Prevalence, awareness, and control of hypertension and associated factors among Royal Thai Army personnel in Thailand from 2017 to 2021.

Hypertension (HTN) is a potential risk factor for cardiovascular diseases. We aimed to determine the prevalence, awareness, and control of HTN among RTA personnel in Thailand. We conducted a series of cross-sectional studies from 2017 to 2021. HTN was defined by systolic blood pressure (BP) ≥ 140 mmHg or a diastolic BP ≥ 90 mmHg from a physical health examination, a history of HTN diagnosed by medical personnel, or taking antihypertensive medication. A total of 504,484 participants were included in the present study. The overall HTN prevalence was 29.4%. The prevalence of HTN among males was 30.5%, while it was 17.1% among females. Of the RTA personnel with HTN, 35.9% were aware of their condition. The overall control of HTN among RTA personnel with HTN was 15.8% in 2017 and 17.6% in 2021. Behavioral factors associated with HTN were current smoking, alcohol consumption, and sedentary behavior. A higher BMI was associated with higher HTN prevalence and HTN awareness but less likely to have controllable HTN. Male participants, younger individuals, current alcohol use, and sedentary behavior were associated with a lower prevalence of HTN awareness and controlled HTN. Current tobacco use was also associated with a lower prevalence of HTN awareness.

Rising trends in the predicted 10-year risk of cardiovascular diseases among Royal Thai Army personnel from 2017 to 2021.

Deaths from cardiovascular diseases (CVD) are becoming a growing threat to global health, including in Thailand. The aim of the present study was to identify the recent trends in the predicted 10-year risk of CVD among Royal Thai Army (RTA) personnel from 2017 to 2021. The predicted 10-year risk for CVD was calculated through the use of the 2008 updated version of the risk algorithm derived from the Framingham Heart Study data. The current study included 346,355 active-duty RTA personnel aged 30-60 years. The age- and sex-adjusted mean of the predicted 10-year risk for CVD significantly increased from 10.8% (95% CI: 10.8-10.9%) in 2017 to 11.7% (95% CI: 11.6-11.7%) in 2021 (p for trend < 0.001). The overall age- and sex-adjusted prevalence of intermediate-to-high predicted 10-year risk for CVD remarkably surged from 24.9% (95% CI: 24.4-25.4%) in 2017 to 29.5% (95% CI: 29.0-30.0%) in 2021 (p for trend < 0.001). The modifiable risk factors for CVD, including high systolic blood pressure, high body mass index, and current smoking in this population, should be alleviated to mitigate the risk for CVD in the future.

Dual role of azo compounds in inhibiting Plasmodium falciparum adenosine deaminase and hemozoin biocrystallization.

Protein-ligand (GOLD) docking of the NCI compounds into the ligand-binding site of Plasmodium falciparum adenosine deaminase (PfADA) identified three most active azo compounds containing 4-[(4-hydroxy-2-oxo-1H-quinolin-3-yl) moiety. These compounds showed IC50 of 3.7-15.4 µM against PfADA, as well as inhibited the growth of P. falciparum strains 3D7 (chloroquine (CQ)-sensitive) and K1 (CQ-resistant) with IC50 of 1.8-3.1 and 1.7-3.6 µM, respectively. The identified compounds have structures similar to the backbone structure (4-N-(7-chloroquinolin-4-yl)) in CQ, and NSC45545 could mimic CQ by inhibiting the bioformation of hemozoin in parasitic food vacuole. The amount of in situ hemozoin in the ring-stage parasite was determined using a combination of synchrotron transmission Fourier transform infrared microspectroscopy and Principal Component Analysis. Stretching of the C-O bond of hemozoin propionate group measured at 1220-1210 cm-1 in untreated intraerythrocytic P. falciparum strains 3D7 and K1 was disappeared following treatment with 1.85 and 1.74 µM NSC45545, similar to those treated with 0.02 and 0.13 µM CQ, respectively. These findings indicate a novel dual function of 4-[(4-hydroxy-2-oxo-1H-quinolin-3-yl) azo compounds in inhibiting both PfADA and in situ hemozoin biocrystallization. These lead compounds hold promise for further development of new antimalarial therapeutics that could delay the onset of parasitic drug resistance.

Prevalence of hypertriglyceridemia among Royal Thai Army personnel and its related cardiometabolic risk factors, from 2017 to 2021.

BACKGROUND: Hypertriglyceridemia is a common health problem independently associated with an increased risk of atherosclerosis cardiovascular diseases (ASCVD), including ischemic heart disease and stroke. This study aims to determine the prevalence of hypertriglyceridemia among Royal Thai Army (RTA) personnel and its behavioral and cardiometabolic risk factors using the RTA personnel database of the physical health examination from 2017 to 2021. METHODS: A serial cross-sectional study was conducted from 2017 to 2021. A total of 257,683 active-duty RTA personnel aged 35-60 years were included in the study. We defined hypertriglyceridemia as fasting triglyceride ≥150 mg/dL. Moreover, we performed a multivariable logistic regression analysis to investigate behavioral and cardiometabolic risk factors for the prevalence of hypertriglyceridemia. The magnitude of the association was presented as an adjusted odds ratio (AOR) with a 95% confidence interval (CI). RESULTS: The hypertriglyceridemia prevalence among RTA personnel was 43.4% (95% CI: 42.9-43.8%) in 2017. It then continuously decreased to 40.3% (95% CI: 39.9-40.7%) in 2020 and slightly rose to 41.0% (95% CI: 40.6-41.4%) in 2021 (p for trend < 0.001). The prevalence of hypertriglyceridemia was higher for males than females (AOR 2.15; 95% CI: 2.07-2.23); RTA personnel aged 40-44 years compared with those aged 35-39 years (AOR 1.05; 95% CI: 1.02-1.08); and RTA personnel residing in the northeast (AOR; 1.15 95% CI: 1.11-1.18) and the north (AOR 1.05; 95% CI: 1.02-1.08) compared with those residing in Bangkok. The independent behavioral factors associated with hypertriglyceridemia included alcohol consumption, smoking, and sedentary behavior. Moreover, cardiometabolic risk factors, including higher body mass index, high fasting plasma glucose (≥ 100 mg/dL), high blood pressure (≥ 140/90 mmHg), and hypercholesterolemia (≥ 200 mg/dL), were significantly related to hypertriglyceridemia. CONCLUSION: Our data demonstrated that hypertriglyceridemia is a frequent health issue, especially among males, participants aged 40-44 years, and RTA personnel residing in the northeast and the north. The prevalence of hypertriglyceridemia in this population was greatly influenced by alcohol consumption, cigarette smoking, and sedentary behavior. Both behavioral and cardiometabolic risk factors are potential targets for intervention to enhance the primary prevention of sequelae of hypertriglyceridemia, including ASCVD.

Model development to improve primary care services using an innovative network of homecare providers (WinCare) to promote blood pressure control among elderly patients with noncommunicable diseases in Thailand: a prospective cohort study.

BACKGROUND: Thailand has been rapidly approaching an aging society in conjunction with an increase in noncommunicable diseases (NCDs) especially hypertension and type 2 diabetes. Demographics and epidemiologic transitions create several challenges to the health system in Thailand in the case of long term care policies, in particular, modality to support home care. Therefore, the model development to facilitate primary care home services for elderly patients with NCDs using an innovative network of homecare providers (WinCare) was established. The study aimed to evaluate the effectiveness of WinCare to improve blood pressure (BP) control as well as health-related quality of life (HRQoL) among elderly patients with NCDs. METHODS: A prospective cohort study was conducted between July 2019 and January 2020 in a suburban area, Chiang Mai Province, Thailand. The intervention included WinCare providers and WinCare application. WinCare provided check-in visits to measure subjects blood pressure and body weight (once weekly), played the roles of other home caregivers for the patients and recorded measurements and activities in the WinCare app for 6 months. The primary outcomes of the study were differences in systolic BP, diastolic BP, and controlled BP (systolic BP < 140 mmHg and diastolic BP < 90 mmHg) at 6-month follow-up between the intervention and control groups, adjusting for age, sex, marital status, comorbidities, alcohol consumption and smoking status. RESULTS: A total of 104 subjects were initially recruited. Of the remaining 98 individuals, 52 were allocated to the intervention group and 46 to the control group. After adjusting baseline characteristics, no association existed between decreasing average systolic BP and intervention groups. However, diastolic BP of patients in the intervention group was on average 5.19 mmHg (95% CI -8.22, - 2.17) lower compared than that of the control group at 6-month follow-up. Furthermore, compared with patients in the control group, those in the intervention group were more likely to control BP, (AOR 3.03; 95% CI 1.02-9.01) at 6-month follow-up. CONCLUSION: Establishing a network of homecare providers (WinCare) was feasible in a community setting. This innovative network was able to facilitate elderly patients with NCDs residing in a suburban community to improve BP control at least at 6-month follow-up. TRIAL REGISTRATION: Trial identification number was TCTR20200312007 , First submitted date:12/03/2020.

Efficiency of the Stool-PCR Test Targeting NADH Dehydrogenase (Nad) Subunits for Detection of Opisthorchis viverrini Eggs.

Opisthorchis viverrini infection is the major parasitic infection problem in Southeast Asian countries, and long-term infection will lead to cholangiocarcinoma (CCA), the bile duct cancer. The early diagnosis of O. viverrini infection may interrupt the progression of the opisthorchiasis and other related illnesses, especially CCA. The current diagnostic procedure is stool examination by microscope-based methods such as direct smear and concentration techniques but it is limited by low parasite egg numbers. The molecular diagnosis prompts the chance to evaluate the light infection with low number of parasite eggs but is currently inconvenient for routine use due to special equipment requirement and unstable sensitivities. Our present study aims to establish the efficiency of OvNad subunits, the mitochondrial gene, for introducing as a potential diagnostic target by conventional PCR, the cheapest and easiest molecular procedure. A total of 166 stool samples were investigated microscopically by the PBS-ethyl acetate concentration technique (PECT); 75 samples were O. viverrini positive with 28 samples that were positive with single parasite (hookworm, A. lumbricoides, S. stercoralis, Taenia spp., and T. trichiura), 11 samples were with mixed infection, and 52 samples were without parasite detection. The detection limits of OvNad subunits were evaluated in artificially spiked samples containing 0, 1, 5, 10, 20, 50, and 100 Ov-eggs. The result suggested that the best detection efficacy was of OvNad5 that had exact detection limits at only 5 eggs. In the PCR amplification of OvNad subunits, there exist 100% specificities with varied sensitivities from 64%, 88%, 80%, and 100% of OvNad1, OvNad2, OvNad4, and OvNad5, respectively. OvNad subunits were amplified specifically without cross reactivity with the other collected parasites. Our study established that OvNad subunits, especially OvNad5, are the potent candidates for PCR amplification of stool containing Ov-eggs with high confidential sensitivity, specificity, PPV, and NPV even in the light infection that would be a benefit for developing as a routine diagnosis of O. viverrini infection.

Prevalence of and factors associated with stroke in hypertensive patients in Thailand from 2014 to 2018: A nationwide cross-sectional study.

Stroke is a significant cause of death and disability. In Thailand, it imposes a major health burden, and the prevalence of stroke is increasing, particularly in patients with hypertension (HT), diabetes mellitus (DM), and dyslipidemia (DLP). We aimed to determine the trends in the prevalence of stroke and the associated factors among Thai patients with HT. Nationwide cross-sectional studies were conducted annually in 2014, 2015 and 2018 based on data obtained from the Thailand DM/HT study. Nationally, representative patients with HT in Thailand were sampled with stratified one-stage cluster sampling. A total of 104,028 participants were included in this study. The prevalence of stroke remained constant, with prevalence rates of 4.0%, 3.8%, and 3.9% in 2014, 2015 and 2018, respectively (p for trend = 0.221). Our findings suggested that the management of stroke patients who are covered by the universal coverage scheme should be evaluated. Effective interventions, including promoting smoking cessation, attenuating cholesterol levels, and controlling blood pressure should be provided to hypertensive patients to prevent ischemic stroke. Young adults with HT should be more concerned about the possibility of stroke. The use of prophylactic low-dose aspirin should be carefully monitored to prevent hemorrhagic stroke.

Improvement of a PCR-based method for the detection of Opisthorchis viverrini eggs in human stool samples by targeting internal transcribed spacer-2 (ITS-2), cytochrome oxidase subunit 1 (cox1), and cytochrome b (cyb).

Opisthorchis viverrini infection causes various complications in patients, ranging from asymptomatic to severe chronic disease including cholangiocarcinoma (CCA). O. viverrini is endemic in Southeast Asia and acting as a risk for CCA. Early diagnosis of O. viverrini infection can reduce the number of CCA cases. The routine diagnosis for opisthorchiasis is direct wet smear, sometimes coupled with concentration techniques, which has limitations when investigating light infection or if done by laboratorians with lack of experiences. PCR-based methods have been established for the detection of O. viverrini egg DNA from stool samples, but have never fully succeeded for light infections when compared to wet smear concentration techniques. This study aims to improve the PCR-based method for detection of O. viverrini eggs in stool samples by targeting the genes ITS-2, cox1, and cyb. The results reveal higher sensitivity than conventional concentration techniques, with all newly designed primers. ITS-2 has an overall sensitivity of 76.9% with 66.7% in the samples with < 50 EPG, while cox1 has shown 96.2% overall sensitivity and 94.1% in the same EPG intervals. Interestingly, the new pointing target, cyb, has shown 100% sensitivity in all egg intervals in this study, particularly for light infections (EPG less than 100). No cross-reactivity was found in Taenia spp., Trichuris trichiura, Ascaris lumbricoides, Capillaria philippinensis, and hookworm. The procedure is convenient, with shorter steps compared to previous reports, and it appears appropriate for use in the diagnosis of light infection with O. viverrini. These three genes are good candidates for use in PCR-based detection of the parasite eggs. Further testing with a larger cluster of samples is however necessary.

Development of loop-mediated isothermal amplification (LAMP) assay using SYBR safe and gold-nanoparticle probe for detection of Leishmania in HIV patients.

Asymptomatic leishmaniasis cases have continuously increased, especially among patients with HIV who are at risk to develop further symptoms of cutaneous and visceral leishmaniasis. Thus, early diagnosis using a simple, sensitive and reliable diagnostic assay is important because populations at risk mostly reside in rural communities where laboratory equipment is limited. In this study, the highly sensitive and selective determination of Leishmania infection in asymptomatic HIV patients was achieved using dual indicators (SYBR safe and gold-nanoparticle probe; AuNP-probe) in one-step LAMP method based on basic instruments. The assay can be simply evaluated under the naked eye due to clear interpretation of fluorescent emission of LAMP-SYBR safe dye-complex and colorimetric precipitate of specific AuNP-probes. The sensitivities and specificities of fluorescent SYBR safe dye and AuNP-probe indicators were equal, which were as high as 94.1 and 97.1%, respectively. Additionally, detection limits were 102 parasites/mL (0.0147 ng/µL), ten times more sensitivity than other related studies. To empower leishmaniasis surveillance, this inexpensive one-step SYBR safe and AuNP-LAMP assay is reliably fast and simple for field diagnostics to point-of-care settings, which can be set up in all levels of health care facilities including resource limited areas, especially in low to middle income countries.

Prevalence and Risk Factors of Chronic Obstructive Pulmonary Disease Among Agriculturists in a Rural Community, Central Thailand.

Purpose: The present study aimed to determine the prevalence and risk factors of chronic obstructive pulmonary disease (COPD) among agriculturists in a remote rural community in central Thailand. Methods: A cross-sectional study was conducted in January 2020. Face-to-face interviews were conducted using standardized questionnaires to determine demographic characteristics and risk behaviors. COPD was defined by the spirometric criterion for airflow limitation constituting a postbronchodilator fixed ratio of FEV1/FVC <0.70 following the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines 2019. Multivariable logistic regression analysis was used to determine the risk factors for COPD, and the magnitude of association was presented as adjusted odds ratio (AOR) with 95% confidence interval (95% CI). Results: A total of 546 agriculturists were enrolled in the study. The overall prevalence of COPD was 5.5% (95% CI: 3.6-7.4). The prevalence of COPD among males was 8.0% (95% CI: 4.7-11.3), and 3.2% (95% CI: 1.1-5.2) among females. The risk factors of COPD included age ≥60 years old (AOR 2.7, 95% CI: 1.1-7.0), higher intensity of smoking (AOR 1.1, 95% CI: 1.0-1.1), swine farm worker (AOR 4.1, 95% CI: 1.7-10.3), cattle farm worker (AOR 3.3, 95% CI: 1.4-8.2) and home cooking (AOR 2.7, 95% CI: 0.8-9.7). Conclusion: Our data emphasized that COPD was one of the significant health problems among agriculturists in a rural community. Agricultural jobs such as animal farmers and behavioral factors such as smoking were associated with COPD. Effective public health interventions, especially, modifying risk behaviors, should be promoted in remote rural areas to prevent the disease and reduce its morbidity and mortality.

Genetic Differentiation of Opisthorchis-Like Eggs in Northern Thailand Using Stool Specimens Under National Strategic Plan to Control Liver Fluke Infection and Cholangiocarcinoma.

Liver fluke infection caused by Opisthorchis viverrini is recognized as a potential risk factor for cholangiocarcinoma (CCA). The National Strategic Plan to Control Liver Fluke Infection and Cholangiocarcinoma has implemented microscopic-based stool examination screening. However, eggs of O. viverrini and minute intestinal flukes (MIFs) are nearly morphologically similar and could result in inaccurate O. viverrini diagnosis. Stool specimens were collected from eight districts of Chiang Mai Province in northern Thailand. Opisthorchis-like eggs were identified with the Kato-Katz technique and differentiated for O. viverrini and MIFs using molecular study by PCR and PCR-restriction fragment length polymorphism targeting the internal transcribed spacer 2 (ITS2) gene. Prevalence of Opisthorchis-like eggs was 5.9% from a total of 9,570 specimens. From PCR assays, all liver flukes were O. viverrini and all MIFs were Haplorchis taichui. The distribution of species was H. taichui (38.2%), O. viverrini (10.5%), coinfection of H. taichui and O. viverrini (37.2%), and 14.1% were negative from PCR. Totally, H. taichui was found in 75.4% of infections from Opisthorchis-like specimens. ITS2 nucleotide sequencing analysis showed a single variant of O. viverrini with no variation and two variants of H. taichui. This study first revealed the genetic background of Opisthorchis-like eggs in northern Thailand. Minute intestinal flukes are occasionally misdiagnosed as O. viverrini leading to misinterpretation and overestimation of the burden of O. viverrini infection. Molecular diagnosis such as PCR could effectively discriminate species of Opisthorchis-like eggs and help shape the robustness of epidemiological data to control liver fluke infection and raise awareness of other risk factors for CCA.

Trends, prevalence and associated factors of obesity among adults in a rural community in Thailand: serial cross-sectional surveys, 2012 and 2018.

BACKGROUND: Obesity is one principle risk factor increasing the risk of noncommunicable diseases including diabetes, hypertension and atherosclerosis. In Thailand, a 2014 study reported obesity (BMI ≥25 kg/m2) in a Thai population aged ≥15 years was 37.5, 32.9 and 41.8% overall and among males and females, respectively. The study aimed to determine trends in the prevalence of obesity among adults residing in a Thai rural community between 2012 and 2018 and investigate the associations between obesity and behavioral factors. METHODS: Serial cross-sectional studies were conducted in 2012 and 2018 among adults in Na-Ngam rural community. In 2012 and 2018, all 635 and 627 individuals, respectively, were interviewed using structured questionnaires related to demographics, risk behaviors, comorbidities and arthrometric measurement. Spot urine was collected by participants and obesity was defined as BMI ≥25 kg/m2. The risk factors for obesity were analyzed in the 2018 survey. RESULTS: A total of 1262 adults in Na-Ngam rural community were included in the study. The prevalence of obesity was 33.9% in 2012 and 44.8% in 2018 (P < 0.001). The average BMI increased from 23.9 ± 4.2 kg/m2 in 2012 to 25.0 ± 4.52 kg/m2 in 2018 (P < 0.001). Obesity was associated with higher age (AOR 0.99; 95%CI 0.97-0.99), smoking (AOR 0.52; 95%CI 0.28-0.94), instant coffee-mix consumption > 1 cup/week (AOR 1.44; 95%CI 1.02-2.04), higher number of chronic diseases (≥1 disease AOR 1.82; 95%CI 1.01-2.68, > 2 diseases AOR 2.15; 95%CI 1.32-3.50), and higher spot urine sodium level (AOR 1.002; 95%CI 0.99-1.01). CONCLUSION: Our data emphasized that obesity constituted a serious problem among adults residing in a rural community. A trend in significant increase was found regarding the prevalence of obesity and average BMI in the rural community over 6 years. Effective public health interventions should be provided at the community level to reduce BMI. Moreover, modifiable risk factors for obesity should be attenuated to inhibit the progression of metabolic syndrome, noncommunicable diseases and their complications.

Synthesis of neocryptolepines and carbocycle-fused quinolines and evaluation of their anticancer and antiplasmodial activities.

This study reported the discovery of novel compounds containing five-membered ring fused quinoline core structures as anticancer and antimalarial agents. Two libraries containing these core structures, neocryptolepines and carbocycle-fused quinolines, were prepared and evaluated. Compound 3h was found to be much more potent than other analogs against cancer cell lines with high selectivity. Meanwhile, carbocycle-fused quinolines 5h and 5s showed moderate anticancer properties but much less cytotoxicity to normal cell than doxorubicin. In addition, compound 3h also showed much lower cytotoxic against human normal kidney cell line compared to doxorubicin standard. However, only compounds 3s and 3p provided acceptable results for antimalarial activities.

An Epidemiological Survey of Opisthorchis viverrini Infection in a Lightly Infected Community, Eastern Thailand.

Human liver fluke infection caused by Opisthorchis viverrini increases the risk of cholangiocarcinoma (CCA) reported along the Mekong basin including Thailand, Lao People's Democratic Republic (PDR), Cambodia, and Vietnam. The highest incidence of CCA has been reported in northeastern Thailand where liver fluke infection is prevalent. This study aimed to investigate the prevalence of O. viverrini infection in a northeastern-descendent community in rural Sa Kaeo Province, eastern Thailand, using stool examination and molecular technique. The Kato-Katz method was performed to determine eggs per gram (EPG) for infection intensity. Phosphate-buffered saline-ethyl acetate concentration was used to prepare specimens for polymerase chain reaction (PCR) and restriction fragment length polymorphism of the internal transcribed spacer 2 (ITS2) region of the ribosomal RNA. From 1,245 specimens, 105 (8.4%) samples were identified as Opisthorchis-like eggs from stool examination, and all positive specimens indicated light infection (< 1,000 EPG). From positive Opisthorchis-like egg samples, 55.2% (58/105) were identified as O. viverrini eggs from ITS2-PCR assay for which low infection intensity might result in a negative PCR result (44.8%). Using multiple logistic regression analysis, males were at 3.1 times higher risk of acquiring O. viverrini infection than females. From phylogenetic analysis, in eastern Thailand, nucleotide sequences of O. viverrini were grouped as a monoclade as those isolated from Greater Mekong, Vietnam, Myanmar, and west Siberia. The results revealed that the surveyed community is a low-grade endemic area of O. viverrini infection. Thus, data from this study can be used to improve health-promoting programs and activities to control the infection and its subsequent CCA.

Molecular discrimination of Opisthorchis-like eggs from residents in a rural community of central Thailand.

BACKGROUND: Opisthorchis viverrini infection is a major public health problem in northern and northeastern Thailand. The chronic infection of O. viverrini is related to cholangiocarcinoma which causes high mortality in endemic areas. Therefore, the diagnosis, treatment, control and prevention of O. viverrini infection are necessary. The morphology of the egg is very similar to that of other species of human liver flukes (Opisthorchis felineus and Clonorchis sinensis) as well as that of small intestinal flukes in the family Heterophyidae. Thus, molecular characterization is crucially required to discriminate species of Opisthorchis-like eggs in fecal examination. METHODOLOGY/PRINCIPAL FINDINGS: We aimed to determine the prevalence of O. viverrini infection among villagers living in Sanamchaikate District, Chachoengsao Province, in central Thailand, where O. viverrini infection has previously been reported. A total of 2,609 fecal samples were examined for Opisthorchis-like eggs using microscopic examination. PCR-RFLP analysis of the ITS2 region was used to discriminate Opisthorchis-like eggs. The genetic structure of O. viverrini infection was demonstrated using nucleotide sequencing of cytochrome c oxidase subunit I (cox1) and NADH dehydrogenase subunit 1 (nad1). Testing of evolutionary neutrality of the cox1 and nad1 sequences of O. viverrini was performed using Tajima's D tests and Fu's Fs tests. Moreover, the haplotype networks and phylogenetic trees were constructed to study the relationships of O. viverrini isolated from different endemic areas. A high prevalence of O. viverrini infection is still observed in a rural community of Chachoengsao Province, central Thailand. The overall prevalence of Opisthorchis-like eggs using microscopic examination was 16.8%. PCR-RFLP profiles showed the predominant infection of O. viverrini (9.6%) including very low infections of other small intestinal flukes, Haplorchis taichui (0.08%) and Euparyphium albuferensis (0.08%). The genetic structure of O. viverrini populations in central Thailand was also described and revealed a non-significant difference in genetic diversity. In addition, the genetic background of the O. viverrini populations was closely related to the isolate from Lao PDR. CONCLUSIONS/SIGNIFICANCE: Our study highlighted the prevalence of O. viverrini infection in central Thailand indicating that control programs and health education regarding opisthorchiasis is still required in this endemic area. Additionally, the study demonstrated the genetic structure of O. viverrini, in central Thailand which could provide information on the molecular epidemiology of this parasite.

A novel in vitro model reveals distinctive modulatory roles of Plasmodium falciparum and Plasmodium vivax on naïve cell-mediated immunity.

BACKGROUND: To date, human peripheral blood mononuclear cells (PBMCs) have been used mainly in immune stimulation assays and the interpretation of data can be influenced by the previous immunological history of donors and cross reactivity with other infectious agents. Resolving these limitations requires an alternative in vitro model to uncover the primary response profiles. METHODS: A novel in vitro model of mononuclear cells (MNCs) generated from haematopoietic stem cells (HSCs) was developed and these cells were then co-cultured with various antigens from Plasmodium falciparum and Plasmodium vivax to investigate the response of naïve immune cells to malaria antigens by flow cytometry. RESULTS: In vitro stimulation of naïve lymphocytes showed that CD4+ and CD8+ T lymphocytes were significantly reduced (P < 0.01) by exposure to lysates of infected erythrocytes or intact erythrocytes infected with P. falciparum. The depletion was associated with the expression of CD95 (Fas receptor) on the surface of T lymphocytes. Maturation of T lymphocytes was affected differently, showing elevated CD3+CD4+CD8+ and CD3+CD4-CD8- T lymphocytes after stimulation with cell lysates of P. falciparum and P. vivax, respectively. In addition, antigen presenting monocytes and dendritic cells derived from haematopoietic stem cells showed impaired HLA-DR expression as a consequence of exposure to different species of malaria parasites. CONCLUSION: These results suggest that naïve mononuclear cells differentiated in vitro from HSCs could provide a valid model for the assessment of immunity. P. falciparum and P. vivax malaria parasites could modulate various populations of immune cells starting from newly differentiated mononuclear cells.

Comparative Diagnosis of Strongyloidiasis in Immunocompromised Patients.

Strongyloides hyperinfection syndrome and disseminated strongyloidiasis frequently occur in immunocompromised persons and can lead to high complication and mortality rates. Thus, detection of Strongyloides stercolaris in those patients is crucial. The present study aimed to determine the prevalence of strongyloidiasis and compare the detection rates of different strongyloidiasis detection methods. We conducted a cross-sectional study of 135 adults with various immunocompromising conditions (corticosteroid usage, chemotherapy, hematologic malignancies, organ transplants, use of immunosuppressive agents, and symptomatic human immunodeficiency virus infection) in Phramongkutklao Hospital, Bangkok, Thailand. All patients were asked to undergo serology testing for Strongyloides IgG by indirect enzyme-linked immunosorbent assay (ELISA), and 3 days of stool collection for use in a simple smear along with formalin-ether concentration and agar plate techniques. Prevalence rates of strongyloidiasis were 5% by stool concentration technique, 5.4% by IgG-ELISA, and 6.7% by agar plate culture. Three of the eight strongyloidiasis cases in this study had hyperinfection syndrome. The tested risk factors of age, sex, occupation, and immunocompromising condition were not associated with Strongyloides infestation. Serology was only 42.9% sensitive (positive predictive value), but it was 96.3% specific (negative predictive value). In conclusion, prevalence rates of strongyloidiasis in this study were 5-7%. Although agar plate culture was the most sensitive technique, the other diagnostic methods might be alternatively used.

Development and evaluation of PCR methods based on cytochrome c oxidase subunit one (cox1) and NADH dehydrogenase subunit one gene (nad1) to detect Opisthorchis viverrini in human fecal samples.

Opisthorchis viverrini is highly prevalent throughout Southeast Asia. Chronic infection of this parasite leads to cholangiocarcinoma (CCA), a fatal bile duct cancer. The early and accurate detection of this parasite is very important; therefore, new PCR methods targeting cytochrome c oxidase subunit one and NADH dehydrogenase subunit one gene to detect O. viverrini in fecal specimens have been developed. Ninety O. viverrini-positive human fecal samples were used in this study. The PCR sensitivity of both genes was compared with internal transcribe spacer 2 (ITS2)-PCR. The sensitivity of cox1-PCR and nad1-PCR was 66.7 and 50 %, respectively. The sensitivity of cox1-PCR and nad1-PCR achieved 89.1 and 71.7 % in specimens containing O. viverrini eggs of >100 eggs per gram (EPG). Additionally, these primers can be used to provide the information on genetic diversity from mitochondrial genes of O. viverrini.

Synthesis of isocryptolepine analogues and their structure-activity relationship studies as antiplasmodial and antiproliferative agents.

Novel isocryptolepine analogues have been conveniently synthesized and evaluated for antimalarial and antiproliferative activities. We have found 3-fluoro-8-bromo-isocryptolepine (1n) to have the highest activities against chloroquine-resistant K1, chloroquine-sensitive 3D7, and chloroquine- and mefloquine-resistant SKF58 and SRIV35 strains. Several fluorine-substituted analogues (1b, 1n, and 1q) also showed excellent selectivities while maintaining good to excellent activities against all four Plasmodium falciparum strains. Additionally, antiproliferative properties of isocryptolepine derivatives against HepG2, HuCCA-1, MOLT-3 and A549 cancer cell lines are reported for the first time in this study. 2-Chloroisocryptolepine (1c) and benzo-fused-2-chloroisocryptolepine (1i) showed significant bioactivities whereas several novel fluorinated compounds and 2-chloro-8-bromoisocryptolepine (1f) displayed excellent selectivities.

Prevalence and gB genotype distribution of human cytomegalovirus among HIV sero-negative and HIV sero-positive orphans in Thailand.

BACKGROUND: Human Cytomegalovirus (HCMIV infects humans in all geographic areas. Polymorphisms ofglycoprotein B (gB) have been usedforgenotypic characterization of HCMV However information of gB genotyping of HCMV in Thailand is not clearly known especially in children. MATERIAL AND METHOD: A cross-sectional study was conducted to assess HCMV infection in 236 HIV seronegative and HIV seropositive children who attended an orphanage in Nonthaburi, Thailand by nested-PCR technique using urine specimens. HCMV gB genotypes were determined by restrictionfragment length polymorphism (RFLP), andDNA sequencing technique. RESULTS: Sixty-one percent (144/236) of the samples were HCMV positive, which consisted of 66.1% (37/56) of the HIV seropositive children and 59.4% (107/180) of the HIVsero-negative children. Multivariate analysis showed that children who living in one particular room were independently associated with HCMVinfection. Genotypic analysis revealed that the most prevalent genotype in these children was gB1; 85.4% (111/130) followed by gB3; 4.6% (6/130), gB2 and gB4 each at 2.3% (3/130). Mixed gB genotypes were identified in 5.4% (7/130) of the samples. CONCLUSION: HCMV infection, in particular gB1 genotype was commonly ident fled among these Thai orphans. Living in one particular room was associated with getting the infection. To prevent the transmission of HCMV infection in this setting, improvement in hygienic behavior ofchildcare workers should be focused.