Ruchusatsawat K, Wongpiyabovorn J, Kawidam C, Thiemsing L, Sangkitporn S, Yoshizaki S, Tatsumi M, Takeda N, Ishii K. An Outbreak of Acute Hepatitis Caused by Genotype IB Hepatitis A Viruses Contaminating the Water Supply in Thailand. Intervirology. 2017 Feb 17;59(4):197-203. doi: 10.1159/000455856.
BACKGROUND: In 2000, an outbreak of acute hepatitis A was reported in a province adjacent to Bangkok, Thailand.
AIMS: To investigate the cause of the 2000 hepatitis A outbreaks in Thailand using molecular epidemiological analysis.
METHODS: Serum and stool specimens were collected from patients who were clinically diagnosed with acute viral hepatitis. Water samples from drinking water and deep-drilled wells were also collected. These specimens were subjected to polymerase chain reaction (PCR) amplification and sequencing of the VP1/2A region of the hepatitis A virus (HAV) genome. The entire genome sequence of one of the fecal specimens was determined and phylogenetically analyzed with those of known HAV sequences.
RESULTS AND CONCLUSIONS: Eleven of 24 fecal specimens collected from acute viral hepatitis patients were positive as determined by semi- nested reverse transcription PCR targeting the VP1/2A region of HAV. The nucleotide sequence of these samples had an identical genotype IB sequence, suggesting that the same causative agent was present. The complete nucleotide sequence derived from one of the samples indicated that the Thai genotype IB strain should be classified in a unique phylogenetic cluster. The analysis using an adjusted odds ratio showed that the consumption of groundwater was the most likely risk factor associated with the disease.
Direk Limmathurotsakul, Gumphol Wongsuvan, David Aanensen, Sujittra Ngamwilai, Natnaree Saiprom, Patpong Rongkard, Janjira Thaipadungpanit, Manas Kanoksil, Narisara Chantratita, Nicholas P.J. Day, and Sharon J. Peacock. Melioidosis Caused by Burkholderia pseudomallei in Drinking Water, Thailand, 2012. Emerging Infectious Diseases Vol. 20, No. 2, February 2014 DOI: http://dx.doi.org/10.3201/eid2002.121891
We identified 10 patients in Thailand with culture confirmed melioidosis who had Burkholderia pseudomallei isolated from their drinking water. The multilocus sequence type of B. pseudomallei from clinical specimens and water samples were identical for 2 patients. This finding suggests that drinking water is a preventable source of B. pseudomallei infection.
Chuah CJ, Lye HR, Ziegler AD, Wood SH, Kongpun C, Rajchagool S. Fluoride: A naturally-occurring health hazard in drinking-water resources of Northern Thailand. The Science of the total environment. 2015 Dec 31;545-546:266-279. doi: 10.1016/j.scitotenv.2015.12.069.
In Northern Thailand, incidences of fluorosis resulting from the consumption of high-fluoride drinking-water have been documented. In this study, we mapped the high-fluoride endemic areas and described the relevant transport processes of fluoride in enriched waters in the provinces of Chiang Mai and Lamphun. Over one thousand surface and sub-surface water samples including a total of 995 collected from shallow (depth: ≤30m) and deep (>30m) wells were analysed from two unconnected high-fluoride endemic areas. At the Chiang Mai site, 31% of the shallow wells contained hazardous levels (≥1.5mg/L) of fluoride, compared with the 18% observed in the deep wells. However, at the Lamphun site, more deep wells (35%) contained water with at least 1.5mg/L fluoride compared with the shallow wells (7%). At the Chiang Mai site, the high-fluoride waters originate from a nearby geothermal field. Fluoride-rich geothermal waters are distributed across the area following natural hydrological pathways of surface and sub-surface water flow. At the Lamphun site, a well-defined, curvilinear high-fluoride anomalous zone, resembling that of the nearby conspicuous Mae Tha Fault, was identified. This similarity provides evidence of the existence of an unmapped, blind fault as well as its likely association to a geogenic source (biotite-granite) of fluoride related to the faulted zone. Excessive abstraction of ground water resources may also have affected the distribution and concentration of fluoride at both sites. The distribution of these high-fluoride waters is influenced by a myriad of complex natural and anthropogenic processes which thus created a challenge for the management of water resources for safe consumption in affected areas. The notion of clean and safe drinking water can be found in deeper aquifers is not necessarily true. Groundwater at any depth should always be tested before the construction of wells.
The findings of this study are not surprising. This is the type of study a communal fluoridation advocate would use to argue for communal water fluoridation. But a move to communal fluoridation will have the effect of a placebo. It will not address the real issue of improving dental hygiene nor will it overcome disparities between peoples. (Fluoride may be naturally occurring. The source of water was considered but drinking water fluoride concentrations were not determined.)
Peltzer K, Mongkolchati A, Satchaiyan G, Rajchagool S, Pimpak T. Sociobehavioral factors associated with caries increment: a longitudinal study from 24 to 36 months old children in Thailand. Int J Environ Res Public Health. 2014 Oct 17;11(10):10838-50. doi: 10.3390/ijerph111010838.
The aim of this study is to investigate sociobehavioral risk factors from the prenatal period until 36 months of age, and the caries increment from 24 to 36 months of the child in Thailand. The data utilized in this study come from the prospective cohort study of Thai children (PCTC) from prenatal to 36 months of the child in Mueang Nan district, Northern Thailand. The total sample size recruited was 783 infants. The sample size with dental caries data was 603 and 597, at 24 months and at 36 months, respectively. The sample size of having two assessment points with a dental examination (at 24 months and at 36 months) was 597. Results indicate that the caries increment was 52.9%, meaning from 365 caries free children at 24 months 193 had developed dental caries at 36 months. The prevalence of dental caries was 34.2% at 24 months (n = 206) and 68.5% at 36 months of age (n = 409). In bivariate analysis, higher education of the mother, lower household income, bottle feeding of the infant, frequent sweet candy consumptions, and using rain or well water as drinking water were associated with dental caries increment, while in multivariate conditional logistic regression analysis lower household income, higher education of the mother, and using rain or well water as drinking water remained associated with dental caries increment. In conclusion, a very significant increase in caries development was observed, and oral health may be influenced by sociobehavioural risk factors.
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