Hepatitis B virus infection among pregnant women in Bahir Dar, Ethiopia, 2018: An institution based cross sectional study

Objective: This study aimed to determine the magnitude of serum HBsAg and the risk factors for Hepatitis B virus infection among pregnant women in Bahir Dar. An institution based cross sectional study was implemented from February 1 to May 1, 2018 among 338 pregnant women attending antenatal care clinic at Felegehiwot referral hospital, Bahir Dar, 2018. Systematic sampling technique was implemented. Blood sample was taken from 338 study participants and serum was tested for Hepatitis B surface antigen (HBsAg) using Enzyme Linked Immuno Sorbent Assay. Results: The overall magnitude of hepatitis B virus infection among pregnant women were 16(4.7%) (95% CI= 2.7, 7.7).Having a history of blood transfusion (AOR=5.2; 95% CI=1.2-22.3), having a history of multiple sexual partners (AOR=4.6; 95% CI=1.1-19.6) and having a history traditional tonsillectomy (AOR=3.4; 95% CI=1.1-10.1) were the major predictor factors for Hepatitis B virus infection.


Introduction
Hepatitis B virus (HBV) is a common cause of acute and chronic viral hepatitis worldwide. According to phylogenetic analyses, HBV can be classified into eight genotypes (A to H) based upon an intergroup divergence. Among these, genotypes B and C are most common among those with chronic HBV, while genotype A is most common among those with acute HBV. HBV is the most crucial type of virus because of their insidiousness at nearly stage of infection and the eventual detection of the disease at a very late stage (1). Hepatitis B virus (HBV) is DNA virus causing hepatitis in humans which is classified as chronic hepatitis B and acute Hepatitis B virus infection. Chronic hepatitis B virus is the single most important risk factor in the development of liver cancer, with 60-80% of the world cases of primary liver cancer (Hepatocellular carcinoma/HCC/) is attributed to chronic hepatitis B.
Acute hepatitis B in pregnancy is not associated with increased abortion rate, stillbirth, or congenital malformation but higher incidence of low birth weight was reported (3,4).
Hepatitis B virus (HBV) is transmitted by: vertical transmission, between family members within households by contact of non-intact skin or mucous membrane with secreting or saliva containing, 3 unsafe sexual intercourse, transfusion of HBV infected blood and blood products, perinatal transmission, horizontal transmission, nosocomial infection( commonly transmitted blood-borne virus in the healthcare setting),and percutaneous inoculation(contaminated medical equipment and sharing of contaminated syringes and needles among injecting drug users) (1,5).
Administration of Hepatitis B Immunoglobulin (HBIG) in combination with hepatitis B vaccines as post exposure prophylaxis is very important since vertical transmission rate is nearly 100% (6,8). Ethiopia is now identifying the magnitude of the problem and implementing the vaccination for health workers but still there is no accessibility and availability of vaccination of hepatitis B virus for those healthy mothers. Hence, this study aimed to determine the magnitude and associated factors of hepatitis B surface antigen virus among pregnant women attending antenatal care at Felegehiwot referral hospital, 2018.

Study setting
Bahir Dar town is located in Amhara region, 565km north-west of Addis Ababa. According to 2007 Ethiopian central statistical agency report, the total populations of Bahir Dar town administration is 221, 991.Of them 108,456 are males and 113,535 females. The hospital has different departments that provide specialized services in outpatient, inpatient and operation theatre departments. It provides services for approximately for more than 7 million people from the surrounding area. It has more than 415 beds and gives services for the western part of Amhara region as a referral hospital.
There are more than 600 members of staff employed by the hospital and a further 200 employed by Bahir Dar university. Felegehiwot referral hospital provides care for the pregnant mothers widely in ANC, Intrapartum and Postpartum period.

Source population
All pregnant women who had antenatal care follow up at Felegehiwot referral hospital.

Study population
All pregnant women who were visited the antenatal care clinic during the first visit at Felegehiwot referral hospital

Inclusion criteria
Women who had first antenatal care follow up at Felegehiwot hospital during the study period

Exclusion criteria
Women whose antenatal care follow up were in another health institutions Women who referred from other health institutions Vaccinated HBV

Study design and Sample size determination
We designed an institutional based cross-sectional with serological supplemented study to estimate magnitude of hepatitis B virus infection. The sample size was estimated using Epi Info 7 software using sample size determination for cross sectional studies. The parameters that were used to estimate the sample size were: confidence level of 95%, 5% margin of error and prevalence of outcome was 7.8%. It was estimated based on one study in Ethiopia prevalence of hepatitis B in Hawassa hospital. Adding a 10% loss rate, the final sample size required for the study were a total of 338 women.

Sampling techniques and Procedures
Systematic random sampling technique was applied to select the study participants. We took 3 months' average sampled population from registration book which was done at ANC clinic which is 626.So as to get k th interval = (source population) N/sample size (n 0 ) =626/338 2. Then the first pregnant mother was randomly selected by lottery method. Then study participants were interviewed every two interval until the sample size was completed through systematic random sampling technique.

Data collection tools and procedures
Data collection was implemented both face to face interview through pretested structured questionnaire and chart review. A pre-tested structured questionnaire was consisting of sociodemographic and socioeconomic characteristics, risky socio cultural and behavioral factors, institution related factors and blood sample test was designed to collect patient serum hepatitis B surface 5 antigen virus status by requesting laboratory investigation. One-day training was given for the supervisor and data collectors about data collection and sampling technique. There were two trained diploma midwives for data collection and one BSc midwife supervisor. Pre testing of questionnaire on 17 (5%) pregnant women was done to assess the questionnaire content and face validity. The investigator and supervisor made spot checking and reviewing the completed questionnaires on daily basis to ensure completeness and consistency of the information collected. Privacy of the participants was kept.

Laboratory Methods
Blood sample was obtained from 338 pregnant women. A standard procedure was used to collect blood and process them for testing. All sera were screened for hepatitis B surface antigen (HBsAg) using Enzyme Linked Immunosorbent Assay (ELISA) (Hepanostika test kit; Biomerieux, Boxtel,

Operational definition
Traditional tonsillectomy: Any traditional malpractice which was attempted to remove the tonsil by the community and cultural malpractice workers especially in the school age group without attending and evaluating in health institutions.
Risky socio cultural and behavior: Is behaviors which are endangers the life of the mother, children, family and the community consisting of unsafe sexual intercourse, multiple sexual partner, tattooing, unsafe injection of drugs without health professionals permission, traditional tonsillectomy, different types of piercing either in the ear or eye any factors which increases healthy mothers prone by acquiring of through different procedures in the health facility as well as in the community.

Data processing and analysis
After declaring for completeness and consistency of the data, the data were entered into Epi Info version-7 and exported in to SPSS version 23 statistical software for data cleaning, coded and analysis respectively. Bivariate logistic regression analysis was done after dichotomizing the dependent variables. After checking associations of the variables, those with p<0.2 in bivariate analysis was processed to multi-variable logistic regression analysis to control confounding factors. P-value of < 6 0.05 was used to express the statistical significance of the variables.

Socio-demographic and socio economic characteristics
A total of 338 pregnant women were participating with a response rate of 100%. The mean age of the women was 26.84 years (ranged from 22 to 40 years) with a SD of ± 4.8 years. Two hundred sixty (76.9%) respondents were urban in residence. (Table S1)  (Table 1)  Under multivariable logistic regression analysis showed that three predictor variables were 7 statistically significant associated with HBV infections.

Discussion
Hepatitis B virus infection is a public health problem and a major cause of morbidity and mortality, particularly in developing countries (10). Worldwide, the prevalence of chronic HBV infection categorize in to three classes which are: high (>8%), intermediate (2-8%), and low (<2%) (11). Most countries in the world still considered intermediate to highly prevalent for HBV infection (11).
In this study found to be that the magnitude of HBsAg among study participants were 16(4.7%) (95%CI=2.7,7.7)with a response rate of 100%. According to established criterion, the prevalence of HBsAg among pregnant women in this study area can be classified as an intermediate category (11).
This finding is in line with different studies were done with a proportion of 5.3% in Debre Tabor general hospital(12), 5.5% in Tigray(13), 3% St. Paul's millennium medical college and Selam health center(14), 3.7% in Jimma (15), 6% in Addis Ababa (45), 6.9% in Deder hospital, eastern Ethiopia.(3), 7.3% in Gondar health center (16),and 4.9% in Dessie Referral hospital (17).This might be due to the sampling method, risky socio cultural and risky behavioral practice and methods used to screen HBsAg infection were the same.
8 But, relatively it is higher than 2.5% of prevalence which were reported from three public hospitals in Addis Ababa (18). This difference might be due to risky socio cultural and risky behavioral practices were low. However, it is lower than the study conducted in Hawassa referral hospital 7.8% (9).This difference might be due to the methods used to screen highly sensitive and specific and risky socio cultural and behavioral practiced were high.
On the other hand in comparison with other countries in line results were reported three studies in Nigeria, 3.8% (19), 4.7 % (20) and6.6%(21), 5.6% in Sudanese (22),Two studies in China 6.71% (23) and 7.44% (24). This similarity might be due to the methods used for screening and sampling techniques was the same.
However, higher results were reported in Mali 8%(25), Yemen 10.8%(26),Uganda 11.8% (27), Nigeria 12%(28) and Kenya 14.1(29). This variation might be due to differences in sampling method, geographical variation, cultural and behav ioral differences regarding possible risk factors of HBV infection, and differences in the test methods employed to detect HBV infection.
In fact, this study demonstrated that having a history of blood transfusion, having a history multiple sexual partners and having a history of tonsillectomy were significant predictors of HBV infection.

Conclusion
This study revealed that the magnitude of HBV infection was low intermediate. Ethical clearance was obtained from the ethical review committee of Bahir Dar University College of medicine and health science. Permission letter was obtained from Amhara regional health bureau and also asked from Felegehiwot comprehensive specialized Hospital. Then the objective of the study was explained to the identified study subjects. Written informed consent had applied when collecting data from pregnant women attending routine antenatal clinics. Anonymity was maintained by using identity numbers instead of patient names. Beside, all the data abstracted was kept confidential and not used for any other purposes than the stated research objective.

Availability of data and materials
All related data has been presented within the manuscript. The data set supporting the conclusions of this article is available from the authors on request

Competing interests
The authors have declared that no competing interests exist.

Author contribution
FK wrote the proposal, participated in data collection, analyzed the data and drafted the paper. FK, GG, AA, and KG approved the proposal with some revisions, participated in data collection, analysis and manuscript writing. All authors read and approved the final manuscript.

Acknowledgement
First of all, we would like to forward our deepest gratitude to Bahirdar University, college of medicine and health science for financial support to conduct this research and APHI was given the official permission letter. Our special thanks and appreciation goes to all the study participants who voluntarily participated in this study and health care personnel of the FHRH and for their consistent support. Last but not least our heartfelt thanks go to all our friends who have partly made their contribution in the development of the proposal and scientific advice.