Management of patients suffering with β-thalassemia is based on adequate and safe blood transfusions and receiving regular iron-chelation therapy, all of which improve the quality of life and survival of patients.[3
This study was designed to determine the prevalence and incidence of transfusion transmitted infections in multiply transfused thalassemia patients during the study period. This study carried out at Prathama Blood Centre, Ahmedabad over a period of 2 years from Jan 2007 to Jan 2009. Cohort of 115 patients was selected from regular transfusion group and they were followed for one and half year and evaluated for the prevalence and development of transfusion transmitted infections. A total of 96 multiply transfused thalassemia patients were prospectively included in the study and investigated for the prevalence and development of transfusion transmitted infections.
Patients with thalassemia major require repeated transfusions of blood exposing them to the risk of Transfusion-Transmitted Diseases (TTDs). The probability of acquiring TTDs is related to the probability of being exposed to the infected units of blood. This probability depends on the prevalence of carriers among the blood donors in the population and the number of units transfused. Thus, the infection rate of TTDs increase with age in subsequent years. The incidence of hepatitis and HIV infections in Indian pediatric patients with thalassemia is high due to high prevalence of hepatitis and HIV in the general population.[8
Transfusion-transmitted infections such as Hepatitis B Virus (HBV), Hepatitis C Virus (HCV), and HIV are dreaded consequences of transfusions, as these can result in long-term morbidity and mortality. In India, it is mandatory to screen donated blood for anti-HIV 1 and 2 (since 1991), anti-HCV (since 2000), HBsAg, syphilis, and malaria. TTI can still occur from blood donations negative for markers for these infections as reported by various Indian investigators[6
] and international studies.[11
] This residual risk of TTI transmission from screened blood depends on the safety of donor population, sensitivity of the screening tests used, window-period donations, and other reasons such as mutant strains.[14
Hepatitis C virus, which was discovered in 1989, is an enveloped virus of size 30-60 nm, and it gets transmitted through the parenteral route. The clinical course seems to be more serious in hepatitis C infection. Studies available from India give prevalence of markers for TTI in donors and recipients.[6
] The prevalence of anti-HCV in multiple-transfused patients is confirmed to be high.[15
] A three-years prospective study from India by Choudhury et al
] observed that anti-HCV prevalence in the same number of thalassemia major patients was 23%, 30.7%, and 35.9% each year, respectively. The present study showed similar result as described by Choudhury et al
Prevalence studies have found that common infections occurring in thalassemic patients are Hepatitis C (2.2%-44%), followed by Hepatitis B (1.2%-7.4%) and HIV (0%-9%).[6
] Karimi et al
] found the prevalence of HCV to be 15.7%, Prati et al
] found it to be 14.8%, and Singh et al
] found a high prevalence of HCV (20%) in multiply transfused thalassemia major patients. Results of these observations were in accordance to the present study in which a high prevalence of HCV (25%) was reported.
In the present study, out of 96 multiply transfused thalassemic patients, 24 (25%) were reactive for anti-HCV. An important finding in the present study, all anti-HCV–reactive patients were above the age of 8 years, which may be because of the HCV untested blood transfusion before June 2001. In the present study, a high prevalence of anti-HCV (25%) was reported probably because of HCV untested blood transfusion before 2001. Anti-HCV test has been made mandatory by the Government of India from June 2001.[15
Transfusion-associated hepatitis is a major problem in South-East Asian countries, including India, due to endemic hepatitis infections in this region. The prevalence of HBV is low in the US and Western Europe (0.1%-0.5%), while in South-East Asia and China, which are endemic areas, this is in the range of 5%-15%. Prevalence of HBV and HCV in blood donors in India is about 1%-5% and 1%, respectively. According to the Drugs and Cosmetic Act (1992), every blood unit has to be tested for HBsAg, anti-HIV I and II, VDRL, and malaria. HBsAg testing is mandatory according to the Act, but it can either be carried out by ELISA or Reverse Passive Hemagglutination Assay (RPHA).[15
Hepatitis B is a special problem in India since it is a medium endemic area. This problem is acutely reflected in blood transfusion services due to dependence on first-degree relative or paid blood donors and lack of non-remunerated repeat voluntary blood donors. Routine HBsAg screening in blood units does not eliminate the risk of HBV transmission. HBsAg test may be negative in the window phase of HBV infection, in the convalescence phase and also in HBV chronic infection, with very low level of viremia. Prevention of post-transfusion hepatitis starts with selection of non-remunerated voluntary blood donors. It has been observed that polyclonal antibody-based ELISA gives better sensitivity and provides better detection of mutants.[15
Hepatitis B Virus may occasionally be transmitted through transfusion of blood units that are HBsAg-negative but HBV DNA-positive. Children with -thalassemia are particularly susceptible to HBV because they receive multiple blood transfusions. Singh et al
] found 5.7% prevalence of HBV in multiply transfused β-thalassemia major patients. Many prevalence studies have found that the HBV infection occurring in multiply transfused thalassemic patients range from 0.53% to 7.4%.[6
] Results of these observations were in accordance of the present study, where prevalence of HBV was 1.04% reported.
The prevalence of HIV infection in thalassemia varies greatly worldwide, from less than 1% to more than 20%. With the use of standard procedures for prevention, it is possible to keep the risk of HIV transmission very low, with the use of the most sensitive screening measures. In the absence of treatment, the median time from HIV seroconversion to the onset of AIDS in transfused patients is about 7-11 years. Factors affecting progression include symptomatic primary infection, age at infection, and viral load. Patients with thalassemia identified with HIV infection should be managed in collaboration with an infectious diseases unit with expertise in HIV.[6
] Results of these observers were in accordance of the present study where prevalence of HIV was reported to be 1.04%.
Cases of AIDS have been reported from India since 1986. The voluntary donors screening for HIV in donated blood was introduced in India in March 1989. The Indian study on multi-transfused thalassemia patients indicate the seropositivity for HIV varying from 0.5% to 3.8%.[8
] The present study showed similar result as described by Choudhury et al
] The preventive measures include careful donor selection, laboratory testing, safe transfusion practice, and blood product sterilization. In India, National AIDS Control Organization (NACO) was established under the Ministry of Health and Family Welfare for the control of HIV infection in India. NACO supplied various equipment for HIV screening and component preparation to blood banks and HIV (ELISA and RAPID) kits are also supplied free of cost. HIV antibody tests are to be carried out according to the prevalence of HIV infection in a particular population.[15