Effect of acetic acid inactivation of SARS-CoV-2.

Effective measures are needed to prevent the spread and infectivity of SARS-CoV-2 that causes COVID-19. Chemical inactivation may help to prevent the spread and transmission of this and other viruses. Hence, we tested the SARS-CoV-2 antiviral activity of acetic acid, the main component of vinegar, in vitro. Inactivation and binding assays suggest that acetic acid is virucidal. We found that 6% acetic acid, a concentration typically found in white distilled vinegar, effectively inactivated SARS-CoV-2 after 15-min incubation with a complete loss of replication of competent virus as measured by TCID50. Transmission electron microscopy further demonstrated that 6% acetic acid disrupts SARS-CoV-2 virion structure. In addition, 6% acetic acid significantly inhibits and disrupts the binding of SARS-CoV-2 spike protein binding to ACE2, the primary SARS-CoV-2 cell receptor, after contact with spike protein for 5, 10, 30 and 60 minutes incubation. Taken together, our findings demonstrate that acetic acid possesses inactivating activity against SARS-CoV-2 and may represent a safe alternative to commonly used chemical disinfectants to effectively control the spread of SARS-CoV-2.

Hands-On Training Courses for Cervical Cancer Screening, Diagnosis, and Treatment Procedures in Low- and Middle-Income Countries.

In 2018, there were approximately 570,000 new cases of cervical cancer worldwide. More than 85% of cases occurred in low- and middle-income countries (LMICs), primarily because of poor access to screening and a limited number of medical providers trained to diagnose and treat cervical precancerous lesions. Our objective was to provide locally arranged, hands-on training courses for medical providers in LMICs to learn to perform cervical cancer screening, diagnosis, and treatment procedures. The courses included didactic lectures and hands-on training stations using low-cost simulation models developed by bioengineers and students at Rice University in Houston, TX, United States, and the Malawi Polytechnic in Blantyre, Malawi. The hands-on training stations included visual inspection with acetic acid (VIA), colposcopy, cervical biopsy, endocervical curettage, loop electrosurgical excision procedure (LEEP), and thermal ablation. Provider pre- and postcourse confidence levels in performing the procedures were evaluated. From February 2017 to January 2020, we arranged 15 hands-on training courses in seven cities across six countries (El Salvador, Mozambique, Trinidad and Tobago, Lesotho, Malawi, and Nepal). Overall, there were 506 participants. The average number of participants per course was 38 (range 19-92). The participants included doctors, nurses, and midwives. The course duration varied from 1 to 3 days. Increased confidence in performing VIA, colposcopy and cervical biopsy, ablation, and LEEP was reported by 69%, 71%, 61%, and 76% of participants, respectively. Our findings suggest that locally arranged, hands-on cervical cancer prevention training courses in LMICs can improve provider confidence in performing cervical cancer screening, diagnosis, and treatment procedures. These courses are part of a larger strategy to build local capacity for delivering and improving cervical cancer prevention services in LMICs.

Addition of digital VIA/VILI to conventional naked-eye examination for triage of HPV-positive women: A study conducted in a low-resource setting.

BACKGROUND: World Health Organization guidelines for cervical cancer screening recommend HPV testing followed by visual inspection with acetic acid (VIA) for triage if HPV positive. In order to improve visual assessment and identification of cervical intraepithelial neoplasia grade 2 and worse (CIN2+), providers may use visual aids such as digital cameras. OBJECTIVES: To determine whether combined examination by naked-eye and digital VIA (D-VIA) and VILI (D-VILI) improves detection of CIN2+ as compared to the conventional evaluation. MATERIALS AND METHODS: Women (30-49 years) living in Dschang (West Cameroon) were prospectively invited to a cervical cancer screening campaign. Primary HPV-based screening was followed by VIA/VILI and D-VIA/VILI if HPV-positive. Health care providers independently defined diagnosis (pathological or non-pathological) based on naked-eye VIA/VILI and D-VIA/VILI. Decision to treat was based on combined examination (VIA/VILI and D-VIA/VILI). Cervical biopsy and endocervical curettage were performed in all HPV-positive participants and considered as reference standard. Diagnostic performance of individual and combined naked-eye VIA/VILI and D-VIA/VILI was evaluated. A sample size of 1,500 women was calculated assuming a prevalence of 20% HPV positivity and 10% CIN2+ in HPV-positive women. RESULTS: Due to the COVID-19 pandemic, the study had to terminate prematurely. A total of 1,081 women with a median age of 40 (IQR 35.5-45) were recruited. HPV positivity was 17.4% (n = 188) and 26 (14.4%) had CIN2+. Naked-eye VIA and D-VIA sensitivities were 80.8% (95% CI 60.6-93.4) and 92.0% (95% CI 74.0-99.0), and specificities were 31.2% (95% CI 24-39.1) and 31.6% (95% CI 24.4-39.6), respectively. The combination of both methods yielded a sensitivity of 92.3% (95% CI 74.9-99.1) and specificity of 23.2% (95% CI 16.8-30.7). A trend towards improved sensitivity was observed, but did not reach statistical significance. CONCLUSION: Addition of D-VIA/VILI to conventional naked-eye examination may be associated with improved CIN2+ identification. Further studies including a larger sample size are needed to confirm these results.

The Efficacy of Common Household Cleaning Agents for SARS-CoV-2 Infection Control.

The COVID-19 pandemic caused by SARS-CoV-2 is having devastating effects on a global scale. Since common household disinfectants are often used to minimise the risk of infection in the home and work environment, we investigated the ability of some of these products to inactivate the virus. We tested generic brands of vinegar, bleach, and dishwashing detergent, as well as laboratory-grade acetic acid, sodium hypochlorite, and ethanol. Assays were conducted at room temperature (18-20 °C, 40% relative humidity), and two time points were used to reflect a quick wipe (30 s) and a brief soak (5 min). Vinegar, and its active ingredient, acetic acid, were completely ineffective at virus inactivation even when exposed to the virus at 90% v/v (a final concentration equivalent to 3.6% v/v acetic acid). In contrast, ethanol was capable of inactivating the virus at dilutions as low as 40% v/v. Dishwashing detergent effectively rendered SARS-CoV-2 inactive when diluted 100-fold (1% v/v). Bleach was found to be fully effective against SARS-CoV-2 at 0.21 g/L sodium hypochlorite after a 30 s exposure (1/200 dilution of commercial product). Given reports of infectious virus recovered from the surface of frozen packaging, we tested the persistence of infectiousness after multiple freeze-thaw cycles and found no change in infectious SARS-CoV-2 titre after seven freeze-thaw cycles. These results should help inform readers of how to effectively disinfect surfaces and objects that have potentially been contaminated with SARS-CoV-2 using common household chemicals.

Hypochlorous acid and white vinegar: Artifact-free COVID-19 disinfection options for photostimulable storage phosphor plates.

OBJECTIVES: To examine the artifacts on intraoral photostimulable storage phosphor (PSP) plate images caused by 3 different disinfectants that are effective against pathogens including SARS-CoV-2. STUDY DESIGN: Nine new PSP plates, to be wiped with hypochlorous acid (HOCl) in group A, alcohol in group B, and white vinegar in group C, were distributed in 3 groups. Twelve images of each PSP plate with increasing numbers of wipes were examined for artifacts. The comparisons were evaluated by Kruskal-Wallis and post hoc tests. The reliability of the measurements was evaluated using the intraclass correlation coefficient (ICC) and Cohen kappa statistic. RESULTS: Artifacts were observed only on group B images. In terms of artifact scores, the difference between group A and group C was not statistically significant (P > .05), whereas group B artifact scores were significantly higher than group A and group C (P < .05). Intraobserver reliability was perfect (ICC and kappa of 1.0) and interobserver reliability was considered excellent (ICC = 0.985) or almost perfect (kappa = 0.956). CONCLUSIONS: HOCl and white vinegar can be alternative disinfection options for PSP plates tested in this study. Unlike alcohol, they did not produce artifacts. Additional research evaluating their effects on image quality is needed to determine if they are appropriate for disinfection.

The diversity and function of sourdough starter microbiomes.

Humans have relied on sourdough starter microbial communities to make leavened bread for thousands of years, but only a small fraction of global sourdough biodiversity has been characterized. Working with a community-scientist network of bread bakers, we determined the microbial diversity of 500 sourdough starters from four continents. In sharp contrast with widespread assumptions, we found little evidence for biogeographic patterns in starter communities. Strong co-occurrence patterns observed in situ and recreated in vitro demonstrate that microbial interactions shape sourdough community structure. Variation in dough rise rates and aromas were largely explained by acetic acid bacteria, a mostly overlooked group of sourdough microbes. Our study reveals the extent of microbial diversity in an ancient fermented food across diverse cultural and geographic backgrounds.

Sourdough bread is an ancient fermented food that has sustained humans around the world for thousands of years. It is made from a sourdough 'starter culture' which is maintained, portioned, and shared among bread bakers around the world. The starter culture contains a community of microbes made up of yeasts and bacteria, which ferment the carbohydrates in flour and produce the carbon dioxide gas that makes the bread dough rise before baking. The different acids and enzymes produced by the microbial culture affect the bread's flavor, texture and shelf life. However, for such a dependable staple, sourdough bread cultures and the mixture of microbes they contain have scarcely been characterized. Previous studies have looked at the composition of starter cultures from regions within Europe. But there has never been a comprehensive study of how the microbial diversity of sourdough starters varies across and between continents. To investigate this, Landis, Oliverio et al. used genetic sequencing to characterize the microbial communities of sourdough starters from the homes of 500 bread bakers in North America, Europe and Australasia. Bread makers often think their bread's unique qualities are due to the local environment of where the sourdough starter was made. However, Landis, Oliverio et al. found that geographical location did not correlate with the diversity of the starter cultures studied. The data revealed that a group of microbes called acetic acid bacteria, which had been overlooked in past research, were relatively common in starter cultures. Moreover, starters with a greater abundance of this group of bacteria produced bread with a strong vinegar aroma and caused dough to rise at a slower rate. This research demonstrates which species of bacteria and yeast are most commonly found in sourdough starters, and suggests geographical location has little influence on the microbial diversity of these cultures. Instead, the diversity of microbes likely depends more on how the starter culture was made and how it is maintained over time.

Use of Vinegar and Water to Identify COVID-19 Cases During a Workplace Entrance Screening Protocol.

OBJECTIVE: To evaluate an empirical olfactory test to identify COVID-19 cases during a workplace entrance screening. METHOD: An active screening for olfactory dysfunction using water and vinegar was conducted in April to June 2020 among 4120 meat packing workers in Latin America. RESULTS: The sensitivity and specificity of the active olfactory screening examination were 41.2% and 85.3%, respectively, using reverse transcription polymerase chain reaction (RT-PCR) tests as a gold standard. 10.6% of employees who tested positive for COVID-19 had an olfactory dysfunction as their only symptom. These individuals would not have been identified with standard workplace screening measures including temperature screening. CONCLUSION: Active screening for olfactory dysfunction may serve as a valuable tool to both identify potential COVID-19 infections and exclude those who do not have infection and should be a part of parallel algorithm combined with standard workplace entrance screening procedures.

Stable dechlorination of Trichloroacetic Acid (TCAA) to acetic acid catalyzed by palladium nanoparticles deposited on H2-transfer membranes.

Trichloroacetic acid (TCAA) is a common disinfection byproduct (DBP) produced during chlorine disinfection. With the outbreak of the Coronavirus Disease 2019 (COVID-19) pandemic, the use of chlorine disinfection has increased, raising the already substantial risks of DBP exposure. While a number of methods are able to remove TCAA, their application for continuous treatment is limited due to their complexity and expensive or hazardous inputs. We investigated a novel system that employs palladium (Pd0) nanoparticles (PdNPs) for catalytic reductive dechlorination of TCAA. H2 was delivered directly to PdNPs in situ coated on the surface of bubble-free hollow-fiber gas-transfer membranes. The H2-based membrane Pd film reactor (H2-MPfR) achieved a high catalyst-specific TCAA reduction rate, 32 L/g-Pd/min, a value similar to the rate of using homogeneously suspended PdNP, but orders of magnitude higher than with other immobilized PdNP systems. In batch tests, over 99% removal of 1 mM TCAA was achieved in 180 min with strong product selectivity (≥ 93%) to acetic acid. During 50 days of continuous operation, over 99% of 1 mg/L influent TCAA was removed, again with acetic acid as the major product (≥ 94%). We identified the reaction pathways and their kinetics for TCAA reductive dechlorination with PdNPs using direct delivery of H2. Sustained continuous TCAA removal, high selectivity to acetic acid, and minimal loss of PdNPs support that the H2-MPfR is a promising catalytic reactor to remove chlorinated DBPs in practice.

Did granny know best? Evaluating the antibacterial, antifungal and antiviral efficacy of acetic acid for home care procedures.

BACKGROUND: Acetic acid has been used to clean and disinfect surfaces in the household for many decades. The antimicrobial efficacy of cleaning procedures can be considered particularly important for young, old, pregnant, immunocompromised people, but may also concern other groups, particularly with regards to the COVID-19 pandemics. This study aimed to show that acetic acid exhibit an antibacterial and antifungal activity when used for cleaning purposes and is able to destroy certain viruses. Furthermore, a disinfecting effect of laundry in a simulated washing cycle has been investigated. RESULTS: At a concentration of 10% and in presence of 1.5% citric acid, acetic acid showed a reduction of > 5-log steps according to the specifications of DIN EN 1040 and DIN EN 1275 for the following microorganisms: P. aeruginosa, E. coli, S. aureus, L. monocytogenes, K. pneumoniae, E. hirae and A. brasiliensis. For MRSA a logarithmic reduction of 3.19 was obtained. Tests on surfaces according to DIN EN 13697 showed a complete reduction (> 5-log steps) for P. aeruginosa, E. coli, S. aureus, E. hirae, A. brasiliensis and C. albicans at an acetic acid concentration of already 5%. Virucidal efficacy tests according to DIN EN 14476 and DIN EN 16777 showed a reduction of ≥4-log-steps against the Modified Vaccinia virus Ankara (MVA) for acetic acid concentrations of 5% or higher. The results suggest that acetic acid does not have a disinfecting effect on microorganisms in a dosage that is commonly used for cleaning. However, this can be achieved by increasing the concentration of acetic acid used, especially when combined with citric acid. CONCLUSIONS: Our results show a disinfecting effect of acetic acid in a concentration of 10% and in presence of 1.5% citric acid against a variety of microorganisms. A virucidal effect against enveloped viruses could also be proven. Furthermore, the results showed a considerable antimicrobial effect of acetic acid when used in domestic laundry procedures.

Remote psychophysical evaluation of olfactory and gustatory functions in early-stage coronavirus disease 2019 patients: the Bologna experience of 300 cases.

BACKGROUND: An objective evaluation of coronavirus disease 2019 in the first days of infection is almost impossible, as affected individuals are generally in home quarantine, and there is limited accessibility for the operator who should perform the test. To overcome this limitation, a recently validated psychophysical self-administered test was used, which can be performed remotely in the assessment of early-stage coronavirus disease 2019 patients. METHODS: Olfactory and gustatory functions were objectively assessed in 300 patients in the first 7 days from coronavirus disease 2019 symptom onset. RESULTS: Seventy per cent of the patients presented olfactory and/or gustatory disorders. The dysfunctions detected were mainly complete anosmia (47 per cent) or ageusia (38 per cent). A significant correlation was found between taste dysfunction and female gender (odds ratio = 1.936, p = 0.014) and fever (odds ratio = 2.132, p = 0.003). CONCLUSION: The psychophysical evaluation protocol proposed is an effective tool for the fast and objective evaluation of patients in the early stages of coronavirus disease 2019. Chemosensitive disorders have been confirmed to be frequent and early symptoms of the coronavirus infection, and, in a significant number of cases, they are the first or only manifestation of coronavirus disease 2019.

Acetic acid disinfection as a potential adjunctive therapy for non-severe COVID-19.

PURPOSE: SARS-CoV-2 is a new pandemic influenza caused by a coronavirus which main route of transmission is through exhaled droplets that primarily infect the nose and the nasopharynx. The aim of this paper is to evaluate the effect of acetic acid, the active component of vinegar, as a potential disinfectant agent for upper airways. METHODS: Twenty-nine patients were enrolled and divided into two groups: group 1 (14 patients) was composed of patients treated with off-label hydroxychloroquine and lopinavir/ritonavir, whereas group 2 (15 patients) was composed of patients treated with hydroxychloroquine only, combined with the inhalation of acetic acid disinfectant at a 0.34% concentration. A questionnaire-based evaluation of symptoms was performed after 15 days in both groups. RESULTS: It appears that the number of patients treated with acetic acid (group 2) that experienced improvement in individual symptoms was double that of the other group of patients (group 1), although numbers are too small for robust statistical analysis. CONCLUSIONS: Considering its potential benefits and high availability, acetic acid disinfection appears to be a promising adjunctive therapy in cases of non-severe COVID-19 and deserves further investigation.