如果有被污染的血液残留在针的内孔或注射器里，然后有人使用它进行毒品注射的话，残留的血液可能会进入血液循环系统中。

If HIV infected blood remains within the bore (inside) of the needle or in the syringe and someone else then uses it to inject themselves, that blood can be flushed into the bloodstream.

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当时瘾君子正在楼梯井注射毒品。

Drug users were jacking up in the stairwells.

《牛津词典》

此外，社区服务、小组辅导和其他活动，如鼓励安全行为和普及预防发放等对于注射毒品使用者来说也很重要。

Also important for injecting drug users are community outreach, small group counselling and other activities that encourage safer behaviour and access to available prevention options.

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