Short-term inhibition of SARS-CoV-2 by hydrogen peroxide in persistent nasopharyngeal carriers

Efficacy of different mouthwashes against COVID-19: A systematic review and network meta-analysis

To evaluate the effectiveness of antiseptic mouthwashes in reducing SARS-CoV-2 load clinically and in vitro. A systematic electronic search (MEDLINE/Scopus/Cochrane) was conducted to identify prospective clinical and in vitro studies published between 2019 included and 16 June 2023 assessing the effectiveness of mouthwashes in reducing SARS-CoV-2 load in saliva or surrogates. Data were summarized in tables and a network meta-analysis was performed for clinical trials. Thirty-five studies (14 RCTs, 21 in vitro) fulfilled the inclusion criteria. The risk of bias was judged to be high for 2 clinical and 7 in vitro studies. The most commonly test product was chlorhexidine alone or in combination with other active ingredients, followed by povidone-iodine, hydrogen peroxide and cetylpyridinium chloride. Overall, the descriptive analysis revealed the effectiveness of the mouthwashes in decreasing the salivary viral load both clinically and in vitro. Network meta-analysis demonstrated a high degree of heterogeneity. Among these studies, only chlorhexidine 0.20% was associated to a significant Ct increase in the saliva 5 min after rinsing compared to non-active control (p = 0.027). Data from clinical and in vitro studies suggested the antiviral efficacy of commonly used mouthwashes. Large well-balanced trials are needed to identify the best rinsing protocols.

Oral SARS-CoV-2 reduction by local treatment: A plasma technology application?

The SARS-CoV-2 pandemic reemphasized the importance of and need for efficient hygiene and disinfection measures. The coronavirus' efficient spread capitalizes on its airborne transmission routes via virus aerosol release from human oral and nasopharyngeal cavities. Besides the upper respiratory tract, efficient viral replication has been described in the epithelium of these two body cavities. To this end, the idea emerged to employ plasma technology to locally reduce mucosal viral loads as an additional measure to reduce patient infectivity. We here outline conceptual ideas of such treatment concepts within what is known in the antiviral actions of plasma treatment so far.

Could mouth rinses be an adjuvant in the treatment of SARS-CoV-2 patients? An appraisal with a systematic review

Objective

A wide variety of mouth rinses are available to combat micro‐organisms in the oral cavity. At the present global pandemic, the need of the hour is to control the viral infection due to the novel corona virus SARS‐COV‐2, as its port of entry is through the receptors located in the oral and pharyngeal mucosa. This systematic literature review focuses on the in vivo studies [randomized control trials (RCTs)] done on the efficacy of existing mouth rinses which have been used in reducing the viral loads.

Methods

The electronic database which includes PubMed‐MEDLINE, Google scholar, Scopus, Web of Science, EMBASE, ProQuest and CINAHL was searched from December 2019 to June 2021 with appropriate Medical Subject Headings (MeSH) terms and Boolean operators. Two reviewers independently reviewed the abstracts.

Results

Of the 2438 retrieved titles, 905 remained after removing duplicates. Twelve articles were eligible to be included in this review of which seven were randomized with adequate sample size.

Conclusions

Mouth washes containing povidone iodine and chlorhexidine decrease the viral load transiently. Large amount of in vivo studies are of paramount importance, especially RCTs, to prove the efficacy of these mouth rinses.

Efficacy of Mouth Rinses Against SARS-CoV-2: A Scoping Review

Introduction:The presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in saliva and nasopharyngeal secretions has challenged the routine practice of dentistry. Use of preprocedural mouth rinses has been recommended by several organizations to potentially reduce the transmission of SARS-CoV-2. This scoping review aimed at evaluating the available evidence on the efficacy of mouth rinses against SARS-CoV-2.

Methods:A thorough literature search on electronic databases (PubMed, Scopus, and Google Scholar) was performed by two independent reviewers and data from articles addressing the aim of this article were extracted.

Results:After exclusion of articles not addressing the end point in question, 12 articles were included in this scoping review. Of the 12 articles, seven werein vitrostudies and five werein vivohuman clinical studies. Thein vitrostudies used a standardized methodology (endpoint dilution assay) to evaluate the efficacy of antimicrobial mouth rinses against SARS-CoV-2. Thein vivostudies were done utilizing polymerase chain reaction assay of samples obtained from saliva or nasopharyngeal swab or a combination of both nasopharyngeal and oropharyngeal swab. The reagents tested in these studies included povidone-iodine, chlorhexidine, hydrogen peroxide (H2O2), essential oils, and quaternary ammonium compounds and demonstrated varied efficacy against SARS-CoV-2.

Conclusion:Based on the available evidence fromin vitrostudies, it can be concluded that mouth rinses have a potential to reduce SARS-CoV-2 viral load; however, effectiveness inin vivoconditions is still inconclusive. Owing to the substantial heterogeneity in reporting of the anti–SARS-CoV-2 efficacy of mouth rinses, this review highlights the need to conduct future research with robust and standardized methodologies to confirm effectiveness of mouth rinses.

Topical Oral and Intranasal Antiviral Agents for Coronavirus Disease 2019 (COVID-19)

With the largest viral loads in both symptomatic and asymptomatic patients with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) present in the oral and nasal cavities, agents that act on these two areas have the potential for large therapeutic and prophylactic benefit. A literature review was conducted to elucidate the possible agents useful in treatment of SARS-CoV-2. These agents were evaluated for their current applications, adverse reactions, their current state of study, and any future considerations in their management of coronavirus disease 2019 (COVID-2019). Our review has found that, while there are many promising agents with proven efficacy in their in-vitro efficacy against SARS-CoV-2, more clinical trials and in-vivo studies, as well as safety trials, must be conducted before these agents can be effectively implemented.

Short-term inhibition of SARS-CoV-2 by hydrogen peroxide in persistent nasopharyngeal carriers

Asymptomatic and convalescent coronavirus disease 2019 (COVID-19) subjects may carry severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for months in their upper respiratory ways. Desiring to permanently clean the mucosal surfaces, we investigated the chemical agents that fit to rapidly degrade the virus. Among these, hydrogen peroxide, initially tested by two of us for tolerability, showed both good performance and acceptable side effects (burning sensation for 15-20 s). We contacted circles of family physicians and the ATS Milano (Territorial Assistance and Prevention Service), and we tested this procedure on eight persistent carriers of SARS-CoV-2, performing swabs before the procedure and after it until the reappearance of the virus or until 14 days (the incubation period), keeping the surfaces clean with a hypertonic solution. Our patients had a median time from exposure or symptom onset of 111 days, and three had relapsed after being declared "cured" (two consecutive negative swabs after quarantine). One patient had a baseline negative swab and was excluded, and two successfully ended the 14 days' course, four suppressed viral elimination for 72 h, and one for 48 h, all rebounding to weak positive (cycle thresholds above 24). Although temporarily effective, such measures may have some place in the control of viral shedding to protect the most fragile subjects.