Work-Related Hazards and Perceived Confined-Space Health Risk : Understanding the Correlation with Mental Workload Among Farmers in Northern Thailand's Shallow Wells

OBJECTIVES

This study examined factors related to perceived health risks in confined spaces (PCSHR) and their correlation with the mental workload among farmers managing agricultural wells in northern Thailand.

METHODS

A cross-sectional, multi-stage sample of 356 farmers was selected from four rural districts' agricultural areas. Data were collected through interviews conducted from August to December 2022, using a self-administered structured questionnaire. The five-part questionnaire gathered demographic data, information on experiences and operations in agricultural wells, knowledge of confined spaces, PCSHR, and the six-dimension NASA Task Load Index (TLX) mental workload. Linear regression and multi-variable analyses were used to investigate factors associated with PCSHR, while Pearson correlations tested the association between PCSHR and mental workload variables.

RESULTS

Most farmers were male (92.4%), worked in wells to install pumping systems (81.7%) and maintain equipment (73.3%), averaging 3.80 times per year, with an average duration of 25.81 minutes. Physical symptoms reported included difficulty breathing (72.8%), feeling swelteringly hot (55.9%), and sweating excessively (27.8%), as well as accidents such as being struck by falling soil or objects (20.2%), and falling into the well while climbing down (14.9%). Farmers' perceived risk scores were high when working while physically exhausted or unprepared and when assisting an unconscious worker without knowing the gas concentration. In addition, the maximal mental workload scores were mental demand and effort subscale. Factors significantly associated with PCSHR (adj.R2 = 60.6%, p < .05) encompassed education higher than lower secondary level, current alcohol consumption, smaller well width, assisted operations, number of physical symptoms experienced, absence of environmental accidents, and confined space knowledge, while increased PCSHR was positively associated with mental workload (Overall r = 0.711, p < .01).

CONCLUSION

Comprehensive education about potential hazards can improve farmers' risk perception, potentially reducing mental workload and preventing fatal accidents. Field studies are recommended to develop community-specific work protocols and accurate measuring instruments suitable for rural settings are needed.

Impact of Atmospheric Conditions and Source Identification of Gaseous Polycyclic Aromatic Hydrocarbons (PAHs) during a Smoke Haze Period in Upper Southeast Asia

Gaseous polycyclic aromatic hydrocarbons were measured in northern Thailand. No previous studies have provided data on gaseous PAHs until now, so this study determined the gaseous PAHs during two sampling periods for comparison, and then they were used to assess the correlation with meteorological conditions, other pollutants, and their sources. The total concentrations of 8-PAHs (i.e., NAP, ACY, ACE, FLU, PHE, ANT, FLA, and PYR) were 125 ± 22 ng m-3 and 111 ± 21 ng m-3, with NAP being the most pronounced at 67 ± 18 ng m-3 and 56 ± 17 ng m-3, for morning and afternoon, respectively. High temperatures increase the concentrations of four-ring PAHs, whereas humidity and pressure increase the concentrations of two- and three-ring PAHs. Moreover, gaseous PAHs were estimated to contain more toxic derivatives such as nitro-PAH, which ranged from 0.02 ng m-3 (8-Nitrofluoranthene) to 10.46 ng m-3 (1-Nitronaphthalene). Therefore, they could be one of the causes of local people's health problems that have not been reported previously. Strong correlations of gaseous PAHs with ozone indicated that photochemical oxidation influenced four-ring PAHs. According to the Pearson correlation, diagnostic ratios, and principal component analysis, mixed sources including coal combustion, biomass burning, and vehicle emissions were the main sources of these pollutants.

Analysis of dairy cattle movements in the northern region of Thailand

Dairy farming in northern Thailand is expanding, with dairy cattle populations increasing up to 8% per year. In addition, disease outbreaks frequently occur in this region, especially foot-and-mouth disease and bovine tuberculosis. Our goal was to quantify the underlying pattern of dairy cattle movements in the context of infectious disease surveillance and control as movements have been identified as risk factors for several infectious diseases. Movements at district levels within the northern region and between the northern and other regions from 2010 to 2017 were recorded by the Department of Livestock Development. Analyzed data included origin, destination, date and purpose of the movement, type of premise of origin and destination, and type and number of moved cattle. Social network analysis was performed to demonstrate patterns of dairy cattle movement within and between regions. The total numbers of movements and moved animals were 3,906 and 180,305, respectively. Decreasing trends in both the number of cattle moved and the number of movements were observed from 2010 to 2016, with increases in 2017. The majority (98%) of the animals moved were male dairy calves, followed by dairy cows (1.7%). The main purpose of the movements was for slaughter (96.3%). Most movements (67.4%) were shipments from central to northern regions, involving 87.1% of cattle moved. By contrast, 56% of the movements for growing and selling purposes occurred within the northern region, commonly involving dairy cows. Constructed movement networks showed heterogeneity of connections among districts. Of 110 districts, 28 were found to be influential to the movement networks, among which 11 districts showed high centrality measures in multiple networks stratified for movement purposes and regions, including eight districts in the northern and one district in each of the central, eastern, and lower northeastern regions of Thailand. These districts were more highly connected than others in the movement network, which may be important for disease transmission, surveillance, and control.

Diagnosis of α0-thalassemia Chiang Rai (--CR) deletion by melt curve analysis in Northern Thailand

A large novel 44.6 kb deletion named α⁰-thalassemia Chiang Rai (--^CR) was first described in the individuals with uncommon Hb Bart's hydrops fetalis and HbH disease. This study aimed to develop a real-time gap PCR and melt curve analysis for the detection of --^CR and investigate its frequency in northern Thailand. Among 4,952 blood samples, the assay was performed in 525 samples with a mean corpuscular volume (MCV) < 80 fL, HbA₂ < 3.5%, HbA₂+E < 25%, and negative for common deletional α⁰-thalassemia --^SEA and --^THAI. The developed method showed T_m values of 85.8 ± 0.0 °C and 91.5 ± 0.1 °C, which were specific for --^CR and wild-type alleles, respectively. Nine (0.18% of 4,952 or 1.71% of 525) were positive for --^CR, in which two were HbH disease and the rest were heterozygous for --^CR. This study demonstrated the success of real-time gap PCR with melt curve analysis for --^CR diagnosis. Additionally, the prevalence of --^CR in the northern Thai population was comparable to --^THAI. Thus, this study implies the importance of --^CR in northern Thailand. Moreover, the developed real-time gap PCR with melt curve analysis is simple and highly accurate, and may be considered as an additional tool for routine α⁰-thalassemia --^CR diagnosis in this region.

Knowledge of COVID-19 and Its Relationship with Preventive Behaviors and Vaccination among Adults in Northern Thailand's Community

(1) Background: the 2019 coronavirus disease outbreak (COVID-19) has posed a major threat to public health and had a significant impact on all areas of people’s lives. Vaccines against COVID-19 have been developed to control the disease, and an array of personal hygiene measures has been introduced. As a result, information that will support and promote vaccination among populations as well as other health measures against COVID-19 are urgently needed. The goal of this research was to look into the knowledge about COVID-19 and how it relates to preventive behaviors and vaccination among people living in rural areas of northern Thailand. (2) Methods: a cross-sectional study was performed in four upper northern provinces of Thailand. A total of 1524 participants were recruited using the probability sampling technique. Questionnaires were distributed to collect data on general health information, as well as knowledge and preventive behaviors regarding COVID-19. (3) Results: more than half (55.9%) of the participants were female and had not received the COVID-19 vaccine (67.2%). Their mean age was 44.13 years. The majority had moderate COVID-19 knowledge and engaged in preventive behaviors (65.5% and 42.0%, respectively). A linear regression model showed that the COVID-19 knowledge score was related to the COVID-19 preventive behaviors score, with a standardized coefficient of 0.510, after adjusting for age, underlying disease, and body mass index (B = 2.64; 95%CI = 2.42, 2.87). Binary logistic regression revealed that after controlling for age, education, occupation, financial status, and current disease (AOR = 1.87; 95%CI = 1.64–2.13), the score of COVID-19 knowledge was significantly associated with having the COVID-19 vaccine. (4) Discussion: knowledge of COVID-19 is very important for people in rural regions to engage in COVID-19 prevention behaviors and vaccination. Relevant government agencies and health network partners should support proactive education campaigns emphasizing the risk of contracting the disease and its severity in order to promote vaccination against COVID-19 among unvaccinated groups. These campaigns can highlight COVID-19’s positive benefit-risk balance in the short and long term and ensure public safety measures against COVID-19.

Subdistrict-Level Reproductive Number for Foot and Mouth Disease in Cattle in Northern Thailand

Foot and mouth disease (FMD) is an important contagious transboundary disease that causes a significant economic loss for several countries. The FMD virus (FMDV) can spread very rapidly by direct and indirect transmission among susceptible animals. The complexity and magnitude of FMDV transmission at the initial stages of the epidemic can be expressed by the basic reproductive number (R ₀), and furthermore, control strategies can be assessed by the estimation of the effective reproductive number. In this study, we aimed to describe FMD outbreaks among smallholder cattle farms by subdistricts in the northern Thailand and compute the effective reproductive number for outbreaks caused by FMDV serotype O and overall serotypes, including serotype O, serotype A, and unidentified serotype, at the subdistrict level (R _sd ) using an epidemic doubling time method. Field data of FMD outbreaks during 2015-2017 that affected 94 subdistricts in northern Thailand were assessed to estimate the R _sd . Results showed that 63.38% (90/142) of the FMD outbreak episodes in cattle were caused by FMDV serotype O. The average doubling time and the R _sd estimated of the outbreaks caused by FMDV serotype O and overall serotype were 2.80 and 4.67 months, and 1.06 and 1.04, respectively. Our results indicated that transmission of FMD in cattle at the subdistrict level in northern Thailand was not controlled (R _sd > 1), which indicates the endemicity of the disease in the region. Although control measures are in place, the results from this study highlighted the need for enhancing FMD monitoring and control strategies in northern Thailand.

Prevalence and Correlates of Alcohol Consumption among Hill-Tribe Adolescents below the Legal Drinking Age-A Community-based Cross-Sectional Study in Northern Thailand

Alcohol drinking has been prevalent among various hill tribes of northern Thailand due to their distinctively different lifestyles, traditions, cultures and beliefs than the general Thai population; the majority of these traditions involve annual rounds of customary rituals that make alcohol abundantly accessible to all age groups. To study the prevalence and predictors of alcohol use, a community-based analytical cross-sectional study was conducted between October 2017-September 2018 among 480 sampled adolescents aged 12 through 18 years drawn by stratified random sampling. A proprietary questionnaire developed by the researchers was used to collect the data which were analyzed using binary logistic regression. The prevalence of alcohol use in the previous 30 days was 46.7%. Drinking predictors were: having at least a drinking parent, drinking peers, ever been sent to buy alcohol, smoking, cordial relationship with peers, gambling, family violence experience, stress and leisure time company. Therefore, our results suggest that prevention interventions should be designed with a focus on discouraging parents from sending children to buy alcohol and drinking or smoking in their presence; to reduce both social and commercial access to alcohol, age limits should be imposed on alcohol intake at all ceremonious events, while strictly reinforcing the law that prohibits selling alcohol to minors.

Association of Hb Shenyang [α26(B7)Ala→Glu, GCG>GAG, HBA2: c.80C>A (or HBA1)] with Several Types of α-Thalassemia in Thailand

Hb Shenyang [α26(B7)Ala→Glu, HBA2: c.80C>A (or HBA1)] is a rare α chain variant. Its genotype-phenotype relationship and origin have not been described in Thailand before. Three Thai subjects (P1-P3) carrying this variant were studied. Hemoglobin (Hb) analysis was performed by capillary electrophoresis (CE) and high performance liquid chromatography (HPLC) as well as molecular characterization using appropriate polymerase chain reaction (PCR) techniques and DNA sequencing. Hemoglobin analysis by HPLC revealed fast-moving abnormal peaks at a retention time (RT) of 1.59-1.62 min., while CE revealed a fast-moving abnormal Hb at zone 12 and ahead of Hb A₂ in three subjects. DNA analysis revealed a C>A transition at codon 26 of the α2-globin gene glutamic acid to replace alanine, corresponding to Hb Shenyang. The Southeast Asian [- -^SEA α-thalassemia-1 (α-thal-1)] deletion was also identified in P1 and his mother, while Hb Constant Spring (Hb CS, HBA2: c.427T > C) was identified in P2. The Hb Shenyang concentration measured by CE revealed 5.1-17.2% heterozygosity with normal red blood cell (RBC) parameters. The α haplotype [+ - S + - + -] [S signifies the inter ζ hypervariable region (HVR)] was associated with the Thai Hb Shenyang. The genotype-phenotype relationship indicates Hb Shenyang is likely a non pathological Hb variant that has neither dramatic clinical symptoms nor hematological anomalies. A simple multiplex allele-specific PCR for rapid diagnosis of Hb Shenyang has been developed.

Monitoring of the Organophosphate Pesticide Chlorpyrifos in Vegetable Samples from Local Markets in Northern Thailand by Developed Immunoassay

Chlorpyrifos is an organophosphate pesticide that is wildly used among farmers for crop protection. However, there are concerns regarding its contamination in the environment and food chain. In the present study, an in-house indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) specific for detecting chlorpyrifos is developed and validated against gas chromatography–flame photometric detection (GC-FPD) as the conventional method. The developed ic-ELISA was used for detecting chlorpyrifos residue in vegetable samples. The developed ic-ELISA showed good sensitivity to chlorpyrifos at an IC₅₀ of 0.80 µg/kg, with low cross-reactivity to other organophosphate pesticides. The 160 samples were collected from local markets located in the Chiang Rai, Chiang Mai, and Nan provinces in northern Thailand. The positive rate of chlorpyrifos residues in the vegetable samples was 33.8%, with the highest levels found in cucumbers, coriander, and morning glory, at 275, 145, and 35.3 µg/kg, respectively. The highest median levels of chlorpyrifos found in the detected samples were Chinese cabbage (332 μg/kg), cucumber (146.3 μg/kg) and Chinese Kale (26.95 μg/kg). The developed ic-ELISA is suitable for the rapid quantitation of chlorpyrifos residues.

Determination of Risk Factors Associated with Foot and Mouth Disease Outbreaks in Dairy Farms in Chiang Mai Province, Northern Thailand

Simple Summary

One hundred and 40 dairy farms that experienced foot and mouth disease (FMD) outbreaks and 307 farms without FMD outbreaks were investigated in this research study. Relevant farm owners were interviewed in order to determine the farm-level risk factors associated with the FMD outbreaks. We established that the risk factors for FMD outbreaks were (1) purchasing a new cow without following quarantine protocol, (2) FMD vaccination administration by non-official livestock personnel, (3) farms located within a 5 km radius of cattle abattoirs, (4) farms located near shared cattle grazing areas in a 10 km radius and (5) no history of FMD outbreaks in the previous year. Most of the risk factors were related to indirect transmissions of FMD and biosecurity practices, thus we have advised dairy farmers to strengthen management practices associated with FMD prevention protocols.

Abstract

Foot and mouth disease (FMD) is considered a highly contagious transboundary disease of cloven-hoofed animals. FMD has become endemic to northern Thailand over the past decade. In 2016, FMD outbreaks were recorded in three districts in Chiang Mai Province. The objective of this study was to determine the farm-level risk factors associated with FMD outbreaks. This study was conducted via a face-to-face interview questionnaire survey at 140 FMD outbreak farms and 307 control farms. Univariable and multivariable logistic regression analyses were used to determine the association between potential risk factors and FMD outbreaks. The final logistic regression model identified factors associated with FMD outbreaks including the purchasing of a new cow without following quarantine protocol (odds ratio = 2.41, 95%CI = 1.45, 4.05), farms located near shared cattle grazing areas in a 10 km radius (OR = 1.83, 95%CI =1.11, 3.02), FMD vaccination administration by non-official livestock personnel (OR = 2.52, 95%CI = 1.39, 4.58), farms located in a 5 km radius of cattle abattoirs (OR = 1.83, 95%CI = 0.99, 3.40) and no history of FMD outbreaks over the previous 12 months in districts where farms were located (OR = 0.44, 95%CI = 0.22, 0.86). The risk factors identified in this study were related to farm biosecurity, FMD vaccination administration and distance from the farms to risk areas. Therefore, it was important to strengthen on-farm biosecurity and to improve farm management practices in order to reduce incidences of FMD at the farm level. Education or training programs for dairy farmers that would enhance knowledge and practices in relation to the assessed topics are needed.

isolated from tilapia (Oreochromis spp.) cultured in river-based cage and earthen ponds in Northern Thailand

Streptococcus spp. are major pathogenic bacteria associated with massive mortality in tilapia. This study investigated the phenotypic and genotypic characterization of Streptococcus agalactiae (GBS) and Streptococcus iniae (S. iniae) isolated from tilapia in river-based floating cage and earthen pond farms in northern Thailand. Isolates were identified by biochemical and molecular analyses. Capsular typing, enterobacterial repetitive intergenic consensus polymerase chain reaction and multilocus sequence typing were performed to investigate the genetic relatedness. Six and one isolates were confirmed as GBS and S. iniae, respectively. All Streptococcus spp. isolates were obtained from 4 river-based cage farms (4/33), while samples collected from earthen pond farms (N = 28) were negative for streptococcosis. All GBS with serotype Ⅲ and sequence type (ST) 283 was observed. The β-haemolytic GBS isolates were resistant to five antimicrobials, while the S. iniae was susceptible to all antimicrobials. This study indicates both GBS and S. iniae are the major bacterial pathogens responsible for streptococcosis infection in farmed tilapia of northern Thailand with GBS as dominant species. This survey highlights that the river-based cage farms seriously impact on the healthy development of the tilapia industry.

Association between stroke knowledge, stroke awareness, and preventive behaviors among older people: A cross-sectional study

In this cross-sectional study, we compared preventive behaviors among Thai people aged >60 years of age, with and without stroke risk, in Chiang Mai Province, Thailand, and examined the associations between stroke knowledge and stroke awareness with preventive behaviors in these two groups (n = 422). Participants completed researcher-developed tools, including the Personal Demographic Questionnaire, the Stroke Knowledge Questionnaire, the Awareness of Stroke Risk and Severity Questionnaire, and the Stroke Preventive Behavior Questionnaire. The findings revealed a significantly higher mean score of preventive behaviors in older people with stroke risk than in those without risk. For people with stroke risk, stroke knowledge did not result in a significant association with stroke-preventive behaviors, while stroke awareness did. For those without stroke risk, both stroke knowledge and stroke awareness were significantly associated with stroke-preventive behaviors. Although the stroke-preventive behaviors of both groups were performed appropriately, it is necessary for people with stroke risk to maintain preventive behaviors, and for health professionals to regularly assess them for stroke symptoms and encourage people to be proactive about stroke-preventive behaviors.

Prevalence of human papillomavirus in oral rinse samples from healthy individuals in northern Thailand

BACKGROUND

The incidence of oral cancers associated with human papillomavirus (HPV) has been increasing in recent years. Therefore, it is necessary to elucidate HPV prevalence in oral cells and exposure to risk factors in various age groups.

METHODS

Oral rinse samples from healthy individuals in northern Thailand were investigated for HPV prevalence and genotyped using the polymerase chain reaction (GP5+/6+ primers) and DNA sequencing of the PCR products.

RESULTS

Samples were collected from 594 participants between 4 and 60 years of age. HPV was detected in 3.7% of samples. The prevalence of HPV-positive cases was 8.6% in the 31-50 age group. HPV prevalence increased with age and was the highest (9.2%) in the 41-50 age group, but decreased (to 3%) in the 51-60 age group. Risk factors significantly associated with HPV-positive cases included alcohol consumption, coffee drinking, sexual activity, and having children. HPV 16 and 18 were common genotypes, especially in the 31-50 age group, and were associated with having sexual activity (odds ratio 19.0 [95% CI: 2.5-142.5]). At follow-up of some individuals in the 4-10 age group, a 9-year-old child was found to be positive for HPV18.

CONCLUSIONS

These results suggest that HPV can be acquired at a young age and the prevalence peaks in the middle age class among healthy individuals in northern Thailand, especially in the 31-50 age group.

Association between hepatitis C infection in Thai patients with oral lichen planus: A case-control study

AIM

The aim of the present study was to investigate the prevalence of hepatitis C virus (HCV) infection and evaluate liver enzyme levels in patients from upper northern Thailand with oral lichen planus (OLP).

METHODS

A case-control study of 101 patients with OLP and 101 patients without OLP was conducted. Peripheral blood was taken from each patient and screened for anti-HCV antibody using immunochromatography. Positive samples were further confirmed using chemiluminescent microparticle immunoassay (CMIA) and reverse transcription-polymerase chain reaction. In addition, liver enzyme levels, alanine transaminase, aspartate transaminase, and alkaline phosphatase were evaluated using spectrophotometry.

RESULTS

Immunochromatography and CMIA revealed that nine patients with OLP (8.9%) were positive for anti-HCV antibodies, whereas only one patient without OLP was HCV positive (odds ratio = 9.78). All patients who were HCV positive had significantly higher liver enzyme levels than patients who were HCV negative.

CONCLUSIONS

The results of the present study indicated that OLP in certain patients was significantly associated with HCV. This could warrant screening for HCV-infected patients with OLP in Thailand.

The correlation of α-globin gene mutations and the XmnI polymorphism with clinical severity of Hb E/β-thalassemia

Clinical severity assessment and molecular analysis of β-, α-globin genes and the -158 (C > T) XmnI polymorphism of the (G)γ-globin gene were performed in 80 pediatric patients with Hb E (HBB: c.79G > A)/β-thalassemia (β-thal) to investigate the effects of coinheritance of α-thalassemia (α-thal) and other molecular determinants on their clinical severity. The mean age was 9.4 ± 5.1 years. By using clinical severity score, 35 (43.8%), 27 (33.8%) and 18 cases (22.5%) had moderate, mild and severe disease, respectively. Nine β-thal mutations were identified. All were β⁰ or severe β⁺ mutations. Five patients (6.3%) had coinherited α⁰-thal. All five patients had mild disease with baseline hemoglobin (Hb) values of 7.9 ± 1.5 g/dL, mild hepatosplenomegaly and close-to-normal growth. Only one required a red blood cell transfusion. The disease severity was significantly different among the groups with and without α-thal (p = 0.025), but was not different among the groups with or without the XmnI polymorphism (p = 0.071). This study demonstrates that coinheritance of α⁰-thal alleviates the degree of disease severity in Hb E/β-thal. All our patients with coinherited α⁰-thal have mild disease.