetics, Medical ; Genome ; Genome-Wide Association Study ; Genomics ; Humans ; Linkage Disequilibrium ; Models, Animal ; Phenotype ; Vaccination ; West Nile virus

OBJECTIVETo prepare a monoclonal antibody (mAb) against the fusion protein preM/EIII of West Nile virus (WNV) for clinical detection of WNV.

METHODSSp2/0 cells were fused with the spleen cells of BALB/c mice immunized with the recombinant fusion protein preM/EIII expressed in E. coil to obtain the hybridoma cell line that secreted preM/EIII mAb. The hybridoma cells were injected into the peritoneal cavity of BALB/c mice and the ascites was collected and purified. The specificity and titer of the obtained mAb were determined using ELISA and Western blotting.

RESULTSOne hybridoma cell line secreting preM/EIII mAb, named ME1, was obtained. The titer of the purified mAb was 10(-6). Identified as a mAb of the Ig subclass IgG1, ME1 was capable of specific reactions with preM/EIII protein and WNV without cross-reactions with other viruses such as JEV, SLEV, YFV and DENV. The accuracy of clinical testing of MNV with ME1 was 97.78%.

CONCLUSIONThe mAb against preM/EIII obtained have a high specificity and accuracy in clinical testing of MNV and can be used in clinical diagnosis of MNV infection.

Animals ; Antibodies, Monoclonal ; immunology ; Blotting, Western ; Cross Reactions ; Hybridomas ; immunology ; Mice ; Mice, Inbred BALB C ; Viral Fusion Proteins ; immunology ; West Nile virus ; immunology

Acute viral encephalitis caused by neurotrophic viruses, such as mosquito-borne flaviviruses, is an emerging and re-emerging disease that represents an immense global health problem. Considerable progression has been made in understanding the pathogenesis of acute viral encephalitis, but the immune-pathological processes occurring during the progression of encephalitis and the roles played by various molecules and cellular components of the innate and adaptive systems still remain undefined. Recent findings reveal the significant contribution of Toll-like receptors (TLRs) and regulatory CD4+ T cells in the outcomes of infectious diseases caused by neurotrophic viruses. In this review, we discuss the ample evidence focused on the roles of TLRs and CD4+ helper T cell subsets on the progression of acute viral encephalitis. Finally, we draw attention to the importance of these molecules and cellular components in defining the pathogenesis of acute viral encephalitis, thereby providing new therapeutic avenues for this disease.
Communicable Diseases ; Dengue Virus ; Encephalitis ; Encephalitis Virus, Japanese ; Encephalitis, Viral ; Flavivirus ; T-Lymphocyte Subsets ; T-Lymphocytes ; Toll-Like Receptors ; West Nile virus