High Prevalence of Hepatitis B Virus Infection Among Pregnant Women Attending Antenatal Care: a Cross-Sectional Study in Two Hospitals in Northern Uganda
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Open Access Research BMJ Open: first published as 10.1136/bmjopen-2014-005889 on 11 November 2014. Downloaded from High prevalence of hepatitis B virus infection among pregnant women attending antenatal care: a cross-sectional study in two hospitals in northern Uganda Pontius Bayo,1 Emmanuel Ochola,1,2 Caroline Oleo,2,3 Amos Deogratius Mwaka3 To cite: Bayo P, Ochola E, ABSTRACT et al Strengths and limitations of this study Oleo C, . High prevalence Objective: To determine the prevalence of the hepatitis of hepatitis B virus infection B viral (HBV) infection and hepatitis B e antigen (HBeAg) ▪ among pregnant In this study, we have evaluated the prevalence positivity among pregnant women attending antenatal women attending antenatal of a sexually transmitted viral infection, a risk care: a cross-sectional study clinics in two referral hospitals in northern Uganda. factor for hepatocellular carcinoma in a popula- in two hospitals in northern Design: Cross-sectional observational study. tion exposed to no condom sexual intercourse in Uganda. BMJ Open 2014;4: Setting: Two tertiary hospitals in a postconflict region in a postconflict region with high rates of HIV infec- e005889. doi:10.1136/ a low-income country. tion, another surrogate marker for sexually trans- bmjopen-2014-005889 Participants: Randomly selected 402 pregnant women mitted infections. attending routine antenatal care in two referral hospitals. ▪ We also investigated the prevalence of the hepa- ▸ Prepublication history for Five women withdrew consent for personal reasons. Data titis B e antigen, a surrogate measure of the risk this paper is available online. were analysed for 397 participants. of vertical transmission of hepatitis B infection. To view these files please Primary outcome: Hepatitis B surface antigen (HBsAg) This is important in determining the need for visit the journal online positivity. immediate vaccinations of babies after birth. (http://dx.doi.org/10.1136/ – ▪ Findings from this study may inform policy on bmjopen-2014-005889). Results: Of 397 pregnant women aged 13 43 years, 96.2% were married or cohabiting. 47 (11.8%) tested routine testing of pregnant women and immun- positive for HBsAg; of these, 7 (14.9%) were HBeAg isation of hepatitis B virus (HBV) exposed babies Received 11 June 2014 http://bmjopen.bmj.com/ Revised 19 August 2014 positive. The highest HBsAg positivity rate was seen in at birth in addition to the current practice of Accepted 3 September 2014 women aged 20 years or less (20%) compared with using combined vaccine at 6 weeks. those aged above 20 years (8.7%), aOR=2.54 (95% CI ▪ The study had some limitations; it was hospital- 1.31 to 4.90). However, there was no statistically based and included a selected population of significant difference between women with positive women with exposure to no condom sexual HBsAg and those with negative tests results with respect intercourse and therefore at high risk of sexually to median values of liver enzymes, haemoglobin level, transmitted infections including HBV and HIV. In absolute neutrophil counts and white cell counts. HIV addition, we could not demonstrate evidence for positivity, scarification and number of sexual partners chronicity of hepatitis B infections because we on September 27, 2021 by guest. Protected copyright. were not predictive of HBV positivity. did not perform tests for hepatitis B core anti- Conclusions: One in eight pregnant women attending bodies and HBV DNA because of logistical antenatal care in the two study hospitals has evidence of reasons. hepatitis B infection. A significant number of these mothers are HBeAg positive and may be at increased risk of transmitting hepatitis B infection to their unborn perinatal period and early childhood.2 The babies. We suggest that all pregnant women attending risk of becoming a chronic hepatitis B infec- antenatal care be tested for HBV infection; exposed tion carrier is 95% for infections acquired 1 babies need to receive HBV vaccines at birth. St. Mary’s Hospital Lacor, during the perinatal period3 compared with Gulu, Uganda 2 only 5% for those acquired during adult- Gulu University Medical 4 School, Gulu, Uganda hood. Up to 50% of HBV carriers die of 3Makerere University College complications including liver cirrhosis and of Health Sciences, School of INTRODUCTION hepatocellular carcinoma.5 Medicine, Kampala, Uganda Four hundred million people in the world Pregnant mothers who test positive for Correspondence to are living with chronic hepatitis B virus both hepatitis B surface antigen (HBsAg) 1 – Dr Pontius Bayo; (HBV) infection. The majority of these indi- and hepatitis B e antigen (HBeAg) have 70 [email protected] viduals acquired the infection during the 90% risk of transmitting infection to their Bayo P, et al. BMJ Open 2014;4:e005889. doi:10.1136/bmjopen-2014-005889 1 Open Access BMJ Open: first published as 10.1136/bmjopen-2014-005889 on 11 November 2014. Downloaded from newborn infants and about 10–40% risk if they test posi- in northern Uganda, and has a laboratory with the cap- tive for only HBsAg.56Therefore, pregnant women acity to separate and store frozen plasma. The Lacor should be routinely screened for HBsAg and hepatitis B Hospital antenatal clinic (ANC) is visited by 50–80 preg- vaccine administered at birth to the infants whose nant women per day, Monday through Friday. The Gulu mothers test positive.78However, this is not the practice regional referral hospital, on the other hand, is a 250-bed in Uganda. government owned referral facility located in the centre of The Uganda National Expanded Program on Gulu town16; the antenatal clinic in Gulu hospital is visited Immunizations (UNEPI) scaled-up childhood immunisa- by about 40–60 pregnant women every working day. tions in 20029 incorporated the hepatitis B vaccine into a combination vaccine whose first dose is administered Study population at 6 weeks of age. The 6 weeks window both limits the We included pregnant women attending ANC at the two efficacy of the vaccine in the prevention of vertical trans- study hospitals from September 2012 until January 2013, mission and also allows for the potential transmission of whose gestation age was 28 weeks or more confirmed by HBV through close contacts.7 The most effective clinical history and examination or an obstetric ultra- method of preventing HBV infection is through immun- sound scan. We excluded women who had emergency isation, which offers over 95% protection against the conditions requiring urgent intervention. The two hospi- development of chronic infection.10 Such immunisation tals receive a majority of pregnant women from Gulu should be done at birth for exposed infants. There is no district; however, some women attend ANC in other evidence of protection against perinatal transmission if private facilities in the town and health centres. the first dose of vaccine is given more than 7 days after birth.11 Sample size and sampling method In Nigeria, the prevalence of HBV infection among We used the Kish Leslie formula (1965) and a preva- pregnant women was 11% with an HbeAg positivity of lence of HBsAg of 30% for sample size determination, 33%.12 In northern Uganda, there is limited knowledge to cater for the North-central Uganda prevalence of on the prevalence of hepatitis B infection among preg- about 20%14 and an additional 10% since pregnant nant women. The civil war in this region between the women are engaged in unprotected sex, a known risk government of Uganda and the Lord’s resistance army factor for STIs compared with the general population.17 from the late 1980s up to 2006 led to the displacement To cater for the possible incomplete responses, we of as many as 1.7 million people from their homes into added 10% of the calculated sample size; hence, 402 internally displaced persons camps.13 These camps were participants were recruited. crowded, traditional and social structures were disrupted and sexually transmitted infections (STIs) such as HBV Sampling procedures seemed to have increased. The Uganda HIV serobeha- Women were sampled on two working days a week in the http://bmjopen.bmj.com/ vioural survey of 2004/2005 estimated the prevalence of two study hospitals: Lacor on Wednesdays and Fridays, hepatitis B in northern Uganda to be between 18.4% while in Gulu, sampling was done on Mondays and and 24.3%, much higher than the national average of Thursdays. All eligible pregnant women attending ANC 10%,14 while in a recent community-based study in Gulu on the study days were verbally informed of the study municipality the prevalence of HBV in the general immediately after routine ANC health education. We population was estimated at 17.6%.15 used systematic random sampling, selecting every fifth In this study, we report the prevalence of HBV infec- woman on the ANC waiting line. tion among pregnant women attending antenatal care on September 27, 2021 by guest. Protected copyright. (ANC) at St. Mary’s Hospital Lacor (Lacor) and Gulu Data collection procedures Regional referral Hospital using the HBsAg test. We also At each study site, two midwives were trained for 2 days report HBeAg positivity, a surrogate measure of infectiv- on study procedures, facts on HBV infections and trans- ity among those women who tested positive for HBsAg, missions, counselling, safety issues, sample collection and describe the factors associated with HBV infection and transportation as well as site testing for HBsAg. among these women, with possible implications for On obtaining written informed consents, a question- testing of pregnant mothers, as well as vaccination of naire was administered to every selected woman to HBV-exposed neonates. obtain sociodemographic information including mater- nal age, gestation age, gravidity, occupation, marital status and highest level of education. Other information METHODS on risk factors for transmission of HBV, including a Study design and setting history of previous blood transfusions and a history of This was a cross-sectional study at the Lacor and Gulu scarification, was also obtained.