Complete Genome Sequence of a Zika Virus Strain Isolated from the Serum of an Infected Patient in Thailand in 2006.

The complete genome of Zika virus (ZIKV) strain CVD_06-274 was isolated from the serum of an infected patient in Thailand in 2006. Phylogenetic analysis showed that this strain belongs to the Asian lineage and also high titers in Vero cells (RCB 10-87). It has potential for development as an inactivated ZIKV vaccine.

Detection of chikungunya virus antigen by a novel rapid immunochromatographic test.

Chikungunya fever is a mosquito-borne disease of key public health importance in tropical and subtropical countries. Although severe joint pain is the most distinguishing feature of chikungunya fever, diagnosis remains difficult because the symptoms of chikungunya fever are shared by many pathogens, including dengue fever. The present study aimed to develop a new immunochromatographic diagnosis test for the detection of chikungunya virus antigen in serum.

Long-term persistence of Chikungunya virus neutralizing antibodies in human populations of North Eastern Thailand.

Background: Chikungunya virus (CHIKV) outbreak recurrences in Thailand are unpredictable and separated by unexplained and often long silent epidemiological periods that can last for several years. These silent periods could be explained in part by the fact that infection with one CHIKV strain confers lasting natural immunity, even against other CHIKV strains. In this study we evaluated the persistence of CHIKV-specific neutralizing antibodies in the population of Chumpae District, Khon Kaen Province, nineteen years after a CHIKV outbreak occurred in the same area in 1991.

Dengue, Japanese encephalitis and Chikungunya virus antibody prevalence among captive monkey (Macaca nemestrina) colonies of Northern Thailand.

The potential of macaque Macaca nemestrina leonina in Thailand to be infected by endemic arboviruses was assessed. The prevalence of antibodies of three arboviruses actively circulating in Thailand was determined by Plaque Reduction Neutralization assay procedures using samples from captive colonies in Northern Thailand. Out of 38 macaques, 9 (24%) presented reacting antibodies against dengue virus, 5 (13%) against Japanese encephalitis virus, and 4 (10%) against Chikungunya virus.

Generation and preclinical evaluation of a DENV-1/2 prM+E chimeric live attenuated vaccine candidate with enhanced prM cleavage.

In the absence of a vaccine or sustainable vector control measures, illnesses caused by dengue virus infection remain an important public health problem in many tropical countries. During the export of dengue virus particles, furin-mediated cleavage of the prM envelope protein is usually incomplete, thus generating a mixture of immature, partially mature and mature extracellular particles. Variations in the arrangement and conformation of the envelope proteins among these particles may be associated with their different roles in shaping the antibody response.

Elevated Japanese encephalitis virus activity monitored by domestic sentinel piglets in Thailand.

Twenty-nine domestic piglets from pig farms located in three provinces of Thailand between 2003 and 2004 were used as sentinel animals for Japanese encephalitis virus (JEV) circulation. Piglets were used as sentinel to underline, on one hand, the role of domestic pigs as JEV amplifying host and, on another hand, to point out the interest of using sentinel animals for Japanese encephalitis surveillance. JEV activity was demonstrated through i/ antibody detection using a specific ELISA test for the identification of Immunoglobulins of class M and G, ii/ virus isolation on cell culture, after experimental mosquito inoculation for virus amplification.

Change in Japanese encephalitis virus distribution, Thailand.

Japanese encephalitis virus (JEV) genotypes in Thailand were studied in pigs and mosquitoes collected near houses of confirmed human JEV cases in 2003-2005. Twelve JEV strains isolated belonged to genotype I, which shows a switch from genotype III incidence that started during the 1980s.

Detection of host virus-reactive antibodies in blood meals of naturally engorged mosquitoes.

Although serosurvey in human or animals is a useful and straightforward strategy routinely used for public health, it often faces different types of impediments: ethics, beliefs, limitation by animal owners, hazard of access to wild animals. To survey virus circulation, we applied the enzyme-linked immunosorbent assay (ELISA) technique to detect Dengue and Japanese encephalitis (JE) virus-reactive antibodies in blood meals collected from mosquitoes without regard to the potential of mosquito species to be a virus vector. ELISA was performed on mosquito colonies and wild specimens collected from farms and urban areas.

Potential association of dengue hemorrhagic fever incidence and remote senses land surface temperature, Thailand, 1998.

A pilot study was designed to analyze a potential association between dengue hemorrhagic fever (DHF) incidence and, temperature computed by satellite. DHF is a mosquito transmitted disease, and water vapor and humidity are known to have a positive effect on mosquito life by increasing survival time and shortening the development cycle. Among other available satellite data, Land Surface Temperature (LST) was chosen as an indicator that combined radiated earth temperature and atmospheric water vapor concentration.

Structure-activity relationships of dengue antiviral polycyclic quinones.

The virucidal and antiviral photoactivities of three compounds, hypericin, tetrabromohypericin and gymnochrome B, were evaluated against dengue viruses. All the three products were active, and both the virucidal and antiviral activities were enhanced by light. Gymnochrome B was more potent than hypericin and tetrabromohypericin.

First isolation of Japanese encephalitis from Culex quinquefasciatus in Thailand.

Isolation of Japanese encephalitis (JE) virus using C6/36 cell and immunofluorescence virus antigen detection techniques was attempted from female mosquitoes collected with CDC gravid traps in Samut Songkhram Province in the central region and in Phuket Province in southern Thailand, in 2003. One thousand and eighty female mosquitoes including 6 species of the Culicidae family (Culex quinquefasciatus, Cx. gelidus, Cx.

Hantavirus infection in Thailand: first clinical case report.

This study involved 115 cases of fever of unknown origin (FUO) patients who were admitted to the Department of Medicine, Siriraj Hospital from May 1999 to November 2000. Among the patient sera screened by ELISA for IgG Hantavirus, five were positive for IgG Hantavirus-reacting antibodies and eight tested positive for IgM Hantavirus-reacting antibodies. One serum had both IgG and IgM antibodies.

Hantavirus infection in Thailand: first clinical case report.

This study involved 115 cases of Fever of Unknown Origin (FUO) in patients who were admitted to the Department of Medicine, Siriraj Hospital from May 1999 to November 2000. Among the patient sera screened by ELISA for IgG Hantavirus, five were positive for IgG Hantavirus-reacting antibodies and eight tested positive for IgM Hantavirus-reacting antibodies. One serum had both IgG and IgM antibodies.

Seroepidemiological survey among schoolchildren during the 2000-2001 dengue outbreak of Ratchaburi Province, Thailand.

From August 2000 to 2001, a dengue outbreak occurred in Mueang district, Ratchaburi Province, Thailand. About 800 cases of dengue infection were reported, and among them, 49.5% were clinically diagnosed as dengue hemorrhagic fever according to the WHO criteria.

Geographic dynamics of viral encephalitis in Thailand.

Viral encephalitis (VE) continues to be a major disease in Asia, causing serious illness which may result in death or have neurological sequelae. This study involves an ecological analysis of the climatic, geographic and seasonal patterns of clinically reported VE in Thailand from 1993 to 1998 to investigate regional and seasonal differences in disease incidence. Three thousand eight hundred and twenty nine cases of VE were clinically diagnosed nationwide during the study period by the Thai Ministry of Public Health.

Hantaan virus antibody prevalence in rodent populations of several provinces of northeastern Thailand.

We conducted a serological survey of 632 rodents from the northeast region of Thailand in order to assess the presence of Hantaan-like viruses that may be a risk to the human population. Rodents were collected from rice fields, houses and domestic gardens in five northeastern provinces and tested for IgG reacting sera to Hantaan antigen using enzyme-linked immunoassays. The overall prevalence of Hantavirus infection in rodents was 2.