NBEO Microbiology Practice Test

Latency in neurons is a hallmark feature of herpesviruses. Among the enveloped DNA viruses listed, herpes simplex virus is the one that establishes lifelong persistence in sensory neurons. After the initial infection, the viral genome persists as an episome in the cell bodies of neurons in sensory ganglia (such as the trigeminal ganglion for oral HSV-1). During latency, most viral genes are silent, with limited expression of latency-associated transcripts that help keep the virus hidden and reduce cell damage. Periodically, the virus can reactivate, traveling back to the mucosal surface to cause recurrent lesions (cold sores or genital herpes) and intermittent shedding.

In contrast, cytomegalovirus also has an envelope and is a herpesvirus, but it remains latent primarily in cells of the myeloid lineage (like monocytes/macrophages), not neurons. Epstein-Barr virus, another enveloped herpesvirus, tends to persist latently in B cells. Adenovirus is non-enveloped and does not establish neuronal latency.