Rapid Response Spatial Information System: Avian Influenza in Thailand
Sitthisak Moukomla, Amonpan Poomchatra
Geo-Informatics and Space Technology Development Agency
196 Phahonyotin Rd. Chatuchak, Bangkok 10900 THAILAND
Email: sittisak@gistda.or.th
1. Introduction
1.1 Avian Influenza - Background
Over 100 years ago, Avian Influenza was first identified during an epidemic in Italy. Subsequently, the disease has spread out at irregular intervals in all world regions. The occurrences of recent outbreaks were in Hong Kong in 1997-1998 and 2003 and in the Republic of Korea in 2003. Moreover, the present outbreak is in Asia When domestic birds are infected, it is difficult to control Avian Influenza and often result in major economic impacts for poultry farmers in several affected countries, because mortality rates are high and infected fowl generally must be destroyed. The technical term is called "culled" to prevent the spread of the disease.
Due to the spread of epidemics in Asia, FAO estimated that approximately 20-25 million birds had been culled in the region as of 28 January 2004, accounting for less than 1 percent of the region's total inventories. Nevertheless, the devastation can impact on local economies and both commercial poultry operations and smallholders especially in Thailand, where the industry heavily relies on trade. In 2003, poultry exports from Thailand accounted for almost 7 percent of global poultry meat trade, with an export value of roughly US$1 billion. (http://www.fao.org/ag/againfo/subjects/en/health/diseases-cards/avian_bg.html)
1.2 Thailand Avian Influenza status
Thailand was one of the hardest hit countries in the Region.Over 36 million birds died or had been destroyed during the control activities. Thailand was the country with human fatalities (8 in totals) similar to Viet Nam. The avian flu hit 41 out of the 76 provinces in the country and had a disastrous effect on export and domestic consumption. The selected control measures were based on the Office International des Epizooties (OIE) recommendations i.e. compulsory culling and movement control. Currently, the outbreak can be considered principally contained.
In the mid of November, 2003, there was an outbreak on one layer farm at Nong Bua district, Nakornsawan province. The outbreak was completely contained. During the end of December, 2003, laboratory result firstly detected in a layer farm, Bangplama district, in Suphanburi province, central region of Thailand. Thailand promptly notified the OIE and announced Suphanburi province as the infectious disease control zone, on January 23rd, 2004. The results of 66,000 laboratory tests, on January 29th, 2004, indicated that 153 samples were found Avian with Influenza. Consequently, the Ministry of Agriculture and Cooperatives announced these areas to be the infectious disease control area. The post outbreak surveillance scheme, however, identified new outbreaks (report ending on March 19th, 2004, source: Department of Livestock Development, Thailand): One outbreak each was confirmed in Chiang Mai province (north), Uttaradith province (north), Ayutthaya province (central) and Chonburi province (east). Layer chickens and ducks were affected in these outbreaks and a total of 29,405 birds were destroyed.
From the report of Coordinating Center for AI Control (private sector) stated that, only in Chonburi province, over 20,000 chickens were recently destroyed after the AI infection was confirmed on 18 March 2004 in layer chickens. (Source: The Daily News, 30 March 2004). This emergence of the disease has adjourned the government's intention to declare the country free of AI. The consumers' confidence in eating poultry meat and eggs has been regained. (http://www.fao.org/ag/aga.html)
Geographic Information System (GIS) is used for further analysis and management. A GIS is a software system, used to collect, store, manage, analyze, and present geographic information, also, its semantic content. Coupling digital database and GIS technology provides the means for a detailed analysis of spatial patterns and distributions. For example, a GIS can be used to calculate the number of animals inside and/or around a specific area, and to identify its locations. It also allows the identification of farms (and farmers) within a specified buffer around a location of interest. This is typical for prevention measures in epidemiological veterinary applications. GIS can handle identification and calculation of animals inside a buffer zone in an automated manner (M. Ehlers et .al, 2002).
2. Objective
2.1. To determine trends and directions of Avian Influenza dispersion in Thailand.
2.2. To specify restricted zone and clearing zone in specific case study area
2.3. To demonstrate the specific case study area being a prototype for other epidemiological cases
3. Methodology
Existing information of this study is limited to regional seek due to the fact that information declaration by the Ministry of Agricultural and Cooperative (Department of Livestock Development) is in District level. This study is separated into 2 parts including overview of Thailand and specific case study area. The detail of each part will be described below.
3.1 Nation -wide case
Due to the AI’s rapid dispersion throughout Thailand, Geo-informatics were utilized of the regional scale. The outbreak areas information from the Ministry of Agricultural and Cooperative (Department of Livestock) were linked with related Geo-database such as Administrative Layer, Transportation Layer etc. Dispersing trend and its direction were surveyed. Following the declaration of affected area at District level, dispersion areas were converted to centroid for identification with the 50 kilometers radius buffer as the restricted zone. All related information had been illustrated on Internet Map Server so that relevant agencies could make use of it through the internet for their decision making process.
3.2 Specific case study area
High resolution satellite imageries along with other geo-information were used to identify affected chicken farms. Geographic Information System (GIS) and Global Positioning System (GPS) were utilized to set up clearing zone with the 5 kilometers radius buffer from the affected farms. The quantity and density of poultry were estimated.