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FMD has been eradicated from the island countries of South-East Asia. Brunei, Indonesia and Singapore have maintained their status as FMD-free countries without vaccination. East Malaysia (Sabah and Sarawak) was certified FMD-free without vaccination by the OIE in 2004. In the Philippines, the island of Mindanao obtained FMD freedom in 2000 and the islands of Visayas, Palawan and Masbate became FMD-free in 2002. Zones 1 and 3 of the Philippine island of Luzon were certified as FMD-free in 2010. In May 2011, OIE recognized Zone 2 of Luzon making the whole of the Philippines FMD-free without vaccination.
FMDV serotypes O, A, and Asia 1 are endemic to countries in mainland Southeast Asia (Cambodia, Laos, peninsula Malaysia, Myanmar, Thailand, and Vietnam) where regular outbreaks of FMD have been reported. Serotype O is the most common and three topotypes have been identified (South-East Asia, pan-Asia and Cathay or pig-adapted strain).
After massive outbreaks in late 1990s due to the incursion of the pan-Asia strain of serotype O, outbreaks started to decline in 2002. However, a resurgence of serotype A in Thailand in 2003 increased the cumulative outbreaks in the sub-region that year. Other epizootics happened in 2006 when the Myanmar 98 strain of serotype O caused massive outbreaks in Vietnam and other countries, and the outbreaks became sporadic from 2007 to 2009. The most recent epizootics were again observed in 2010/2011 that peaked from December 2010 until February 2011. As expected, sporadic outbreaks continued to decline in the following months.
It is critical that early detection and immediate control of isolated outbreaks be actively pursued to prevent any outbreaks being propagated that could develop into a full-blown epizootic. This means that 2012 to 2013 will be a critical period for the FMD control campaign.
Serotype A is the only serotype currently circulating on the mainland, although a few antigenic changes have been observed since 1990; these have led to replacement of seed virus strains for vaccines.
The predominant strains of FMD in China are serotypes O and Asia 1. However, in 2009, China reported outbreaks of serotype A that were similar to the strain circulating in the Mekong sub-region. In 2010, outbreaks of the Myanmar 98 strain of serotype O were also reported. A key facet of China’s FMD control strategy is mass vaccination. It is estimated that 4.2 billion vaccines are used each year to protect 115 million cattle, 652 million pigs, 171 million sheep and 196 million goats. China is examining its vaccination options to deal with the new strains. The recent outbreaks of FMD in the Republic of Korea and Japan caused by viruses closely related to viruses circulating in South-East Asia demonstrates that even countries with more developed veterinary services are not exempt from FMD incursions. FMD-free countries in the Region and in Oceania must remain vigilant and prevent entry of FMD into their countries. This applies equally to free countries and zones in the Southeast Asia - China FMD (SEACFMD) programme.
FMD in mainland South-East Asia countries and China follows a cyclical pattern of epizootics. Increase in outbreaks were observed in late 1990s and early 2000, followed in 2006, then the most recent one was in late part of 2010 that lasted until early 2011. In the first half of 2010, the overall incidence of FMD in South- East Asia was seen at its lowest compared to the previous three years. However, starting in September 2010 increased outbreaks were reported in Cambodia, Lao PDR, Thailand and Vietnam. The epizootics peaked in December until February 2011, and sporadic outbreaks were reported in the following months. The distribution and movement of FMD viruses in the region is a reflection of the trade-driven movement of livestock. There is great disparity across the region in the strength and resources of the animal health services and this has a direct impact on FMD control.
Thanh Long To. Foot-and-Mouth disease in Southeast Asia. The 6th Asian Pig Veterinary Society Congress. 2013.