Meaning of "behind the initial outbreak" in the following sentences?

Question

What is the meaning of "behind the initial outbreak" in the following sentences,

The death toll has now topped 3,000 in China, where experts say they have identified two of the virus. That team, based at Beijing’s Peking University, suggested a more aggressive strain was behind the initial outbreak and accounts for 70 per cent of cases, while a milder version is now spreading faster.

(Source : "Coronavirus ‘is like a combination of SARS and AIDS’, doctors say " By Sam Corbishley )

Does "a more aggressive strain was behind the initial outbreak" mean "a more agressive strain was spreading slower" ?

Answer 1

The meaning of ‘behind’ that you have observed is roughly synonymous with ‘following’, or ‘coming after’, as in

‘He was running behind me’.

It can also be used as ‘getting less points than’, as in

The red team is behind the blue team.

(‘Points’ there can be used as any kind of number that you keep track of.)

However, behind can also mean controlling something, or causing it, as in

“I knew Moriarty was behind that plot!” cried Holmes.

Sherlock Holmes doesn’t mean to say that he knew that Moriarty was physically following after ‘that plot’, or that Moriarty had less ‘numbers’ than ‘that plot’, but rather that he knew that Moriarty had caused ‘that plot’ to happen, whatever it may be.

Likewise, the text doesn’t mean to say that ‘a more aggressive strain was spreading slower’, that it was behind or in ‘points’ (in this case people infected). Nor does it mean that the more aggressive strain was physically behind, or somehow ‘running after’ the initial outbreak, as in some kind of absurd ‘foot-race of the diseases’. Rather, it means that the more aggressive strain caused the initial outbreak.

Hope that helps!