Science Snippet: Viruses and Bacteria May Remain Hidden in Bodies

Even after powerful drugs eliminate disease-causing viruses and bacteria from blood, many of these agents can “hide away” in various compartments in the body. The average human body is made up of 37.2 trillion individual cells, which is at least 800 trillion more than the known galaxies in the universe. There must be lots of hiding places among 37.2 trillion body cells. Sixteen authors studied HIV-infected individuals who had been treated with antiviral drugs until blood samples showed no evidence of the virus. When tissue samples were examined for the virus, to the researcher’s surprise, they found evidence that HIV activity was continuing in certain lymph nodes. What this means is unclear, although it is known that antiviral drugs have trouble accessing lymph node compartments. The bottom line is that many infectious agents can remain hidden away in the body, sometimes for years, before initiating a recurrence of the disease state. (Lorenzo-Redondo, R., et al, 2015, “Persistent HIV-1 replication maintains the tissue reservoir during therapy,” Nature, February 4; Science, 2016, Jan. 28; other sources)