Prevalence, incidence and residual risk of transfusion-transmitted hepatitis C virus and human immunodeficiency virus after the implementation of nucleic acid testing in Italy: a 7-year (2009-2015) survey.

BACKGROUND In Italy nucleic acid testing (NAT) became mandatory for hepatitis C virus (HCV) in 2002 and for human immunodeficiency virus (HIV) and hepatitis B virus in 2008. The aim of this study was to monitor the incidence and prevalence of HIV and HCV infections in Italian blood donors and the current residual risk of these infections after the introduction of NAT. MATERIALS AND METHODS The Italian national blood surveillance system includes data from tests used to screen for transfusion-transmissible infections. During the period of this survey (2009-2015), the NAT methods used were the transcription-mediated amplification test, for individual donor testing, and polymerase chain reaction analysis, mainly for pools of six donors. Prevalence and incidence were calculated. Three published formulae were applied to estimate the residual risk (the window period ratio model and the formulae recommended by the European Medicines Agency and the World Health Organization). RESULTS Overall, 12,258,587 blood donors and 21,808,352 donations were tested for HCV and HIV. The prevalence of HCV decreased from 110.3×105 to 58.9×105 in years 2009 and 2015, respectively, while that of HIV remained stable over time (15.5×105 vs 15.4×105). The incidence of HCV decreased from 3.19×105 in 2009 to 1.58×105 in 2015, while the incidence of HIV did not show any significant fluctuations (average incidence 4.39×105). The residual risk of a viraemic unit entering the blood supply was estimated to be 0.077×106 or 1 in 12,979,949 donations for HCV and 0.521×106 or 1 in 1,917,250 for HIV, according to the window period ratio model, and lower with the other two formulae. DISCUSSION HCV infection has declined over time in both first-time and repeat donors, while the data for HIV infection are stable. All three methods employed in this study showed that the residual risk of transmitting HCV or HIV through an infected blood unit is currently very low in Italy, but there are considerable differences in estimates between methods. Thus, harmonisation of these methods is advisable.

[1]  S. Sauleda,et al.  Epidemiological trends of HIV‐1 infection in blood donors from Catalonia, Spain (2005‐2014) , 2017, Transfusion.

[2]  R. Burbano,et al.  Residual risk of transmission of human immunodeficiency virus and hepatitis C virus infections by blood transfusion in northern Brazil , 2017, Transfusion.

[3]  S. Glynn,et al.  A comparison of methods for estimating the incidence of human immunodeficiency virus infection in repeat blood donors , 2017, Transfusion.

[4]  S. O’Brien,et al.  Donor deferral policies for men who have sex with men: where are we today? , 2016, Current opinion in hematology.

[5]  H. Kamel,et al.  Risk factors for retrovirus and hepatitis virus infections in accepted blood donors , 2015, Transfusion.

[6]  S. Pupella,et al.  Changing blood donor screening criteria from permanent deferral for men who have sex with men to individual sexual risk assessment: no evidence of a significant impact on the human immunodeficiency virus epidemic in Italy. , 2013, Blood transfusion = Trasfusione del sangue.

[7]  J. Allain,et al.  Current incidence and residual risk of HIV, HBV and HCV at Canadian Blood Services , 2012, Vox sanguinis.

[8]  S. Stramer,et al.  Donor testing and risk: current prevalence, incidence, and residual risk of transfusion-transmissible agents in US allogeneic donations. , 2012, Transfusion medicine reviews.

[9]  P. Cochat,et al.  Et al , 2008, Archives de pediatrie : organe officiel de la Societe francaise de pediatrie.

[10]  J. Lefrère,et al.  Estimate of the residual risk of transfusion‐transmitted human immunodeficiency virus infection in sub‐Saharan Africa: a multinational collaborative study , 2011, Transfusion.

[11]  M. Vermeulen,et al.  Refinement of a viral transmission risk model for blood donations in seroconversion window phase screened by nucleic acid testing in different pool sizes and repeat test algorithms , 2011, Transfusion.

[12]  A. Zanetti,et al.  Impact of nucleic acid testing for hepatitis B virus, hepatitis C virus, and human immunodeficiency virus on the safety of blood supply in Italy: a 6‐year survey , 2008, Transfusion.

[13]  R. Dodd,et al.  A method for estimating incidence rate of infectious diseases among first‐time blood donors , 2008, Transfusion.

[14]  A. Giampaolo,et al.  Residual risk of transfusion‐transmitted human immunodeficiency virus, hepatitis C virus, and hepatitis B virus infections in Italy , 2005, Transfusion.

[15]  K. Soldan,et al.  Estimates of the frequency of HBV, HCV, and HIV infectious donations entering the blood supply in the United Kingdom, 1996 to 2003. , 2005, Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin.

[16]  S. Glynn,et al.  A new strategy for estimating risks of transfusion‐transmitted viral infections based on rates of detection of recently infected donors , 2005, Transfusion.

[17]  S. Laperche,et al.  Trends in risk of transfusion-transmitted viral infections (HIV, HCV, HBV) in France between 1992 and 2003 and impact of nucleic acid testing (NAT). , 2005, Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin.

[18]  K. Soldan,et al.  Estimates of the frequency of HBV, HCV, and HIV infectious donations entering the blood supply in the United Kingdom, 1996 to 2003. , 2005, Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin.

[19]  A. Hall,et al.  Estimation of the risk of hepatitis B virus, hepatitis C virus and human immunodeficiency virus infectious donations entering the blood supply in England, 1993–2001 , 2003, Vox sanguinis.

[20]  A. Keller,et al.  Assessing the accuracy of three viral risk models in predicting the outcome of implementing HIV and HCV NAT donor screening in Australia and the implications for future HBV NAT , 2002, Transfusion.

[21]  S. Glynn,et al.  International application of the Incidence Rate/Window Period model , 2002, Transfusion.

[22]  S. Stramer,et al.  Current prevalence and incidence of infectious disease markers and estimated window‐period risk in the American Red Cross blood donor population , 2002, Transfusion.

[23]  R. S. Ross,et al.  Transmission of hepatitis C virus. , 2001, The New England journal of medicine.

[24]  J. Barbara,et al.  Prospective investigation of transfusion transmitted infection in recipients of over 20 000 units of blood , 2000, BMJ : British Medical Journal.

[25]  S. Kleinman,et al.  A method for estimating hepatitis B virus incidence rates in volunteer blood donors. National Heart, Lung, and Blood Institute Retrovirus Epidemiology Donor Study , 1997, Transfusion.

[26]  K. Calman,et al.  Cancer: science and society and the communication of risk , 1996, BMJ.

[27]  S. Kleinman,et al.  The Risk of Transfusion-Transmitted Viral Infections , 1996 .

[28]  G. Satten,et al.  Estimated risk of transmission of the human immunodeficiency virus by screened blood in the United States. , 1995, The New England journal of medicine.