Transmission of hepatitis C virus in a gynecological surgery setting

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.

[Sepsis outbreak associated with use of contaminated propofol: A new case series and literature review]

INTRODUCTION

Propofol is the most commonly used hypnotic agent for the induction and maintenance of general anesthesia. Due to its lipid-based composition, propofol requires a strict handling protocol to avoid an increased risk of extrinsic contamination.

METHODS

On September 09, 2021, 05 patients with post-anaesthetic Enterobacter cloacae infections were identified in the pediatric exploration department of the Hassan II University Hospital of Fez in Morocco. We describe the investigation into this outbreak. All patient medical records were reviewed to determine patient characteristics and potential risk factors. For the literature review, we identified relevant articles by searching PubMed, Medline, Embase and Science Direct.

RESULTS

Our study included five patients, 80% were boys. The average age was 4.6 years (1-7 years), with no medical history. All five patients underwent exploratory procedures. Immediately after the procedures, all 5 patients presented with chills, tachycardia and fever in the same order of admission. They were all admitted to hospital and blood samples were taken. Blood cultures were positive for E. cloacae. All patients had elevated levels of C-reactive protein (CRP) and an elevated white blood cell count. Bacteriological investigation revealed that the infection was caused by extrinsic contamination of the intravenous anesthetic propofol by E. cloacae.

CONCLUSION

Fatal infections due to contaminated drugs, including propofol, have been reported worldwide. Propofol is a potential source of infections due to its lipophilic nature which promotes microbial growth. This probably remains an underestimated problem that deserves awareness for early recognition.

A cross sectional study of the risk factors of hepatitis C infection in North Egypt

Hepatitis C is a viral infection that has been declared as a global health problem by the World Health Organization. Egypt has the highest prevalence of hepatitis C virus (HCV) which results in a high morbidity and mortality from chronic liver disease, cirrhosis, and even hepatocellular carcinoma. Cities have lower rates of infection than rural areas. Studies about the abnormally high prevalence of HCV in Egypt ascribed that to the governmental campaign to treat Schistosoma. However, these treatment campaigns have stopped more than 35 years ago, which means that some other modes of transmission must have been involved. The objective of this work is to study the main reasons of HCV prevalence in the Egyptian Delta valley. A questionnaire-based study was conducted by members of the HCV Fighters project. Responses were collected from 949 volunteers (451 HCV patients and 498 healthy volunteers as control). The data were analyzed using SPSS version 19.0. The two-sample proportion test was used for statistical comparison between groups. The most probable risk factors of HCV transmission in Egypt included regular visits to dental clinics (55.2%), previous surgical operations (54.4%), former blood transfusion (52%), intrafamilial HCV infection (45.9%) and history of bilharzial infection (44.3%). Increasing public awareness about modes of transmission and risk factors of HCV infection is a must, especially within family members of HCV patients. Strict commitment to proper medical care precautions by health care practitioners is required.

Infectious Disease Risk Associated with Contaminated Propofol Anesthesia, 1989-2014(1)

Transmission of illness to 144 patients, resulting in 10 deaths, has been linked to extrinsic contamination.

Administration of propofol, the most frequently used intravenous anesthetic worldwide, has been associated with several iatrogenic infections despite its relative safety. Little is known regarding the global epidemiology of propofol-related outbreaks and the effectiveness of existing preventive strategies. In this overview of the evidence of propofol as a source of infection and appraisal of preventive strategies, we identified 58 studies through a literature search in PubMed, Embase, and Lilacs for propofol-related infections during 1989–2014. Twenty propofol-related outbreaks have been reported, affecting 144 patients and resulting in 10 deaths. Related factors included reuse of syringes for multiple patients and prolonged exposure to the environment when vials were left open. The addition of antimicrobial drugs to the emulsion has been instituted in some countries, but outbreaks have still occurred. There remains a lack of comprehensive information on the effectiveness of measures to prevent future outbreaks.

How Long Is Too Long? The Prespiked Intravenous Debate

BACKGROUND

As the number of operative cases increases, there is a greater emphasis on reducing inefficiency while maintaining patient safety. Recently, the issue of prespiking intravenous (IV) bags was raised. No study has assessed whether the risk of infection is related to the length of time a sterile (IV) fluid bag has been spiked. After completion of a pilot study revealed no microbial growth within 24 hours of an IV spike, a larger formal study was undertaken to determine whether there was an increased infection risk within 4 hours of spiking an intravenous fluid bag.

METHODS

Five IV administration sets were spiked and hung in busy perioperative areas once a week for a 5-week period. Five samples were drawn from each IV set. Approximately 10 mL was collected per sample. All samples were inoculated in 2 separate growth media. If any growth was noted, the sample was marked as positive.

RESULTS

A total of 125 samples were collected over a period of 5 weeks, yielding 250 specimens. No samples were excluded from the study. No growth was identified in any of the specimens. The 95% confidence interval was estimated to be 0, 0.063.

DISCUSSION

There was no bacterial growth in prespiked normal saline IV bags in a perioperative environment. Thus, prespiking of normal saline IV bags in advance should pose no risk of infection to a patient if prepared within 4 hours.

HCV transmission in industrialized countries and resource-constrained areas

HCV is a blood-borne virus transmitted by percutaneous exposure to infected blood or blood-derived body fluids. The main routes of transmission are blood transfusions, medical procedures and injection drug use. In industrialized countries, HCV transmission through blood transfusions has been virtually eliminated and iatrogenic transmission occurs only sporadically during local breaches of infection control procedures. As most new cases originate from injection drug use, harm-reduction programmes (including opiate substitution, needle exchange and health education) can greatly reduce HCV transmission. Currently, the main approach to reduce the HCV disease burden is by increasing awareness of both the public and health-care providers to hepatitis C, enhancing screening opportunities and treatment of the infected population. In resource-limited countries, the priority is reducing transmission through blood transfusions and invasive medical procedures. This approach requires training of health-care providers and also structural changes and financial investments in countries where antibody screening, disposable materials and effective sterilization procedures are not routinely available. In these countries, reducing the HCV burden has been hampered by limited access to treatment, largely owing to the cost of drugs. Access to treatment is moving up on the agenda of international and non-governmental organizations in conjunction with the future availability of highly efficacious oral drug regimens.

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.

Comparison of methicillin-resistant and methicillin-sensitive Staphylococcus aureus strains isolated from a tertiary hospital in Terengganu, Malaysia

Staphylococcus aureus is a persistent human pathogen responsible for a variety of infections ranging from soft-tissue infections to bacteremia. The objective of this study was to determine genetic relatedness between methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) strains. We isolated 35 MRSA and 21 MSSA strains from sporadic cases at the main tertiary hospital in Terengganu, Malaysia, screening them for the presence of virulence genes. Their genetic relatedness was determined by accessory gene regulator (agr) types, PCR-restriction fragment length polymorphism (RFLP) of the coa gene, pulsed-field gel electrophoresis (PFGE), S. aureus protein A (spa), and multilocus-sequence typing (MLST). We found that 57% of MRSA and 43% of MSSA strains harbored enterotoxin genes. The majority (87.5%) of the strains were agr type I. PCR-RFLP and PFGE genotyping of the coa gene revealed that MRSA strains were genetically related, whereas MSSA strains had higher heterogeneity. The combined genotype, MLST-spa type ST239-t037, was shared among MRSA and MSSA strains, indicating that MRSA strains could have evolved from MSSA strains. Two combined MLST-spa types were present in MRSA strains, whereas 7 different MLST-spa types were detected in MSSA strains, including 2 combined types (ST779-t878 and ST1179-t267) that have not been reported in Malaysia. In conclusion, enterotoxin genes were more prevalent in MRSA than in MSSA strains in the Terengganu hospital. The MSSA strains were genetically more diverse than the MRSA strains.

Minimizing the risk of non-vertical, non-sexual HIV infection in children--beyond mother to child transmission

After witnessing an episode of poor injection safety in large numbers of children in a rural under-resourced hospital in Uganda, we briefly review our own experience and that of others in investigating HIV infection in children considered unlikely to be through commonly identified routes such as vertical transmission, sexual abuse or blood transfusion. In the majority of cases, parents are HIV uninfected. The cumulative experience suggests that the problem is real, but with relatively low frequency. Vertical transmission is the major route for HIV to children. However, factors such as poor injection safety, undocumented surrogate breast feeding, an HIV-infected adult feeding premasticated food to a weaning toddler, poor hygienic practice in the home and using unsterilised equipment for minor surgical or traditional procedures are of cumulative concern.

Behavioral and healthcare-associated risk factors for chronic hepatitis C virus infection in Korea

The risk factors related to hepatitis C virus (HCV) infection showed geographic and temporal differences. We investigated HCV-related risk factors in Korea where intravenous drug use (IVDU) is uncommon. The HCV-related risk factors were investigated in a prospective, multicenter chronic HCV cohort (n = 711) using a standardized questionnaire in four university hospitals. The results were compared with those of 206 patients with chronic liver diseases not related to either of HCV or hepatitis B virus infection (comparison group). The IVDU was found in 3.9% and remote blood transfusion (≥ 20 yr ago) in 18.3% in HCV cohort group, while that in comparison group was in none and 5.3%, respectively. In a multivariate logistic analysis, transfusion in the remote past (odds ratio [OR], 2.99), needle stick injury (OR, 4.72), surgery (OR, 1.89), dental procedures (OR, 2.96), tattooing (OR, 2.07), and multiple sexual partners (2-3 persons; OR, 2.14, ≥ 4 persons; OR, 3.19), were independent risk factors for HCV infection. In conclusion, the major risk factors for HCV infection in Korea are mostly related to conventional or alterative healthcare procedures such as blood transfusion in the remote past, needle stick injury, surgery, dental procedure, and tattooing although multiple sex partners or IVDU plays a minor role.

Transmission of hepatitis C virus to recipients of parenteral vitamin therapy in a primary care facility

BACKGROUND AND OBJECTIVES

The Australian prevalence of hepatitis C virus (HCV) is approximately 1%, with the majority of cases acquired through injecting drug use. However, occasionally HCV infection occurs in healthcare settings. Three new HCV infections were identified amongst patients attending a general practice in Sydney, Australia, specialising in parenteral vitamin therapy.

STUDY DESIGN

An investigation was conducted to identify the source of infection and mechanism of transmission. Molecular analysis was conducted by sequencing the HCV NS5A, Core and NS5B regions.

RESULTS

Two sources were identified using molecular epidemiology - a genotype 3a case was the source for a case acquired in late 2004 and a genotype 1b case the source for one case acquired in late 2006 and another in early 2007. The common risk factor was parenteral vitamin C therapy.

CONCLUSIONS

Inadequate infection control was apparent and likely to have resulted in blood contamination of the healthcare workers, their equipment, the clinic environment and parenteral medications. Molecular and clinical epidemiology clearly identified parenteral transmission of HCV, highlighting the risks of blood contamination of parenteral equipment and use of multi-dose flasks on more than one patient.

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.

An overview about hepatitis C: a devastating virus

Hepatitis C (HCV) is the disease that has affected around 200 million people globally. HCV is a life threatening human pathogen, not only because of its high prevalence and worldwide burden but also because of the potentially serious complications of persistent HCV infection. Chronicity of the disease leads to cirrhosis, hepatocellular carcinoma and end-stage liver disease. HCV positive hepatocytes vary between less than 5% and up to 100%, indicating the high rate of replication of viral RNA. HCV has a very high mutational rate that enables it to escape the immune system. Viral diversity has two levels; the genotypes and Quasiaspecies. Major HCV genotypes constitute genotype 1, 2, 3, 4, 5 and 6 while more than 50 subtypes are known. All HCV genotypes have their particular patterns of geographical distribution and a slight drift in viral population has been observed in some parts of the globe.

APIC position paper: safe injection, infusion, and medication vial practices in health care

Outbreaks involving the transmission of bloodborne pathogens or other microbial pathogens to patients in various types of health care settings due to unsafe injection, infusion, and medication vial practices are unacceptable. Each of the outbreaks could have been prevented by the use of proper aseptic technique in conjunction with basic infection prevention practices for handling parenteral medications, administration of injections, and procurement and sampling of blood. This document provides practice guidance for health care facilities on essential safe injection, infusion, and vial practices that should be consistently implemented in such settings.

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.

Horizontally-acquired HIV infection in Kenyan and Swazi children

Despite many reports of HIV-infected African children who have HIV-uninfected mothers, little is known about the extent and modes of horizontal HIV transmission in African children. We estimated the extent of horizontal HIV transmission in Swazi children by comparing child and mother HIV statuses in the 2006–2007 Swaziland Demographic and Health Survey (DHS). To identify correlates of horizontal HIV transmission, we conducted a case-control study of Kenyan children with horizontally acquired HIV infections and their uninfected siblings. Of 50 HIV-positive Swazi children in the DHS, 11 (weighted percent = 20, 95% confidence interval 11–33%) had HIV-negative mothers. These 11 children represented 0.6% of all Swazi children aged 2–12 who lived with their mothers. In the Kenyan study, children with horizontally acquired HIV infections had more kinds of blood exposures than their uninfected siblings. In particular, punctures related to health care for suspected malaria (phlebotomy, injection and infusion), injections while hospitalized and dental surgery (especially by informal providers) were more common in infected children. Horizontal HIV transmission appears to be common in some sub-Saharan African countries, and blood exposures seem to be the most likely routes of transmission. Rigorous surveillance and investigation of horizontally acquired HIV infection in children are urgently needed, along with universal public education about risks of specific blood exposures and ways to avoid them.

Determinant roles of environmental contamination and noncompliance with standard precautions in the risk of hepatitis C virus transmission in a hemodialysis unit

BACKGROUND

Nosocomial transmission is the second most frequent cause of hepatitis C virus (HCV) infection. A prospective observational study was conducted to assess the roles of environmental contamination and noncompliance with standard precautions in HCV cross-transmission in a hemodialysis unit.

METHODS

Patients undergoing chronic hemodialysis in a French university hospital unit were systematically screened, revealing 2 sporadic cases of HCV transmission. An investigation was launched to determine whether the patients were infected in the hemodialysis unit and the possible roles of environmental contamination and noncompliance with standard precautions. We examined possible relationships among new cases of HCV infection, environmental contamination by blood and HCV RNA, and compliance with guidelines on hand hygiene and glove use.

RESULTS

Two patients experienced seroconversion to HCV during the study period. Phylogenetic analyses showed that 1 of these patients was infected with the same strain as that affecting a chronically infected patient also treated in the unit. Of 740 environmental surface samples, 82 (11%) contained hemoglobin; 6 (7%) of those contained HCV RNA. The rate of compliance with hand hygiene was 37% (95% confidence interval, 35%-39%), and gloves were immediately removed after patient care in 33% (95% confidence interval, 29%-37%) of cases. A low ratio of nurses to patients and poor hand hygiene were independent predictors of the presence of hemoglobin on environmental surfaces.

CONCLUSION

Blood-contaminated surfaces may be a source of HCV cross-transmission in a hemodialysis unit. Strict compliance with hand hygiene and glove use and strict organization of care procedures are needed to reduce the risk of HCV cross-transmission among patients undergoing hemodialysis.

Self-limited febrile syndromes temporally associated with the use of propofol for sedation in gastrointestinal endoscopic procedures

PURPOSE

To investigate cases of febrile illnesses in patients who received propofol for sedation during gastrointestinal endoscopy.

METHODS

Active case finding for patients who underwent endoscopy between 1 April and 30 May 2007 and suffered unexplained fever, chills, or myalgia within 48 hour after the procedure. We reviewed medications and clinical practices to find factors associated with the reactions.

RESULTS

Seventy-four cases at eight facilities in five states were identified yielding a rate of 36 reactions per 1000 procedures, compared with a baseline rate of 0.6 per 1000. The majority of patients experienced self-limited fever (89.2%), chills (73.0%), or myalgia (63.5%). Blood samples from five patients were collected for culture; no organisms grew. All health care facilities that reported cases and fully participated in the investigation (n = 7) had received a common lot of propofol just before recognition of the first case. Bacterial endotoxin and sterility testing on unopened vials from this lot of propofol showed no abnormalities. Cases terminated after facilities stopped using the associated lot of propofol.

CONCLUSIONS

We found a temporal association between a particular lot of propofol and an outbreak of febrile illnesses at several healthcare facilities performing endoscopy. When propofol is used to sedate patients for endoscopy, fever is a rare outcome and healthcare professionals should investigate clusters of these reactions. Post-procedure surveillance is important to identify possible medication reactions.

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.

High prevalence of hepatitis C virus infection in the largest province of Pakistan

OBJECTIVE

To estimate the prevalence and spectrum of hepatitis C virus (HCV) infection in the general population of Pakistan.

METHODS

A total of 6817 blood samples were collected randomly from apparently healthy people in the Punjab, Pakistan from March 1999 to April 2001 and September 2006 to August 2007. Detailed socioeconomic information for each participant was recorded. All the samples were tested for anti-HCV antibodies and all seropositive samples were further tested for HCV RNA by polymerase chain reaction (PCR).

RESULTS

Of the total 6817 serum samples tested, 998 (14.63%) were positive for anti-HCV antibodies. HCV RNA PCR was detected in 494 (49.50%) anti-HCV-positive samples. The prevalence of anti-HCV antibodies were significantly higher in males (15.09%) than in females (12.3%) (P < 0.009). A significant difference was also noted in the anti-HCV prevalence rate among different age groups tested (P < 0.01). In a multivariate logistic regression analysis, injected drug use (adjusted OR 6.6 [95%CI 4.1-9.9]), blood transfusion (adjusted OR 5.9 [95%CI 2.9-12.3]), pricked with a needle (adjusted OR 2.2 [95%CI 1.6-3.1]), re-use of syringes (adjusted OR 1.7 [95%CI 0.8-3.6]) and being over 35 years old (adjusted OR 1.3 [95%CI 0.9-1.9]) were independent risk factors for HCV infection.

CONCLUSION

The study showed a high seroprevalence of anti-HCV antibodies in a general and apparently healthy population of the Punjab province of Pakistan. Drug injection, blood transfusion and needle stuck were the factors most strongly associated with HCV infection.

The course of hepatitis C viraemia in transfusion recipients prior to availability of antiviral therapy

Knowing the likely distribution of intervals from hepatitis C infection to first RNA-negativity is important in deciding about therapeutic intervention. Prospectively collected sera and data from the Transfusion-transmitted Viruses Study (1974-1980) provide specific dates of infection and pattern of alanine aminotransferase (ALT) elevations. We examined frequency, timing and correlates of spontaneous resolution for 94 acutely infected transfusion recipients followed for a median of 9.5 months. Later, follow-up sera (>10 years) were available for 27 of the 94 cases from a Veterans Administration (VA) Study (1989-1990). Twenty-five (27%) of the 94 cases were classified as probably resolved during the episode itself. First RNA negativity occurred at 6-50 weeks (median, 19.5 weeks) after infection, and 5-43 weeks (median, 11 weeks) after ALT elevation. Thirteen of the 25 cases remained RNA-negative subsequently; 12 others had 1-6 RNA-positive sera intercalated between first and last RNA-negative results. RNA negativity, therefore, began variably and was interrupted in 12 cases of 25 (48%) by transient RNA-positive sera. Five of these 25 patients who were RNA-negative in the last study specimen had late, Veterans Administration Study follow-up; none showed viraemia. Of the remaining 69 transfusion transmitted virus study recipients, whose last serum was RNA-positive, two cleared viraemia after the last study serum but before late follow-up. Eleven (16%) had 23 intercalated RNA-negative sera before last positivity. RNA status, therefore, needs monitoring for many months before judging the spontaneous outcome as transient negativity may occur. Resolution was significantly more common in women and symptomatic cases; it was not associated with viral load in the infectious donation, HCV genotype, or the recipient's age.

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.

Iatrogenic transmission of hepatitis C virus (HCV) by an anesthesiologist: comparative molecular analysis of the HCV-E1 and HCV-E2 hypervariable regions

BACKGROUND

Transmission of hepatitis C virus (HCV) from infected health care workers to patients rarely occurs. In 2003, a cluster of patients with HCV infection was identified at a medical center in Israel. All patients had a common history of various surgical procedures performed during the period 2001-2003. All patients had been anesthetized by an anesthesiologist who was an injection drug user and was infected with genotype 2a HCV. Screening was initiated by the hospital to identify newly infected patients with HCV infection and to determine the source of the iatrogenic HCV infection outbreak using comparative molecular analysis of the HCV E1 and HCV E2 hypervariable regions (HVR1 and HVR2).

METHODS

A total of 1200 patients who were anesthetized by the anesthesiologist (the related group) and 873 hospital personnel and patients anesthetized by other anesthetists (the unrelated group) were examined. Serum samples were screened for anti-HCV antibodies, HCV RNA, and genotype. Sequence analysis of HVR1 and HVR2 was performed after reverse-transcriptase polymerase chain reaction.

RESULTS

HCV type 2a was found in 33 patients in the related group but in only 1 patient in the unrelated group. The differences between the sequences isolated from the related group serum samples and the sequences isolated from genotype 2a control group serum samples (obtained from 15 patients) were highly statistically significant. The genetic distances from the anesthesiologist sequence were 1.4%-4.4% in the HVR1 and 0%-3% in the HVR2 in the related group serum samples, whereas in the HCV genotype 2a control group serum samples, the genetic distances were 22%-45% and 10%-35%, respectively.

CONCLUSIONS

Molecular analysis revealed sequence similarity of HVR1 and HVR2 in the related group, suggesting that the anesthesiologist with chronic HCV infection may have transmitted HCV to 33 patients.

Article Commentary: Occupational Risks of Blood Exposure in the Operating Room

Bloodborne pathogens continue to be a source of occupational infection for healthcare workers, but particularly for surgeons. Over 1 per cent of the U.S. population has one or more chronic viral infections. Hepatitis B is the infection that has the longest known role as an occupational pathogen, but infection with this virus is largely preventable with the use of the effective hepatitis B vaccine. Hepatitis C affects the largest number of people in the United States, and there is no vaccine available for the prevention of this infection. HIV infection still has not been associated with a documented transmission in the operating room environment, but six cases of probable occupational transmission have been reported. A total of 57 healthcare workers have had documented occupational infection since the epidemic of HIV infection began. Infection of blood-borne pathogens to patients from infected surgeons remains a concern. Surgeons who are e-antigen-positive for hepatitis B have been well documented to be an infection risk to patients in the operating room. Only four surgeons have been documented to transmit hepatitis C, although other transmissions have occurred in the care of patients when practices of infection control have been violated. No surgical transmission of HIV to a patient has been identified at this time. Prevention of occupational infection requires use of protective barriers, avoidance of exposure risk by modification of techniques, and a constant awareness of sharp instruments in the operating room. Blood exposure in the operating room carries risk of infection and should be avoided. It is likely that other infectious agents will emerge as operating room threats. Surgeons must maintain vigilance in avoiding blood exposure and percutaneous injury.

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.

Transmission of hepatitis C virus by blood transfusions and other medical procedures: a global review

Hepatitis C virus (HCV) is a leading cause of chronic blood-borne infection and chronic liver disease. The global epidemic of HCV infection emerged in the second half of the 20th century, and several lines of evidence indicate that it was primarily triggered and fed iatrogenically by the increasing use of parenteral therapies and blood transfusion. In developed countries, the rapid improvement of healthcare conditions and the introduction of anti-HCV screening for blood donors have led to a sharp decrease in the incidence of iatrogenic hepatitis C, but the epidemic continues to spread in developing countries, where the virus is still transmitted through unscreened blood transfusions and non-sterile injections. This article reviews the published literature concerning HCV transmission through blood transfusions and other unsafe medical procedures. Given the substantial difference in current disease transmission patterns between the northern and southern hemispheres, the situation in developed and developing countries is separately analysed.

Propofol EDTA and reduced incidence of infection

Propofol formulated in a lipid vehicle supports the growth of microorganisms. There have been worldwide reports of extrinsic microbial contamination of propofol leading to outbreaks of serious postoperative nosocomial infections. Therefore it is essential that medical professionals follow strict aseptic precautions when handling propofol, as recommended by manufacturers of propofol and the Centers for Disease Control and Prevention. Non-adherence to these recommendations increases the risk of nosocomial postoperative infections, which impose a heavy burden of morbidity and mortality and have serious economic consequences. It has also been recommended that the use of EDTA-containing formulations of propofol be considered. In vitro studies have confirmed that EDTA added to propofol retards microbial growth. Data on the incidence of nosocomial infections before and after the introduction of propofol with EDTA indicates that there have been no further cluster outbreaks and individual nosocomial infections appear to have been reduced. The addition of EDTA is an additional safety precaution to good aseptic practice.

Characterization of HCV strains in an oncohematological pediatric department reveals little horizontal transmission but multiple introductions by un-screened blood products in the past

Because several children were found infected with hepatitis C virus (HCV) at a pediatric oncohematological department in Vilnius, 474 children were tested for anti-HCV. Fifty-eight percent of 96 children treated with blood and plasma products manufactured before the introduction of anti-HCV screening of blood in Lithuania in 1994 were positive for anti-HCV versus 3.4% of those treated after 1994. The possible route of transmission for 45 of these was investigated by phylogenetic analyses within the NS5B region. Children treated before 1995 were infected with a multiplicity of strains of different subtypes, predominantly 1b found in 21 cases, 3a in 5 cases, 2 in 3 cases, 1a in 1 case, and not subtypeable genotype 1 strains in 2 cases. Children who had received blood products after 1994 were infected with only two subtypes, 1b in six and 3a in seven. Genetic analysis showed multiple introductions of HCV before 1995 and that horizontal spread between patients had occurred only to a minor extent at the department. However, two transmission chains involved children treated before 1995. Another chain involved five children treated after 1994. Since the most important risk factor for acquiring hepatitis C was blood products manufactured before the introduction of donor screening for anti-HCV, the spread between children would not have been revealed without molecular tools. These and the background strains provide the first reported sequence data on Lithuanian HCV strains. In general, these were shown to form autochthonous clades, except the 3a strains that were related to strains from the former USSR.

Prevalence of hepatitis C infection in a population of asymptomatic people in a checkup unit in Mexico city

Hepatitis C virus (HCV) infection has an estimated prevalence of 3% around the world. Unfortunately, many persons with HCV infection are asymptomatic. The aim of this study was to determine the prevalence of hepatitis C Virus infection in asymptomatic persons. This study was carried out in a population-based cross-sectional study in the Checkup Unit of University Hospital in Mexico City. Patients with two or more HCV risk factors were studied. Serum specimens from all patients were screened for HCV RNA by qualitative polymerase chain reaction (PCR). HCV RNA-positive serum was also screened by quantitative PCR and for HCV genotype. Three hundred asymptomatic people were included, 194 men and 106 women, with a mean age of 46.8+/-11.9. Six (2%) of the 300 people were positive and viremic. The most common risk factors in positive patients were manicures or pedicures with a nonpersonal instrument and more than three sexual partners. We concluded that hepatitis C is frequent in asymptomatic people, and those people are often viremic. In addition, this study suggests that the spectrum of liver disease in asymptomatic and newly diagnosed HCV-positive persons is broad.

Use of the minimum spanning tree model for molecular epidemiological investigation of a nosocomial outbreak of hepatitis C virus infection

The minimum spanning tree (MST) model was applied to identify the history of transmission of hepatitis C virus (HCV) infection in an outbreak involving five children attending a pediatric oncology-hematology outpatient ward between 1992 and 2000. We collected blood samples from all children attending since 1992, all household contacts, and one health care worker positive for antibody to HCV (anti-HCV). HCV RNA detection was performed with these samples and with smears of routinely collected bone marrow samples. For all isolates, we performed sequence analysis and phylogenetic tree analysis of hypervariable region 1 of the E2 gene. The MST model was applied to clinical-epidemiological and molecular data. No additional cases were detected. All children, but not the health care worker, showed genotype 3a. On six occasions, all but one child had shared the medication room with another patient who later seroconverted. HCV RNA detection in bone marrow smears revealed, in some cases, a delay of several months in anti-HCV responses. Sequence analysis and phylogenetic tree analysis revealed a high identity among the isolates. The MST model applied to molecular data, together with the clinical-epidemiological data, allowed us to identify the source of the outbreak and the most probable patient-to-patient chain of transmission. The management of central venous catheters was suspected to be the probable route of transmission. In conclusion, the MST model, supported by an exhaustive clinical-epidemiological investigation, appears to be a useful tool in tracing the history of transmission in outbreaks of HCV infection.

Medical procedures and the risk of iatrogenic hepatitis C infection: case-controlled study in north-eastern Poland

Many hepatitis C virus (HCV)-infected individuals do not have any obvious risk factors and one of the putative sources of infection may be inadvertent exposure to infected blood or body fluids in the clinical setting. The aim of this study was to assess the role of medical procedures in transmission of hepatitis C in north-eastern Poland. In total, 194 patients with chronic hepatitis C were eligible for the study. The control group consisted of 275 age- and sex-matched individuals. Patients with a history of intravenous drug use were excluded. On multivariate analysis, transfusions [odds ratio (OR) = 3.7, 95% confidence interval (CI) 2.2-6.3], minor surgery (OR = 3.2, 95% CI 1.5-6.7) and dental care (OR = 2.3, 95% CI = 1.4-4.0) were independently associated with HCV infection. We conclude that apart from transfusion, minor medical procedures and dental care may carry a significant risk of hepatitis C infection. Improvements in basic hygiene routines and strict adherence to universal precautions may be essential to prevent iatrogenic transmission of the infection.

A large nosocomial outbreak of hepatitis C and hepatitis B among patients receiving pain remediation treatments

BACKGROUND AND OBJECTIVE

In August 2002, the Oklahoma State Department of Health received a report of six patients with unexplained hepatitis C virus (HCV) infection treated in the same pain remediation clinic. We investigated the outbreak's extent and etiology.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a retrospective cohort study of clinic patients, including a serologic survey, interviews of infected patients, and reviews of medical records and staff infection control practices. Patients received outpatient pain remediation treatments one afternoon a week in a clinic within a hospital. Cases were defined as HCV or hepatitis B virus (HBV) infections among patients who reported no prior diagnosis or risk factors for disease or reported previous risk factors but had evidence of acute infection.

RESULTS

Of 908 patients, 795 (87.6%) were tested, and 71 HCV-infected patients (8.9%) and 31 HBV-infected patients (3.9%) met the case definition. Multiple HCV genotypes were identified. Significantly higher HCV infection rates were found among individuals treated after an HCV-infected patient during the same visit (adjusted odds ratio [AOR], 6.2; 95% confidence interval [CI95], 2.4-15.8); a similar association was observed for HBV (AOR, 2.9; CI95, 1.3-6.5). Review of staff practices revealed the nurse anesthetist had been using the same syringe-needle to sequentially administer sedation medications to every treated patient each clinic day.

CONCLUSIONS

Reuse of needles-syringes was the mechanism for patient-to-patient transmission of HCV and HBV in this large nosocomial outbreak. Further education and stricter oversight of infection control practices may prevent future outbreaks.

[Sporadic transmission of hepatitis C in dental practice]

Percutaneous contact with contaminated blood is the principal mode of transmission of the hepatitis C virus (HCV). However, the diagnosis of infection in patients in whom no parenteral risk factor can be identified allows speculation on the existence of other routes of transmission. In the field of dentistry, the role of saliva has still not been defined as a potential vehicle for infection nor the role of dental treatment as a possible occult factor in the sporadic transmission of hepatitis C. HVC-RNA is detectable in the saliva of over 50% of patients with chronic hepatitis C. The infectivity of the HVC particles detected in the saliva has not been determined, though it may be deduced from epidemiological studies that their potential for transmission, if it exists, is extremely limited. There has been no documented case of HVC transmission in a dental clinic. Studies which propose a history of dental treatment as a risk factor for HVC infection have not achieved conclusive results. The age distribution of the prevalence of HVC could indicate that a risk of iatrogenic transmission existed in the past, before the systematic application of universal barriers. The transmission of HVC in dental clinics may be considered a very infrequent occurrence as long as the norms for the control of cross-infection are respected.

Managing occupational risks for hepatitis C transmission in the health care setting

Hepatitis C virus (HCV) infection is a significant contemporary health problem in the United States and elsewhere. Because it is primarily transmitted via blood, hepatitis C infection presents risks for both nosocomial transmission to patients and occupational spread to health care workers. Recent insights into the pathogenesis, immunopathogenesis, natural history, and treatment of infection caused by this unique flavivirus provide a rationale for the use of new strategies for managing occupational hepatitis C infections when they occur. This article reviews this developing information. Recently published data demonstrate success rates in the treatment of "acute hepatitis C syndrome" that approach 100\%, and although these studies are not directly applicable to all occupational infections, they may provide important clues to optimal management strategies. In addition, the article delineates approaches to the prevention of occupational exposures and also addresses the difficult issue of managing HCV-infected health care providers. The article summarizes currently available data about the nosocomial epidemiology of HCV infection and the magnitude of risk and discusses several alternatives for managing exposure and infection. No evidence supports the use of immediate postexposure prophylaxis with immunoglobulin, immunomodulators, or antiviral agents. Based on the very limited data available, the watchful waiting and preemptive therapy strategies described in detail in this article represent reasonable interim approaches to the complex problem of managing occupational HCV infections, at least until more definitive data are obtained.

Evidence of patient-to-patient transmission of hepatitis C virus through contaminated intravenous anaesthetic ampoules

Two separate cases of acute hepatitis C virus (HCV) infection following medical procedures, arthroscopy and colonoscopy, are reported. In both episodes, patient risk factors were reviewed, and staff and other patients' sera were tested for HCV antibodies and RNA. HCV RNA positive samples were genotyped, sequenced, and subjected to phylogenetic analysis. No risk factors for HCV infection were identified for either case except for medical procedures. HCV RNA positive patients were identified preceding both cases on the respective theatre lists. HCV infection in a second low risk patient was also identified. Nucleic acid sequencing and phylogenetic analysis of HCV from the two putative source patients and the three recipient patients demonstrated a high degree of relatedness respectively. The results suggest that patient-to-patient transmission occurred in both episodes via contamination of intravenous anaesthetic ampoules with HCV used on multiple patients. Injectable medication ampoules should not be used for more than one patient.