Question normal

Here in MS, our test results are positive only about 1 out of 5. A few days ago, the positive test percentage acc to Washington state’s Dept of Health was 7%. Is the test reliable? If so, does the high percentage of negative Results suggest that it takes significant exposure to test positive? If not, why are we focusing on these tests, especially since we are now saying that there is a significant percentage of asymptomatic spreaders?

I realize that this is something dangerous, esp for old guys like me, and I understand that even a small percentage of very sick patients can potentially break the health care system. But I’m having a difficult time (consistently) juxtaposing test result numbers, especially since tests are only done on patients with high index of suspicion) with consensus that this is highly infectious.