04 February 2021

---

HSV Oral Infection in Clinical Dental Practice

Authors:Martina Salvatorina Murgia, Maria Elisabetta Murgia, Alessandra Scano, Cinzia Casu, Germano Orrù

---

Herpes simplex 1 (HSV-1) infection is often underestimated, despite the global seroprevalence of the virus, present in about 3709 million people. It is estimated that both HSV-1 and Herpes simplex type 2 (HSV-2) are present in the oral cavity even in the absence of symptoms and clinical lesions. This infectious disease can result in severe and highly relapsing forms, especially in immunosuppressed patients, and it can cause serious complications. Our aim was to consider three issues:
(i) the rate of the asymptomatic diffusion of both HSV-1 and HVS-2, from the oral cavity of immunosuppressed and immunocompetent patients;
(ii) the re-exacerbation following dental treatments;
(iii) the professional risk for the members of the medical team, in order to apply the appropriate safety procedures.

Materials and Methods
Three systematic analyzes/inclusion criteria were performed by using medical and health databases: (i) only in vivo human studies and clinical investigations based only on samples taken from oral sites with direct positive laboratory diagnosis; (ii) the second one included the papers in which is reported recurrent herpetic infection after dental treatment; (iii) the third one included all cases of herpetic infection, got by the medical teams in their work structures, in any tissue site. Various combinations of keywords were used: Herpes simplex virus, HSV-1, HSV-2, saliva, dental extraction, procedure, treatment, transmission, dentist, occupational risk. Out of a total of 1282 studies, 73 fitted the inclusion criteria.

Results 
Results point out that the main HSV spread mode is asymptomatic, regardless of the immune status of individuals. According to our literature analysis, HSV-1 is the most excreted virus in immunocompetent subjects, while HSV-2 is also detected in subjects with altered immune status, although it occurs less frequently and often in association with the recurrent genital lesion. The amount of total and type I HSV DNA is statistically more detectable in HIV positive and oncological patients than in immunocompetent patients (p<0,01) but not in transplant patients (p>0,01). HSV-2 is more detectable in HIV positive patients than healthy ones (p<0,01) but not in cancer and transplant patients (p>0,01).

Conclusions
As for the exacerbation of HVS-1 after dental treatments, studies in literature are discordant: some show a significant correlation, others opposite outcomes. Finally, as for the professional risk, the dental medical team appears to be more exposed to the infection than common population. Indeed, several cases of herpetic infection have been reported following the treatment of patients with active lesions; most of them are represented by herpetic whitlow, which incidence has decreased, i.e. as ocular keratitis, thanks to the use of individual protection devices, DPI.

Clinical implications
The morbidity related with HSV infection is often associated with the increasing number of immunocompromised patients observed in these last decades has significant implications in daily outpatient treatment. In addition, the presence of severe and refractory lesions in apparently healthy individuals must always be carefully evaluated by dentists. At the present, there are no well-standardized protocols regarding the treatment of patients with oral herpetic infection. In this context an exhaustive procedure is strictly needed in supporting a good clinical governance in the oral medical practice.