Rapid Bedside Inactivation of Ebola Virus for Safe Nucleic Acid Tests

Assessment and verification of chemical inactivation of peste des petits ruminants virus by virus isolation following virus capture using Nanotrap magnetic virus particles

IMPORTANCE

Research including diagnosis on highly contagious viruses at the molecular level such as PCR and next-generation sequencing requires complete inactivation of the virus to ensure biosafety and biosecurity so that any accidental release of the virus does not compromise the safety of the susceptible population and the environment. In this work, peste des petits ruminants virus (PPRV) was inactivated with chemical agents, and the virus inactivation was confirmed by virus isolation (VI) using Vero cells. Since the chemical agents are cytotoxic, inactivated virus (PPRV) was diluted 1:100 to neutralize cytotoxicity, and the residual viruses (if any) were captured using Nanotrap magnetic virus particles (NMVPs). The NMVPs and the captured viruses were subjected to VI. No CPE was observed, indicating complete inactivation, and the results were further supported by real-time RT-PCR. This new protocol to verify virus inactivation can be applicable to other viruses.

Art of the Kill: Designing and Testing Viral Inactivation Procedures for Highly Pathogenic Negative Sense RNA Viruses

The study of highly pathogenic viruses handled under BSL-4 conditions and classified as Select Agents frequently involves the transfer of inactivated materials to lower containment levels for downstream analyses. Adhering to Select Agent and BSL-4 safety regulations requires validation or verification of the inactivation procedures, which comes with an array of challenges for each method. This includes the use of cytotoxic reagents for chemical inactivation and defining the precise inactivation parameters for physical inactivation. Here, we provide a workflow for various inactivation methods using Ebola, Nipah, and Lassa viruses as our examples. We choose three distinct inactivation methods (TRIzol/TRIzol LS, aldehyde fixation using different fixatives, and heat) to highlight the challenges of each method and provide possible solutions. We show that, whereas published chemical inactivation methods are highly reliable, the parameters for heat inactivation must be clearly defined to ensure complete inactivation. In addition to the inactivation data, we also provide examples and templates for the documentation required for approval and use of inactivation SOPs, including an inactivation report, the procedure sections of developed SOPs, and an electronic inactivation certificate that accompanies inactivated samples. The provided information can be used as a roadmap for similar studies at high and maximum containment laboratories.

Unbiased Virus Detection in a Danish Zoo Using a Portable Metagenomic Sequencing System

Metagenomic next-generation sequencing (mNGS) is receiving increased attention for the detection of new viruses and infections occurring at the human-animal interface. The ability to actively transport and relocate this technology enables in situ virus identification, which could reduce response time and enhance disease management. In a previous study, we developed a straightforward mNGS procedure that greatly enhances the detection of RNA and DNA viruses in human clinical samples. In this study, we improved the mNGS protocol with transportable battery-driven equipment for the portable, non-targeted detection of RNA and DNA viruses in animals from a large zoological facility, to simulate a field setting for point-of-incidence virus detection. From the resulting metagenomic data, we detected 13 vertebrate viruses from four major virus groups: (+)ssRNA, (+)ssRNA-RT, dsDNA and (+)ssDNA, including avian leukosis virus in domestic chickens (Gallus gallus), enzootic nasal tumour virus in goats (Capra hircus) and several small, circular, Rep-encoding, ssDNA (CRESS DNA) viruses in several mammal species. More significantly, we demonstrate that the mNGS method is able to detect potentially lethal animal viruses, such as elephant endotheliotropic herpesvirus in Asian elephants (Elephas maximus) and the newly described human-associated gemykibivirus 2, a human-to-animal cross-species virus, in a Linnaeus two-toed sloth (Choloepus didactylus) and its enclosure, for the first time.

Evaluation of Five Buffers for Inactivation of Monkeypox Virus and Feasibility of Virus Detection Using the Panther Fusion® Open Access System

Rapid diagnosis is key to containing viral outbreaks. However, for the current monkeypox outbreak the major deterrent to rapid testing is the requirement for higher biocontainment of potentially infectious monkeypox virus specimens. The current CDC guidelines require the DNA extraction process before PCR amplification to be performed under biosafety level 3 unless vaccinated personnel are performing assays. This increases the turn-around time and makes certain laboratories insufficiently equipped to handle specimens from patients with suspected monkeypox infection. We investigated the ability of five commercially available lysis buffers and heat for inactivation of monkeypox virus. We also optimized the use of monkeypox virus in Hologic^® Panther Specimen Lysis Buffer for detection of virus in the Panther Fusion^® Open Access System using published generic and clade specific monkeypox virus primers and probes.

Methods of Inactivation of Highly Pathogenic Viruses for Molecular, Serology or Vaccine Development Purposes

The handling of highly pathogenic viruses, whether for diagnostic or research purposes, often requires an inactivation step. This article reviews available inactivation techniques published in peer-reviewed journals and their benefits and limitations in relation to the intended application. The bulk of highly pathogenic viruses are represented by enveloped RNA viruses belonging to the Togaviridae, Flaviviridae, Filoviridae, Arenaviridae, Hantaviridae, Peribunyaviridae, Phenuiviridae, Nairoviridae and Orthomyxoviridae families. Here, we summarize inactivation methods for these virus families that allow for subsequent molecular and serological analysis or vaccine development. The techniques identified here include: treatment with guanidium-based chaotropic salts, heat inactivation, photoactive compounds such as psoralens or 1.5-iodonaphtyl azide, detergents, fixing with aldehydes, UV-radiation, gamma irradiation, aromatic disulfides, beta-propiolacton and hydrogen peroxide. The combination of simple techniques such as heat or UV-radiation and detergents such as Tween-20, Triton X-100 or Sodium dodecyl sulfate are often sufficient for virus inactivation, but the efficiency may be affected by influencing factors including quantity of infectious particles, matrix constitution, pH, salt- and protein content. Residual infectivity of the inactivated virus could have disastrous consequences for both laboratory/healthcare personnel and patients. Therefore, the development of inactivation protocols requires careful considerations which we review here.

Species-specific quantification of circulating ebolavirus burden using VP40-derived peptide variants

Six ebolavirus species are reported to date, including human pathogens Bundibugyo virus (BDBV), Ebola virus (EBOV), Sudan virus (SUDV), and Taï Forest virus (TAFV); non-human pathogen Reston virus (RESTV); and the plausible Bombali virus (BOMV). Since there are differences in the disease severity caused by different species, species identification and viral burden quantification are critical for treating infected patients timely and effectively. Here we developed an immunoprecipitation-coupled mass spectrometry (IP-MS) assay for VP40 antigen detection and quantification. We carefully selected two regions of VP40, designated as peptide 8 and peptide12 from the protein sequence that showed minor variations among Ebolavirus species through MS analysis of tryptic peptides and antigenicity prediction based on available bioinformatic tools, and generated high-quality capture antibodies pan-specific for these variant peptides. We applied this assay to human plasma spiked with recombinant VP40 protein from EBOV, SUDV, and BDBV and virus-like particles (VLP), as well as EBOV infected NHP plasma. Sequence substitutions between EBOV and SUDV, the two species with highest lethality, produced affinity variations of 2.6-fold for p8 and 19-fold for p12. The proposed IP-MS assay differentiates four of the six known EBV species in one assay, through a combination of p8 and p12 data. The IP-MS assay limit of detection (LOD) using multiple reaction monitoring (MRM) as signal readout was determined to be 28 ng/mL and 7 ng/mL for EBOV and SUDV respectively, equivalent to ~1.625-6.5×105 Geq/mL, and comparable to the LOD of lateral flow immunoassays currently used for Ebola surveillance. The two peptides of the IP-MS assay were also identified by their tandem MS spectra using a miniature MALDI-TOF MS instrument, greatly increasing the feasibility of high specificity assay in a decentralized laboratory.

Use of Guanidine Thiocyanate-Based Nucleic Acid Extraction Buffers to Inactivate Poliovirus in Potentially Infectious Materials

The efforts of the Global Poliovirus Eradication Initiative (GPEI) have brought about the near elimination of poliovirus worldwide. The World Health Organization has issued guidelines for the safe handling and containment of infectious materials (IM) and potentially infectious materials (PIM) following poliovirus eradication. Inactivation of poliovirus in IM and PIM is needed to prevent inadvertent re-introduction of polioviruses post-eradication. In this study, we investigated the use of guanidine thiocyanate-based nucleic acid extraction buffers from commercially available nucleic acid extraction kits to inactivate poliovirus in cell culture isolates and stool suspensions, two common types of poliovirus IM and PIM, respectively. Incubation with selected nucleic acid extraction buffers or extraction buffers supplemented with ethanol reduced the infectivity of high-titer wild poliovirus type 1 (WPV1), wild poliovirus type 3 (WPV3), Sabin 1 (SL1), and Sabin 3 (SL3) cell culture isolates below the limit of detection in CCID₅₀ assays. Stool suspensions containing WPV1, WPV3, SL1, SL2, or SL3 were also inactivated by the extraction buffers tested. Blind passage of WPV1-spiked stool suspensions confirmed complete inactivation of WPV1 after incubation with extraction buffers. Moreover, treatment with a buffer consisting of 4 M guanidine thiocyanate with 30% ethanol inactivated a high-titer WPV1 culture isolate and a WPV1-spiked stool suspension. Taken together, these results show that guanidine thiocyanate-based nucleic acid extraction buffers are an effective means of inactivating poliovirus IM and PIM, and thus will be instrumental in ensuring containment compliance and preventing potential re-emergence of contained polioviruses.

Assessment of hepatitis B virus pregenomic RNA in high and low viremic chronic hepatitis B patients

Aim of the study

Intrahepatic covalently closed circular DNA (cccDNA) is the main cause of hepatitis B virus (HBV) persistence. Therefore, a noninvasive serum biomarker that can reflect intrahepatic cccDNA is required for evaluation of HBV virological, biochemical activity and therapeutic response. Aim of the study was to assess serum hepatitis B pregenomic RNA in low viremia patients (HBV DNA < 2000 IU/ml) and high viremia (HBV DNA > 2000 IU/ml).

Material and methods

This study was carried out on two groups of chronic hepatitis B patients: group A - 40 patients with low viremia (HBV DNA < 2000 IU/ml); group B - 40 patients with high viremia (HBV DNA > 2000 IU/ml when diagnosed). They were assessed before treatment and after 6 months of treatment (entecavir 0.5 mg/24 h). Serum HBV pregenomic RNA was quantified using RT-PCR.

Results

Pregenomic RNA (pgRNA) was significantly lower in group A than in group B (before treatment). Moreover, it was significantly lower after 6 months of treatment than before treatment in group B. A significant positive correlation was observed between pgRNA and HBV DNA in groups A and B (before treatment); however, after 6 months of treatment of group B patients, although 35 patients had undetectable HBV DNA, they showed detectable levels of serum pgRNA and pgRNA > 4000 IU/ml was associated with virological and biochemical activity.

Conclusions

Serum HBV pregenomic RNA might be a promising marker for assessment of HBV virological, biochemical activity and evaluating therapeutic responses.

Inactivation of foot-and-mouth disease virus A/IRN/8/2015 with commercially available lysis buffers

Laboratories working with foot-and-mouth disease virus (FMDV) must maintain a high level of biocontainment. However, if infectious virus is reliably inactivated during sample processing, molecular and serological testing can be performed at a lower level of containment. In this study, three commercial lysis buffers (AL, AVL, and MagMAX CORE) were tested in two laboratories for their ability to inactivate FMDV A/IRN/8/2015 in different sample matrices (cell culture supernatant, epithelial tissue suspension and milk). Residual infectivity after the addition of lysis buffer was evaluated by inoculating susceptible cell cultures. No cytopathic effect was observed for all three lysis buffers, indicating that the buffers are capable of reducing viral infectivity (estimated range 3.1 to >5.1 Log₁₀). These results highlight the capacity of lysis buffers to decrease FMDV infectivity; however, additional validation experiments should be conducted, particularly if different sample matrices and/or lysis buffers are used.

Development of a quantitative real-time RT-PCR assay that differentiates between Kyasanur Forest disease virus and Alkhurma hemorrhagic fever virus

Kyasanur Forest disease virus (KFDV) and Alkhurma hemorrhagic fever virus (AHFV) are enveloped, positive-stranded RNA viruses of clinical importance with complex enzootic life cycles involving hematophagous ticks which feed on small and large mammals. Humans and monkeys are dead-end hosts for these viruses. Recent trends in epidemiological data suggest both virus incidences are steadily increasing and their geographical distribution expanding out of previously known circulation regions. For the detection and discrimination of these two closely related flaviviruses, we have developed quantitative real-time RT-PCR assays with 100 % sensitivity and 100 % specificity for KFDV, 100 % sensitivity and 99.4 % specificity for AHFV as determined using 550 clinical samples collected between 2015-2018 from Western Ghats region of India. This rapid and sensitive assay will enable researchers to accurately diagnose the presence of the virus during viremia in human and animal blood samples, and also from tick specimens. Incorporation of these new tests into a routine diagnosis will help in the diagnosis of KFDV as well as AHFV in the endemic areas and also would provide an early warning of the spread of this virus to newer regions with similar epidemiology.

Diagnostic comparison of serum and EDTA-stabilized blood samples for the detection of foot-and-mouth disease virus RNA by RT-qPCR

Foot-and-mouth disease (FMD) remains a globally important disease but there have only been occasional recent outbreaks in Europe, e.g. in the U.K. in 2001, U.K. 2007 and Bulgaria 2010/2011. However, this infection still poses a threat to Europe as the disease occurs close to its borders and incursions can occur through importation of contaminated animal products and through the air. To deal with a suspected outbreak, fast sampling, transportation and accurate laboratory diagnosis are critical; testing for FMDV is normally performed on epithelium samples or serum. Assessment of the use of stabilized blood in assays for FMDV RNA is useful as this sample material can be prepared on site for safe transportation and rapid analysis at the laboratory. Such samples are also collected for diagnosis of other diseases giving similar clinical signs. Testing serum and EDTA-stabilized blood samples from FMDV-infected cattle and pigs, using real time quantitative RT-PCR assays, yielded similar results. However, detection of FMDV RNA was less sensitive (about 10-fold) when using EDTA-stabilized blood compared to serum. Thus, diagnosis of FMD can be achieved using EDTA-stabilized blood samples in an outbreak situation on a herd basis, but serum is preferred at the single animal level for optimal sensitivity.

Recent advances in the development and evaluation of molecular diagnostics for Ebola virus disease

INTRODUCTION

The 2014-16 outbreak of ebola virus disease (EVD) in West Africa resulted in 11,308 deaths. During the outbreak only 60% of patients were laboratory confirmed and global health authorities have identified the need for accurate and readily deployable molecular diagnostics as an important component of the ideal response to future outbreaks, to quickly identify and isolate patients. Areas covered: Currently PCR-based techniques and rapid diagnostic tests (RDTs) that detect antigens specific to EVD infections dominate the diagnostic landscape, but recent advances in biosensor technologies have led to novel approaches for the development of EVD diagnostics. This review summarises the literature and available performance data of currently available molecular diagnostics for ebolavirus, identifies knowledge gaps and maps out future priorities for research in this field. Expert opinion: While there are now a plethora of diagnostic tests for EVD at various stages of development, there is an acute need for studies to compare their clinical performance, but the sporadic nature of EVD outbreaks makes this extremely challenging, demanding pragmatic new modalities of research funding and ethical/institutional approval, to enable responsive research in outbreak settings. Retrospective head-to-head diagnostic comparisons could also be implemented using biobanked specimens, providing this can be done safely.

Development, validation and clinical evaluation of a broad-range pan-filovirus RT-qPCR

BACKGROUND

During the five decades since their discovery, filoviruses of four species have caused human hemorrhagic fever outbreaks: Marburg (MARV) marburgvirus, and Zaire (EBOV), Sudan (SUDV) and Bundybugyo (BDBV) ebolaviruses. The largest, devastating EBOV epidemic in West Africa in 2014-16, has been followed by outbreaks of MARV in Uganda, 2017, and EBOV in Democratic Republic of Congo, 2018, emphasizing the need to develop preparedness to diagnose all filoviruses.

OBJECTIVES

The aim of this study was to optimize a new filovirus RT-qPCR to detect all filoviruses, define its limits of detection (LOD) and perform a field evaluation with outbreak samples.

STUDY DESIGN

A pan-filovirus RT-qPCR targeting the L gene was developed and evaluated within the EbolaMoDRAD (Ebola virus: modern approaches for developing bedside rapid diagnostics) project. Specificity and sensitivity were determined and the effect of inactivation and PCR reagents (liquid and lyophilized format) were tested.

RESULTS

The LODs for the lyophilized pan-filovirus L-RT-qPCR assay were 9.4 copies per PCR reaction for EBOV, 9.9 for MARV, 1151 for SUDV, 65 for BDBV and 289 for Taï Forest virus. The test was set at the Pasteur Institute, Dakar, Senegal, and 83 Ebola patient samples, with viral load ranging from 5 to 5 million copies of EBOV per reaction, were screened. The results for the patient samples were in 100% concordance with the reference EBOV-specific assay.

DISCUSSION

Overall, the assay showed good sensitivity and specificity, covered all filoviruses known to be human pathogens, performed well both in lyophilized and liquid-phase formats and with EBOV outbreak clinical samples.

Effective chemical virus inactivation of patient serum compatible with accurate serodiagnosis of infections

Objectives

Highly pathogenic viruses such as EBOV are a threat to routine laboratory workers. Inactivation procedures with Triton X-100 0.1% and/or heat are currently recommended, but have unknown effects on the accuracy of serological testing. Furthermore, virus inactivation by Triton X-100 0.1% was shown to be ineffective in serum. This study aimed to demonstrate virus inactivation in serum by Triton X-100 1% and maintained accuracy of serological testing.

Methods

A panel of 19 serological tests was run on patient serum samples after treatment with Triton X-100 1%, 0.1%, and 0.1% + heat inactivation at 60°C for 1 h. Mean differences between measurements (bias) were calculated applying the Bland–Altman method. To determine effectiveness of virus inactivation, herpes simplex virus 1 (HSV-1) was spiked into medium containing 90% or 1% serum, and treated with Triton X-100 0.1% or 1%. Infectious titres were then determined on Vero cells.

Results

Serological measurements showed good agreement between controls and samples treated with Triton X-100 0.1% and 1%, with an estimated bias of 0.6 ± 9.2% (n = 258) and –0.1 ± 18.6% (n = 174), respectively. Discordant qualitative results were rare. Conversely, heat inactivation alone and combined with Triton X-100 0.1% triggered a bias of 17.5 ± 66.4% (n = 200) and 37.9 ± 79.8% (n = 160), respectively. Triton X-100 1% completely inactivated HSV-1 in 1% and 90% serum while Triton X-100 0.1% failed to do so in 90% serum.

Conclusions

Unlike heat inactivation, Triton X-100 1% enabled accurate serological testing and completely inactivated HSV-1 in serum. This simple method could allow safe routine serological diagnostics in high-risk patients.

Rapid, Safe, and Simple Manual Bedside Nucleic Acid Extraction for the Detection of Virus in Whole Blood Samples

The rapid diagnosis of an infection is essential for the outbreak management, risk containment, and patient care. We have previously shown a method for the rapid bedside inactivation of the Ebola virus during blood sampling for safe nucleic acid (NA) tests by adding a commercial lysis/binding buffer directly into the vacuum blood collection tubes. Using this bedside inactivation approach, we have developed a safe, rapid, and simplified bedside NA extraction method for the subsequent detection of a virus in lysis/binding buffer-inactivated whole blood. The NA extraction is directly performed in the blood collection tubes and requires no equipment or electricity. After the blood is collected into the lysis/binding buffer, the contents are mixed by flipping the tube by hand, and the mixture is incubated for 20 min at room temperature. Magnetic glass particles (MGPs) are added to the tube, and the contents are mixed by flipping the collection tube by hand. The MGPs are then collected on the side of the blood collection tube using a magnetic holder or a magnet and a rubber band. The MGPs are washed three times, and after the addition of elution buffer directly into the collection tube, the NAs are ready for NA tests, such as qPCR or isothermal loop amplification (LAMP), without the removal of the MGPs from the reaction. The NA extraction method is not dependent on any laboratory facilities and can easily be used anywhere (e.g., in field hospitals and hospital isolation wards). When this NA extraction method is combined with LAMP and a portable instrument, a diagnosis can be obtained within 40 min of the blood collection.

Murthy AR. Laboratory Processing of Specimens

Although not always the first topic discussed when preparing for a bioemergency, the availability of a competent clinical laboratory is vital for the optimal care of a patient with a risk group 4 (RG-4) high-consequence pathogen. The recent development of highly specialized facilities in the United States to assess and treat patients with highly hazardous communicable diseases has led to the design of dedicated laboratories or the redesign of laboratory space to safely process and test specimens that might contain one of these pathogens. For frontline and other acute care facilities to be prepared, safety practices need to be assessed and reviewed as necessary as pertaining to all laboratory activities, to include the pre-analytical (specimen collection and processing), analytical (specimen testing), and post-analytical (specimen disposal/waste management and reporting) processes. Laboratorians and administrative personnel need to consider the risks in handling specimens containing these pathogens and subsequently develop or revise processes to mitigate risks. In addition, issues such as scalability to handle large volume testing, the availability of trained staff, and long-term sustainability to meet the requirements of regulatory agencies need to be adopted within a fiscally responsible budget setting. This chapter provides generalized information on how clinical laboratories, from those supporting small frontline medical facilities to highly specialized laboratories supporting acute care treatment centers, can safely manage specimens from a patient known or potentially infected with a high-consequence pathogen.

The effect of a non-denaturing detergent and a guanidinium-based inactivation agent on the viability of Ebola virus in mock clinical serum samples

The 2014 Ebola outbreak in West Africa required the rapid testing of clinical material for the presence of potentially high titre Ebola virus (EBOV). Safe, fast and effective methods for the inactivation of such clinical samples are required so that rapid diagnostic tests including downstream analysis by RT-qPCR or nucleotide sequencing can be carried out. One of the most commonly used guanidinium - based denaturing agents, AVL (Qiagen) has been shown to fully inactivate EBOV once ethanol is added, however this is not compatible with the use of automated nucleic acid extraction systems. Additional inactivation agents need to be identified that can be used in automated systems. A candidate inactivation agent is Triton X-100, a non-denaturing detergent that is frequently used in clinical nucleic acid extraction procedures and has previously been used for inactivation of EBOV. In this study the effect of 0.1% and 1.0% Triton X-100 (final concentration 0.08% and 0.8% respectively) alone and in combination with AVL on the viability of EBOV (10⁶ TCID₅₀/ml) spiked into commercially available pooled negative human serum was tested. The presence of viable EBOV in the treated samples was assessed by carrying out three serial passages of the samples in Vero E6 cells (37°C, 5% CO₂, 1 week for each passage). At the end of each passage the cells were observed for evidence of cytopathic effect and samples were taken for rRT-PCR analysis for the presence of EBOV RNA. Before cell culture cytotoxic components of AVL and Triton X-100 were removed from the samples using size exclusion spin column technology or a hydrophobic adsorbent resin. The results of this study showed that EBOV spiked into human serum was not fully inactivated when treated with either 0.1% (v/v) Triton X-100 for 10 mins or 1.0% (v/v) Triton X-100 for 20 mins (final concentrations 0.08% and 0.8% Triton X-100 respectively). AVL alone also did not consistently provide complete inactivation. Samples treated with both AVL and 0.1% Triton X-100 for 10 or 20 mins were shown to be completely inactivated. This treatment is compatible with downstream analysis by RT-qPCR and next generation sequencing.

Evaluation of the inactivation effect of Triton X-100 on Ebola virus infectivity

BACKGROUND

The recent Ebola virus disease outbreak occurred in West Africa since December 2013 highlighted the need of appropriate virus inactivation procedures to be set up to allow the necessary processing of specimens outside BSL-4 facilities and to perform laboratory tests without affecting clinical decisions. For this purpose, international guidelines suggest the pre-treatment of the samples with Triton X-100.

OBJECTIVES

Due to the limited scientific evidence about the efficacy of Triton X-100 on enveloped-viruses, the aim of this work was to evaluate the effect of Triton X-100 on the virus infectivity and to establish the optimal conditions for its use.

STUDY DESIGN

We evaluated the effect of Triton X-100 on the infectivity of enveloped-viruses such as West Nile virus (WNV) and Ebola virus (EBOV) at different experimental conditions. The residual virus infectivity was measured by limiting dilution assay on Vero E6 cells. Repeated experiments were performed, as specified, and for the titration of residual infectivity each dilution was tested in triplicate.

RESULTS

Results obtained with WNV showed that infectivity was reduced by 6 Logs, after 1h of treatment with different concentrations of Triton X-100 (ranging from 0.5% to 0.05%). This effect was not time-dependent using 0.1% Triton X-100. Subsequently, we applied the method on EBOV and one hour exposure to 0.1% Triton X-100 strongly affected EBOV infectivity (4 Logs of infectivity reduction).

CONCLUSIONS

We report that Triton X-100, when used alone, is able to strongly reduce the infectivity of a classical enveloped virus such as WNV and we provide, for the first time, scientific evidence that 0.1% Triton X-100 efficaciously affect Ebola virus infectivity. Even though a complete virus inactivation is not achieved, Triton X-100 certainly can contribute to mitigate the risk for the workers of accidental infection and improve the overall safety of the laboratory procedures. Further studies must be performed to deeply investigate alternative solutions able to balance higher level of safety and good performance in clinical chemistry and hematology parameters analysis, necessary for the appropriate and effective management of EVD patients.