Chikungunya virus was isolated in Thailand, 2010

Chikungunya fever (CHIKF) is an acute febrile illness caused by a mosquito-borne alphavirus, chikungunya virus (CHIKV). This disease re-emerged in Kenya in 2004, and spread to the countries in and around the Indian Ocean. The re-emerging epidemics rapidly spread to regions like India and Southeast Asia, and it was subsequently identified in Europe in 2007, probably as a result of importation of chikungunya cases. On the one hand, chikungunya is one of the neglected diseases and has only attracted strong attention during large outbreaks. In 2008–2009, there was a major outbreak of chikungunya fever in Thailand, resulting in the highest number of infections in any country in the region. However, no update of CHIKV circulating in Thailand has been published since 2009. In this study, we examined the viral growth kinetics and sequences of the structural genes derived from CHIKV clinical isolates obtained from the serum specimens of CHIKF-suspected patients in Central Thailand in 2010. We identified the CHIKV harboring two mutations E1-A226V and E2-I211T, indicating that the East, Central, and South African lineage of CHIKV was continuously circulating as an indigenous population in Thailand. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11262-014-1105-5) contains supplementary material, which is available to authorized users

Border Malaria Associated with Multidrug Resistance on Thailand-Myanmar and Thailand-Cambodia Borders: Transmission Dynamic, Vulnerability, and Surveillance

This systematic review elaborates the concepts and impacts of border malaria, particularly on the emergence and spread of Plasmodium falciparum and Plasmodium vivax multidrug resistance (MDR) malaria on Thailand-Myanmar and Thailand-Cambodia borders. Border malaria encompasses any complex epidemiological settings of forest-related and forest fringe-related malaria, both regularly occurring in certain transmission areas and manifesting a trend of increased incidence in transmission prone areas along these borders, as the result of interconnections of human settlements and movement activities, cross-border population migrations, ecological changes, vector population dynamics, and multidrug resistance. For regional and global perspectives, this review analyzes and synthesizes the rationales pertaining to transmission dynamics and the vulnerabilities of border malaria that constrain surveillance and control of the world’s most MDR falciparum and vivax malaria on these chaotic borders

Helminth Infections in Cattle and Goats in Kanchanaburi, Thailand, with Focus on Strongyle Nematode Infections

Gastrointestinal helminths are major enteric parasites affecting the health of important livestock ruminants, such as cattle and goats. It is important to routinely survey these animals for helminth infections to allow effective management and control programs to be implemented. A cross-sectional helminth survey carried out in Kanchanaburi Province, Thailand, revealed the infection rate of gastrointestinal helminths in cattle (n = 157) and goats (n = 117) to be 35.7% and 88%, respectively, by microscopic fecal examination, and a 100% herd prevalence was observed in goats. Eggs of strongyle nematodes, Strongyloides spp., Trichuris spp., Capillaria spp., Paramphistomum spp., and Moniezia spp. were detected, with a relatively high rate of strongyle nematode infection in both cattle (28.7%) and goats (86.3%). Mixed infections were observed in 14.3% and 35.9% of egg-positive samples from cattle and goats, respectively. Risk factor analysis showed that dairy cattle were 5.1 times more likely to be infected with strongyles than meat cattle. In contrast, meat goats were 9.3 times more likely to be infected with strongyles than dairy goats. The inverse findings in cattle and goats are discussed. Female gender was associated with a higher risk of strongyle infection in goats. DNA sequencing and in-house semi-nested PCR with primers specific to a region in the internal transcribed spacer 2 (ITS2) were successfully used to identify strongyle genera in randomly selected egg-positive cattle (n = 24) and goat (n = 24) samples. Four strongyle genera, i.e., Cooperia spp., Haemonchus spp., Oesophagostomum spp., and Trichostrongylus spp. were identified by DNA sequencing. By semi-nested PCR, Cooperia spp. were detected as a major parasite of cattle (70.8%), whereas Haemonchus spp. were abundant in goats (100%). The majority of samples from cattle (58.3%) and goats (95.8%) were found to coinfect with at least two strongyle genera, suggesting that coinfection with multiple strongyle genera was more common than single infection in these animals

Detection of SARS-CoV-2 and Variants in Hospital Wastewater in a Developing Country

Wastewater-based epidemiology (WBE) is a beneficial tool for comprehensive health information on communities, especially during the COVID-19 pandemic. In developing countries, including Thailand, the application of WBE is limited. Few SARS-CoV-2 detections and variants have been monitored in wastewater in these countries. This is because of the time-consuming, low recovery of viruses in the concentration techniques and difficulties in finding the proper primers and amplification kits. Therefore, this study aimed to quantify SARS-CoV-2 RNA concentration using a commercial clinical kit. We identified the SARS-CoV-2 variants and estimated the detection costs in the wastewater samples. One hundred and fifty hospital wastewater samples were filtered with commercial ultrafiltration (UF) and then detected for the SARS-CoV-2 concentration using a Sansure Biotech SARS-CoV-2 kit. The recovery of the virus concentration technique in UF was studied using a surrogate (porcine epidemic diarrhea virus). The virus detection in wastewater was quantified by RT-qPCR. In addition, the mutation sites in the partial spike glycoprotein (S) gene of SARS-CoV-2 were verified using short nested RT-PCR. The results showed a high recovery of the commercial UF (80.53%), and 24.6% of hospital wastewater contained SARS-CoV-2. The detection of SARS-CoV-2 in wastewater cost USD 35.43 per sample. The virus variants revealed V70del, H69del, and V144del mutations in the partial S gene of SARS-CoV-2 in B.1.1.7 (SARS-CoV-2 Alpha variant), and T95I and G142D mutations in B.1.617.2 (Delta variant)

Detection of SARS-CoV-2 and Variants in Hospital Wastewater in a Developing Country

Wastewater-based epidemiology (WBE) is a beneficial tool for comprehensive health information on communities, especially during the COVID-19 pandemic. In developing countries, including Thailand, the application of WBE is limited. Few SARS-CoV-2 detections and variants have been monitored in wastewater in these countries. This is because of the time-consuming, low recovery of viruses in the concentration techniques and difficulties in finding the proper primers and amplification kits. Therefore, this study aimed to quantify SARS-CoV-2 RNA concentration using a commercial clinical kit. We identified the SARS-CoV-2 variants and estimated the detection costs in the wastewater samples. One hundred and fifty hospital wastewater samples were filtered with commercial ultrafiltration (UF) and then detected for the SARS-CoV-2 concentration using a Sansure Biotech SARS-CoV-2 kit. The recovery of the virus concentration technique in UF was studied using a surrogate (porcine epidemic diarrhea virus). The virus detection in wastewater was quantified by RT-qPCR. In addition, the mutation sites in the partial spike glycoprotein (S) gene of SARS-CoV-2 were verified using short nested RT-PCR. The results showed a high recovery of the commercial UF (80.53%), and 24.6% of hospital wastewater contained SARS-CoV-2. The detection of SARS-CoV-2 in wastewater cost USD 35.43 per sample. The virus variants revealed V70del, H69del, and V144del mutations in the partial S gene of SARS-CoV-2 in B.1.1.7 (SARS-CoV-2 Alpha variant), and T95I and G142D mutations in B.1.617.2 (Delta variant)

HIV and syphilis knowledge, perceptions, and practices among Myanmar migrant workers in Samut Sakhon Province, Thailand

Abstract Background Thailand has been one of the largest migration hubs in Southeast Asia for the past four decades and keeps attracting migrants from neighboring countries. Due to difficulties associated with their status, migration can place individuals at a heightened risk for sexually transmitted diseases. This study aimed to examine factors influencing HIV and syphilis preventive behaviors among Myanmar migrants in Samut Sakhon, Thailand. Methods A cross-sectional mixed-method study was conducted among Myanmar migrants aged 18 years and above in Samut Sakhon Province, Thailand. To fulfill this study's aims, four hundred seventy-three respondents completed a survey to provide quantitative data, and eight participants completed in-depth qualitative interviews. The factors associated with protective sexual behaviors were identified with multiple logistic regression analysis of the quantitative study data and thematic analysis of the qualitative data. Results The respondents showed good knowledge of HIV and syphilis (50.1%), but over half (55.6%) exhibited the negative perception of sexually transmitted disease prevention; about 81.4% of male respondents never used a condom when they had sexual intercourse in the past year. Based on multivariate analysis, income expenses-balance (adjusted odds ratio (AOR) = 2.379, 95% confidence interval (CI): 1.002–5.731, p = 0.049), number of sex partners (AOR = 3.044, 95% CI: 1.339–6.924, p = 0.008), and having sex with a prostitute (AOR = 6.085, 95% CI: 1.28–28.918, p = 0.023) were all statistically associated with unprotected sex. In the qualitative analysis, knowledge, understanding, beliefs; the influence of culture, community, and environment; and condom perceptions were also important factors. Conclusion Low use of condoms in sexual practice was identified, and the appropriate intervention or approach to improve the utilization of condoms in the community was provided

PREVALENCE OF INTESTINAL PARASITE AND RELATED FACTORS AMONG SCHOOL CHILDREN IN SUAN PHUENG SUBDISTRICT, RATCHABURI, THAILAND

Background: Intestinal parasitic infections are still regarded as the major public health problems in Thailand, especially in rural areas. The presence of intestinal parasites in school children is a wellaccepted indicator of poor personal hygiene and low economic standards. This study aimed to determine the prevalence of intestinal parasitic infections and its associated risk factors among primary school children (Grade 4 to 6) in Suan Phueng sub-district, Ratchaburi, Thailand, where is located atThai-Myanmar border areas. Methods: A cross-sectional study was conducted at three selected governmental primary schools. A total of 252 school children (130 boys, 51.6% and 122 girls, 48.4%) were recruited in this study. Intestinal parasites were detected from their stool samples by using formalin ethyl-acetate concentration technique. Socio-demographic status and personal hygiene were assessed by a validated structured questionnaire. Results: An overall prevalence of intestinal parasitic infection was 19%. Poly-parasitism was found in 4% of school children. The most common parasite was Entamoeba coli (6.4%) followed by Ascaris lumbricoides (4.5%), Endolimax nana cyst (4.0%), and Giadia lumbria (1.8%). Additionally, family income, drinking water sources from school and home, hand-washing habit after using toilet, anal cleansing after defecation, and parents’ education level were significantly associated with intestinal parasitic infections.  Conclusions: High prevalence of intestinal parasitic infections was found in primary school children at Suan Phueng sub-district, Ratchaburi, Thailand. Therefore, health promotion, modern health education, water sanitation, and hygiene (WASH) programs are crucial for prevention of intestinal parasitic infections in primary schools, particularly in Thai-Myanmar border areas. Reducing theprevalence of parasitic infections in school children may be of immense benefits on child growth, development, and educational  outcomes. &nbsp

Arbovirus Seroprevalence Study in Bangphae District, Ratchaburi Province, Thailand: Comparison between ELISA and a Multiplex Rapid Diagnostic Test (Chembio DPP^® ZCD IgG)

Arboviruses, particularly dengue virus (DENV), Zika virus (ZIKV), and Chikungunya virus (CHIKV), pose a growing threat to global public health. For disease burden estimation and disease control, seroprevalence studies are paramount. This study was performed to determine the prevalence of DENV, ZIKV, and CHIKV on healthy individuals aged from 1–55 years old in Bangphae district, Ratchaburi province, Thailand. Enzyme-linked immunosorbent assays (ELISAs) and rapid diagnostic tests (RDTs) were performed on archived samples from a dengue serological survey conducted from 2012–2015. All 2012 samples had been previously tested using an anti-DENV immunoglobulin (Ig)G ELISA, and 400 randomly selected samples stratified by age, sex, and residential area were assessed by an in-house anti-ZIKV IgG ELISA and a commercial anti-CHIKV IgG ELISA to determine virus-specific antibody levels. An RDT (Chembio DPP® ZCD IgM/IgG System) was also used to investigate the presence of antibodies against DENV, ZIKV, or CHIKV. The ELISA results indicate that the seroprevalences of DENV, ZIKV, and CHIKV were 84.3%, 58.0%, and 22.5%, respectively. The youngest age group had the lowest seroprevalence for all three arboviruses, and the seroprevalences for these viruses were progressively higher with increasing participant age. The DPP® IgG sensitivities, as compared with ELISAs, for DENV, ZIKV, and CHIKV were relatively low, only 43.92%, 25.86%, and 37.78%, respectively. The ELISA results indicate that 16% of the study population was seropositive for all three viruses. DENV had the highest seroprevalence. ZIKV and CHIKV were also circulating in Bangphae district, Ratchaburi province, Thailand. The DPP® ZCD rapid test is not sensitive enough for use in seroprevalence studies

Variation at position 350 in the Chikungunya virus 6K-E1 protein determines the sensitivity of detection in a rapid E1-antigen test

Abstract Chikungunya virus (CHIKV), a mosquito-borne pathogen, consists of three genotypes: East/Central/South African (ECSA), West African (WA), and Asian. Although a current rapid immunochromatographic (IC) test detecting CHIKV E1-antigen showed high sensitivity to ECSA-genotype viruses, it showed poor performance against the Asian-genotype virus that is spreading in the American continents. To understand the basis for the low performance of this IC test against Asian-genotype virus, we re-examined the anti-CHIKV monoclonal antibodies (mAbs) used in the assay for their interaction with E1-antigen of the three CHIKV genotypes. We found that the reactivity of one mAb for Asian-genotype virus was lower than that for ECSA virus. Comparison of E1 amino acid sequences revealed that the ECSA virus used to generate these mAbs possesses glutamic acid (E) at position 350, in contrast to WA and Asian, which possess aspartic acid (D) at this position. Site-directed mutagenesis confirmed that the mutation altered mAb reactivity, since E-to-D substitution at position 350 in ECSA reduced recognition by the mAb, while D-to-E substitution at this position in Asian and WA increased affinity for the mAb. Taken together, these results indicate that residue 350 of the CHIKV 6K-E1 is a key element affecting the performance of this IC assay