High seroprevalence of hepatitis A virus among migrant workers from Myanmar, Cambodia and Laos who are living in Thailand.

摘要

In Thailand, the socio-economic development that has occurred over the last few decades has brought general improvements in living standards, sanitation and hygiene. In consequence, there has been a gradual decline in the general seroprevalence of infection with hepatitis A virus (HAV), from a hyper-endemic situation to the current meso-endemicity (Poovorawan et al., 1997; Chatchatee et al., 2002; Chatproedprai et al., 2007). There is, however, some concern that areas with large populations of migrants from the neighbouring countries of Myanmar, Cambodia and Laos may still be hyper-endemic for HAV, although little is known about the HAV situation among these migrants or in their countries of origin. In 2004, the Thai Department of Employment estimated, that there were > 1,200,000 people from Myanmar, Cambodia and Laos working in Thailand (lib.doe.go.th/doeinfor/pagedata/ebookdoc/ 020400006369_l.pdf), and this estimate took no account of unregistered and illegal migrants. The annual influx of migrants is predicted to increase over the next few decades, and it is clear that the health problems of these workers could well have an impact on the non-migrant population.