lungworm

These pigs had acquired lungworm infestations presumably containing masked influenza virus under natural conditions.

这些猪在自然条件下已受含有隐蔽流感毒的肺寄生。

As a rule the swine infested with the lungworms carrying the "masked virus" did not develop swine influenza immediately upon infestation with the lungworm.

通常，受了“隐蔽毒”的肺袭的猪，并不因肺的袭立即发生流感。