HSV-1 commonly becomes latent in which structure?

• A. Facial nerve
• B. Trigeminal nerve
• C. Maxillary nerve
• D. Cervical root ganglia

Answer: (B)

HSV-1 establishes latency in sensory ganglia, most commonly the trigeminal ganglion. After initial oral infection, the virus travels along sensory neurons to the trigeminal ganglion, where its genome persists in a latent state within the neuron. Reactivation can occur periodically, with the virus traveling back to the orofacial epithelium to cause cold sores. This is why the trigeminal nerve’s sensory ganglion is the correct structure for latency—the latent reservoir sits in those neuron cell bodies. The other structures don’t serve as the usual latent site: the facial nerve is mainly motor, cervical root ganglia are from spinal nerves, and a peripheral branch like the maxillary nerve does not house the latent HSV-1 reservoir.