Background: Leptospirosis, a disease caused by Leptospira species, a spirochaete bacterium that can develop in an appropriate environment and/or grow in human and/or animal hosts, is a serious problem for the Ministry of Public Health, Thailand. Objective: To investigate people's perceptions and behavioral risks regarding leptospirosis infection. Methods: The cross-sectional descriptive study collected data in May, 2013. Data on individuals' perceptions and risky behaviors concerning leptospirosis were collected from 104 completed questionnaires. Results: Regarding perceptions of leptospirosis, we found them to be at a high level (97.1%) and risky behaviors regarding leptospirosis were reported at a moderate level (74.0%). The study found no correlation between perceptions and risky behaviors regarding leptospirosis (r 0.186, p-value 0.059). Conclusion: This study suggest that people in these areas have good knowledge about leptospirosis. However, some people have risky behavior associated with leptospirosis. Thus, a behavioral change campaign should be promoted to encourage people awareness of the dangers of such behavior.

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Background The pathogenic Leptospira can survive and contaminate surface water based on physicochemical factors. This study aimed to determine how the physicochemical properties of water sources influence the growth and effect of iron on the gene expression of Leptospira spp. P47. Methods Surface water samples (n=55) were collected and used for Leptospira spp. P47 cultivation. Physicochemical factors, including iron, calcium, magnesium and pH, were analyzed. The association between Leptospira spp. P47 viability at days 5, 10 and 15 with the physicochemical factors were analyzed. In addition, this bacterium was cultured in six selected water samples. The effect of iron in water on HemO and LipL32 gene expression was determined by relative quantification real-time PCR. Results Leptospira viability at day 5 was not significantly correlated with physicochemical factors, while Leptospira viability at day 10 was associated with both pH and iron. The Leptospira viability rate at day 15 had a significantly positive association with pH and iron and a negative association with calcium. HemO expression was significantly increased, mostly in selected water samples and under iron-depleted conditions. Conversely, LipL32 expression was significantly decreased in all water samples. Conclusions Physicochemical factors in natural surface waters are key factors for bacterial survival in the environment, which may increase the chance of Leptospira infection in humans.

Melioidosis is a public health problem in the tropical regions, occurring to meteorological variability. For 10 years of melioidosis outbreaks, we create probability maps of melioidosis distribution during 2009–2018 and determine the association with meteorological factors. The monthly average rainfall and incidence of melioidosis were high from July to September but they not significantly associated (P = 0.576). However, the monthly maximum and minimum temperature were significantly associated with melioidosis incidence (P = 0.002 and P = 0.029, respectively). We estimated the spatial distribution of rainfall and maximum and minimum temperature using the Co-Kriging interpolation method which found that the spatial distribution of the melioidosis incidence was significantly associated with rainfall in 2009, 2010, and 2015; with the maximum temperature in 2009, 2010, 2011, 2013, and 2015; and with the minimum temperature in 2010, 2011, and 2015. Our finding approach may support information and classify a pattern for melioidosis distribution. Keywords: Incidence, Melioidosis, Meteorological factors

Widespread use of pesticides in Thai agriculture has led to serious adverse health impacts on users. This study developed a GIS database using the QGIS tool to investigate insecticide usage and toxicity tofarmers in Ubon RatchathaniProvince in northeastern Thailand. Primary data collection involved recording exact locations of residential houses using geographic positioning system (GPS). Secondary dataincluding transport routes, natural and environmental resources, and records of rainfall and ground temperatureswere also collected. The data were integrated asGIS mapping data. Eighteen farmers participated in the study and submitted themselves tomeasurements of cholinesterase (ChE) levels and 2 blood sample collections for comparison with standard ChE levels. Results revealed the GIS database to bean effective tool to capture, store, manage, search, analyze, and represent spatial data and correlate them with insecticide usage. The GIS databaserevealed that ChE levels of volunteers for pre-post-exposure were within normal ranges. Liver enzymes (AST and ALT) were also within normal ranges. Further study should broaden collection of essential data including demographic information and basic knowledge and perceptions of self-protection regarding insecticides. Further evaluation and refining of the GIS databaseapproach arerecommended to improve itseffectiveness as an analytical tool to enhance safe use of pesticides.