The cause of the disease is difficult to pin down precisely.

病因目前还难以解释清楚。

《牛津词典》

None of the doctors knew the cause of the disease.

没有一个医生知道这种病的病因。

youdao

Zhong spent much time in finding the cause of the disease.

钟南山花了很多时间来寻找病因。

youdao

But most important is finding the cause of the disease so it can be prevented or cured.

VOA: standard.2010.08.09

The Centers for Disease Control and Prevention says heart disease is the leading cause of death in the United States.

VOA: special.2010.06.08

The World Health Organization says mosquitoes carry organisms that cause disease and death for millions of people throughout the world.

VOA: special.2009.05.26

Neurologists fiercely debate whether the amyloid clumps are the cause of the disease--or merely a consequence.

FORBES: Alzheimer's Drug Showdown

Even after decades of research, the case that amyloid buildup is the main cause of the disease is hardly airtight.

FORBES: Magazine Article

"The cause of the disease may not be new, but the scale at which it is occurring has not been observed in recent years, " the WHO said in an email.

WSJ: Unexplained Disease Kills Over 60 Children in Cambodia