A new bird flu is infecting patients across China, currently 16 patients have tested positive for the virus and six have died. But some flu watchers are convinced that the test that doctors are using to detect the H9N7 virus are faulty — that they aren't sensitive enough.

Even patients on their death beds are only "weakly positive" Laurie Garrett, senior editor for the Council on Foreign Relations and flu-outbreak-follower notes on twitter:

I'm convinced something is wrong w/ #H7N9 test. Even in patients in critical condition tests are "weakly positive" news.qq.com/a/20130405/000… — Laurie Garrett (@Laurie_Garrett) April 5, 2013

Are #H7N9 tests missing cases? news.com.au/breaking-news/…> Person in close contact w/victim had flu-like symptoms but tested negative for H7N9, — Laurie Garrett (@Laurie_Garrett) April 5, 2013

This could mean that the test is missing vital cases before they get to the seriously ill stage, so we won't know who is infected until it gets really bad. It could also mean the virus is more widespread than tests are showing us.

This is especially important for the 520 people that the WHO is monitoring for infection. These people were in close contact with people who died or became seriously ill. Reports yesterday said that one of these people showed flu-like symptoms but tests later confirmed to show negative results.

If that test was faulty.... that person could still have the virus. And it would be a sign that the virus can spread between humans — a very dangerous omen.

There are also reports that animals are falling ill with the disease, even birds falling out of the sky. These animals test negative for the virus, but if the tests are faulty, that could be a big problem.