Frequency of putative enteric zoster diagnosed using saliva samples in patients with abdominal pain: a prospective study.

Background Varicella-zoster virus (VZV) infects and establishes latency in neurons in the ganglia of the cranial nerve, dorsal root and enteric ganglia. VZV reactivation in enteric neurons (enteric zoster) can cause non-specific abdominal pain and/or serious gastrointestinal dysfunction without cutaneous manifestations. Detection of VZV DNA in saliva may be useful for identifying enteric zoster. We evaluated the frequency of putative enteric zoster based on the presence of salivary VZV DNA in patients with acute abdominal pain. Methods Adult patients who visited the emergency room due to moderate to severe acute abdominal pain were prospectively enrolled at a tertiary hospital between May 2019 and November 2019. Abdominopelvic computed tomography (APCT) was performed in all patients. We also evaluated the presence of salivary VZV DNA in patients with confirmed coronavirus disease-19 (COVID-19) who were under stressful conditions. Saliva samples were collected from all studied patients. Enteric zoster was suspected based on the presence of salivary VZV DNA, detected using real-time polymerase chain reaction (PCR). Results Fifty patients with moderate to severe abdominal pain were enrolled. Five of 50 patients exhibited positive VZV-DNA PCR results. APCT revealed that among these five patients, two had pancreatic head cancer, two had small bowel obstruction after intra-abdominal surgery, and one had no remarkable findings. However, all 14 patients with COVID-19 showed negative salivary VZV-DNA PCR results. Conclusions Approximately 10% of patients with moderate to severe acute abdominal pain showed positivity for salivary VZV DNA. Further studies are warranted on whether antiviral therapy based on salivary VZV-DNA PCR results may relieve abdominal pain in the studied patient population. Trial registration clinicaltrial.gov, number NCT03862092.