Knowledge, Attitudes and Practices of Hepatitis B Prevention and Immunization of Pregnant Women and Mothers in Viet Nam

Background and Aim Vietnam’s high burden of liver cancer is largely attributable to the high prevalence of chronic hepatitis B virus infection (HBV). Infection at birth due to mother-to-child (MTC) transmission is the most common cause of chronic HBV in Vietnam and increases the risk of liver cancer later in life. This study was undertaken to examine the knowledge, attitudes, and practices of pregnant women and mothers in Vietnam concerning HBV prevention and immunization. Methods A cross-sectional study was conducted in Quang Ninh and Hoa Binh provinces in 2017. A pre-designed questionnaire was administered to women when they received care at primary and tertiary maternal health clinics. Correct responses were summarized as knowledge scores. Data was analyzed using a multivariable regression model across participant demographics. Results Among the 404 women surveyed, 57.6% were pregnant and 42.4% were postpartum. Despite 73.5% of participants reporting having received information about HBV during their pregnancy, gaps in knowledge and misconceptions are evident. Overall, only 10.6% provided correct answers to all questions regarding HBV transmission routes and prevention measures. Around half of the participants incorrectly believed that HBV is transmitted through sneezing, contaminated water or sharing foods with chronic HBV patients. Although 96.4% of participants believed that HBV vaccination is necessary for infants, only 69.1% were willing to have their own child vaccinated within 24 hours. More than a third of participants expressed concern about having casual contacts or sharing foods with chronic HBV patients. In multivariable analysis, having received information about HBV during their pregnancy were consistently associated with better knowledge score for transmission, prevention and immunization. However, knowledge of women who received information about HBV during their pregnancy was still suboptimal. Conclusions The results highlight the need to prioritize educating pregnant women and mothers in future public health campaigns in order to increase knowledge, reduce misperception, and improve HBV vaccine coverage in Vietnam.


INTRODUCTION
Liver cancer is the fourth most common cause of death from cancer and carried the second highest rate of absolute years of life lost among amongst cancers globally in 2016 [1]. The 2016 Global Burden of Disease also estimates that HBV infection alone accounts for about 42% of liver cancer death.
Vietnam has the 6th highest incidence of liver cancer and the third highest rate of death from liver cancer in the world in 2018 [2]. In 2018, liver cancer was the third leading cause of cancer death in Vietnam with a male-to-female ratio of 3.5 for age-standardized mortality. HBV accounts for close to half (46%) of the liver cancer deaths in Vietnam [3]. The reported prevalence of the HBV surface antigen (HBsAg) in the general population ranged from 15-20% [4][5][6][7]. Current estimates suggests 10.8% of the population or 9.6 million people in Vietnam are HBsAg positive and are living with chronic hepatitis B [5].
The spread and development of serious HBV sequelae can be effectively prevented through immunization with the hepatitis B vaccine. Infant hepatitis B vaccination was introduced to Vietnam in 1997 and expanded nationwide in 2002. To combat the significant risk of infection at birth due to MTC transmission, a birth dose administered within 24 hours after birth was added to the immunization schedule in 2003 [8]. The results of a nationwide survey comparing HBsAg prevalence in children born 2000-2003 to children born 2007-2008 showed a 2% reduction in prevalence. Additionally, infants vaccinated > 7 days after birth showed a 1.68% increase in HBsAg prevalence compared to those vaccinated within the 24 hour following the immunization guideline [9]. Such findings demonstrate the profound impact of both implementation and timely vaccine administration in reducing the risk of chronic hepatitis B infection.
Despite these encouraging results, birth-dose vaccination coverage has struggled to stay consistent since its implementation. Birth dose coverage dropped to its lowest rate in 2010 at 21.4%, rose to its highest in 2012 at 75% before dropping to 56% in 2013. The reporting of adverse events following immunization (AEFIs) in 2007 and 2013 that were blamed on newborn hepatitis B vaccination in conjunction the emergence of anti-vaccination movements may contribute to this volatility. The impact of a 19% drop in coverage was estimated to increase burden by 130,675 new chronic HBV infections and 25,197 HBV-associated deaths for children born in 2013 [10]. As perinatal transmission continues to be the major route of transmission in Vietnam, it is critical to initiate strategies to improve and sustain vaccine coverage rates. A pertinent strategy will be to recruit pregnant women and postnatal mothers to become active participants in their own health as well as advocates for the health of their children. There is currently a dearth in data regarding knowledge, attitudes, and sources of misconception regarding HBV prevention and care in Vietnamese mothers and pregnant women. The findings from this survey will be used to identify putative areas where targeted public health initiatives will be most effective in eliminating HBV and liver cancer in Vietnam.

Study population
This was a cross sectional study recruiting a sample size of 404 pregnant or postnatal women at 16 selected maternal clinics at primary and tertiary hospitals in Hoa Binh and Quang Ninh provinces. Women who visited maternal health units were approached after their visit and invited to participate if they were pregnant or within 60 days postpartum. Trained data collectors administered a pre-designed questionnaire at maternal care clinics. Written consent form was obtained from the participants before interviewing.

Questionnaire
The questionnaire was developed in Vietnamese by the Asian Liver Center at Stanford University based on its past experience with administering HBV knowledge surveys in other populations. The questionnaire consisted of four sections: i) demographic and personal HBVrelated health history; ii) disease burden and consequences; iii) transmission routes and prevention measures; iv) postnatal mother HBV vaccination practices. The first section surveyed

Statistical methods
Descriptive statistics were generated from variables in the data obtained from the 404 pregnant and postnatal women who completed the survey. A correct response to each question received one point and incorrect or missing responses received no points. The knowledge score was calculated based on the sum of correct answers to the 12 transmission and prevention questions and 4 immunization questions. Association between demographic factors, access to HBV education during pregnancy and knowledge scores was estimated using a multivariable regression model.

RESULTS
Demographics and pregnancy characteristics of the study population (N = 404) are presented in Table 1

General knowledge and access to information about HBV
Knowledge about HBV prevalence and its serious consequences was inadequate amongst pregnant women and mothers. About two thirds were not aware of the high prevalence of chronic hepatitis B infection in Vietnam. Only 58.8% of participants were aware that chronic HBV can cause serious consequences such as liver cirrhosis, liver failure, liver cancer, or premature death (Table 2). 69.5% of participants reported that they received information about HBV during their pregnancy. 81.7% reported that they have previously received information about the benefit of HBV vaccine for infants. Healthcare workers were the primary source of this information (90.1%) followed by equal contribution from common public outreach methods such as flyers, newspapers, radio, television, and the internet ( Table 2).

Knowledge and attitude regarding HBV transmission and prevention
Out of 12 questions about HBV transmission and prevention knowledge, the mean score was 8.2 ± 2.67 (mean +-SD) and the median score was 8.0. Study participants were largely aware that HBV can be transmitted through mother-to-child (85.1%), unprotected sex (75.3%), and blood transfusions (86.7%). However, there were common misconceptions that HBV can be transmitted through sneezing or coughing (58.5%), contaminated water (55.2%), and eating with or sharing food with chronic HBV patients (47.1%) (  (Table   3).  In multivariable analysis, having received information about HBV during pregnancy was the only factor independently associated with transmission and prevention score. Age, number of children, family per-capital income and education level were not associated with transmission and prevention knowledge score (Table 5). While women who received information about HBV during pregnancy provided higher percentages of correct answers to almost all individual questions related to HBV transmission and prevention compared to those who did not, their knowledge were still suboptimal. Only 62.6%, 68.5% and 51.8% respectively provided correct answers to whether HBV can be transmitted through contaminated water, coughing/sneezing and sharing foods. Only 28.2% provided correct answer to whether cleaning and cooking food thoroughly can prevent HBV transmission or not; 41.8% provided correct answers to whether avoiding sharing food/utensils or eating with a person with chronic HBV or not (Table 3).

HBV screening and immunization knowledge and attitude
Out of 4 questions about HBV screening and immunization, the mean knowledge score for was 3.0 ± 0.98 (mean ± SD) and the median was 3.0. Majority of surveyed women believed that pregnant women need to be tested for HBV (83.2%), vaccination is necessary for infants (96.4%) and the best time to provide a healthy and stable child the first dose of HBV vaccine is within 24 hours after birth (80.9%). However, only 54.5% of participants knew that infants born to chronic HBV mothers should receive the first dose of the hepatitis B vaccine and the HBIG shot within 12 hours of birth followed by completion of the vaccine series to prevent mother to child infection (Table 6).  In multivariate analysis, characteristics independently associated with higher screening and immunization knowledge scores included ages of participants and having received information about HBV during pregnancy (Table 8). Younger women tend to have lower screening and immunization score compared to their peers of older age. Number of children, family per-capital income and mother education were not associated with screening and immunization knowledge score. Received information about HBV during pregnancy.

HBV screening and immunization practice
In the subgroup of 203 postnatal women surveyed, 68.4% reported they received hepatitis B testing during their current or most recent pregnancy. Among them, 20% reported having positive results and 16% were unsure of their results. 71.6% reported the newborn were administered the first dose of the hepatitis B vaccine within 24 hours of birth. 13.7% were vaccinated between 24 to 48 hours after birth and 14.7% did not receive any vaccine until 1 month of age. When asked why the infants were not vaccinated within 24 hours of birth, the following responses were given: mother did not think it was safe (30.9%); no vaccine available (17.7%); child was sick (14.7%); mother did not think it was necessary (13.2); doctor said it was not necessary (10.3%) and child has low birth weight (2.9%) ( Table 8). In multivariable analysis, having received information about benefits of HBV vaccination for newborn before and delivering at provincial health clinics were independently associated with whether the newborns received the hepatitis B birth dose or not. Age, education level, number of children, family per-capital income and knowledge score on HBV screening and immunization were not associated with whether the newborns received the hepatitis B birth dose or not (Table 9)  [11][12][13]. Multivariable analysis showed that mothers who received HBV information during pregnancy consistently had better knowledge regarding HBV transmission, prevention and immunization than who did not. However, this knowledge among women who received HBV information during pregnancy was still sub-optimal. Our findings emphasize a need to implement education programs targeting women of childbearing ages with basic HBV information. It is also necessary to review existing antenatal educational programs and materials to ensure that key messages are effectively conveyed to the target audiences.
This study also revealed significant stigma associated with people having chronic HBV in This low confidence in HBV vaccine safety among HCWs may significantly contributed to high hesitance among pregnant women because they are the main source from which pregnant women received hepatitis B vaccine related information. These together underscored a critical need to address this concern to re-establish and sustain confidence in hepatitis B vaccine at a wider scope, targeting HCWs, pregnant women and general community.

Study Limitations
This study was conducted in two Northern provinces of Vietnam with low HBV birth dose coverage at the study point; thus, the results may not be applicable to other parts of the country. In addition, the self-reported HBV screening and immunization practices by study participants could not be validated.

Conclusion
This study showed that pregnant women and mothers have insufficient knowledge regarding HBV infection regardless of age, education, economic condition, childbearing status and historical exposure to HBV information during pregnancy. Misconceptions about HBV transmission through contaminated water, sharing foods and casual contacts were common and perpetuates the stigma associated with chronic HBV infection. Although most participants were aware of benefits of hepatitis B vaccine, concerns about vaccine safety for newborn was prevalent. These emphasized a need to enhance public health education efforts to improve hepatitis B knowledge among women in reproductive age and in the antenatal period, and to demystify issues surrounding HBV transmission and vaccine safety to improve hepatitis B birth dose vaccination rate and eliminate mother to child transmission.