But that doesn't always work because the bacteria or virus may not be present in the blood or other easily accessible area.

但是这个方法常常不会凑效，因为病原不会总是出现在血液或者其他容易被发现的地方。

youdao

The results showed that there is 6.3% dead larvae caused by infection of pathogenic fungi in EAB nature population, no finding that of pathogenic bacteria or virus.

通过在洋白蜡和水曲柳等受害林地进行解剖调查，发现白蜡窄吉丁自然种群中幼虫的自然感病死亡率为6.3％，均为真菌感染，没有发现病原细菌和病毒感染致死的情况。

youdao

HIV is hard to transmit because lots of bacteria or virus has to have direct contact with susceptible tissues and it is not possible to carry enough bacteria on the hands.

HIV是很难传播的因为细菌和病毒必须直接和易被感染的细胞组织接触，但在手上没有可能带来足够多的病毒。

youdao

He says normally a protein in healthy immune cells causes the cells to die after they attack an invading virus or bacteria.

VOA: special.2010.05.19

The tissue may contain evidence of the virus or bacteria that caused the person to die.

VOA: special.2010.06.29

And how the cells shutdown is they actually die Harris Perlman says a protein in healthy immune cells causes them to die after they attack an invading virus or bacteria.

VOA: special.2010.03.16

However, Haseltine says the odds of a medicine working against a bacteria like anthrax or a virus like smallpox are very high after even early-stage tests.

FORBES: Genomics Pioneer Takes On Anthrax

Unlike a virus or bacteria, it contains no genetic information of its own, and does not spread by reproducing or making copies of itself.

BBC: vCJD and BSE - the link

The acute conditions are usually caused by viruses such as the "common cold" virus or by common bacteria.

CNN: What can I do for my chronic sinusitis?