Transfusion Transmitted Viral Infections in Transfusion Dependent Patients with Thalassemia in Turkey: A Multicenter Study.

Thalassemia Major (TM) represent one of the largest groups requiring regular transfusions lifelong. A total of 3830 patients are currently registered with homozygous b-Thalassemia in Turkey. This study is designated to reveal the seropositivity status of thalassemia patients on chronic transfusion treatment for blood-borne infections. A questionnaire inquiring the demographics and medical history of the patients as well as serological status for hepatitis B, C and HIV, was sent to 12 Thalassemia Centers which are generally settled down in the University or big government hospitals with high capacity blood banks where the packed red cells were provided. The collected data of 999 patients who have regular transfusions of 1–2 Unit red cells, every 3–4 weeks beginning from the first years of life and screened for transfusion transmitted viruses (TTV) 6 monthly was analyzed. The patients were aged between 0–53 years (median 16 years). Overall HBsAg and Anti-HCV positivity were found 2.5% and 12.6% respectively. Confirmed Anti-HIV positivity was 0.2% in the study group and consistent with the low frequency of the disease among blood donors in Turkey. Age distribution of sero-positivity within the patients was as follows: 0.7% in 0–5 years, 17% in 6–10 years, 48.3% in 11–20 years and 34% over 21 years, indicating the strong relation between the sero-prevalence of TTV and transfused blood volume and the gradually increased safety of blood in Turkey. The highest prevalence rate was seen in the age of 11–20 years which also represents highest number of patients. Donated blood screening for HBsAg, anti-HIV 1/2 (since 1985), anti-HCV (since1996), and RPR for syphilis is obliged by law in Turkey. Although, widespread use of HBV vaccination in transfusion dependent patients has been started since 1990s, the data confirmed that this measurement is insufficient alone for eradicating the HBV transmission in this group. Vaccination against HBV has been scheduled routine vaccination program of infancy by the health authority since 1999. However, the positive reflection of this policy in blood safety would be seen in the next generations. In that point of view, vaccination against hepatitis B can be practised in blood donors as a preventive measure in Turkey which is considered as in the middle endemic region regarding hepatitis B infection. Although, Anti-HCV screening in blood donors caused significant decrease in HCV infection, it still represents the main cause of morbidity following cardiomyopathy in this group of patients. This study clearly shows that the threat of TTV infections among multi-transfused thalassemia patients and underlines the importance of strengthen blood donor selection and implementing the sensitive screening assays for TTV at blood centers.