Collection and transportation of SARS-CoV-2 and influenza A virus diagnostic samples: Optimizing the usage of guanidine-based chaotropic salts for enhanced biosafety and viral genome preservation.

Many virus lysis/transport buffers used in molecular diagnostics, including the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA, contain guanidine-based chaotropic salts, primarily guanidine hydrochloride (GuHCl) or guanidine isothiocyanate (GITC). Although the virucidal effects of GuHCl and GITC alone against some enveloped viruses have been established, standardized data on their optimum virucidal concentrations against SARS-CoV-2 and effects on viral RNA stability are scarce. Thus, we aimed to determine the optimum virucidal concentrations of GuHCl and GITC against SARS-CoV-2 compared to influenza A virus (IAV), another enveloped respiratory virus. We also evaluated the effectiveness of viral RNA stabilization at the determined optimum virucidal concentrations under high-temperature conditions (35°C) using virus-specific real-time reverse transcription polymerase chain reaction. Both viruses were potently inactivated by 1.0 M GITC and 2.5 M GuHCl, but the GuHCl concentration for efficient SARS-CoV-2 inactivation was slightly higher than that for IAV inactivation. GITC showed better viral RNA stability than GuHCl at the optimum virucidal concentrations. An increased concentration of GuHCl or GITC increased viral RNA degradation at 35°C. Our findings highlight the need to standardize GuHCl and GITC concentrations in virus lysis/transport buffers and the potential application of these guanidine-based salts alone as virus inactivation solutions in SARS-CoV-2 and IAV molecular diagnostics.

Insight into the role of copper-based materials against the coronaviruses MHV-3, a model for SARS-CoV-2, during the COVID-19 pandemic.

Coating high-touch surfaces with inorganic agents, such as metals, appears to be a promising long-term disinfection strategy. However, there is a lack of studies exploring the effectiveness of copper-based products against viruses. In this study, we evaluated the cytotoxicity and virucidal effectiveness of products and materials containing copper against mouse hepatitis virus (MHV-3), a surrogate model for SARS-CoV-2. The results demonstrate that pure CuO and Cu possess activity against the enveloped virus at very low concentrations, ranging from 0.001 to 0.1% (w/v). A greater virucidal efficacy of CuO was found for nanoparticles, which showed activity even against viruses that are more resistant to disinfection such as feline calicivirus (FCV). Most of the evaluated products, with concentrations of Cu or CuO between 0.003 and 15% (w/v), were effective against MHV-3. Cryomicroscopy images of an MHV-3 sample exposed to a CuO-containing surface showed extensive damage to the viral capsid, presumably due to the direct or indirect action of copper ions.

Evaluation of in vitro SARS-CoV-2 inactivation by a new quaternary ammonium compound: Bromiphen bromide.

The pneumonia (COVID-19) outbreak caused by the novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which unpredictably exploded in late December of 2019 has stressed the importance of being able to control potential pathogens with the aim of limiting their spread. Although vaccines are well known as a powerful tool for ensuring public health and controlling the pandemic, disinfection and hygiene habits remain crucial to prevent infection from spreading and maintain the barrier, especially when the microorganism can persist and survive on textiles, surfaces, and medical devices. During the coronavirus disease pandemic, around half of the disinfectants authorized by the US Environmental Protection Agency contained quaternary ammonium compounds (QACs); their effectiveness had not been proven. Herein, the in vitro SARS-CoV-2 inactivation by p-bromodomiphen bromide, namely bromiphen (BRO), a new, potent, and fast-acting QAC is reported. This study demonstrates that BRO, with a dose as low as 0.02%, can completely inhibit SARS-CoV-2 replication in just 30 s. Its virucidal activity was 10- and 100-fold more robust compared to other commercially available QACs, namely domiphen bromide and benzalkonium chloride. The critical micellar concentration and the molecular lipophilicity potential surface area support the relevance of the lipophilic nature of these molecules for their activity.

Polyphenols from Maackia amurensis Heartwood Protect Neuronal Cells from Oxidative Stress and Prevent Herpetic Infection.

Here, we continued the investigation of anti-HSV-1 activity and neuroprotective potential of 14 polyphenolic compounds isolated from Maackia amurensis heartwood. We determined the absolute configurations of asymmetric centers in scirpusin A (13) and maackiazin (10) as 7R,8R and 1″S,2″S, respectively. We showed that dimeric stilbens maackin (9) and scirpusin A (13) possessed the highest anti-HSV-1 activity among polyphenols 1-14. We also studied the effect of polyphenols 9 and 13 on the early stages of HSV-1 infection. Direct interaction with the virus (virucidal activity) was the main mechanism of the antiviral activity of these compounds. The neuroprotective potential of polyphenolic compounds from M. amurensis was studied using models of 6-hydroxydopamine (6-OHDA)-and paraquat (PQ)-induced neurotoxicity. A dimeric stilbene scirpusin A (13) and a flavonoid liquiritigenin (6) were shown to be the most active compounds among the tested polyphenols. These compounds significantly increased the viability of 6-OHDA-and PQ-treated Neuro-2a cells, elevated mitochondrial membrane potential and reduced the intracellular ROS level. We also found that scirpusin A (13), liquiritigenin (6) and retusin (3) considerably increased the percentage of live Neuro-2a cells and decreased the number of early apoptotic cells. Scirpusin A (13) was the most promising compound possessing both anti-HSV-1 activity and neuroprotective potential.

The Novel A-Type Proanthocyanidin-Rich Phytocomplex SP4™ Acts as a Broad-Spectrum Antiviral Agent against Human Respiratory Viruses.

The appearance of new respiratory virus infections in humans with epidemic or pandemic potential has underscored the urgent need for effective broad-spectrum antivirals (BSAs). Bioactive compounds derived from plants may provide a natural source of new BSA candidates. Here, we investigated the novel phytocomplex formulation SP4™ as a candidate direct-acting BSA against major current human respiratory viruses, including coronaviruses and influenza viruses. SP4™ inhibited the in vitro replication of SARS-CoV-2, hCoV-OC43, hCoV-229E, Influenza A and B viruses, and respiratory syncytial virus in the low-microgram range. Using hCoV-OC43 as a representative respiratory virus, most of the antiviral activity of SP4™ was observed to stem primarily from its dimeric A-type proanthocyanidin (PAC-A) component. Further investigations of the mechanistic mode of action showed SP4™ and its PAC-A-rich fraction to prevent hCoV-OC43 from attaching to target cells and exert virucidal activity. This occurred through their interaction with the spike protein of hCoV-OC43 and SARS-CoV-2, thereby interfering with spike functions and leading to the loss of virion infectivity. Overall, these findings support the further development of SP4™ as a candidate BSA of a natural origin for the prevention of human respiratory virus infections.

A Reliable Multifaceted Solution against Foodborne Viral Infections: The Case of RiLK1 Decapeptide.

Food-borne transmission is a recognized route for many viruses associated with gastrointestinal, hepatic, or neurological diseases. Therefore, it is essential to identify new bioactive compounds with broad-spectrum antiviral activity to exploit innovative solutions against these hazards. Recently, antimicrobial peptides (AMPs) have been recognized as promising antiviral agents. Indeed, while the antibacterial and antifungal effects of these molecules have been widely reported, their use as potential antiviral agents has not yet been fully investigated. Herein, the antiviral activity of previously identified or newly designed AMPs was evaluated against the non-enveloped RNA viruses, hepatitis A virus (HAV) and murine norovirus (MNV), a surrogate for human norovirus. Moreover, specific assays were performed to recognize at which stage of the viral infection cycle the peptides could function. The results showed that almost all peptides displayed virucidal effects, with about 90% of infectivity reduction in HAV or MNV. However, the decapeptide RiLK1 demonstrated, together with its antibacterial and antifungal properties, a notable reduction in viral infection for both HAV and MNV, possibly through direct interaction with viral particles causing their damage or hindering the recognition of cellular receptors. Hence, RiLK1 could represent a versatile antimicrobial agent effective against various foodborne pathogens including viruses, bacteria, and fungi.

Efficient Inactivation of Monkeypox Virus by World Health Organization‒Recommended Hand Rub Formulations and Alcohols.

Increasing nonzoonotic human monkeypox virus (MPXV) infections urge reevaluation of inactivation strategies. We demonstrate efficient inactivation of MPXV by 2 World Health Organization‒recommended alcohol-based hand rub solutions. When compared with other (re)emerging enveloped viruses, MPXV displayed the greatest stability. Our results support rigorous adherence to use of alcohol-based disinfectants.

Rapid Virucidal Activity of Japanese Saxifraga Species-Derived Condensed Tannins against SARS-CoV-2, Influenza A Virus, and Human Norovirus Surrogate Viruses.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A virus (IAV), and norovirus are global threats to human health. The application of effective virucidal agents, which contribute to the inactivation of viruses on hands and environmental surfaces, is important to facilitate robust virus infection control measures. Naturally derived virucidal disinfectants have attracted attention owing to their safety and eco-friendly properties. In this study, we showed that multiple Japanese Saxifraga species-derived fractions demonstrated rapid, potent virucidal activity against the SARS-CoV-2 ancestral strain and multiple variant strains, IAV, and two human norovirus surrogates: feline calicivirus (FCV) and murine norovirus (MNV). Condensed tannins were identified as active chemical constituents that play a central role in the virucidal activities of these fractions. At a concentration of 25 µg/mL, the purified condensed tannin fraction Sst-2R induced significant reductions in the viral titers of the SARS-CoV-2 ancestral strain, IAV, and FCV (reductions of ≥3.13, ≥3.00, and 2.50 log10 50% tissue culture infective doses [TCID50]/mL, respectively) within 10 s of reaction time. Furthermore, at a concentration of 100 µg/mL, Sst-2R induced a reduction of 1.75 log10 TCID50/mL in the viral titers of MNV within 1 min. Western blotting and transmission electron microscopy analyses revealed that Sst-2R produced structural abnormalities in viral structural proteins and envelopes, resulting in the destruction of viral particles. Furthermore, Saxifraga species-derived fraction-containing cream showed virucidal activity against multiple viruses within 10 min. Our findings indicate that Saxifraga species-derived fractions containing condensed tannins can be used as disinfectants against multiple viruses on hands and environmental surfaces. IMPORTANCE SARS-CoV-2, IAV, and norovirus are highly contagious pathogens. The use of naturally derived components as novel virucidal/antiviral agents is currently attracting attention. We showed that fractions from extracts of Saxifraga species, in the form of a solution as well as a cream, exerted potent, rapid virucidal activities against SARS-CoV-2, IAV, and surrogates of human norovirus. Condensed tannins were found to play a central role in this activity. The in vitro cytotoxicity of the purified condensed tannin fraction at a concentration that exhibited some extent of virucidal activity was lower than that of 70% ethanol or 2,000 ppm sodium hypochlorite solution, which are popular virucidal disinfectants. Our study suggests that Saxifraga species-derived fractions containing condensed tannins can be used on hands and environmental surfaces as safe virucidal agents against multiple viruses.

In Vitro Potential Virucidal Effect Evaluation of Xibornol on Human Adenovirus Type 5, Human Rhinovirus Type 13, Human Coronavirus 229E, Human Parainfluenza Virus Type 1, and Human Respiratory Syncytial Virus.

The availability of virucidal compounds to reduce the impact of respiratory viruses is a relevant topic for public health, especially during the recent coronavirus disease (COVID-19) pandemic. Antimicrobial properties of Xibornol are known since the 1970s, but its activity on viruses is currently little explored. In this study, Xibornol activity at a fixed concentration of 0.03 mg/100 ml has been evaluated on five respiratory viruses (Human Adenovirus 5, Human Rhinovirus type 13, Human Coronavirus 229E, Human Parainfluenza Virus type 1, and Human Respiratory Syncytial Virus) through in vitro experiments based on adapted European standard UNI EN 14476-20019. The experiments were carried out under two different environmental conditions, one with the addition of fetal bovine serum to simulate an in vivo condition (dirty condition) and the other without the addition of any organic substances (clean condition). The viral abatement of Xibornol (expressed as Log10 reduction - LR) was statistically significant under both clean and dirty environmental conditions. Namely, in clean condition, LR ranged from 2.67 to 3.84, while in the dirty one the abatement was slightly lower (from 1.75 to 3.03). Parainfluenza Virus and Human Adenovirus were most resistant compared to the other viruses. The obtained data confirmed Xibornol activity and its use as topic substance for viral inactivation to prevent upper respiratory tract disease.

Thyme essential oil inhibits intracellular replication of CyHV-3 and inactivates extracellular virus. An in vitro study.

Cyprinid herpesvirus 3 (CyHV-3) can induce up to 100% mortality among carp populations. To date, there has been no safe method to prevent the consequences of the activity of CyHV-3. Thyme is widely used in cooking due to its flavour. Both thyme and thyme essential oil (TEO) are used in traditional herbal medicine, mainly to treat respiratory system disorders. In this study, TEO containing predominantly cymene and thymol was applied to explore its antiviral effect. The toxicity of TEO was examined in MTT and crystal violet assays. The anti-CyHV-3 activity of TEO in the intracellular and extracellular stages of the viral replication cycle was explored in a plaque assay and TaqMan qPCR. TEO interfered with the intracellular stages of the CyHV-3 replication cycle with selectivity indexes (SI) of around 5. It also displayed virucidal activity in a dose- and time-dependent manner. Two-hour preincubation of CyHV-3 with TEO generated SI, ranging from 13.37 to 18.47 depending on cell line and method of examination. Preincubation of cells with TEO at a safe concentration did not decrease the intracellular viral DNA copy number, which suggests that TEO does not disturb the attachment of the virus to the cells. Further research regarding the antiviral activity of compounds of TEO is required in order to indicate the most potent molecules that could be considered candidates for application in aquaculture.

In Vitro Virucidal Effects of Ultraviolet Light Prototypes on RNA viruses.

Ultraviolet-C (UVC) has been used to cause virus inactivation. The virucidal activity of three UV light lamps [UVC high frequencies (HF), UVC+B LED and UVC+A LED] was evaluated against the enveloped feline coronavirus (FCoVII), a surrogate model of SARS-CoV-2, the enveloped vesicular stomatitis virus (VSV), and the naked encephalomyocarditis virus (EMCV). Virucidal assays were performed at different time points of UV-light exposure (i.e., 5, 30 minutes and 1, 6, and 8 hours), placing each virus 180 cm below the perpendicular irradiation of the lamp and 1 and 2 meters from the perpendicular axis. We found that the UVC HF lamp had virucidal effects (≥96.8% of virus inactivation) against FCoVII, VSV and EMCV after 5 minutes of irradiation at each distance analyzed. Moreover, the UVC+B LED lamp had the highest inhibitory effects on FCoVII and VSV infectivity (≥99% of virus inactivation) when these viruses were settled below the perpendicular axis of the lamp for 5 minutes. Conversely, the UVC+A LED lamp was the least effective, achieving ≥85.9% inactivation of enveloped RNA viruses after 8 hours of UV exposure. Overall, UV light lamps, and in particular UVC HF and UVC+B LED ones, had a rapid and strong virucidal activity against distinct RNA viruses, including coronaviruses.

Comparative Virucidal Activities of Essential Oils and Alcohol-Based Solutions against Enveloped Virus Surrogates: In Vitro and In Silico Analyses.

The large-scale use of alcohol (OH)-based disinfectants to control pathogenic viruses is of great concern because of their side effects on humans and harmful impact on the environment. There is an urgent need to develop safe and environmentally friendly disinfectants. Essential oils (EOs) are generally recognized as safe (GRAS) by the FDA, and many exhibit strong antiviral efficacy against pathogenic human enveloped viruses. The present study investigated the virucidal disinfectant activity of solutions containing EO and OH against DENV-2 and CHIKV, which were used as surrogate viruses for human pathogenic enveloped viruses. The quantitative suspension test was used. A solution containing 12% EO + 10% OH reduced > 4.0 log10 TCID50 (100% reduction) of both viruses within 1 min of exposure. In addition, solutions containing 12% EO and 3% EO without OH reduced > 4.0 log10 TCID50 of both viruses after 10 min and 30 min of exposure, respectively. The binding affinities of 42 EO compounds and viral envelope proteins were investigated through docking analyses. Sesquiterpene showed the highest binding affinities (from -6.7 to -8.0 kcal/mol) with DENV-2 E and CHIKV E1-E2-E3 proteins. The data provide a first step toward defining the potential of EOs as disinfectants.

In vitro virucidal activity of mouthwashes on SARS-CoV-2.

OBJECTIVES: The objective of the study was to evaluate the in vitro virucidal activity of commercial mouthwashes against SARS-CoV-2 and variants of concern. MATERIALS AND METHODS: Antiviral activity was assessed at different time intervals, based on common use of these products by titrating residual viral infectivity on Vero E6 cells. RESULTS: All the mouthwashes were effective to reduce the infectious titers of SARS-CoV-2 and its tested variants. Mouthwashes Listerine® Cool Mint milder taste and Listerine® Cavity Protection milder taste reduced the infectious viral titer by up to 3.9 log10 after 30 s, while mouthwash Cetilsan® Sugar Free was able to reduce the viral titer by 2.2-2.9 log10 at all tested time intervals. Mouthwash Curasept® ADS DNA Intensive treatment was less effective to decrease viral infectivity (0.7-2.2 log10 TCID50/ml at all tested time intervals). Interestingly, the Gamma variant appeared more resistant to treatment in vitro with the different mouthwashes. CONCLUSIONS: In this study, we were able to assess the ability of different mouthwashes to in vitro decrease the infectivity of SARS-CoV-2 and its variants, and we observed that Gamma variant of concern was more resistant to treatment with mouthwashes.

Virucidal activity in vitro of mouthwashes against a feline coronavirus type II.

Transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can occur through saliva and aerosol droplets deriving from the upper aerodigestive tract during coughing, sneezing, talking, and even during oral inspection or dental procedures. The aim of this study was to assess in vitro virucidal activity of commercial and experimental mouthwashes against a feline coronavirus (FCoV) strain. Commercial and experimental (commercial-based products with addition of either sodium dodecyl sulfate (SDS) or thymus vulgaris essential oil (TEO) at different concentrations) mouthwashes were placed in contact with FCoV for different time intervals, that is, 30 s (T30), 60 s (T60), and 180 s (T180); subsequently, the virus was titrated on Crandell Reese Feline Kidney cells. An SDS-based commercial mouthwash reduced the viral load by 5 log10 tissue culture infectious dose (TCID)50 /50 µl at T30 while a cetylpyridinium (CPC)-based commercial mouthwash was able to reduce the viral titer of 4.75 log10 at T60. Furthermore, five experimental mouthwashes supplemented with SDS reduced the viral titer by 4.75-5 log10 according to a dose- (up to 4 mM) and time-dependent fashion.

Cationic Surfactants as Disinfectants against SARS-CoV-2.

The virucidal activity of a series of cationic surfactants differing in the length and number of hydrophobic tails (at the same hydrophilic head) and the structure of the hydrophilic head (at the same length of the hydrophobic n-alkyl tail) was compared. It was shown that an increase in the length and number of hydrophobic tails, as well as the presence of a benzene ring in the surfactant molecule, enhance the virucidal activity of the surfactant against SARS-CoV-2. This may be due to the more pronounced ability of such surfactants to penetrate and destroy the phospholipid membrane of the virus. Among the cationic surfactants studied, didodecyldimethylammonium bromide was shown to be the most efficient as a disinfectant, its 50% effective concentration (EC50) being equal to 0.016 mM. Two surfactants (didodecyldimethylammonium bromide and benzalkonium chloride) can deactivate SARS-CoV-2 in as little as 5 s.

Phenol Derivatives Obtained from Grape Seed Extract Show Virucidal Activity against Murine Norovirus.

Human noroviruses are the most common pathogens known to cause acute gastroenteritis, a condition that can lead to severe illness among immunocompromised individuals such as organ transplant recipients and the elderly. To date, no safe and effective vaccines or therapeutic agents have been approved for treating norovirus infections. Therefore, we aimed to demonstrate the virucidal activity of grape seed extract (GSE), which contains >83% proanthocyanidins, against murine norovirus (MNV), a surrogate for human norovirus. GSE showed virucidal activity against MNV in a dose- and time-dependent manner. Atomic force microscopic analysis showed viral particle aggregates after treatment of MNV with GSE. MNV treated with 50 µg/mL of GSE for 10 min resulted in the absence of pathogenicity in an animal model of infection, indicating that GSE has irreversible virucidal activity against MNV particles. Thus, GSE may aid in the development of treatments for norovirus infections.

Severe Acute Respiratory Syndrome Coronavirus-2 Inactivation Activity of the Polyphenol-Rich Tea Leaf Extract with Concentrated Theaflavins and Other Virucidal Catechins.

Since severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is producing a large number of infections and deaths globally, the development of supportive and auxiliary treatments is attracting increasing attention. Here, we evaluated SARS-CoV-2-inactivation activity of the polyphenol-rich tea leaf extract TY-1 containing concentrated theaflavins and other virucidal catechins. The TY-1 was mixed with SARS-CoV-2 solution, and its virucidal activity was evaluated. To evaluate the inhibition activity of TY-1 in SARS-CoV-2 infection, TY-1 was co-added with SARS-CoV-2 into cell culture media. After 1 h of incubation, the cell culture medium was replaced, and the cells were further incubated in the absence of TY-1. The viral titers were then evaluated. To evaluate the impacts of TY-1 on viral proteins and genome, TY-1-treated SARS-CoV-2 structural proteins and viral RNA were analyzed using western blotting and real-time RT-PCR, respectively. TY-1 showed time- and concentration-dependent virucidal activity. TY-1 inhibited SARS-CoV-2 infection of cells. The results of western blotting and real-time RT-PCR suggested that TY-1 induced structural change in the S2 subunit of the S protein and viral genome destruction, respectively. Our findings provided basic insights in vitro into the possible value of TY-1 as a virucidal agent, which could enhance the current SARS-CoV-2 control measures.

Inactivation Activities of Ozonated Water, Slightly Acidic Electrolyzed Water and Ethanol against SARS-CoV-2.

This study aimed to compare the SARS-CoV-2-inactivation activity and virucidal mechanisms of ozonated water (OW) with those of slightly acidic electrolyzed water (SAEW) and 70% ethanol (EtOH). SARS-CoV-2-inactivation activity was evaluated in a virus solution containing 1%, 20% or 40% fetal bovine serum (FBS) with OW, SAEW or EtOH at a virus-to-test solution ratio of 1:9, 1:19 or 1:99 for a reaction time of 20 s. EtOH showed the strongest virucidal activity, followed by SAEW and OW. Even though EtOH potently inactivated the virus despite the 40% FBS concentration, virus inactivation by OW and SAEW decreased in proportion to the increase in FBS concentration. Nevertheless, OW and SAEW showed potent virucidal activity with 40% FBS at a virus-to-test solution ratio of 1:99. Real-time PCR targeting the viral genome revealed that cycle threshold values in the OW and SAEW groups were significantly higher than those in the control group, suggesting that OW and SAEW disrupted the viral genome. Western blotting analysis targeting the recombinant viral spike protein S1 subunit showed a change in the specific band into a ladder upon treatment with OW and SAEW. OW and SAEW may cause conformational changes in the S1 subunit of the SARS-CoV-2 spike protein.

Virucidal activity and the antiviral mechanism of acidic polysaccharides against Enterovirus 71 infection in vitro.

Enterovirus 71 (EV71) is the predominant pathogen for severe hand, foot, and mouth disease (HFMD) in children younger than 5 years, and currently no effective drugs are available for EV71. Thus, there is an urgent need to develop new drugs for the control of EV71 infection. In this study, LJ04 was extracted from Laminaria japonica using diethylaminoethyl cellulose-52 with 0.4 mol/l NaCl as the eluent, and its virucidal activity was evaluated based on its cytopathic effects on a microplate. LJ04 is composed of fucose, galactose, and mannose and mainly showed good virucidal activity against EV71. The antiviral mechanisms of LJ04 were the direct inactivation of the virus, the blockage of virus binding, disruptions to viral entry, and weak inhibitory activity against the nonstructural protein 3C. The two most important findings from this study were that LJ04 inhibited EV71 proliferation in HM1900 cells, which are a human microglia cell line, and that LJ04 can directly inactivate EV71 within 2 hr at 37°C. This study demonstrates for the first time the ability of a polysaccharide from L. japonica to inhibit viral and 3C activity; importantly, the inhibition of 3C might have a minor effect on the antiviral effect of LJ04. Consequently, our results identify LJ04 as a potential drug candidate for the control of severe EV71 infection in clinical settings.

Decontamination efficacy of sodium hypochlorite solutions for poliovirus.

Effective decontamination procedures are critical to the successful manufacture and control of poliovirus vaccines to minimize the risk to personnel and the environment. Polio viruses have been reported to be more resistant to disinfectants than many other viruses. We assessed the efficacy of sodium hypochlorite-containing disinfectants for decontamination for three poliovirus serotypes to implement decontamination procedures that are fully compliant with the WHO GAP III and Health authorities' requirements. A 10.4 log reduction was observed with a 0.63% sodium hypochlorite solution in a suspension with high protein and high poliovirus concentrations diluted 10-fold compared with a 6 log reduction in an undiluted sample. Treatment efficacy increased with sodium hypochlorite content and decreased with sample protein content. The surface tests showed that two 1-min treatments, 5-min apart, with a 0.63% Chl sodium hypochlorite solution effectively reduced the concentration of all poliovirus serotypes by 10 log10, irrespective of the protein and virus concentration in the sample. Sodium hypochlorite solutions lower than 0.52% were less effective for complete inactivation of poliovirus. In conclusion, we demonstrated that a high level of virus reduction (>10 log10) can be achieved with sodium hypochlorite solutions with poliovirus in suspension and dried on surfaces.