Survival Of Hepatitis A Virus Research Articles

Survival of murine norovirus and hepatitis A virus in bottled drinking water, strawberries, and oysters

The survival of murine norovirus (MNV) and hepatitis A virus (HAV) in bottled drinking water, strawberries, and oysters stored at different temperatures for various durations was investigated. In drinking water, over 6.4 and 1.6 log 10 plaque-forming units (PFU/mL) reductions of viable MNV and HAV were observed after 20 days of incubation at 35 °C. After 160 days of incubation at 20 °C, there was a sharp decrease in the MNV (>6.4 log 10 PFU/mL) and HAV (>2.9 log 10 PFU/mL) load but only a slight reduction at 4 °C. In fresh strawberry, the MNV and HAV titers reduced by 1.0 and 0.9 log 10 PFU/g after incubation for 2 days at 25 °C, by 0.85 and 1.22 log 10 PFU/g after 3 days of incubation at 15 °C, and by 0.7 and 1.1 log 10 PFU/g after 7 days of incubation at 4 °C, respectively. After 3 days of incubation at 4, 15, and 25 °C in oyster reductions of over 0.3, 0.4, and 0.6 log 10 PFU/mL in the MNV load and 0.16, 0.28, and 0.52 log 10 PFU/mL in the HAV load were observed, respectively. Even though, survival of the two viruses fluctuated with temperature and food commodity. Therefore, our results indicate that major enteric foodborne viruses such as MNV and HAV can survive for long periods, with only a partial reduction in their titers. Owing to the persistence of foodborne viruses, preventive measures need to be taken to prevent food contamination. • MNV and HAV survival in drinking water, strawberries, and oysters was investigated. • MNV and HAV survivability varies with temperature and food type. • Enteric foodborne viruses can persist for a long time at 4 °C. • Study results could lay the foundation for the development of food hazard assessment models.

Survival of Hepatitis A Virus on Two-Month Stored Freeze-Dried Berries

Imported berries have contributed to U.S. hepatitis A virus (HAV) infections. Minimal processing by freeze-drying is preferred by industry for preserving food quality, but virus inactivation by this process may be limited. This study investigated HAV survival on strawberries during 24-h freeze-drying followed by 22°C storage. The outer surfaces of strawberry slices were prepared and each inoculated with 5 to 6 log PFU HAV, air dried for 20 min, frozen for 1 h at -80°C, and freeze-dried for 24 h with radiant heating up to 36°C. Infectious HAV levels eluted from berry slices were quantified on FRhK-4 cells grown onto six-well dishes. Freeze-drying trials (n = 17) with radiant heating inactivated ≤1 log PFU per trial, although HAV inactivation was significantly (P < 0.01) greater at 36°C than at 15°C heating. Average HAV reduction rate on dried berries continuously decreased as storage time increased: 0.2-, 0.09-, 0.08-, 0.04-, 0.04-, and 0.03-log reduction per day at day 2, 7, 14, 28, 42, and 56, respectively, with the cumulated log reduction divided by storage days. Therefore, the best-fit regression for the total or cumulative virus reduction (Y) at any given day (X) is Y = 0.2882X0.4503 (r2 = 0.97), with a maximum 2.7-log reduction on berries throughout the drying and subsequent 2-month storage. HAV showed the greatest decline within the first 14 days of storage of dried berries (ca. 70% weekly reduction from its previous week's level), but the HAV reduction rates were still lower than that occurring on fresh produce.

Hepatitis A Virus Survival on Drug Paraphernalia

Background: The ongoing hepatitis A outbreak in the United States has concerned public health authorities since March 2017. The outbreak has already spread throughout 30 states and includes primarily homeless individuals and persons who use drugs, including persons who inject drugs (PWIDs). Contaminated drug injection paraphernalia and sharing of these items are suspected to be one of multiple causes of hepatitis A virus (HAV) transmission in those populations. Methods: We used a standard plaque assay to investigate HAV infectivity. Liquid suspensions of HAV were tested to examine the effects of time and temperature on viral infectivity. We also examined HAV survival on commonly used drug paraphernalia, such as needles, syringes, cookers, tourniquets, and cotton balls/filters frequently shared among PWIDs. We investigated the effect of low pH on HAV survival using citric acid, which is frequently used by PWIDs during dose preparation. We also compared the plaque assay results with those concurrently obtained by RT-PCR to establish whether viral HAV RNA levels could be used as surrogates for plaque assay results. Results: We found that HAV suspended in PBS at room temperature was able to infect FRhk4 cells for &gt;17 weeks. HAV remained viable in syringes and needles (ie, semidry conditions) for up to 10 weeks depending on the size of the needles and the syringe dead volume. HAV survival in dry conditions on cooker, tourniquet, and cotton balls/filter surfaces did not exceed 4 weeks. HAV retained its infectivity for &gt;10 weeks at pH as low as 2. PCR results suggest that RNA is amplified from both infectious and noninfectious HAV. Conclusions: Our findings show that HAV can survive and remain infective in the PWID setting for 4–10 weeks depending on the type of paraphernalia examined. These findings suggest that sharing drug paraphernalia by the homeless and PWIDs can potentially facilitate the transmission of HAV within these populations. Moreover, our results confirm that the plaque assay is currently the only reliable method to determine the infectivity of HAV in vitro.Funding: NoneDisclosures: None

Hepatitis A virus survival on drug paraphernalia.

The ongoing hepatitis A outbreaks in multiple states in the United States have concerned public health authorities since March 2017. The outbreaks have spread throughout 30 states and include primarily persons who use drugs, including persons who inject drugs (PWID) and persons experiencing homelessness. Contaminated drug injection paraphernalia and sharing of these items could potentially aid in transmission of hepatitis A virus (HAV) among these populations. We examined HAV survival on drug paraphernalia frequently shared among PWIDs. The effect of low pH on HAV survival using citric acid, which is frequently used by PWIDs during dose preparation, was investigated. We compared the plaque assay results with those concurrently obtained by qRT-PCR to establish whether HAV RNA levels could be used as surrogates for plaque assay results. HAV suspended in minimal essential media at room temperature infected FRhK4 cells for more than 17weeks. HAV remained viable in syringes/needles for up to 10weeks depending on the gauge of the needles and the syringe dead volumes, and on cookers, tourniquets and cotton balls/filter surfaces for up to 4weeks. HAV retained its infectivity for more than 10weeks at pH as low as 2. In conclusion, our findings show that HAV survives and remains infective in or on injection drug use equipment for 1 to 10weeks depending on the type of paraphernalia examined and environmental conditions. These findings suggest that contaminated drug paraphernalia can potentially facilitate the transmission of HAV within populations who share these items.

Survival of hepatitis A virus and Aichi virus in cranberry-based juices at refrigeration (4 °C)

Viral foodborne illness continues to be a health-concern globally, with numerous fruit and juice outbreaks of Hepatitis A virus (HAV) reported worldwide. Aichi virus (AiV) is an emerging pathogen with limited epidemiological data. Both, HAV and AiV are resistant to low pH and can survive under adverse environmental conditions leading to transmission ease. The objective of this study was to evaluate the survival of HAV and AiV in commercially-available cranberry-based juices (Cranberry juice cocktail, CJ and a 100% juice with cranberry, MJ) over 21 days at refrigeration (4 °C). Equal volumes of juice was mixed with each virus individually (final titer of 6 log PFU/mL) and stored at refrigeration over 21 days. At each time interval, the inoculated juices were serially diluted in cell culture media and infectious virus survival was determined by standard plaque assays. Each experiment was carried out in duplicate and replicated thrice. Reductions of 0.72 ± 0.06 (after day 1) to 2.3 ± 0.18 log PFU/mL (after day 21) and 0.63 ± 0.02 (after day 1) to 1.84 ± 0.14 log PFU/mL (after day 21) were obtained for AiV with MJ and CJ, respectively. Reductions ranging from 0.67 ± 0.03 (after day 1) to 1.09 ± 0.1 log PFU/mL (after day 21) and 0.93 ± 0.27 (after day1) to 1.49 ± 0.18 log PFU/mL (after day 21) were obtained for HAV at refrigeration in MJ and CJ, respectively. HAV showed greater survival than AiV in these juices over refrigerated storage. These results provide survival data of HAV and AiV in cranberry-based juices that can be used in risk-modeling and risk assessment studies.

Survival of hepatitis A virus on various food-contact surfaces during 28 days of storage at room temperature

Hepatitis A virus (HAV) infections constitute one of the leading causes of food-borne disease outbreaks. HAV spreads readily from one infected person to another through contaminated water or food, via the fecal–oral route. The prevention of HAV infection is therefore important in the preparation of food. The objective of this study was to investigate the survival of HAV on six different food-contact surfaces: ceramic, wood, rubber, glass, stainless steel and plastic. The survival of HAV was measured during storage at room temperature for 28days. On the food-contact surfaces, the greatest reduction in HAV was 2.3log10plaque-forming units (PFU)/coupon, observed on stainless steel, while the lowest HAV reduction was 1.4log10PFU/coupon, observed on wood. The values of dR (time required to reduce the virus by 99%) on survival plots of HAV determined by a modified Weibull model were 1396.9h (R2=0.97) on ceramic, 1676.4h (R2=0.98) on wood, 852.7h on rubber (R2=0.95), 1386.4h (R2=0.97) on glass, 428.6h (R2=0.96) on stainless steel and 833.0h (R2=0.97) on plastic. The infectivity of the virus on all six food-contact surfaces was maintained after 28days. Studies show that HAV from food preparation or processing will survive persistently on cookware. This study provides information useful for the control of HAV on different food-contact surfaces and the prevention of food-borne disease.

Influence of NaCl on the inactivation of murine norovirus-1 and hepatitis A virus in the Korean traditional salted oyster product “Eoriguljeot” during storage

Enteric noroviruses (NoV) and hepatitis A virus (HAV) are the leading causes of non-bacterial shellfish-borne gastroenteritis. This study examined the effects of different concentrations of NaCl on the survival of murine norovirus-1 (MNV-1), which was used as a human NoV surrogate, and HAV in experimentally contaminated raw oysters during 72-h storage at 10°C. Both MNV-1 and HAV titers significantly (p<0.05) decreased by stepwise increases in NaCl and storage time; however, MNV-1 was more resistant to NaCl than HAV. The overall reductions in MNV-1 and HAV titers in oysters incubated with 10%, 7%, 5%, 3%, and 0% NaCl were 0.61 and 1.20, 0.50 and 0.89, 0.35 and 0.64, 0.25 and 0.42, and 0.07 and 0.25 log10 50% tissue culture infectious dose (TCID50)/mL, respectively. A 1.23 log (94.11%) reduction of MNV-1 and 2.45 log (99.65%) reduction of HAV survival also occurred in 10% NaCl-containing oysters at 72h of storage. Using the first-order reaction model, we determined that the MNV-1 decimal reduction time (D-value) was 64h at 10% NaCl, whereas D-values of 63h, 47h, and 31h were obtained for HAV at 5%, 7%, and 10% NaCl, respectively. This study suggests that NaCl concentrations of ≥10% could be potentially used for inactivation of NoV and HAV in traditional Korean foods, including those containing raw oysters such as Eoriguljeot and fermented Jeotgals.

Temperature-Dependent Survival of Hepatitis A Virus during Storage of Contaminated Onions

Pre- or postharvest contamination of green onions by hepatitis A virus (HAV) has been linked to large numbers of food-borne illnesses. Understanding HAV survival in onions would assist in projecting the risk of the disease associated with their consumption. This study defined HAV inactivation rates in contaminated green onions contained in air-permeable, moisture-retaining high-density polyethylene packages that were stored at 3, 10, 14, 20, 21, 22, and 23°C. A protocol was established to recover HAV from whole green onions, with 31% as the average recovery by infectivity assay. Viruses in eluates were primarily analyzed by a 6-well plaque assay on FRhK-4 cells. Eight storage trials, including two trials at 3°C, were conducted, with 3 to 7 onion samples per sampling and 4 to 7 samplings per trial. Linear regression correlation (r(2) = 0.80 to 0.98) was observed between HAV survival and storage time for each of the 8 trials, held at specific temperatures. Increases in the storage temperature resulted in greater HAV inactivation rates, e.g., a reduction of 0.033 log PFU/day at 3.4 ± 0.3°C versus 0.185 log PFU/day at 23.4 ± 0.7°C. Thus, decimal reduction time (D) values of 30, 14, 11, and 5 days, respectively, were obtained for HAV in onions stored at 3, 10, 14, and 23°C. Further regression analysis determined that 1 degree Celsius increase would increase inactivation of HAV by 0.007 log PFU/day in onions (r(2) = 0.97). The data suggest that natural degradation of HAV in contaminated fresh produce is minimal and that a preventive strategy is critical to produce safety. The results are useful in predicting the risks associated with HAV contamination in fresh produce.

Survival and Persistence of Norovirus, Hepatitis A Virus, and Feline Calicivirus in Marinated Mussels

Noroviruses (NV) and hepatitis A virus (HAV) are foodborne enteric viruses associated with outbreaks of disease following consumption of raw or lightly cooked bivalve shellfish. Marinated mussels are a popular delicacy, but there is no published information on whether enteric viruses survive the marination process. The survival and persistence of HAV, NV, and a surrogate calicivirus, feline calicivirus (FCV), in marinated mussels over time was determined. NV, HAV, and FCV were inoculated into marinated mussels and marinade liquid and then held at 4°C for up to 4 weeks. Survival of HAV and FCV was quantified by determining the 50% tissue culture infectious dose (TCID50), and these results were correlated with those of the reverse transcription (RT)–PCR assay. The persistence of nonculturable NV was determined by RT–PCR assay only. Over 4 weeks, HAV survived exposure to acid marinade at pH 3.75. There was a 1.7-log reduction in HAV TCID50 titer but no reduction in NV or HAV RT-PCR titer after 4 weeks in marinated mussels. FCV was inactivated in acid conditions although it was still detectable by RT-PCR. To simulate preharvest virus contamination and commercial marination processing, experiments using fresh mussels infected with HAV and NV were performed. HAV and NV persistence was determined using semiquantitative real-time RT-PCR, and HAV infectivity was determined by the TCID50 assay. HAV retained infectivity following simulated commercial marination and exposure to acid conditions over 4 weeks. The survival of pathogenic enteric viruses in marinated mussels constitutes a potential health risk and so is of concern to public health authorities.

Hepatitis A virus attachment to agri-food surfaces using immunological, virological and thermodynamic assays.

This study was designed to investigate the ability of hepatitis A virus (HAV) to attach to various food contact surfaces. HAV attachment was demonstrated after elution of attached viruses from solid surfaces by an immunofluorescent method using anti-HAV-specific antibodies and confocal microscopy. Attachment and survival of HAV on stainless steel, copper, polythene and polyvinyl chloride (PVC) at 20 and 4 degrees C after 2 and 4 h were quantified by plaque assay. HAV was shown to attach almost instantaneously to all four surfaces tested. Attachment of HAV depended on initial viral concentration and was slightly greater at 4 degrees C. The total surface energy (gammaTOT), nonpolar Lifshitz-Van der Waals (gammaLW) and polar short range (gammaSR) hydrogen-bonding components for HAV and each surface as well as total free energy of the system were determined by contact angle measurements using an extended Young equation [Young (1805) Philosophical Transactions of The Royal Society (London) 95, 65-87). The calculation of these parameters predicted the favourable conditions for attachment of HAV to all four surfaces tested. HAV particles attach to stainless steel, copper, polythene and PVC at 20 and 4 degrees C and the total free energy of the interaction is optimal for this attachment. Comprehension of viral attachment to the solid surfaces will permit to successfully disinfect these surfaces and to establish a better surveillance programme for control of viral food-borne illnesses.

Survival of hepatitis A virus on modified atmosphere-packaged (MAP) lettuce

Experiments were designed to study the effect of various modified atmospheres (MA) on the survival rate of hepatitis A virus (HAV) on lettuce. Pieces of lettuce inoculated with HAV were incubated at room temperature (RT) and 4°C for 12 days in ambient air and under various modified atmospheres (CO2:N2at 30:70, 50:50, 70:30 and 100% CO2) inside plastic bags of low O2permeability. Samples were removed on days 1, 3, 6, 9 and 12 and the virus was recovered and plaque-assayed to determine residual titer. Incubation for 12 days at 4°C showed that the lowest HAV survival rate (47·5%) was on lettuce stored in a petri-dish (atmospheric air), whereas the greatest survival rates (83·6%) was on lettuce stored under 70% CO2. Statistical analysis of virus survival at 4°C indicated that HAV titers decreased for all packages, but without a significant (P>0·05) difference between the package types. At RT, however, a significantly (P<0·05) lower HAV survival rate (0·01%) was evident on lettuce stored in a petri dish, whereas survival rates as high as 42·8% were observed on lettuce stored under 70% CO2; much lower survival rates (≤8·6%) were obtained on lettuce stored under other MAP environments at RT. Statistical analysis of the RT data indicated that there was a highly significant (P<0·05) decrease in HAV titre with increasing storage time and between package types, except for lettuce stored under 70% CO2. These data indicate that MAP does not influence HAV survival when present on the surface of produce incubated at 4°C. A slight improvement in virus survival on lettuce was seen in the presence of high CO2levels at RT. This may have been attributed to the inhibition of spoilage-causing enzymatic activities in the lettuce, which may have reduced exposure of the virus to potential toxic by-products.

Survival of enteric viruses on environmental fomites.

The survival of human enteric viruses on several porous (paper and cotton cloth) and nonporous (aluminum, china, glazed tile, latex, and polystyrene) environmental surfaces has been evaluated. Viruses persisted for extended periods on several types of materials commonly found in institutions and domestic environments. The stability of the viruses was generally influenced by environmental factors such as relative humidity (RH), temperature, and the type of surface contaminated. Overall, hepatitis A virus (HAV) and human rotavirus (HRV) were more resistant to inactivation than enteric adenovirus (ADV) and poliovirus (PV). The resistance to the desiccation step appears to be of major significance in determining the survival of a virus dried on fomites. ADV and PV showed a pronounced decrease in titer at this stage, whereas HAV and HRV displayed little decay at the desiccation step. HAV and HRV persistence was not affected by the presence of fecal material. On nonporous surfaces, PV and ADV persisted better in the presence of feces. However, on porous fomites the presence of fecal material had a negative influence on the survival of PV and ADV. Except for HRV, greater virus survival was observed at 4 degrees than at 20 degrees C. PV and HAV survival was enhanced at high RH; the survival of the latter was enhanced at least for nonporous materials. When dried on porous materials, HRV also exhibited greater persistence at high RH. The survival of ADV was not affected by RH. The validity of using bacteriophages of Bacteroides fragilis as indicators of human viruses dried on fomites was evaluated.(ABSTRACT TRUNCATED AT 250 WORDS)