In Mexico, half had no underlying health problems; in Canada 70 per cent had no major illness beforehand.

在墨西哥，半数人群没有基础疾病；在加拿大，70%的人之前都没有重病。

youdao

However the ability to smell drops off much quicker in older people who were taking medications - also an indicator of underlying health problems.

然而，服用药物的老年人的嗅觉能力减退更快。服用药物也是表明存在潜在健康问题的指标之一。

youdao

The people who do get more serious cases that lead to hospitalization have tended to have underlying health conditions like heart problems, lung ailments, immune diseases, and diabetes.

那些病情严重以致住院的人往往与其自身的健康状况有关，如心脏问题、肺部疾病、免疫性疾病以及糖尿病。

youdao

But poverty, substandard, overcrowded housing and underlying health problems are thought to be the most likely culprits, he says.

BBC: Flu hits Canada's native peoples

Children aged between six months and 10 years who do not suffer from underlying health problems will now be given one vaccine dose instead of two.

BBC: Change to swine flu jab advice

He had underlying health problems but his mother, Angela Colfer, is angry that he was not diagnosed with measles until after his death despite him being seen by doctors hours before he died.

BBC: Swansea measles: Clinic quizzed over single jab claims