I have heard some people with HIV referred to as being "non-detectable positive". Does this mean that people can be HIV positive but have such a low viral load that they test negative? If so, can such people transmit HIV? In other words, does one need to be concerned about getting HIV from someone (in a monogamous relationship) who has been very promiscuous, yet tests negative?

Hi,

You are confusing two different tests here. The tests for detecting whether or not someone is HIV-positive (ELISA tests, antibody tests, confirmatory Western Blot tests) will always remain positive in a person infected with the virus. The "non-detectable" terminology refers to a completely different type of test that measures viral load (how actively the virus is replicating). These tests can measure down to a certain level. Below that, we say a person is "non-detectable." That person would still test HIV-positive, despite his/her non-detectable viral load. I hope that answers your questions.

Dr. Bob