Relationships of varicella zoster virus (VZV)-specific cell-mediated immunity and persistence of VZV DNA in saliva and the development of postherpetic neuralgia in patients with herpes zoster.

There are no surrogate markers for the development of postherpetic neuralgia (PHN) in patients with herpes zoster (HZ). All patients with HZ were prospectively enrolled to evaluate the associations of saliva varicella zoster virus (VZV) DNA persistence and VZV-specific cell-mediated immunity (CMI) with the development of PHN. Slow clearers were defined if salivary VZV DNA persisted after day 15. Salivary VZV was detected in 60 (85.7%) of a total of 70 patients with HZ on initial presentation. Of 38 patients for whom follow-up saliva samples were available, 26 (68.4%) were classified as rapid clearers and 12 (31.6%) as slow cleares. Initial VZV-specific CMI was lower in slow clearers than rapid clearers (median 45 vs 158 spot forming cells/10 6 cells, P = .02). Of the 70 patients with HZ, 22 (31.4%) eventually developed PHN. Multivariate analysis showed that slow clearers (OR, 15.7, P = .01) and lower initial VZV-specific CMI (OR, 13.8, P = .04) were independent predictors of the development of PHN, after adjustment for age and immunocompromised status. Initial low VZV CMI response and persistence of VZV DNA in saliva may be associated with the development of PHN.

Diagnostic Usefulness of Varicella-Zoster Virus Real-Time Polymerase Chain Reaction Analysis of DNA in Saliva and Plasma Specimens From Patients With Herpes Zoster.

Background: We evaluated the diagnostic usefulness of polymerase chain reaction (PCR) analysis for detecting varicella-zoster virus (VZV) infection and reactivation of VZV, using DNA extracted from saliva and plasma specimens obtained from subjects with suspected herpes zoster and from healthy volunteers during stressful and nonstressful conditions. Methods: There were 52 patients with a diagnosis of herpes zoster (group 1), 30 with a diagnosis of zoster-mimicking disease (group 2), and 27 healthy volunteers (group 3). Saliva and plasma samples were evaluated for VZV DNA by real-time PCR analysis. Results: Among patients with suspected herpes zoster (ie, patients in groups 1 and 2), the sensitivity of PCR analysis of salivary DNA for detecting VZV (88%; 95% confidence interval [CI], 74%-95%) was significantly higher than that of PCR analysis of plasma DNA (28%; 95% CI, 16%-44%; P < .001), whereas the specificity of PCR analysis of salivary DNA (100%; 95% CI, 88%-100%) was similar to that of PCR analysis of plasma DNA (100%; 95% CI, 78%-100%; P > .99). VZV DNA was not detected in saliva and plasma samples from group 3 (0%; 95% CI, 0%-14%). Conclusions: Real-time PCR analysis of salivary DNA is more sensitive than that of plasma DNA for detecting VZV among patients with suspected herpes zoster. We found no subclinical reactivation of VZV in group 3 following exposure to common stressful conditions.

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.

Dynamics of Viral Shedding and Symptoms in Patients with Asymptomatic or Mild COVID-19.

We conducted a prospective cohort study at a community facility designated for the isolation of individuals with asymptomatic or mild COVID-19 between 10 January and 22 February 2021 to investigate the relationship of viral shedding with symptom changes of COVID-19. In total, 89 COVID-19 adult patients (12 asymptomatic, 16 presymptomatic, 61 symptomatic) were enrolled. Symptom scores, the genomic RNA and subgenomic RNA of SARS-CoV-2 from saliva samples with a cell culture were measured. Asymptomatic COVID-19 patients had a similar viral load to symptomatic patients during the early course of the disease, but exhibited a rapid decrease in viral load with the loss of infectivity. Subgenomic RNA and viable virus by cell culture in asymptomatic patients were detected only until 3 days after diagnosis, and the positivity of the subgenomic RNA and cell culture in symptomatic patients gradually decreased in both from 40% in the early disease course to 13% at 10 days and 4% at 8 days after the symptom onset, respectively. In conclusion, symptomatic patients have a high infectivity with high symptom scores during the early disease course and gradually lose infectivity depending on the symptom. Conversely, asymptomatic patients exhibit a rapid decrease in viral load with the loss of infectivity, despite a similar viral load during the early disease course.

Recombinant vesicular stomatitis virus glycoprotein carrying a foot-and-mouth disease virus epitope as a vaccine candidate.

Foot-and-mouth disease (FMD) is one of the most highly contagious animal diseases. In an effort to overcome the drawbacks of the currently used inactivated foot-and-mouth disease virus vaccine, a novel recombinant protein carrying foot-and-mouth disease virus VP1 GH loop epitope linked to vesicular stomatitis virus glycoprotein was expressed in a baculovirus system. Its antigenicity was confirmed with ELISA using monoclonal antibody against foot-and-mouth disease virus. Twice immunizations one month apart in field pigs resulted in a significant antibody increase compared to the glutathione S-transferase carrier containing the same epitope and the commercial vaccine. To my knowledge, this is the first report that the recombinant protein vaccine was superior to the current vaccine. Although further studies are required to examine their immunogenicity in a large number of animals, this study sheds light on the development of a novel recombinant protein vaccine that could be easily produced in a general laboratory as an alternative to the current FMD vaccine, which requires a biosafety level 3 containment facility for vaccine production.

Ruptured abdominal aortic aneurysms due to Salmonella, not of typhi species.

Ruptured aortic aneurysms due to Salmonella not of typhi species are rare and associated with high morbidity and mortality. We present three patients with Salmonella-infected ruptured aortic aneurysms successfully treated with an in situ prosthetic bypass graft. One patient had a saccular aneurysm at the infrarenal aorta and two patients had fusiform aneurysms at the aortic bifurcation. All the patients were treated with wide debridement of the infected aortic tissue followed by in situ graft replacement and long-term systemic antibiotic therapy. The method of revascularization, in situ bypass or extraanatomic bypass, remains controversial. On the basis of our clinical experience and recent literature focusing on more than 10 cases, in situ bypass reconstruction may be a feasible surgical technique for Salmonella-infected ruptured aortic aneurysm.

Brain abscess due to Gemella haemolysans.

We present a case of brain abscess due to Gemella haemolysans and Bacteroides species in a 60-year-old-immunocompetent man who underwent dental procedures. The patient completely recovered following intravenous therapy with ampicillin and metronidazole for 6 weeks.