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Routes of nosocomial transmission of HCV

Routes of nosocomial transmission of HCV. Valentina Liakina Centre of Hepatology, Gastroenterology and Dietetics Faculty of Medicine Vilnius University St. Petersburg, 2012-04-03. Topicality.

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Routes of nosocomial transmission of HCV

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  1. Routes of nosocomial transmission of HCV Valentina Liakina Centre of Hepatology, Gastroenterology and Dietetics Faculty of Medicine Vilnius University St. Petersburg, 2012-04-03

  2. Topicality Nosocomial transmissions of HCV account for a large proportion of new HCV infections in the Western world. For instance: hospital admission was the only risk factor in about two-thirds of acute hepatitis C cases in Spain [Santantonio T, 2006] and Italy [Martinez-Bauer E, 2008] and in 15% of patients registered in Hep-Net acute HCV database of Germany [Deterding K, 2008]

  3. Data from the study of risk factors for HCV acquisition in chronic hepatitis C patients Chronic hepatitis C cohort, n=1158 Multivariate logistic regressionanalysis of HCV risk factors depending on the age: Surgery OR=1.571, p=.0236 Long-lasting and multiple hospitalizations OR=2.330, p=.0045 are independent risks for HCV acquisition Multivariate logistic regressionanalysis of HCV risk factors depending on the gender: Donations OR=0.285, p<.001; Long-lasting and multiple hospitalizations OR=0.383, p=.0144; Surgery OR=2.314, p=.0013; Occupational exposure OR=4.329, p=.0059 [Liakina V, 2009]

  4. Data from the study of anti-HCV prevalence in general population of Lithuania General population, n=1514 No one of risk factor studied was confirmed as independent by multivariate logistic regression analysis. Univariate logistic regression analysis of risk factors for anti-HCV positivity: Intravenous drug use OR=42.5, p<.0001 Long-lasting and multiple hospitalizations OR=3.056, p=.0064; Tooth removal OR=4.141, p=.0048; Childbirth OR=5.056, p=.0224 Surgery, abortions, dentistry, hemodialysis, blood donations and transfusions were not confirmed as risks for anti-HCV positivity. [Liakina V, 2012]

  5. How HCV can be transmitted in the health care unites Breaches in aseptic techniques Blood and blood products transfusions (paid donations) Asymptomatic HCV carriers (patients and health care staff)

  6. Why aseptic techniques are not save concerning HCV transmission? • HCV contaminated materials and infusions represent a substantial risk for transmission, because HCV is surprisingly stable at room temperature (up to 2 weeks), even dried and stored HCV plasma is infectable up to 16 hours[Kamili S, 2007] • HCV infectivity in a liquid environment was detectable for up to 5 month at lowertemperatures. [Ciesek S, 2010] • Different alcohols and commercially available antiseptics reduced the infectivity of HCV to undetectable levels. However, diluting the hand disinfectants abrogated the virucidal activity. [Ciesek S, 2010] • Until now there are lack of data available regarding HCV stability and sensitivity toward chemical disinfectants

  7. Why blood donation still are not save concerning HCV transmission? • Sufficient HCV RNA quantity for detection appears only after 4-5 days of HCV infection. Even when HCV RNA is tested separately in every donation, not in pools, and NAT sensitivity is 3.01 IU/ml only ≥8 copies per 1 ml can be detected. • Still up to 8 copies of viral RNA per 1 ml blood can be transfused to the recipient. 400 ml blood=~3200 HCV Insufficient sensitivity of HCV RNA detection methods • HCV carriers are asymptomatic and feel themselves healthy • The risk to get HCV-infected blood increases when paid donations are practiced • The risk of HCV infection may not accurately be reflected by determination of HCV RNA levels, because viral infectivity and HCV RNA copy numbers did not directly correlate.

  8. Asymptomatic HCV carriers (patients and health care staff) • Patient-to-patient HCV transmission • Provider-to-patient HCV transmission • Patient-to-provider HCV transmission

  9. Patient-to-patient HCV transmission • In hemodialysis settings because of: • contaminated dialysis machines [Delarocque-Astagneau E, 2002], • inadequate infection control of procedures [Abacioglu J, 2000], • dialyzing infected and noninfected patients in the same area [Petrosillo N, 2001] HCV-infected hemodialized patients worldwide 4% – 70% [Wreghitt T, 1999], in USA: 1.7% in staff, 8.4% in patients [Tokars J, 2002] • Gynecological and endocrinological procedures [Massari M, 2001] • Contamination of multidose vials and intravenous administration devices (shared saline bags, contaminated when reused syringes were used to draw blood from venous catheters [Macedo de Oliveira A, 2005]) • Contaminated equipment: spring-loaded finger-stick devices [Desenclos JC, 2001], anesthesia assistant's interventions [Ross R, 2002], endoscopy [Muscarella L, 2001], colonoscopy [Bronowicki J, 1997, Gonzalez-Candelas F, 2010] • Organ transplantation [Wreghitt T, 1994] • Dentistry • Assisted reproduction procedures [Abou-Setta A, 2004] • In oncology wards [Dencs A, 2011] Some, if not most, of these instances of HCV transmission most likely represent cross-contamination, due, at least in part, to inadequate infection control procedures or inadequate disinfection of devices or objects

  10. Provider-to-patient HCV transmission Iatrogenic transmission of HCV from HCV-infected providers to their patients has been uncommon. The first suggestion of iatrogenic infection was reported from England in 1995 ( from HCV-infected surgeon during cardiovascular surgery [Public Health Laboratory Service, 1995]), than in Spain (6 from 222 patients been operated for valve replacement by infected surgeon [Esteban J, 1996], coronary artery bipass surgery [PHLS, 1999]. Till 2000 4,500 individuals get the same HCV stains as surgeons had [Pugliese G, 2000; PHLS, 2000] Overall in UK 0.12% of patients get virus from the provider Cardiothoracic surgeon [Brouwn P, 1999] HCV-infected gynecologists (caesarian section and other procedures) [PHLS, 1999; 7-years retrospective investigation: Ross R, 2002] Orthopedic surgeon (3 out of 207) [Ross R, 2002] Anesthesiologists and anesthesia assistant's interventions [Cody S, 2002, Shemer-Avni Y, 2007] Eye surgery [Jatoi Shm, 1999] [Lot F, 2007],

  11. A review carried out in 2005 documented that worldwide five healthcare workers had transmitted hepatitis C to a total of 232 patients. [Reitsma A, 2005] HCV-infected mother transmit virus to her hemophilic child after she stuck her own finger with the needle for the infusion [Morb. Mortal.Wkly., 1997]

  12. “SHEA Guideline for Management of Healthcare Workers Who Are Infected with Hepatitis B Virus, Hepatitis C Virus, and/or Human Immunodeficiency Virus 2010 USA” [Henderson DK, 2010] This guideline provides the updated recommendations of the Society for Healthcare Epidemiology of America (SHEA) regarding the management of healthcare providers who are infected with hepatitis B virus (HBV), hepatitis C virus (HCV), and/or the human immunodeficiency virus (HIV). HCV-infected provider is allowed to perform I and II categories of procedures using double-gloving for all invasive procedures, but not allowed to perform III category procedures

  13. This guidance is intended to assist in implementation of the joint chief professionals’ letter HSS(MD)9/2011 Hepatitis C Infected Healthcare Workers: Guidance on the prevention of healthcare-related hepatitis C and workplace management of hepatitis C infected clinical healthcare workers. It is also available on the DHSSPS web site at www.dhsspsni.gov.uk/hss-md-9-2011-guidance.pdf, 2011 For all surgeons, dentists, other practitioners performing EPPs. Existing healthcare workers who know that they have been infected with hepatitis C (i.e. who have antibodies to hepatitis C virus) and who carry out EPPs should be tested for hepatitis C virus RNA. Those found to be carrying the virus (i.e. who are hepatitis C virus RNA positive) should be restricted from performing EPPs in future, unless they have responded successfully to treatment. Healthcare workers, who perform EPPs should promptly seek and follow confidential professional advice on whether they should be tested for hepatitis C. Testing should be for antibodies to hepatitis C virus, and if positive, for hepatitis C virus RNA. *EPPs are those invasive procedures where there is a risk that injury to the worker may result in exposure of the patient's open tissues to the blood of the worker.

  14. Patient-to-provider HCV transmission 1997 and 2007 there were 14 patient-to-healthcare-worker transmissions in England [Health Protection Agency, 2008]

  15. What would be good to do: • Check every patient for anti-HCV before invasive procedure; • Control of health care providersHCV status; • Use only voluntary blood donations; • In medical apparatus avoid multiple used tips and other details been in contact with pacient’s liquids; • Use as reliable as possible aseptic techniques. To define rigorous disinfection protocols.

  16. Environmental HCV stability

  17. Stability of blood samples infected with HCV • Samples stored at 25 °C maintain their HCV RNA titre during 14 days • samples at 5 °C were stable for at least 3 months • Independently of the HCV RNA concentration, the results show absence of decay in HCV RNA detectability at -20 °C, -70 °C during 7 years of follow-up. [Jose M, 2003] • Dried and stored HCV plasma is infectable up to 16 hours at room temperature [Kamili S, 2007]

  18. Heating kill HCV • 65°C – 4 min • 60°C – 8 min • 56°C – 40 min [Song H, 2010] • 37°C for 2 days, • room temperature –16 days [Sattar SA, 2004] • 4°C - the virus was relatively stable without drastic loss of infectivity for at least 6 weeks. [Song H, 2010] • At lowertemperatures - HCV infectivity in a liquid environment was detectable for up to 5 month. [Ciesek S, 2010]

  19. UVC light irradiation • wavelength = 253.7 nm with an intensity of 450 μW/cm2 – 2 min. [Song H, 2010] (this could be a good flat surfaces sterilization method, but not suitable for rough and hollow parts of the medicine equipment)

  20. Organic solvents and detergents • Formaldehyde • glutaraldehyde, • ionic or nonionic detergents inactivate HCV effectively (depending on concentration) [Song H, 2010]

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