Seroprevalence of Transfusion Transmitted Infections Among Blood Donors in a Tertiary Care Hospital in Andhra Pradesh

Introduction Blood transfusion is a life-saving procedure as even a single unit of blood and its components can save multiple recipients in need.[1] Though it’s a safe procedure, the risk of transmission of infections like HIV, syphilis, hepatitis B and hepatitis C are still seen.[2] Over the past two to three decades, several measures have been introduced into the screening of blood donations to detect diseases that may be transmitted via blood transfusions with the aim of improving the quality and safety of the blood supply.[3] It has been found that there was 1% chance of transfusion associated problems that can occur with every unit of blood.1 It is due to the factors such as immunologically variant viruses, inadvertent laboratory testing errors, disease in pre-seroconservation or window phase of the infection, highly expensive screening tests and immuno silent carriers.[1,4]


Introduction
Blood transfusion is a life-saving procedure as even a single unit of blood and its components can save multiple recipients in need. [1] Though it's a safe procedure, the risk of transmission of infections like HIV, syphilis, hepatitis B and hepatitis C are still seen. [2] Over the past two to three decades, several measures have been introduced into the screening of blood donations to detect diseases that may be transmitted via blood transfusions with the aim of improving the quality and safety of the blood supply. [3] It has been found that there was 1% chance of transfusion associated problems that can occur with every unit of blood. 1 It is due to the factors such as immunologically variant viruses, inadvertent laboratory testing errors, disease in pre-seroconservation or window phase of the infection, highly expensive screening tests and immuno silent carriers. [1,4] HIV has become a major problem to mankind and its prevalence and incidence is increasing day by day. India has a population of more than 1.2 billion with 5.7 (reduced to 2.5) million Human Immunodeficiency Virus (HIV) positive, 43 million HBV positive and 15 million HCV positive persons. [5] The risk of transfusion transmission of these viruses may be alarming due to high seroprevalence of anti-HIV-1, anti-HCV, and HBsAg (0.5%, 0.4%, and 1.4%, respectively) in blood donors. [6] The incidence of TTI is common in Asia and Africa whereas it is relatively rare in western countries. [7] HCV leads to 8000 to 10000 deaths annually in developed countries like US with an estimated global burden of 3.9 million people. [8] In 50% of the patients with TTI, there is associated morbidity and mortality depending upon the number of transfusions received and underlying condition of the patient. 3 Transmission of infection during the asymptomatic phase results in higher incidence of TTIs. This incidence can be reduced by regular implementation of donor selection procedures and donor screening by sensitive tests and effective inactivation procedures .3 Both WHO and Indian National AIDS Control Origination (NACO)also recommends comprehensive screening for all blood donations, using a quality control system to screen for HBV, HCV, HIV, and syphilis. 3,9 The objective of this study was to determine the frequency of HBsAg, HCV, HIV and Syphilis in various ABO and Rh (D) blood groups donors.

Materials and Methods
In this retrospective study, data of the healthy blood donors obtained from the records of the blood bank of a tertiary care hospital in Chitoor, Andhra Pradesh were analysed. The study was conducted over the period of three and half years (Jan 2014 -May 2017) after obtaining approval from the Institutional Ethical Committee.
Study population included a total of 8260 blood units of both voluntary and replacement donors over a period of 3.5 years. The replacement donors were family members, friends or relatives of the patients concerned. Donors were selected and screened thoroughly as per the standard guidelines of government of India, Drugs and cosmetics act. 10 Data such as donors age, nature of donor (whether replacement or voluntary), gender and results of screening tests for TTI's were collected.
Sampling Technique: Following informed consent, 5ml of blood from each donor was used for screening transfusion transmitted infections such as HIV, HBV, HCV and Syphilis. The hepatitis B surface antigen (HBsAg) and Hepatitis C Virus were tested by 3 rd generation ELISA methods. HIV(1and 2) was tested by 3rd &4th generation ELISA (Tridot) methods using NACO approved commercially available kits. Screening for syphilis wasdone by Rapid Plasma Reagin (RPR) method which detects the presence of treponemal antibodies. The reactive samplewas retested in duplicate before considering it seropositive.

Statistical analysis:
The data was collected and analyzed by using Statistical Package for Social Sciences (SPSS) software. Chi square test was applied as test of significance.

Results
A total of 8260 blood donors were screened for transfusion transmitted infections. Out of the total 8260 blood donors, 4217 (51%) were voluntary donors and 4043 (49%) were replacement donors. On sex distribution, very higher percentage for male population constituting 98.8% and 98.9% were noted for both voluntary and replacement blood donors respectively. Female accounted for around 1% in both the donor groups. (Table 1) In the present study, Sero-positivity for TTIs was found consistent from 2014 to 2017 and it was found to be statistically significant (P < 0.05). Yearly distribution of TTIs among blood donors are shown in Table 2.
The overall prevalence of HIV, HBV, HCV and Syphilis was found to be 0.06%, 2.1 % , 0.15% and 0.4% respectively. The highest percentage of prevalence was observed for HBV, followed by syphilis, HCV and HIV in decreasing order (p<0.05). The Hepatitis B had shown a static phase in the first two years and then a decreasing trend over a period of time whereas syphiliswas found more in the year 2016 ( Figure 1).
Age, sex and donors distribution of TTI's positive blood donorswere described in Table 3. The majority of TTIs were found positive among male donors representing 98.7% of the TTI cases. TTI positive replacement blood donors were found in majority constituting 60.7%. 51.7% of blood donors belonging to age group of 18-30 years showed positivity for TTI's followed by 31-40 years of age group (37%).     Various social and economic factors like less awareness about nutrition, lower literacy rate, misconceptions about blood donations have been implicated.
The prevalence of TTIs as reported in various studies on blood donors is depicted in Table 4 and 5. According to the report of National Aids Control Organization, higher incidence of HIV was found in the states of South India and Maharashtra. 6 Even the studies done within India showed higher prevalence when compared to the present study (0.06%). [12][13][14][15][16][17] Studies conducted by Khedmatet al 18 13,17,22 The low prevalence of HCV when compared with HBV might be due to the fact that HCV is less infective when compared with HBV and HCV is transmitted mainly through transfusion of blood or blood products, intravenous drug abuse and needle sharing which may not be common in southern part of Andhra Pradesh.
Prevalence of syphilis in the present study was almost similar when compared to other Indian studies. [12][13][14][15][16][17] Study conducted in Iran showed the least prevalence of syphilis(0.005%) while the study conducted in Pakistan showed higher percentage of prevalence of syphilis (2.08%). 18,22 Significant prevalence of TTIs was noted in sexually active young age groups between 18 -30 years which was similar to the study conducted by Leena et al in South India. 12 Also it was noted that there was significant prevalence of about 60.7% of TTI's were found occurring in replacement donors and that could be prevented by conducting various awareness programs to motivate safe voluntary donors instead of replacement donors. Number of TTI's cases can also be brought down by using higher sensitivity tests like Nuclei acid amplification testing (NAT) for HIV and HCV, detection of antibodies to core antigen (HBcAg) and IgM for HBsAg.

Conclusion
Several efforts should be made to increase the voluntary blood donations such as awareness and motivational programs for safe voluntary blood donation, health compaigns and encouragement of female donors for blood donation. Following strict donor eligibility criteria and effecting high sensitive screening methods can bring down the prevalence of TTI's. Proper treatment and follow-up counselling can help in preventing further transmission of infections in the community.