Bangkok: Dr. Yong Poovorawan, a prominent virologist from Chulalongkorn University, has issued a warning regarding a hepatitis A outbreak spreading in eastern Thailand, advising caution when consuming seafood that is raw or undercooked. The outbreak seems to affect primarily those under 40 years old, as older populations generally possess immunity to the virus.
According to Thai News Agency, Dr. Yong shared insights on Facebook about this year's significant increase in hepatitis A cases. The virus, part of the enterovirus group, is spread via fecal contamination and can lead to outbreaks, particularly affecting vulnerable groups. While hepatitis A features multiple genotypes, it has only one serotype, granting lifetime immunity post-infection.
The outbreak is notably contagious, with many under 40 lacking immunity if unvaccinated. Approximately half of those aged 40-50, and most over 60, have immunity from natural infection. Improved modern hygiene means younger individuals now require vaccinations, unlike those born 50-60 years ago who gained immunity through common practices of their time, such as sharing drinking bowls.
Typically, hepatitis A outbreaks occur at the beginning of the rainy season, but this year's spread began in the summer, raising concerns about increased cases as the rainy season progresses. The Ministry of Public Health often attributes outbreaks to contaminated water, though initial outbreak sources are hard to identify. It is believed that migrant workers may introduce and spread the virus within factory settings.
Maintaining hygiene in food production and restaurant settings is critical, particularly handwashing after restroom use. Vaccinating personnel in these areas is vital to curtailing the disease's spread. Seafood is another significant outbreak source, as the virus endures in seawater and shellfish can ingest it. Cooking seafood to temperatures above 85 degrees Celsius is necessary to kill the virus, making thoroughly cooked food safe for consumption. However, inadequately cooked shellfish, like cockles or raw oysters, pose a risk of transmission, reminiscent of a past outbreak in Shanghai.
The situation requires ongoing attention and further updates will be provided. Stay informed for more details.