High diversity of Blastocystis subtypes isolated from asymptomatic adults living in Chiang Rai, Thailand

Blastocystis is a common and broadly distributed microbial eukaryote inhabiting the gut of humans and other animals. The genetic diversity of Blastocystis is extremely high comprising no less than 17 subtypes in mammals and birds. Nonetheless, little is known about the prevalence and distribution of Blastocystis subtypes colonising humans in Thailand. Molecular surveys of Blastocystis remain extremely limited and usually focus on the central, urban part of the country. To address this knowledge gap, we collected stool samples from a population of Thai adults (n=178) residing in Chiang Rai Province. The barcoding region of the small subunit ribosomal RNA was employed to screen for Blastocystis and identify the subtype. Forty-one stool samples (23%) were identified as Blastocystis positive. Six of the nine subtypes that colonise humans were detected with subtype (ST) three being the most common (68%), followed by ST1 (17%) and ST7 (7%). Comparison of subtype prevalence across Thailand using all publicly available sequences showed that subtype distribution differs among geographic regions in the country. ST1 was most commonly encountered in the central region of Thailand, while ST3 dominated in the more rural north and northeast regions. ST2 was absent in the northeast, while ST7 was not found in the center. Thus, this study shows that ST prevalence and distribution differs not only among countries, but also among geographic regions within a country. Potential explanations for these observations are discussed herewith

Molecular epidemiology and clinical features of hand, foot and mouth disease in northern Thailand in 2016: a prospective cohort study

Abstract Background Hand, foot and mouth disease (HFMD) is a major communicable disease in children ≤6 years old, particularly in several countries in the Asia-Pacific Region, including Thailand. HFMD impacts public health and the economy, especially in northern Thailand. Methods A prospective cohort study was conducted to estimate the incidence rate and to identify the serotype and clinical features of HFMD among children in northern Thailand. A validated questionnaire and throat swab were used for data collection. Polymerase chain reaction (PCR) was used to detect human enterovirus and identify its serotypes. Participants were recruited from 14 hospitals in two provinces in northern Thailand, specifically, Chiang Rai and Pha Yao Province, between January 1, 2016, and December 31, 2016. Chi-square or Fisher’s exact test was used to detect the associations of signs and symptoms with HFMD serotype. Logistic regression was used to detect the associations of variables with a positive enterovirus at alpha = 0.05. Result In total, 612 children aged ≤6 years from Chiang Rai and Pha Yao Province who were diagnosed with HFMD by a throat swab were recruited for the analysis. Approximately half of the cohort was male (57.2%), 57.5% was aged  6 months, and children who had mother who worked as farmers, daily wage employees, and unprofessional skilled jobs had a greater chance of enterovirus infection than those who had unemployed mothers. Coxsackievirus-infected children had a higher rate of rashes on the buttocks, knee, and elbow and fever but a lower rate of lethargy and malaise than EV-A71-infected children. Conclusions EV-A71 is a major cause of HFMD in children < 6 years old in northern Thailand, but rash, fever, and mouth ulcers are mostly found in participants with coxsackievirus infection. Breastfeeding should be promoted during early childhood for at least 6 months to prevent HFMD particularly those mother who are working in unprofessional skill jobs

Effect of Sin Lek rice intervention on cognitive function, dietary patterns, and fecal microbiota of elementary school children in Chiang Rai, Thailand

Thailand has struggled with malnutrition rates in young children. Rice is a key component of Southeast Asian diets and a whole grain rice varietal (Sin Lek) may support improved nutrition. Diet can influence cognitive function and human gut microbiota, which were explored in the context of a rice intervention. We conducted a pilot study using a non-randomized, crossover clinical trial of Sin Lek rice versus traditional white rice consumption in elementary school children in Chiang Rai, Thailand. Outcomes related to diet, anthropological factors, cognitive function (e.g., short-term working memory, attention, impulsivity), and gut microbial populations were measured at baseline and over a period of 71 weeks. A total of 127 school children (grades 1-6) were enrolled and completed study measures, which were interrupted by COVID-19. At baseline, females had higher short-term working memory than males. Differences in attention and impulsivity were observed based on feeding method at the time of birth. Diet and cognitive function were not related at baseline. Eleven bacterial taxa and total bacteria were measured and revealed gut microbiota associations with dietary behavior and anthropology. Ongoing analyses are exploring the relationship between microbial composition and cognitive outcomes. Our study was effective at measuring diet, cognitive function, and microbiome outcomes among Thai school children. Sin Lek rice was accepted by Thai school children. Preliminary results highlight relationships between dietary habits and gut microbiome composition at baseline. Further analyses are needed to examine the contribution of the rice intervention on cognitive function and gut microbial composition