Seroprevalence and trend of Hepatitis B virus infection among the blood donors of North Karnataka: A Nine Year Study

Introduction: Hepatitis B is one of the leading transfusion transmissible infections. The prevalence of this infection varies across the different geographical areas with intermediate prevalence in India. Studying the trend in seroprevalence is useful to assist the preventive strategies. The aim of this study was to determine the trend of seroprevalence of hepatitis B in North Karnataka region over a nine-year period (2007-2015). Materials & Methodology: The study was conducted at one of the largest blood banks of Northern Karnataka of an apex health care institution serving predominantly the people of North Karnataka. A retrospective analysis of blood donors over a period of nine years (2007-2015) was done to assess the seroprevalence and the trend of hepatitis B infection among them. ELISA was used to detect the hepatitis B surface antigen in the donors as a marker of infection. Results: A total of 80,312 blood donors were undertaken for the study. About 1613 (2%) were positive for HBsAg, which falls under the “intermediate prevalence (2%-7%) zone” as per World Health Organization (WHO) guidelines. An increasing trend in first five years (2007-2011) and then decreasing trend over next four years (2012-2015) was observed in the present study. Replacement donors and male blood donors showed significantly higher seropositivity compared to voluntary donors and female donors respectively. Conclusion: North Karnataka has an intermediate prevalence of hepatitis B in blood donors with increasing trend in initial five years and decreasing trend over the last four-year period.


Introduction
Hepatitis B virus (HBV) infection is a leading cause of acute and chronic liver disease [1]. The infected person has higher risk of probability for cirrhosis and liver cancer. Approximately 30% of the world's population or about 2 billion persons have serological evidence of either current or past infection with hepatitis B virus [2]. The prevalence of chronic HBV infection in India ranges from 2% to 10% as shown by different studies [2].
Hepatitis B infection transfusion transmissible infections; which demands for meticulous pretransfusion testing and screening for HBsAg [3]. Millions of lives are saved every year through blood transfusion; provision of safe blood is of paramount importance for any health care delivery system. Burden of the disease and loss of life resulting from unsafe blood transfusions is very serious problem for the communities in developing countries.
The improved screening and testing of blood donors will significantly reduced transfusion transmitted diseases in most countries. The disease trends and blood assessment can better be done by the study of seroprevalence rate of hepatitis B in blood donors and indexed accurately in general population [4].
The present study was carried out with the aim to find out the seroprevalence of Hepatitis B and its trend among the blood donors a hospital based blood transfusion service set up in northern Karnataka over a period of nine years.

Materials and Method
This prospective observational study was carried out at the Blood Bank (under Department of Pathology), Karnataka Institute of Medical Sciences, a tertiary care Government hospital, retrospectively from January 1, 2007 to December 31, 2015 over a period of nine years. This blood bank is one of the largest blood banks of the state of Karnataka and caters to entire Northern Karnataka. The experiment on data size 80312 donors who donated blood during the nine years were conducted as in given below Step I-Clinically healthy individuals of age group (18-60yrs), body weight (>45 kg), hemoglobin (>12.5 g/dl) and not donated blood in the last three months is the qualification criteria for blood donation in the study group.
Step II-Sera of these qualified blood donors are screened for hepatitis B surface antigen (HBsAg) using standard Enzyme Linked Immunosorbent Assay (ELISA) kits.
Step III-The procedure of test is followed according to manufacturer's instruction. Samples showing reactivity are considered positive.
All apparently healthy blood donors (voluntary/ replacement) who donated blood at this hospital during the study period were included for the study. People who donate blood without expecting any favor in return or in voluntary blood donation camps were classified as voluntary blood donors.
The replacement donors were the friends or relatives, recruited by patients or their relatives to replace blood used or expected to be used for the patients from the blood bank.
Information regarding gender, number of previous donations, and type of donation (replacement / voluntary) and HBsAg status of each donor was obtained from the records. Data were entered in Microsoft Excel and analyzed by using Epi Info 7 statistical package. Prevalence of HBV was noted with respect to gender, type of donor and year.
Significance of the seroprevalence according to gender and type of donor was determined by chi square test. P value <0.05 was considered to be statistically significant.

Results
The data of 80312 donors who donated blood during the nine years study period were analyzed. Among them, 77306 (96.25%) were male donors and 3006 (3.75%) were female donors. Replacement donations 50735 (63.2%) were the majority whereas, only 29577 (36.8%) donations were from the voluntary donors (Table 1)

Discussion
In the present retrospective study, a total of data of 80312 blood donors were analyzed. Majority of the donors were males (96.25%) and the rest 3.75% were female donors. Similar findings observed by other studies include Fernandes et al [3], Rose et al. [4] in Vellore, Arora D et al [5]. in Southern Haryana, Singh K et al [6] in Coastal Karnataka, Pahuja et al [7] in Delhi and Singh B et al [8] noting more than 90% of the male donors. However, the statistical analysis (chisquare test) revealed the difference in the seroprevalence according to the gender to be significant (p value <0.0001). A significantly higher HBsAg seroprevalence in males than in females is also reported in other studies [8,9] [15,16]. According to India's Drugs and Cosmetics Act (1945), each blood unit has to be tested for hepatitis B virus infection [17]. In our study the overall prevalence of Hepatitis B was found to be 2%, comparable to study done by Sri Krishna et al. [18] in Bangalore. India has been placed in the intermediate zone of prevalence of hepatitis B by the World Health Organization (2-7% prevalence rates) with a HbsAg prevalence rate of 1-2% reported by Lodha et al. [7].
Supporting this, HbsAg prevalence in Punjab blood donors was 1.7% [19], while Rajasthan had 3.44% [20] and Delhi had 2.23% [7]. In Karnataka, coastal area [6] had 0.62% of HBV seropositivity. Singh et al. have reported a HbsAg prevalence of 1.8% whereas Joshi and Ghimere have reported a prevalence of 2.71% in healthy Nepalese males [8,9]. On the other hand, the prevalence of HBV infection is lower in the United States and Western Europe (0.1-0.5%) and is reported to be higher, 5-15% in South East Asia and China [7].
One of the greatest challenges of transfusion medicine is the prevention of transmission of infectious diseases through blood transfusion.  [21]. With the implementation of strict donor criteria and use of sensitive screening tests, it may be possible to reduce the incidence of TTI in the Indian scenario.
The present study revealed a decreasing trend in seroprevalence was noticed over nine years study period. The lower prevalence and decreasing trend may be a result of several factors. The awareness about the disease and modes of prevention may be one reason for the declining trend in HBV infection. Secondly, the implementation of National Blood policy with uniform guidelines and pre-donation counseling and strict donor selection criteria help in excluding the possibly infected donors. The absence of HBsAg in blood donors may not be sufficient to ensure the lack of circulating HBV and hence there are chances of missing occult HBV infection

Conclusion
Present study showed that most of the donors were replacement donors with male preponderance. There was increased Hepatitis B positivity rate amongst the replacement donors as compared to the voluntary donors. Ensuring the safety of patients by reducing the residual risk of transfusion transmitted hepatitis is the concern of every transfusion center. The decreasing trend of seropositivity reflects the effective safety

Research Article
Tropical Journal of Pathology & Microbiology Available online at: www.pathologyreview.in 252 | P a g e strategy among general population and transfusion medicine services. Apart from these, other factors like public awareness, prohibition of professional blood donation have also contributed to the decrease in trend of Hepatitis B.
There should be an establishment of a nationally coordinated blood transfusion services with the implementation of strict donor selection criteria, use of sensitive screening tests and establishment of strict guidelines for blood transfusion may be helpful to further reduce the incidence of Hepatitis B in India.
Funding: Nil, Conflict of interest: None initiated, Permission from IRB: Yes