Thermostability of seven hepatitis C virus genotypes in vitro and in vivo

Hepatitis C Contamination of Medication Vials Accessed with Sterile Needles and Syringes

BACKGROUND

Health care-associated hepatitis C virus outbreaks from contaminated medication vials continue to be reported even though most practitioners deny reusing needles or syringes. The hypothesis was that when caring for hepatitis C virus-infected patients, healthcare providers may inadvertently contaminate the medication vial diaphragm and that subsequent access with sterile needles and syringes can transfer hepatitis C virus into the medication, where it remains stable in sufficient quantities to infect subsequent patients.

METHODS

A parallel-arm lab study (n = 9) was performed in which contamination of medication vials in healthcare settings was simulated using cell culture-derived hepatitis C virus. First, surface-contaminated vials were accessed with sterile needles and syringes, and then hepatitis C virus contamination was assessed in cell culture. Second, after contaminating several medications with hepatitis C virus, viral infectivity over time was assessed. Last, surface-contaminated vial diaphragms were disinfected with 70% isopropyl alcohol to determine whether disinfection of the vial surface was sufficient to eliminate hepatitis C virus infectivity.

RESULTS

Contamination of medication vials with hepatitis C virus and subsequent access with sterile needles and syringes resulted in contamination of the vial contents in sufficient quantities to initiate an infection in cell culture. Hepatitis C virus remained viable for several days in several commonly used medications. Finally, a single or 2- to 3-s wipe of the vial diaphragm with 70% isopropyl alcohol was not sufficient to eliminate hepatitis C virus infectivity.

CONCLUSIONS

Hepatitis C virus can be transferred into commonly used medications when using sterile single-use needles and syringes where it remains viable for several days. Furthermore, cleaning the vial diaphragm with 70% isopropyl alcohol is not sufficient to eliminate the risk of hepatitis C virus infectivity. This highlights the potential risks associated with sharing medications between patients.

Hepatitis C virus treatment in people who inject drugs (PWID) in Bangladesh

BACKGROUND

Given the considerable social marginalization experienced by people who inject drugs (PWID), treatment of hepatitis C virus (HCV) in this population presents unique challenges. This study assessed the feasibility of treating HCV infection with direct-acting antiviral (DAA) medications among PWID receiving harm reduction services from a Drop-in-Center in Dhaka, Bangladesh.

METHODS

In this prospective study conducted between December 2016 and May 2018, 200 PWID with either recent injecting drug use (i.e., within the previous two months) or a history of injecting drug use and are currently receiving opioid substitution therapy were recruited. Blood was collected to conduct relevant laboratory tests. Eligible PWID who tested positive for HCV RNA (n = 55), were provided daily daclatasvir (60 mg) and sofosbuvir (400 mg) for 12 weeks after which adherence level, sustained virologic response (SVR), and reinfection were assessed.

RESULTS

At baseline, 40% (n = 79) of the 200 participants recruited to the study tested positive for antibodies to HCV and 34% (n = 68) had detectable HCV RNA in their blood. Of 55 eligible PWID who initiated treatment, 93% (n = 51) completed treatment while 87% (n = 48) were available for follow-up SVR assessment, all of whom achieved SVR. Thus, intent-to-treat SVR was 87% and the modified intent-to-treat SVR was 100% with one reinfection (4•2 cases per 100 person-years). Further, 75% (i.e., 41 out of the 55 participants) were at least 90% adherent to therapy.

CONCLUSION

Our findings strongly suggest that HCV treatment using sofosbuvir+daclatasvir for PWID enrolled in existing harm reduction programs in Bangladesh is feasible but may require additional interventions such as Opioid Substitution Therapy, intense follow up by outreach workers, and services and counselling provided by full time clinicians.

Nosocomial transmission of hepatitis C virus in a liver transplant center in Hong Kong: implication of reusable blood collection tube holder as the vehicle for transmission

BACKGROUND

A liver transplant recipient developed hospital-acquired symptomatic hepatitis C virus (HCV) genotype 6a infection 14 months post transplant.

OBJECTIVE

Standard outbreak investigation.

METHODS

Patient chart review, interviews of patients and staff, observational study of patient care practices, environmental surveillance, blood collection simulation experiments, and phylogenetic study of HCV strains using partial envelope gene sequences (E1-E2) of HCV genotype 6a strains from the suspected source patient, the environment, and the index patient were performed.

RESULTS

Investigations and data review revealed no further cases of HCV genotype 6a infection in the transplant unit. However, a suspected source with a high HCV load was identified. HCV genotype 6a was found in a contaminated reusable blood-collection tube holder with barely visible blood and was identified as the only shared item posing risk of transmission to the index case patient. Also, 14 episodes of sequential blood collection from the source patient and the index case patient were noted on the computerized time log of the laboratory barcoding system during their 13 days of cohospitalization in the liver transplant ward. Disinfection of the tube holders was not performed after use between patients. Blood collection simulation experiments showed that HCV and technetium isotope contaminating the tip of the sleeve capping the sleeved-needle can reflux back from the vacuum-specimen tube side to the patient side.

CONCLUSIONS

A reusable blood-collection tube holder without disinfection between patients can cause a nosocomial HCV infection. Single-use disposable tube holders should be used according to the recommendations by Occupational Safety and Health Administration and World Health Organization.

Environmental Stability and Infectivity of Hepatitis C Virus (HCV) in Different Human Body Fluids

Background: Hepatitis C virus (HCV) is a hepatotropic, blood-borne virus, but in up to one-third of infections of the transmission route remained unidentified. Viral genome copies of HCV have been identified in several body fluids, however, non-parental transmission upon exposure to contaminated body fluids seems to be rare. Several body fluids, e.g., tears and saliva, are renowned for their antimicrobial and antiviral properties, nevertheless, HCV stability has never been systematically analyzed in those fluids. Methods: We used state of the art infectious HCV cell culture techniques to investigate the stability of HCV in different body fluids to estimate the potential risk of transmission via patient body fluid material. In addition, we mimicked a potential contamination of HCV in tear fluid and analyzed which impact commercially available contact lens solutions might have in such a scenario. Results: We could demonstrate that HCV remains infectious over several days in body fluids like tears, saliva, semen, and cerebrospinal fluid. Only hydrogen-peroxide contact lens solutions were able to efficiently inactivate HCV in a suspension test. Conclusion: These results indicate that HCV, once it is present in various body fluids of infected patients, remains infective and could potentially contribute to transmission upon direct contact.

Gold aggregating gold: A novel nanoparticle biosensor approach for the direct quantification of hepatitis C virus RNA in clinical samples

The affordable and reliable detection of Hepatitis C Virus (HCV) RNA is a cornerstone in the management and control of infection, affecting approximately 3% of the global population. However, the existing technologies are expensive, labor intensive and time consuming, posing significant limitations to their wide-scale exploitation, particularly in economically deprived populations. Here, we utilized the unique optical and physicochemical properties of gold nanoparticles (AuNPs) to develop a novel assay platform shown to be rapid and robust in sensing and quantifying unamplified HCV RNA in clinical samples. The assay is based on inducing aggregation of citrate AuNPs decorated with a specific nucleic acid probe. Two types of cationic AuNPs, cysteamine and CTAB capped, were compared to achieve maximum assay performance. The technology is simple, rapid, cost effective and quantitative with 93.3% sensitivity, high specificity and detection limit of 4.57IU/µl. Finally, our data suggest that RNA folding impact the aggregation behavior of the functionalized AuNPs, with broader applications in other nucleic acid detection technologies.

Survival of Hepatitis C Virus in Syringes Is Dependent on the Design of the Syringe-Needle and Dead Space Volume

Background

Many people who inject drugs (PWID) use syringes with detachable needles, which have high dead space (HDS). Contaminated HDS blood may substantially contribute to the transmission of HIV, hepatitis C (HCV), and other blood-borne viruses within this population. Newly designed low dead space (LDS) syringe-needle combinations seek to reduce blood-borne virus transmission among PWID. We evaluated the infectivity of HCV-contaminated residual volumes recovered from two LDS syringe-needle combinations.

Methods

We tested two different design approaches to reducing the dead space. One added a piston to the plunger; the other reduced the dead space within the needle. The two approaches cannot be combined. Recovery of genotype-2a reporter HCV from LDS syringe-needle combinations was compared to recovery from insulin syringes with fixed needles and standard HDS syringe-needle combinations. Recovery of HCV from syringes was determined immediately following their contamination with HCV-spiked plasma, after storage at 22°C for up to 1 week, or after rinsing with water.

Results

Insulin syringes with fixed needles had the lowest proportion of HCV-positive syringes before and after storage. HCV recovery after immediate use ranged from 47%±4% HCV-positive 1 mL insulin syringes with 27-gauge ½ inch needles to 98%±1% HCV-positive HDS 2 mL syringes with 23-gauge 1¼ inch detachable needles. LDS combinations yielded recoveries ranging from 65%±5% to 93%±3%. Recovery was lower in combinations containing LDS needles than LDS syringes. After 3 days of storage, as much as 6-fold differences in virus recovery was observed, with HCV recovery being lower in combinations containing LDS needles. Most combinations with detachable needles required multiple rinses to reduce HCV infectivity to undetectable levels whereas a single rinse of insulin syringes was sufficient.

Conclusions

Our study, the first to assess the infectivity of HCV in residual volumes of LDS syringes and needles available to PWID, demonstrates that LDS syringe-needle combination still has the greater potential for HCV transmission than insulin syringes with fixed needles. Improved LDS designs may be able to further reduce HCV recovery, but based on the designed tested, LDS needles and syringes remain intermediate between fixed-needle syringes and HDS combinations in reducing exposure to HCV.

Animal models for the study of HCV

The development and evaluation of effective therapies and vaccines for the hepatitis C virus (HCV) and the study of its interactions with the mammalian host have been hindered for a long time by the absence of suitable small animal models. Immune compromised mouse models that recapitulate the complete HCV life cycle have been useful to investigate many aspects of the HCV life cycle including antiviral interventions. However, HCV has a high propensity to establish persistence and associated histopathological manifestations such as steatosis, fibrosis, cirrhosis and hepatocellular carcinoma (HCC). Better understanding of these processes requires the development of a permissive and fully immunocompetent small animal model. In this review we summarize the in vivo models that are available for the study of HCV.

Disinfection of syringes contaminated with hepatitis C virus by rinsing with household products

PWID “disinfect” used syringes with readily available household products when new syringes are inaccessible. Household products tested were more effective in fixed-needle syringes (low residual volume) than in syringes with detachable-needles (high residual volume). Bleach was the most effective disinfectant.

Background. Hepatitis C virus (HCV) transmission among people who inject drugs (PWID) is associated with the sharing of injection paraphernalia. People who inject drugs often “disinfect” used syringes with household products when new syringes are unavailable. We assessed the effectiveness of these products in disinfecting HCV-contaminated syringes.

Methods. A genotype-2a reporter virus assay was used to assess HCV infectivity in syringes postrinsing. Hepatitis C virus-contaminated 1 mL insulin syringes with fixed needles and 1 mL tuberculin syringes with detachable needles were rinsed with water, Clorox bleach, hydrogen peroxide, ethanol, isopropanol, Lysol, or Dawn Ultra at different concentrations. Syringes were either immediately tested for viable virus or stored at 4°C, 22°C, and 37°C for up to 21 days before viral infectivity was determined.

Results. Most products tested reduced HCV infectivity to undetectable levels in insulin syringes. Bleach eliminated HCV infectivity in both syringes. Other disinfectants produced virus recovery ranging from high (5% ethanol, 77% ± 12% HCV-positive syringes) to low (1:800 Dawn Ultra, 7% ± 7% positive syringes) in tuberculin syringes.

Conclusions. Household disinfectants tested were more effective in fixed-needle syringes (low residual volume) than in syringes with detachable needles (high residual volume). Bleach was the most effective disinfectant after 1 rinse, whereas other diluted household products required multiple rinses to eliminate HCV. Rinsing with water, 5% ethanol (as in beer), and 20% ethanol (as in fortified wine) was ineffective and should be avoided. Our data suggest that rinsing of syringes with household disinfectants may be an effective tool in preventing HCV transmission in PWID when done properly.

Mechanisms of methods for hepatitis C virus inactivation

Virus inactivation by chemical disinfectants is an important instrument for infection control in medical settings, but the mechanisms involved are poorly understood. In this study, we systematically investigated the effects of several antiviral treatments on hepatitis C virus (HCV) particles as model for enveloped viruses. Studies were performed with authentic cell culture-derived viruses, and the influence of chemical disinfectants, heat, and UV treatment on HCV was analyzed by the determination of infectious particles in a limiting-dilution assay, by quantitative reverse transcription-PCR, by core enzyme-linked immunosorbent assay, and by proteolytic protection assay. All different inactivation methods resulted in a loss of HCV infectivity by targeting different parts of the virus particle. Alcohols such as ethanol and 2-propanol did not affect the viral RNA genome integrity but disrupted the viral envelope membrane in a capsid protection assay. Heat and UV treatment of HCV particles resulted in direct damage of the viral genome since transfection of viral particle-associated RNA into permissive cells did not initiate RNA replication. In addition, heat incubation at 80°C disrupted the HCV envelope, rendering the viral capsid susceptible to proteolytic digest. This study demonstrated the molecular processes of viral inactivation of an enveloped virus and should facilitate the development of effective disinfection strategies in infection control not only against HCV but also against other enveloped viruses.

HCV animal models and liver disease

The development and evaluation of effective therapies and vaccines for the hepatitis C virus (HCV) and the study of its interactions with the mammalian host have been hindered for a long time by the absence of suitable small animal models. Due to the narrow host tropism of HCV, the development of mice that can be robustly engrafted with human hepatocytes was a major breakthrough since they recapitulate the complete HCV life cycle. This model has been useful to investigate many aspects of the HCV life cycle, including antiviral interventions. However, studies of cellular immunity, immunopathogenesis and resulting liver diseases have been hampered by the lack of a small animal model with a functional immune system. In this review, we summarize the evolution of in vivo models for the study of HCV.

Serological assay and genotyping of hepatitis C virus in infected patients in zanjan province

BACKGROUND

Hepatitis C Virus (HCV), a public health problem, is an enveloped, single-stranded RNA virus and a member of the Hepacivirus genus of the Flaviviridae family. Liver cancer, cirrhosis, and end-stage liver are the outcomes of chronic infection with HCV. HCV isolates show significant heterogeneity in genetics around the world. Therefore, determining HCV genotypes is a vital step in determining prognosis and planning therapeutic strategies.

OBJECTIVES

As distribution of HCV genotypes is different in various geographical regions and HCV genotyping of patients has not been investigated in Zanjan City, this study was designed for the first time, to determine HCV genotypes in the region and to promote the impact of the treatment.

MATERIALS AND METHODS

Serum samples of 136 patients were collected and analyzed for anti-HCV antibodies using ELISA (The enzyme-linked immunosorbent assay) method. Then, positive samples were exposed to RT-PCR, which was performed under standard condition. Afterwards, they investigated for genotyping using allele-specific PCR (AS-PCR), and HCV genotype 2.0 line probe assay (LiPA).

RESULTS

Samples indicated 216 bp bands on 2% agarose gel. Analyses of the results demonstrated that the most dominant subtype was 3a with frequency of 38.26% in Zanjan Province followed by subtypes of 1b, 1a, 2, and 4 with frequencies of 25.73%, 22.05%, 5.14%, and 4.41%, respectively. The frequency of unknown HCV genotypes was 4.41%.

CONCLUSIONS

According to the results, it was found that HCV high prevalent genotype in Zanjan is subtype 3a. Analysis of the results provides identification of certain HCV genotypes, and these valuable findings could affect the type and duration of the treatment.

Hepatitis C virus maintains infectivity for weeks after drying on inanimate surfaces at room temperature: implications for risks of transmission

BACKGROUND

Healthcare workers may come into contact with fomites that contain infectious hepatitis C virus (HCV) during preparation of plasma or following placement or removal of venous lines. Similarly, injection drugs users may come into contact with fomites. Hypothesizing that prolonged viability of HCV in fomites may contribute significantly to incidence, we determined the longevity of virus infectivity and the effectiveness of antiseptics.

METHODS

We determined the volume of drops misplaced during transfer of serum or plasma. Aliquots equivalent to the maximum drop volume of plasma spiked with the 2a HCV reporter virus were loaded into 24-well plates. Plates were stored uncovered at 3 temperatures: 4°C, 22°C, and 37°C for up to 6 weeks before viral infectivity was determined in a microculture assay.

RESULTS

The mean volume of an accidental drop was 29 µL (min-max of 20-33 µL). At storage temperatures 4°C and 22°C, we recovered viable HCV from the low-titer spots for up to 6 weeks of storage. The rank order of HCV virucidal activity of commonly used antiseptics was bleach (1:10) > cavicide (1:10) > ethanol (70%).

CONCLUSIONS

The hypothesis of potential transmission from fomites was supported by the experimental results. The anti-HCV activity of commercial antiseptics varied.