The mainland may not have an official caste system, but hepatitis B is an almost insurmountable barrier that divides10 per cent of its population from the rest.

• 也许在中国大陆并没有官方的社会等级划分，但乙型肝炎几乎成为了一道不可逾越的障碍，把它十分之一的公民与其他人相区别开来。