Limits...
Spatio-temporal distribution and hotspots of Hand, Foot and Mouth Disease (HFMD) in northern Thailand.

Samphutthanon R, Tripathi NK, Ninsawat S, Duboz R - Int J Environ Res Public Health (2013)

Bottom Line: The results indicate that the disease can occur at any time of the year, but appears to peak in the rainy and cold seasons.When separated by season, it was found that there was a significant correlation with the direction of the southwest monsoon at the same time.In particular, a new hotspot was found in the recent year in Mae Hong Son province.

View Article: PubMed Central - PubMed

Affiliation: Remote Sensing and Geographic Information Systems Field of Study, School of Engineering and Technology, Asian Institute of Technology, P.O. Box 4, Klong Luang, Pathumthani 12120, Thailand. ratchaphon.samphutthanon@ait.ac.th.

ABSTRACT
Hand, Foot and Mouth Disease (HFMD) is an emerging viral disease, and at present, there are no antiviral drugs or vaccines available to control it. Outbreaks have persisted for the past 10 years, particularly in northern Thailand. This study aimed to elucidate the phenomenon of HFMD outbreaks from 2003 to 2012 using general statistics and spatial-temporal analysis employing a GIS-based method. The spatial analysis examined data at the village level to create a map representing the distribution pattern, mean center, standard deviation ellipse and hotspots for each outbreak. A temporal analysis was used to analyze the correlation between monthly case data and meteorological factors. The results indicate that the disease can occur at any time of the year, but appears to peak in the rainy and cold seasons. The distribution of outbreaks exhibited a clustered pattern. Most mean centers and standard deviation ellipses occurred in similar areas. The linear directional mean values of the outbreaks were oriented toward the south. When separated by season, it was found that there was a significant correlation with the direction of the southwest monsoon at the same time. An autocorrelation analysis revealed that hotspots tended to increase even when patient cases subsided. In particular, a new hotspot was found in the recent year in Mae Hong Son province.

Show MeSH

Related in: MedlinePlus

Linear directional mean for each season and the annual monsoon direction in Thailand.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3924446&req=5

ijerph-11-00312-f012: Linear directional mean for each season and the annual monsoon direction in Thailand.

Mentions: GIS and a global spatial analysis method with spatial autocorrelation were applied to study the occurrence of the disease at the village level over the study period from 2003 to 2012. The results showed that the distribution patterns were clustered throughout all years except 2007, during which the cases exhibited a dispersed pattern. The most intense clustering occurred in 2004, with a Moran’s I of 0.634. Viewed by season, the most prominent outbreaks were found during the rainy and cold seasons. The mean center site remained in the northern part of Lampang province over the whole period. The Standard Deviation Ellipses of the villages affected by the disease covered nearly the entire area in the middle north and the northeast with seven out of all nine provinces. The trend of the global diffusion pattern was from northeast to southwest. The Linear Directional Mean classified by season revealed the influence of the annual monsoon (Figure 12). Significant differences occurred between the individual rainy seasons, but all LDMs followed a similar path in the northern direction. This corresponds to the southwest monsoon during this time of the year, and it indicates that the movement of the MC during this period is influenced by the southwest monsoon. This is consistent with studies conducted in China reporting that from May to June, intense disease clusters began to move from the south to the north [46]. The LDMs in the summer months showed different, irregular patterns. The monthly LDMs of the cold season, even though not clearly associated with the northeast monsoon, showed significantly similar patterns.


Spatio-temporal distribution and hotspots of Hand, Foot and Mouth Disease (HFMD) in northern Thailand.

Samphutthanon R, Tripathi NK, Ninsawat S, Duboz R - Int J Environ Res Public Health (2013)

Linear directional mean for each season and the annual monsoon direction in Thailand.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3924446&req=5

ijerph-11-00312-f012: Linear directional mean for each season and the annual monsoon direction in Thailand.
Mentions: GIS and a global spatial analysis method with spatial autocorrelation were applied to study the occurrence of the disease at the village level over the study period from 2003 to 2012. The results showed that the distribution patterns were clustered throughout all years except 2007, during which the cases exhibited a dispersed pattern. The most intense clustering occurred in 2004, with a Moran’s I of 0.634. Viewed by season, the most prominent outbreaks were found during the rainy and cold seasons. The mean center site remained in the northern part of Lampang province over the whole period. The Standard Deviation Ellipses of the villages affected by the disease covered nearly the entire area in the middle north and the northeast with seven out of all nine provinces. The trend of the global diffusion pattern was from northeast to southwest. The Linear Directional Mean classified by season revealed the influence of the annual monsoon (Figure 12). Significant differences occurred between the individual rainy seasons, but all LDMs followed a similar path in the northern direction. This corresponds to the southwest monsoon during this time of the year, and it indicates that the movement of the MC during this period is influenced by the southwest monsoon. This is consistent with studies conducted in China reporting that from May to June, intense disease clusters began to move from the south to the north [46]. The LDMs in the summer months showed different, irregular patterns. The monthly LDMs of the cold season, even though not clearly associated with the northeast monsoon, showed significantly similar patterns.

Bottom Line: The results indicate that the disease can occur at any time of the year, but appears to peak in the rainy and cold seasons.When separated by season, it was found that there was a significant correlation with the direction of the southwest monsoon at the same time.In particular, a new hotspot was found in the recent year in Mae Hong Son province.

View Article: PubMed Central - PubMed

Affiliation: Remote Sensing and Geographic Information Systems Field of Study, School of Engineering and Technology, Asian Institute of Technology, P.O. Box 4, Klong Luang, Pathumthani 12120, Thailand. ratchaphon.samphutthanon@ait.ac.th.

ABSTRACT
Hand, Foot and Mouth Disease (HFMD) is an emerging viral disease, and at present, there are no antiviral drugs or vaccines available to control it. Outbreaks have persisted for the past 10 years, particularly in northern Thailand. This study aimed to elucidate the phenomenon of HFMD outbreaks from 2003 to 2012 using general statistics and spatial-temporal analysis employing a GIS-based method. The spatial analysis examined data at the village level to create a map representing the distribution pattern, mean center, standard deviation ellipse and hotspots for each outbreak. A temporal analysis was used to analyze the correlation between monthly case data and meteorological factors. The results indicate that the disease can occur at any time of the year, but appears to peak in the rainy and cold seasons. The distribution of outbreaks exhibited a clustered pattern. Most mean centers and standard deviation ellipses occurred in similar areas. The linear directional mean values of the outbreaks were oriented toward the south. When separated by season, it was found that there was a significant correlation with the direction of the southwest monsoon at the same time. An autocorrelation analysis revealed that hotspots tended to increase even when patient cases subsided. In particular, a new hotspot was found in the recent year in Mae Hong Son province.

Show MeSH
Related in: MedlinePlus