Patient-to-Patient Transmission of Hepatitis C Virus Through the Use of Multidose Vials During General Anesthesia

Screening for hepatitis C virus at the time of mammography using rapid diagnostic tests in women aged between 50 and 74 years (Mamm'OC NCT05067374)

Chronic hepatitis C Virus (HCV) infection presents a global health challenge, with significant morbidity and mortality worldwide. Despite remarkable progress in treatment options, achieving elimination targets by 2030, as set by the World Health Organization, remains elusive. Our study aimed to address this gap by integrating HCV screening into a national breast cancer screening program. Between March 2022 and March 2023, a prospective cross-sectional multicenter study was conducted in four radiology centers in Montpellier, France. We proposed HCV screening to consecutive women undergoing mammography, targeting 1,500 participants aged 50-74 years. A rapid diagnostic test (RDT) for HCV antibodies (HCV Ab) was performed on capillary whole blood, with positive cases undergoing serological and RNA confirmation. Participants also completed a questionnaire on demographic data and risk factors. Acceptance rates, HCV prevalence, and linkage to care were assessed. The acceptance rate for this integrated screening approach was 82.4%. Notably, the seroprevalence of HCV was found to be 0.65%. Linkage to care was prompt, and the cascade of care demonstrated successful treatment outcomes. Importantly, the majority of detected infections were successfully resolved. These findings underscore the feasibility and acceptability of integrating HCV screening with breast cancer screening programs providing updated prevalence data and valuable insights for refining future screening strategies.

Risk of parenterally transmitted hepatitis following exposure to invasive procedures in Italy: SEIEVA surveillance 2000-2021

BACKGROUND & AIMS

Surgical interventions and invasive diagnostic/therapeutic procedures are known routes of transmission of viral hepatitis. Using data from the Italian surveillance system for acute viral hepatitis (SEIEVA), the aim of this study was to investigate the association between specific types of invasive procedures and the risk of acute HBV and HCV infections.

METHODS

Data from SEIEVA (period 2000-2021) were used. The association between acute HBV and HCV infection and potential risk factors, i.e. surgical interventions and diagnostic/therapeutic procedures (given according to the ICD-9-CM classification), was investigated in comparison to age-matched hepatitis A cases, used as controls, by conditional multiple logistic regression analysis.

RESULTS

A total of 8,176 cases with acute HBV, 2,179 with acute HCV, and the respective age-matched controls with acute HAV infection were selected for the main analysis. Most of the procedures evaluated were associated with the risk of acquiring HBV or HCV. The strongest associations for HBV infection were: gynaecological surgery (odds ratio [OR] 5.19; 95% CI 1.12-24.05), otorhinolaryngological surgery (OR 3.78; 95% CI 1.76-8.09), and cardiac/thoracic surgery (OR 3.52; 95% CI 1.34-9.23); while for HCV infection, they were: neurosurgery (OR 11.88; 95% CI 2.40-58.85), otorhinolaryngological surgery (OR 11.54; 95% CI 2.55-52.24), and vascular surgery (OR 9.52; 95% CI 3.25-27.87). Hepatitis C was also strongly associated with ophthalmological surgery (OR 8.32; 95% CI 2.24-30.92). Biopsy and/or endoscopic procedures were significantly associated with both HCV (OR 3.84; 95% CI 2.47-5.95) and, to a lesser extent, HBV infection (OR 1.48; 95% CI 1.16-1.90).

CONCLUSIONS

Despite the progress made in recent years, invasive procedures still represent a significant risk factor for acquiring parenterally transmitted hepatitis viruses, thus explaining the still numerous and unexpected cases diagnosed among the elderly population in Italy. Our results underline the importance of observing universal precautions to control the iatrogenic transmission of hepatitis viruses.

IMPACT AND IMPLICATIONS

Cases of parenterally transmitted acute viral hepatitis in the elderly population, that are difficult to explain based on the most widely recognised risk factors, continue to be diagnosed in Italy. Based on the Italian SEIEVA surveillance of acute viral hepatitis data, this study highlights an increased risk of acquiring hepatitis B and C following exposure to invasive procedures, which might explain the observed cases in elderly individuals. Furthermore, this finding emphasises the need to observe universal precautions strictly, in healthcare settings, including in the case of minor surgical procedures.

An outbreak of hepatitis C virus attributed to the use of multi-dose vials at a colonoscopy clinic, Waterloo Region, Ontario

Background

Hepatitis C virus (HCV) transmission has been epidemiologically linked to healthcare settings, particularly out-of-hospital settings such as endoscopy clinics and hemodialysis clinics. These have been largely attributed to lapses in infection prevention and control practices (IPAC).

Objective

To describe the public health response to an outbreak of HCV that was detected among patients of a colonoscopy clinic in Ontario, and to highlight the risks of using multi-dose vials and the need for improved IPAC practices in out-of-hospital settings.

Methods

Screening for HCV was conducted on patients and staff who attended or worked at the clinic within the same timeframe as the index case's procedure. Blood samples from positive cases underwent viral sequencing. Inspections of the clinic assessed IPAC practices, and a chart review was done to identify plausible mechanisms for transmission.

Outcome

A total of 38% of patients who underwent procedures at the clinic on the same day as the index case tested positive for HCV. Genetic sequencing showed a high degree of similarity in the HCV genetic sequence among the samples positive for HCV. Chart review and clinic inspection identified use of multi-dose vials of anesthesia medication across multiple patients as the plausible mechanism for transmission.

Conclusion

Healthcare workers, especially those in out-of-hospital procedural/surgical premises, should be vigilant in following IPAC best practices, including those related to the use of multi-dose vials, to prevent the transmission of bloodborne infections in healthcare settings.

Práctica de inyecciones seguras por parte del personal de la salud: revisión integrativa

Introducción: Las prácticas de inyecciones seguras han recobrado importancia en las últimas dos décadas, como consecuencia de las infecciones asociadas con su aplicación incorrecta. Objetivo: Analizar la evidencia disponible sobre las prácticas de inyecciones seguras ejecutadas por el personal de la salud en su práctica clínica. Método: Revisión integrativa de la literatura, realizada en 12 bases de datos entre 1999 y 2018. Resultados: Se seleccionaron 29 artículos y se identificaron prácticas riesgosas como el reúso de los dispositivos de inyección en el mismo paciente o en otros, fallas en la técnica aséptica, ausencia o no seguimiento del protocolo posexposición, reencapuchado de la aguja y ausencia de inmunización contra el virus de hepatitis B. Conclusiones: Los esfuerzos orientados a la seguridad del paciente deben enfocarse también en acciones concretas dirigidas a la administración de los medicamentos.

The infection rate of intralesional triamcinolone and the safety of compounding in dermatology for intradermal and subcutaneous injection: A retrospective medical record review

BACKGROUND

Intralesional injection of sterile medications remains a mainstay in dermatology, enabling a tailored, low-cost, in-office therapy. After the 2012 United States outbreak of fungal meningitis from contaminated intrathecally administered corticosteroids, there has been increased regulation of in-office compounding, regardless of the administration route. Studies demonstrating the safety data of in-office corticosteroid compounding for intradermal or subcutaneous use are lacking.

OBJECTIVE

To assess the incidence of infection caused by compounded in-office intralesional triamcinolone.

METHODS

A retrospective medical record review identified patients who received in-office intralesional corticosteroid injections in 2016. Medical documentation within 30 days of injection was reviewed for suspected infection.

RESULTS

The records of 4370 intralesional triamcinolone injections were assessed, of which 2780 (64%) were compounded triamcinolone with bacteriostatic saline. We identified 11 (0.25%) suspected localized infections, with 4 of the 11 in the compounding cohort. Of these, 7 of 11 occurred after injection of an "inflamed cyst." No hospitalizations or deaths occurred. No temporal or locational relationships were identified.

LIMITATIONS

This study was limited to 2 academic institutions. A 30-day postinjection time frame was used.

CONCLUSION

In-office compounding for intralesional dermal and subcutaneous administration is safe when sterile products are used by medical practitioners. There is no increased risk of compounded triamcinolone relative to noncompounded triamcinolone.

Modeling suggests that microliter volumes of contaminated blood caused an outbreak of hepatitis C during computerized tomography

BACKGROUND & AIMS

Acute hepatitis C (AHC) is not frequently identified because patients are usually asymptomatic, although may be recognized after iatrogenic exposures such as needle stick injuries, medical injection, and acupuncture. We describe an outbreak of AHC among 12 patients who received IV saline flush from a single multi-dose vial after intravenous contrast administration for a computerized tomography (CT) scan. The last patient to receive IV contrast with saline flush from a multi-dose vial at the clinic on the previous day was known to have chronic HCV genotype 1b (termed potential source, PS). Here we sought to confirm (via genetic analysis) the source of infection and to predict the minimal contaminating level of IV saline flush needed to transmit infectious virus to all patients.

METHODS

In order to confirm the source of infection, we sequenced the HCV E1E2 region in 7 CT patients, in PS, and in 2 control samples from unrelated patients also infected with HCV genotype 1b. A transmission probabilistic model was developed to predict the contamination volume of blood that would have been sufficient to transmit infectious virus to all patients.

RESULTS

Viral sequencing showed close clustering of the cases with the PS. The transmission probabilistic model predicted that contamination of the multi-dose saline vial with 0.6-8.7 microliters of blood would have been sufficient to transmit infectious virus to all patients.

CONCLUSION

Analysis of this unique cohort provides a new understanding of HCV transmission with respect to contaminating volumes and viral titers.

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.

Bacterial Contamination of Anaesthetic and Vasopressor Drugs in the Operating Theatres: Ameliyathanelerde Anestetik ve Vazopressör İlaçların Bakteriyel Kontaminasyonu

OBJECTIVE

The aim of this study was to determine the incidence of bacterial and fungal contamination in anaesthetic and vasopressor drugs before and after use in operating theatres.

METHODS

A cross-sectional study was conducted in the operating theatres of a university hospital. We collected 945 samples of three different drugs, namely, propofol, vecuronium and ephedrine, from 20 operating rooms and refrigerators where the unused drugs were stored. Each drug was divided into two groups, the pre-use group and the post-use group. The pre-use drugs were cultured before the patient received the drug. The post-use drugs were cultured after the patient had received the drug or after the drugs had been transferred to other syringes. The culture results were reported as either positive or negative.

RESULTS

Out of the 945 drug samples, 26 (2.8%, 95% confidence interval=1.8%-4.0%) gave a positive culture. Of the 317 propofol samples, 20 (6.3%) were found to have bacterial contamination, 11 in the pre-use group and 9 in the post-use group. Of the 318 ephedrine samples, 6 (1.9%) were found to be positive on culture, one in the pre-use group and five in the post-use group. Vecuronium gave no positive cultures. All organisms were non-pathogenic, and no fungal contamination was found.

CONCLUSION

The incidence of bacterial contamination in anaesthetic and vasopressor drugs was 2.8%. Anaesthetic teams must be aware of contamination issues in anaesthetic drugs that have been prepared for later use and, in order to reduce the risk of contamination, they must improve the methods of administering drugs to patients.

Outbreak of hepatitis C among patients admitted to the Department of Gynecology, Obstetrics, and Oncology

BACKGROUND

In Poland, nosocomial infections account for 32% of all patients' claims against public hospitals, with hepatitis B virus and hepatitis C virus (HCV) being the most common causes. We present a major nosocomial outbreak of the HCV infection in the Department of Gynecology, Obstetrics, and Oncology and the results of detailed sanitary and epidemiologic research.

METHODS

A retrospective analysis of medicolegal opinions issued at the request of the civil court regarding the suspicion of HCV nosocomial infections was conducted.

RESULTS

The detailed medical data analysis proved 26 patients aged 19 to 72 years with recent HCV hepatitis hospitalized on the same gynecology ward. Twenty women were operated on for neoplasm. The State Sanitary Inspection's investigation revealed a number of malpractices: incorrect sterilization procedures, insufficient hygiene habits of health care workers, poor condition of premises, and equipment being in poor condition. Numerous cases of staff breaking basic sanitary rules and hygiene standards and a lack of crucial procedures were discovered. The high number of women infected and the multiple errors recognized led to closure of the ward.

CONCLUSION

Outbreaks of HCV hepatitis may be the result of ineffective infection control systems and remains a significant public health problem. Asymptomatic HCV nosocomial infections might go unnoticed or concealed and underreported. Auditing medical centers and health care workers for compliance with sanitary and epidemiologic requirements is an essential need.

Patient notification for bloodborne pathogen testing due to unsafe injection practices in the US health care settings, 2001-2011

BACKGROUND

Syringe reuse and other unsafe injection practices can expose patients to bloodborne pathogens (eg, hepatitis B and C viruses and human immunodeficiency virus). Evidence of such infection control lapses has resulted in patient notifications, but the scope and magnitude of these events have not been well characterized.

OBJECTIVES

To summarize patient notification events resulting from unsafe injection practices in the US health care settings.

METHODS

We examined records of events that involved communications to groups of patients, conducted during 2001-2011, advising bloodborne pathogen testing stemming from potential exposures to unsafe injection practices.

RESULTS

We identified 35 patient notification events related to unsafe injection practices in at least 17 states, resulting in an estimated total of 130,198 patients notified. Among the identified notification events, 83% involved outpatient settings and 74% occurred since 2007, including the 4 largest events (>5000 patients per event). The primary breach identified (≥16 events; 44%) was syringe reuse to access shared medications (eg, single-dose or multidose vials). Twenty-two (63%) notifications stemmed from the identification of viral hepatitis transmission, whereas 13 (37%) were prompted by the discovery of unsafe injection practices, absent evidence of bloodborne pathogen transmission.

CONCLUSIONS

Unsafe injection practices represent a form of medical error that have manifested as large-scale adverse events, affecting thousands of patients in a wide variety of health care settings. Our findings suggest that increased oversight and attention to basic infection control are needed to maintain patient safety, along with research to identify best practices for triggering and managing patient notifications.

Reuse of medical devices: implications for infection control

Reuse of both single-use and multiuse medical devices is a common practice and can result in transmission of infection when appropriate sterilization or reprocessing does not occur. Reuse of single-use devices can be problematic because there are no clear standards for reprocessing, although data regarding adverse outcomes are limited. Single-use devices are commonly reused, appropriately or inappropriately, in resource-limited settings because of cost constraints. Reuse of medical devices raises important legal and ethical questions.

Population risk of syringe reuse: estimating the probability of transmitting bloodborne disease

BACKGROUND

In 2008, the Medical Officer of Health at Alberta Health Services (Edmonton, Canada) was notified that, in some practice settings, a syringe was used to administer medication through the side port of an intravenous circuit and then the syringe, with residual drug, was used to administer medication to other patients in the same manner. This practice has been implicated in several outbreaks of bloodborne infection in hospital and clinic settings.

METHODS

A risk assessment model was developed to predict the risk of a patient contracting a bloodborne viral infection from the practice. The risk of transmission was defined as the product of 5 factors: (1) the population prevalence of a specific bloodborne pathogen, (2) the probability of finding a viral bloodborne pathogen in an intravenous circuit, (3) the rate of syringe reuse, (4) the probability of causing disease given a bloodborne pathogen exposure, and (5) the susceptibility of the exposed person.

RESULTS

The risk was modeled first with consistent use of the proximal port of the intravenous circuit. The risk of transmission of hepatitis B virus was approximately 12-53 transmission events per 1,000,000 exposure events for a range of practice probabilities (ie, frequency of the risk practice) from 20% to 80%, respectively. The risk of transmission of hepatitis C virus was approximately 1.0-4.3 transmission events per 1,000,000 exposure events for the same practice probability range, and the risk of transmission of human immunodeficiency virus was approximately 0.03-0.15 transmission events per 1,000,000 exposure events for the same practice probability range. The use of the distal port was associated with a 10-fold decrease in the risk.

CONCLUSIONS

Practitioners must practice safe, aseptic injection techniques. The model presented here can be used to estimate the risk of disease transmission in situations where reuse has occurred and can serve as a framework for informing public health action.

Current risks of occupational blood-borne viral infection

BACKGROUND

Human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), and other viruses remain occupational risks for both surgeons and patients in the operating room environment. In the past, this concern attracted great attention, but recently, this subject has been given much less attention.

METHODS

Review of the literature over the past 50 years on occupational risks of viral infection in the operating room.

RESULTS

Transmission of HIV still looms as a potential pathogen in the operating room, but no case has been documented in the United States. Infection with HBV can be prevented by a safe and effective vaccine. Chronic HCV infection is present in more than three million U.S. residents and remains a risk that can be managed only by adhering to strict infection control practices and avoiding blood exposure.

CONCLUSIONS

The risks of viral infection in the operating room remain the same as a decade ago even though attention to this issue has waned. The avoidance of blood exposure to prevent transmission of both known and unknown blood-borne pathogens continues to be a goal for all surgeons.

Patient-to-patient transmission of hepatitis C virus (HCV) during colonoscopy diagnosis

Background

No recognized risk factors can be identified in 10-40% of hepatitis C virus (HCV)-infected patients suggesting that the modes of transmission involved could be underestimated or unidentified. Invasive diagnostic procedures, such as endoscopy, have been considered as a potential HCV transmission route; although the actual extent of transmission in endoscopy procedures remains controversial. Most reported HCV outbreaks related to nosocomial acquisition have been attributed to unsafe injection practices and use of multi-dose vials. Only a few cases of likely patient-to-patient HCV transmission via a contaminated colonoscope have been reported to date. Nosocomial HCV infection may have important medical and legal implications and, therefore, possible transmission routes should be investigated. In this study, a case of nosocomial transmission of HCV from a common source to two patients who underwent colonoscopy in an endoscopy unit is reported.

Results

A retrospective epidemiological search after detection of index cases revealed several potentially infective procedures: sample blood collection, use of a peripheral catheter, anesthesia and colonoscopy procedures. The epidemiological investigation showed breaches in colonoscope reprocessing and deficiencies in the recording of valuable tracing data. Direct sequences from the NS5B region were obtained to determine the extent of the outbreak and cloned sequences from the E1-E2 region were used to establish the relationships among intrapatient viral populations. Phylogenetic analyses of individual sequences from viral populations infecting the three patients involved in the outbreak confirmed the patient pointed out by the epidemiological search as the source of the outbreak. Furthermore, the sequential order in which the patients underwent colonoscopy correlates with viral genetic variability estimates.

Conclusions

Patient-to-patient transmission of HCV could be demonstrated although the precise route of transmission remained unclear. Viral genetic variability is proposed as a useful tool for tracing HCV transmission, especially in recent transmissions.

Molecular epidemiology of a hepatitis C virus epidemic in a haemodialysis unit: outbreak investigation and infection outcome

Background

HCV is a leading cause of liver chronic diseases all over the world. In developed countries the highest prevalence of infection is reported among intravenous drug users and haemodialysis (HD) patients. The present report is to identify the pathway of HCV transmission during an outbreak of HCV infection in a privately run haemodialysis (HD) unit in Italy in 2005.

Methods

Dynamics of the outbreak and infection clinical outcomes were defined through an ambi-directional cohort study. Molecular epidemiology techniques were used to define the relationships between the viral variants infecting the patients and confirm the outbreak. Risk analysis and auditing procedures were carried out to define the transmission pathway(s).

Results

Of the 50 patients treated in the HD unit 5 were already anti-HCV positive and 13 became positive during the study period (AR = 28.9%). Phylogenic analysis identified that, all the molecularly characterized incident cases (10 out of 13), were infected with the same viral variant of one of the prevalent cases. The multivariate analysis and the auditing procedure disclosed a single event of multi-dose vials heparin contamination as the cause of transmission of the infection in 11 out of the 13 incident cases; 2 additional incident cases occurred possibly as a result of inappropriate risk management.

Discussion

More than 30% of all HCV infections in developed countries results from poor application of standard precautions during percutaneous procedures. Comprehensive strategy which included: educational programmes, periodical auditing on standard precaution, use of single-dose vials whenever possible, prospective surveillance for blood-borne infections (including a system of prompt notification) and risk assessment/management dedicated staff are the cornerstone to contain and prevent outbreaks in HD

Conclusions

The outbreak described should serve as a reminder to HD providers that patients undergoing dialysis are at risk for HCV infection and that HCV may be easily transmitted whenever standard precautions are not strictly applied.

Outbreak of severe sepsis due to contaminated propofol: lessons to learn

Nosocomial infections are a frequent concern in healthcare. Despite the available knowledge on nosocomial infections and preventive measures, outbreaks of infections continue to occur. An outbreak of severe sepsis in patients who underwent minor procedures in an operating theatre during two consecutive days is described and analysed in this study. We performed a retrospective cohort study using epidemiological data in order to investigate the source of infection together with microbiological and on-site investigations and interviews. Seven patients met the case definition of postoperative systemic inflammatory response syndrome (SIRS). All other patients operated on over the same period served as controls. Of the risk factors investigated, general anaesthesia and propofol were statistically significant (P=0.003). Klebsiella pneumoniae and Serratia marcescens were cultured from opened vials of propofol, propofol-related devices and from blood cultures from two of the patients. These strains were genotypically indistinguishable. Lapses in aseptic preparation, handling and storage of the propofol were observed, and were the most probable cause of the extrinsic contamination. The daily procedure of handling propofol was not performed according to the manufacturer's recommendations, the main departure being the use of a single-use vial for multiple patients. This study documents the risk of infection due to contaminated propofol and the importance of having written guidelines for its handling.

Multiple clusters of hepatitis virus infections associated with anesthesia for outpatient endoscopy procedures

BACKGROUND & AIMS

Hepatitis B virus (HBV) and hepatitis C virus (HCV) can be transmitted during administration of intravenous anesthesia when medication vials are used for multiple patients using incorrect technique. We investigated an outbreak of acute HBV and HCV infections among patients who received anesthesia during endoscopy procedures from the same anesthesiologist (anesthesiologist 1), in 2 different gastroenterology clinics.

METHODS

Chart reviews, patient interviews, clinic site visits and infection control assessments, and molecular sequencing of patient isolates were performed. Patients treated by anesthesiologist 1 on specific procedure days were offered testing for blood-borne pathogens. Endoscopy and anesthesia procedures were reviewed; HCV quasispecies analysis was performed.

RESULTS

Six cases of outbreak-associated HCV infection and 6 cases of outbreak-associated HBV infection were identified in clinic 1. One outbreak-associated HCV infection was identified in clinic 2. HCV quasispecies sequences from the patients were nearly identical (96.9%-100%) to those from source patients with chronic viral hepatitis. All affected patients in both clinics received propofol from anesthesiologist 1, who inappropriately used a single-patient-use vial of propofol for multiple patients. Reuse of syringes to redose patients, with resulting contamination of medication vials used for subsequent patients, likely resulted in viral transmission.

CONCLUSIONS

Twelve persons acquired HBV and HCV infections (6 hepatitis C, 5 hepatitis B, and 1 coinfection) in 2 separate offices as a result of receiving anesthesia from anesthesiologist 1. Gastroenterologists are urged to review carefully the injection, medication handling, and other infection control practices of all staff under their supervision, including providers of anesthesia services.

Infection control guidelines for prevention of health care-associated transmission of hepatitis B and C viruses

Viral hepatitis was first identified as an occupational hazard for health care workers more than 60 years ago. For the past few decades, hepatitis B has been one of the most significant occupational infectious risks for health care providers. With the increasing prevalence of hepatitis C infections around the world, occupational transmission of this flavivirus from infected patients to their providers has also become a significant concern. Several factors influence the risk for occupational blood-borne hepatitis infection among health care providers, among them: the prevalence of infection among the population served, the infection status of the patients to whom workers are exposed (ie, the source patient's circulating viral burden), the types and frequencies of parenteral and mucosal exposures to blood and blood-containing body fluids, and whether the patient or provider has been immunized with the hepatitis B vaccine. This article reviews patient-to-provider, patient-to-patient, and provider-to-patient transmission of hepatitis B and C in the health care setting. Current prevention strategies, precautions, and guidelines are discussed.

Molecular epidemiology of health care-associated transmission of hepatitis B and C viruses

The term "molecular epidemiology" has been ascribed to a host of different activities that involve gene-sequence analysis. Some examples of molecular epidemiology include modeling exercises of phylogenetic trees to reconstruct epidemics; studies of the evolution of hepatitis C virus (HCV); rates of nucleotide substitution in the hepatitis B virus (HBV) surface (S) gene; variations in the core promoter/pre-core/core region of HBV genotype C from different sources; analysis of HBV surface antigen mutations; molecular clock analyses of the short-term evolution of HCV; and analyses of clades and surface antigen polymorphisms of HBV. However, for most epidemiologists molecular epidemiology of viral hepatitis usually refers to studies of gene-sequence homology in HBV or HCV recovered from people in the community or an institution that allows better characterization and assignment of related clusters of infection.

Assessment and proposal of a new combination of screening criteria for hepatitis C in France

BACKGROUND

The current French hepatitis C virus infection screening programme is not yet reaching all populations at risk. In order to better identify individuals that would benefit from a screening test, we investigated an expanded combination of personal characteristics as potential screening criteria for this infection.

METHODS

We constructed two multiple-regression models predicting hepatitis C antibody seropositivity using the population sample from the 2004 French national hepatitis C antibody seroprevalence survey (SPS) (n = 14 416): one representing current screening guidelines and another constructed from personal characteristics collected for the SPS. Performance of the two predictive models was statistically compared and we internally validated the better performing model.

RESULTS

The expanded screening criteria model better discriminated seropositive and seronegative individuals [area under the ROC curve (AUC) 0.869 (95% CI 0.861-0.873)] than the current screening guidelines model [AUC 0.821 (95% CI 0.810-0.824)]. This performance difference was statistically significant (P < 0.00001). The expanded criteria model contains the variables age, sex, pre-1992 blood transfusion, intra-venous drug use, receipt of medical welfare for precarious individuals, previous surgeries, illicit nasal drug use, previous hepatitis C screening, tattoo, raised alanine aminotransferase level and birth in a hepatitis C high/moderate-prevalence country.

CONCLUSION

Results indicate that an expanded combination of screening criteria better predicted hepatitis C antibody status and thus individuals needing screening than the current French-screening guidelines. The proposed combination of screening criteria could more effectively target hepatitis C risk-populations in France and could serve as the basis for a decision-making screening tool for the general population.

Transmission of hepatitis C virus in an orthopedic hospital ward

Healthcare-associated infections with hepatitis C virus (HCV) hitherto have been observed mainly in hemodialysis settings as well as in hematology and oncology wards. In this communication, molecular and epidemiologic investigations to elucidate an HCV outbreak in an orthopedic ward are reported. One hundred and thirty-five patients hospitalized in the ward and 104 staff members were tested. In addition to extensive epidemiologic reviews and hygienic inspections, direct sequencing of HCV PCR fragments and phylogenetic analysis of more than 300 partial HCV sequences obtained by end-point limiting-dilution real-time PCR assay were carried out. Six patients were infected with very closely related HCV variants. Patient-to-patient spread of the virus was inferred to have started from one patient with previous HCV infection to the other five patients during their hospital stay. Inspections did not reveal substantial breaches in basic infection control practices and did not identify a specific activity that might have led to nosocomial transmission. As a result of the investigations, the hospital corrected the documentation of all medical and nursing activities undertaken in the ward, abandoned the use of all multidose saline and other medication vials, and included explicitly recommendations for the safe preparation and administration of injectable drugs into internal infection control guidelines. Thereafter, no further nosocomial transmissions of HCV have been recorded in the orthopedic ward. The events observed suggest that nosocomial transmission of HCV is not limited to hemodialysis, hematology or oncology settings, and they also reinforce the mandatory adherence to basic infection control practices.

The safety of multi-dose vials in allergy immunotherapy

OBJECTIVE

To prospectively evaluate the risks of vial contamination after routine clinical use of multiple-dose vials for immunotherapy.

STUDY DESIGN

Prospective observational study of immunotherapy vial cultures from June 2007 to January 2008.

SETTING

Tertiary care outpatient otolaryngology clinic.

RESULTS

Over an 8-month period, 136 consecutive vials were cultured for aerobic and anaerobic bacteria at the 3-month expiration date after regular use in an outpatient allergy clinic and dispensation of multiple doses of injection immunotherapy from each vial. All vials had negative cultures.

CONCLUSION

Immunotherapy vials are at low risk to undergo contamination in routine use. Important factors include aseptic technique, bacteriostatic agents, and expiration dating.

Epidemiological characteristics and medical follow-up of 61 patients with acute hepatitis C identified through the hepatitis C surveillance system in France

This study aimed to describe current epidemiological and clinical characteristics, medical follow-up and outcome in the real practice of acute hepatitis C (AHC) patients. AHC cases were retrospectively identified through the French Hepatology Reference Centres Surveillance system and additional data were collected. Sixty-one patients with AHC were identified (sex ratio: M/F 1.7/1; mean age 39 years). Forty-four (72%) had documented seroconversion within a 6-month period. Main reported risk exposures were intravenous or nasal drug use (35%), invasive medical procedures (25%) and sexual contact with a HCV-positive partner (20%). Spontaneous clearance of HCV RNA was observed in seven out of 16 patients followed without therapy. This study confirms the major role of drug use in HCV transmission and highlights the role of invasive medical procedures and occupational exposure.

Transmission of hepatitis C virus during computed tomography scanning with contrast

Six cases of acute hepatitis C related to computed tomography scanning with contrast were identified in 3 hospitals. A patient with chronic hepatitis C had been subjected to the same procedure immediately before each patient who developed acute infection. Viral molecular analysis showed identity between isolates from cases with acute and chronic hepatitis C.

The changing epidemiology of hepatitis C virus infection in Europe

The epidemic of hepatitis C virus (HCV) infection in Europe is continuously evolving and epidemiological parameters (prevalence, incidence, disease transmission patterns and genotype distribution) have changed substantially during the last 15 years. Four main factors contribute to such changes: increased blood transfusion safety, improvement of healthcare conditions, continuous expansion of intravenous drug use and immigration to Europe from endemic areas. As a result, intravenous drug use has become the main risk factor for HCV transmission, prevalent infections have increased and genotype distribution has changed and diversified. Hence, prevalence data from studies conducted a decade ago may not be useful to estimate the current and future burden of HCV infection and additional epidemiological studies should be conducted, as well as new preventive strategies implemented to control the silent epidemic. This review summarizes recently published data on the epidemiology of HCV infection in Europe focusing on the factors currently shaping the epidemic.

Nosocomial transmission of hepatitis C virus during contrast-enhanced computed tomography scanning

We have investigated two cases of acute hepatitis C that occurred in patients who underwent digestive endoscopy and contrast-enhanced computed tomography (CT) scanning at two different centers. Investigations to identify the sources of infection included an on-site review of diagnostic procedures, interview of the involved healthcare staff, serological testing of the patients who underwent the procedures before and after the index cases and a molecular analysis of viral isolates from the patients and from potential viremic sources. In both cases, the epidemiological investigation identified a chronic hepatitis C virus (HCV) carrier who had been subjected to CT-scanning immediately before the index patient. Genetic distance and molecular phylogenetic analyzes of HCV sequences showed a close relationship between the isolates from these carriers and those from the acute-hepatitis patients, strongly suggesting that patient-to-patient transmission had occurred during CT. This is the first report describing two well documented cases of HCV nosocomial patient-to-patient transmission during contrast-enhanced CT scanning.

An incident case-control study of modes of hepatitis C virus transmission in France

PURPOSE

Risk factors for hepatitis C virus (HCV) infection have rarely been estimated using incident case-control studies in the "general" population. We undertook a case-control study of incident HCV infection to identify persistent modes of transmission in France.

METHODS

Two types of case-patients were included: (1) repeat blood donors who seroconverted between 1998 and 2001 (with a last negative third-generation test reported from 1995 or after) and (2) seroconverters referred to hepatology departments in 2000 through 2001. For each case-patient, four age- and sex-matched controls were randomly selected from the population of occurrence. Data on risk factors were recorded for each case-patient's and matched control's referent exposure period (between last negative and first positive tests).

RESULTS

Sixty-four case-patients and 227 controls were included. In univariate analysis, endoscopy (matched odds ratios [mORs] = 8.0; 95% confidence intervals [CI] = 2.3-27.2), general anesthesia (mOR = 5.6; 95% CI = 2.2-14.7), tattooing or body piercing (mOR = 8.8; 95% CI = 1.7-44.1), and intravenous (IV) drug use (p < 0.0001; mOR not defined) were associated with HCV seroconversion. In multivariate analysis, risk factors associated with HCV seroconversion were drug use (adjusted OR [aOR] = 109.0; 95% CI = 11.7-1015.8), digestive endoscopy (aOR = 5.7; CI = 1.4-23.8), and invasive radiology procedures (aOR = 11.6; CI = 1.7-78.5).

CONCLUSIONS

The results showed the continuing major role of IV drug use and suggested that transmission related to invasive health care remained a potential source of new HCV infection between 1995 and 2001.

Clinical course and outcome of a nosocomial outbreak of hepatitis C in a urology ward

This paper describes a prospective study of the clinical course and outcome of a nosocomial outbreak of hepatitis C virus (HCV) infection in six male urology patients at a hospital in Stara Zagora, Bulgaria. These patients had been previously hospitalised in the urology ward, during which all had received intravenous therapy. Approximately three weeks later, all six were admitted to the infectious diseases unit with acute hepatitis, shown to be caused by HCV genotype 1b. The diagnosis was confirmed by polymerase chain reaction during the first week of their hospital stay. Infected patients were followed up for 30 months following diagnosis and 54 potential contacts for 6 months post-exposure. Four patients recovered completely; one developed chronic HCV infection and one died. The latter already had cirrhosis due to co-infection with hepatitis B virus. The investigation established the index case as a patient with chronic hepatitis C, who had been an in-patient on the same ward at the same time. The most likely route of transmission was intravenous heparin flushes administered with a common syringe. Contrary to the common assumption that acute HCV infection often leads to chronic disease, only one chronic case was observed during the 30-month period of investigation.

[Risk of hepatitis C related to traditional medicine: a case control study in Ho Chi Minh City, Vietnam]

BACKGROUND

The transmission of hepatitis C virus (HCV) is strongly associated with blood transfusion and drug abuse. However, in about a third of HCV-infected subjects, the risk factors are not clearly identified though some cases are likely to be healthcare associated. In an Asian country such as Vietnam, invasive procedures used for traditional and beauty care could be potential risk factors. The aim of the present study was to identify the risk factors of HCV infection in a population sample in Ho Chi Minh City.

METHOD

A case-control study matched by gender and age was performed among blood adults donors at the Centre of hematological diseases and blood transfusion. Cases were defined as blood donors with HCV-positive Elisa. Controls were selected at random among ELISA HCV-negative donors. A standardized questionnaire was used to collect data focusing on invasive medical procedures, beauty care and on invasive procedures related to traditional medicine.

RESULT

Among the 80 cases and 240 controls, the independent predictors of anti-HCV positivity using a stepwise logistic regression were: blood transfusion, intravenous drug abuse, acupuncture, ventoused scarification and practice of scarification (adjusted odds ratio and IC95%: 3.8 [1.1-13.1], 3.5 [1.7-7.3], 5.4 [2.3-12.7], 5.4 [2.5-11.7], 6.6 [1.6-26.4] respectively). The other risk factors such as past hospitalization surgery, tattooing, being a healthcare worker, or practising tattooing or piercing were not associated with HCV infection.

CONCLUSION

To be exposed to ventoused scarifications or acupuncture are risk factors for the transmission of HCV in Vietnam. A wide information campaign on hygiene practices for general population as well as the practitioners is needed to ensure safer health cares in traditional medicine.

[Principles of an outbreak investigation in public health practice]

An outbreak (or epidemic) is a higher number of cases of a given disease in a given population and time interval. A timely investigation has for aim to identify the source and vehicle of the outbreak and provides unique opportunities to better understand its occurrence and the role of contributing risk factors to implement the most appropriate measures to control it and prevent further recurrences. The investigation of an outbreak is based on a multidisciplinary approach (clinical, epidemiological, environmental, and microbiological) with a descriptive and analytical (hypothesis testing) phase. In this article, we describe the methodological approach of a field outbreak investigation illustrated by examples taken from our experience. The investigation includes the following steps: establishing the existence of the outbreak; defining the disease; finding cases; describing cases by time, place, and person characteristics; establishing a hypothesis related to the mode of occurrence; testing the hypotheses; conducting an environmental investigation; conducting a microbiological investigation; controlling the outbreak, preventing further occurrences, and writing an investigation report to share experience with the public health and scientific community. The investigation of an outbreak is an evolving process: information gathered or conclusions made at a given stage must be fully used for following steps. The social, institutional, and political background associated with outbreaks usually makes their investigation complex and should be taken into account. The earlier the outbreak is detected and investigated in close relation with public health authorities, the greater will be the potential preventive impact of control measures.

Hospital-acquired infections related to contaminated substances

Drug-related outbreaks are frequently reported from various medical departments. A systematic review was performed to describe characteristics of these outbreaks and to determine the most frequent occasions in which contamination of substances for patient care take place. Articles were assessed by a search of the outbreak database, a search of PubMed, and hand search of reference lists from relevant articles. Articles published before 1990 were excluded. Data on affected patients, hospital-acquired infections, substances, pathogens and graded information about the location of the contamination incidence were extracted. A total of 2250 patients in 128 articles were included, mostly from intensive care units or haematological departments. Septicaemia was the most frequent hospital-acquired infection. Most often articles report contamination of blood products and heparin-sodium chloride solutions. The most frequent pathogens were hepatitis A virus, Yersinia enterocolitica, and Serratia spp. for blood products and Burkholderia cepacia and Enterobacter spp. for substances other than blood products. Mortality was highest if red blood cells or total parenteral nutrition formulas were contaminated. In 64 of the outbreaks multi-dose vials had been used against the manufacturers' recommendations. Thus, drug-related outbreaks are likely to occur particularly when basic hygiene measures are disobeyed. A large proportion of drug-related nosocomial infections could have been prevented, for example, by avoiding the use of multi-dose vials.

Proper use of multidose vials

PROBLEM

Every month when we inspect our facilities we find multidose vials (MDVs) used or stored inappropriately. It's frustrating to toss costly drugs and biologics into the trash. What can we do to heighten awareness of proper MDV handling?

SOLUTION

Staff probably know the proper procedures for safe use of MDVs, but job stress, time constraints, and poor staffing levels can underlie a medication giver's decision to skip or omit steps in the process. Hurried or careless staff may have inadequate handwashing hygiene, reuse a single-use needle or syringe, or fail to decontaminate the vial's stopper. Potential contamination is an out-of-sight, out-of-mind problem. To ensure better policy adherence, it helps to reinforce staff's understanding of the repercussion of increased infections when shortcuts are taken.

Hepatitis C virus genotype distribution among intravenous drug user and the general population in Hong Kong

This study describes the distribution of hepatitis C genotypes among 106 intravenous drug users and 949 non-drug users in Hong Kong. Genotypes were identified by multiplex RT-PCR targeting the core region of viral genome. The accuracy of this typing system in identifying genotypes 1b and 6a was assessed by phylogenetic analysis. The distribution of hepatitis C virus (HCV) genotypes amongst non-drug users was 63.6% for genotype 1b, 23.6% for 6a, 4.5% for 1a, 3.9% for 3a, and 3.1% for 2a; whereas amongst the intravenous drug users, it was 58.5% for genotype 6a, 33.0% for 1b, 5.7% for 3a, 0.9% for 1a, and 0.9% for 2a. The proportion of genotype 6a was significantly higher (P < 0.001), whereas that for genotype 1b was significantly lower (P = 0.001) for the intravenous drug user group. Multivariate analysis revealed significant independent associations for the distribution of HCV genotypes 1b and 6a with age, sex, and intravenous drug user status. The co-circulation of a common (1b) and a rare (6a) HCV genotype in Hong Kong provides a unique opportunity for future studies to compare their transmission efficiency, clinical course, and response to treatment.