Hepatitis B chronic infection among pregnant women attending the antenatal care in Bor State Referral Hospital, South Sudan

Author(s): Tereza Ajoh Jok and Shalini Ninan Cherian

Jonglei Health Sciences Institute, Bor, South Sudan 

Correspondence: Shalini Ninan Cherian Email: [email protected] 

Submitted: May 2023 Accepted: July 2023 Published: August 2023

Citation: Jok and Cherian. Hepatitis B chronic infection among pregnant women attending the antenatal clinic in Bor State Referral Hospital. South Sudan Medical Journal 2023;16(3):87-92 © 2023 The Author(s) License: This is an open access article under CC BY-NC DOI: https://dx.doi.org/10.4314/ssmj.v16i3.2 

Abstract

Introduction: Hepatitis B virus (HBV) is a major public health problem affecting 400 million people worldwide, and is a common cause of chronic liver failure (cirrhosis) and hepatocellular carcinoma. Sixty-eight percent of infected people are from the African and Pacific regions. Vertical transmission from mother to newborn baby is one of the mechanisms by which chronic hepatitis virus infection spreads, besides infections from contaminated needles and syringes and sexual contact. Hepatitis B chronic infection is endemic in many poor countries, especially in Africa. 

Method: A cross-sectional study was conducted between July and August 2021. Pregnant women attending the antenatal care (ANC) in Bor State referral hospital, South Sudan, were interviewed to collect information on their socio-demographic characteristics and risk factors for hepatitis B infection. The objective was to determine the seroprevalence of hepatitis B chronic infection through blood testing. Prevalence ratios for certain risk factors were calculated.

Results: Two hundred pregnant women were enrolled. The Prevalence Rate for chronic infection with hepatitis B virus, diagnosed using the rapid immune-chromatographic assay for Hepatitis B surface antigen (HBsAg), was 8.5%. (95% CI; 4.7% - 12.3%). None of the suspected risk factors studied were found to be significantly associated with testing positive for HBV, except for a history of previous jaundice.

Conclusion: The prevalence of HBV chronic infection among pregnant women in Bor, Jonglei State, is high hence there is a need for established public health interventions that can lead to a reduction of HBV vertical transmission. Treatment of pregnant women with HBV chronic infection using anti-viral medications during pregnancy might curb the vertical transmission rates.

Key words: Hepatitis B virus, chronic infection, sero-prevalence, immuno-chromatography, prevalence ratio, South Sudan

INTRODUCTION

Hepatitis B virus (HBV) is a deoxyribonucleic acid (DNA) virus that belongs to the family of Hepadnaviridae that causes acute and chronic diseases of the liver. HBV infection is a dangerous worldwide public health problem, which usually affects the liver and may cause acute hepatitis, fulminant hepatitis, hepatic encephalopathy and chronic conditions like liver cirrhosis and hepatocellular carcinoma (HCC).

HBV can be spread through blood, serum, semen, and vaginal secretions as well as from mother to new born. It also gives rise to a carrier state (chronic infection state) where the asymptomatic person can pass the infection to others.[1] HBV is one of the infections that should be screened for during antenatal check-ups of the mother to reduce the risk of vertical transmission to the infant,[2] a recommendation endorsed by various countries to reduce hepatitis B new infections. The World Health Organization (WHO), in its Global Health sector strategy, suggested a reduction of hepatitis B and C new infections by 90% and hepatitis deaths by 65% by the year 2030.[3]

In 2015, WHO estimated that 257 million persons or 3.5% of the population are living with chronic HBV infection. Of these, 68% are from the African and Pacific regions with 2.7 million people are co-infected with HIV.[3] Vertical transmission from mother to newborn baby is commonly caused by chronic hepatitis virus infection in the expectant mother. This is a great health problem in endemic areas, and especially in Africa where resource allocation for hepatitis screening programmes is limited. 

In the WHO Hepatitis Global Report 2017, most of the infants born to untreated HBV-infected mothers become infected during birth. Hence, one of the most effective ways to reduce vertical transmission is by vaccination of newborns immediately  within 24 hours of life. It has been reported that the risk of getting chronic liver disease is more if the infection is acquired during childhood.[3,4] Furthermore, this report states that those living with HBV infection are persons born before hepatitis B vaccination at birth was available and that the infection was usually due to vertical transmission.

METHOD

The research proposal was approved by Jonglei Health Sciences Institute Research Ethics Board. A cross-sectional design was used to determine the sero-prevalence of HBV infection among pregnant women who were attending the antenatal care (ANC) in Bor State Referral Hospital (BSRH) using a one-time rapid immune-chromatographic assay for hepatitis B surface antigen (HBsAg).

The objectives were to determine the number of women who will require treatment during pregnancy and the number of newborns who will require birth-dose of hepatitis B vaccine to prevent vertical transmission, and to find the most common risk factors associated with sero-positivity for HBV chronic infection.

BSRH is a public hospital in Jonglei State and is one of the two teaching hospitals in greater Jonglei. It is the main referral centre in the state with 11 counties and a population of more than one million. It receives patients from the neighbouring Lake State, Pibor Administrative Area and a few foreigners. The hospital handles an average of 1,000 deliveries per year and, in the antenatal clinic, an average of 30 women are seen daily from Monday to Friday.

The study population was all pregnant women attending the ANC at BSRH. Starting 1st July 2021, all mothers who came for antenatal booking were counselled for hepatitis B screening in addition to the routine screening. Those who gave consent to be a part of the study were recruited.

The sample size was determined from data available in the country in 2021 that found that the sero-prevalence of HBV infection among pregnant women was 11%.[5] The sample size of 200 women was chosen to determine the prevalence of hepatitis B in pregnant women with a possible 5% error and a CI of 95%. So, the first two hundred pregnant women who consented were screened for hepatitis B using an immunochromatographic test to detect the presence of hepatitis B surface antigen. The required sample size was reached on 31st August 2021.

The study outcome was seropositivity using immunochromatographic testing, and the independent variables were potential risk factors for HBV infection, determined by administering a structured questionnaire during face-to-face interview of the women.

The data were entered into an Excel spreadsheet and analysed using SPSS.

RESULTS

Table 1 gives the socio-demographic characteristics of the 200 women interviewed.

Table 1. Socio-demographic characteristics of the women (N = 200)

 

 

Frequency

n (%)

Age (years)

15-19 years

52 (26.0

20-24 years

68 (34.0)

25-29 years

44 (22.0)

30-34 years

30 (15.0)

35-39 years

6 (3.0)

Education

Illiterate

81 (40.5)

 

Primary

77 (38.5)

Secondary

36 (18.0)

College and more

6 (3.0)

Occupation

Housewife

166 (83.0)

Daily labourer

17 (8.5)

Salaried

16 (8.0)

Students

1 (0.5)

Residence

Urban

136 (68.0)

Rural

64 (32.0)

Marital status

Married

185 (92.5)

Single

0 (0.0)

Divorced

2 (1.0)

Widowed

13 (6.5)

Parity

Nullipara

56 (28.0)

1-2

39 (19.5)

3-4

44 (22.0)

4-5

25 (12.5)

>5

36 (18.0)

Gestation age

1-12 weeks

36 (18.0)

13-28 weeks

126 (63.0)

29-delivery

38 (19.0)

HBV was positive in 17 out of 200 pregnant women indicating a prevalence of 8.5% (95% CI: 4.7% - 12.3%).

Risk factors for HBV infection

Although the sample size was not large enough to produce reliable statistically significant results, nine potential risk factors for acquiring hepatitis B infection were investigated using relative risk or prevalence ratio (PR). They were (see Table 2):

  • Previous delivery by a traditional birth attendant (TBA).
  • Previous surgical procedure.
  • Ear piercing or any other piercing. 
  • Prior dental procedures.
  • Blood transfusions.
  • Having multiple sexual partners.
  • Family member with hepatitis B.
  • History of jaundice.
  • Currently positive for HIV.

Table 2. Potential risk factors related to sero-positivity for hepatitis B surface antigen

Risk factor

Hep B +ve

n

Hep B -ve

n

Total

n

PR (CI)

p-value

History of previous delivery by TBA

Yes

9

87

96

0.90 (0.32, 2.54)

0.842

No

5

43

48

History of previous surgery

Yes

1

13

14

0.83 (0.12, 5.81)

0.851

No

16

170

186

History of ear piercing

Yes

17

183

200

 

 

No

0

0

0

History of dental procedure

Yes

10

83

93

1.64 (0.65, 4.15)

0.292

No

7

100

107

History of blood transfusion

Yes

3

11

14

2.85 (0.93, 8.75)

0.068

No

14

172

186

History of multiple partners

Yes

2

16

18

1.35 (0.33, 5.43)

0.674

No

15

167

182

History of family member having Hep B

Yes

5

33

38

1.78 (0.67, 4.74)

0.251

No

12

150

162

History of jaundice

Yes

9

53

62

2.50 (1.01, 6.18)

0.047

No

8

130

138

Currently tested + for HIV

Yes

1

4

5

2.44 (0.40, 14.97)

0.336

No

16

179

195

The analysis compared exposed persons (persons with risk factors) who had the disease (developed hepatitis B) with the proportion of non-exposed (those with no risk factors) who did not have the disease (did not developed hepatitis B). The PR is the prevalence of the disease in the exposed over the prevalence of the disease in the unexposed. Values of PR greater than one indicate an increased risk, less than one, a reduced risk. 

All the potential factors in Table 2 show PRs for hepatitis B infection above one, except body piercings, for which PR could not be calculated, and previous delivery by TBA, which had a PR just below one.

Statistical tests of association between the risk factors and hepatitis B

Table 2 also shows confidence intervals and p-values for the PRs. Only prior history of jaundice was a statistically significant risk factor for chronic hepatitis B infection. 

Women were asked about their willingness to prevent the child from getting hepatitis B infection - Table 3.

Table 3. Willingness to protect child from acquiring hepatitis B infection

Willingness to protect child

Frequency

n (%)

No

10 (5.0)

Yes, if free

20 (10.0)

Yes, if less than 500SSP

15 (7.5)

Yes, if 500-1,000SSP

3 (1.5)

Yes, if >10,000SSP

2 (1.0)

Whatever the cost

150 (75.0)

SSP = South Sudanese pounds. 1 USD=600SSP.

Seventy five percent of mothers were willing to spend any amount to prevent their children from acquiring hepatitis B. While 5% were not concerned if hepatitis B were passed on to their children or not, 10% were willing to take treatment to prevent transmission only if it was free. The remaining were willing to prevent the transmission only if it was affordable to them.

DISCUSSION

1. Prevalence of hepatitis B chronic infection among pregnant mothers

The overall prevalence rate of HBV chronic infections, as diagnosed by the presence of HBsAg, among pregnant women in this study was 8.5%. The global epidemiology of HBV infection has traditionally been described according to three categories of endemicity—high, intermediate, and low—depending on the proportion of the population that is seropositive for HBsAg. Countries with high endemicity are those where HBsAg seroprevalence is greater than or equal to 8%; countries with intermediate endemicity are those where seroprevalence is 2–7%; and those with low endemicity are those where seroprevalence is less than 2%. 

Pregnant women are a good representation of a population hence according to this study the urban population of Bor town can be classified as an area of high endemicity for hepatitis B. Our prevalence of 8.5% is the same as among pregnant women in South Darfur State, Sudan, that was reported in a study in 2018-2019.[6] Low prevalence in pregnant women has been reported in Libya, 1.5%,[7] while in Rwanda a study reported 3.7%,[8] a low intermediate prevalence rate.[9] The highest prevalences reported were from north Uganda, 11.8%,[10] and Juba, South Sudan, 11% in 2017.[11]

From this study and the standard rate of vertical transmission from other publications,[12,13] we conclude that, in a population of 200 pregnant women with prevalence rate of 8.5% of chronic hepatitis B infection, eight infants  are likely to be infected with HBV because of the absence of a strategy to prevent vertical transmission.

2. Risk factors associated with acquiring chronic hepatitis B infection

We did not find a significant relationship between mother’s history of ear piercing and positive HBsAg using PR (100%). This is consistent with a similar study conducted in South Darfur state, Sudan[6] in 2019 but was in contrast with the study conducted in Uganda in 2019.[14] In the current study, pregnant women who had a home delivery by traditional birth attendants (TBAs) had a slight, but non-significant, decrease in HBV infection risk, in contrast to studies done in Northwest Ethiopia[15] which showed a significant increased risk and also found that dental procedures, multiple sexual partners and household contact were predictors of HBV infection. 

The association between having multiple sexual partners and HBV infection was also recorded in Ethiopia,[16] Kenya,[17] Nigeria[18] and another study from Ethiopia.[19] In our study, none of these risk factors were found to be statistically significant probably because of our small sample size.

Our choice of potential risk factors was driven mainly by knowledge of the ways that hepatitis B chronic infection is acquired.

Acute adult hepatitis is commonly due to hepatitis A virus. Acute hepatitis due to HBV is symptomatic with icterus/jaundice in one third of patients. Acute adult hepatitis (acquired by sexual practices or needle sharing) is less likely to lead to chronic infection when compared to childhood or perinatal acquisition of the virus. 

Acute hepatitis B infection going on to become chronic infection depends of the patient’s immunosuppression state, and on indicators of rapid viral replication as indicated by presence of Hep-e-antigen and Hepatitis B DNA activity.[23] 

CONCLUSION

With the Sustainable Developmental Goals and Global Health Sector Strategy including hepatitis B as one of the diseases to be targeted for eradication, there is a need to have a multipronged approach that includes wide spread vaccination and minimizing vertical transmission which is often neglected especially in the African region. 

Screening all pregnant mothers for HBV chronic infection [20] and either providing the newborn infants with a birth dose of hepatitis B vaccine or providing anti-viral medications[21] or both[22] to all seropositive women should become part of a public health initiative in South Sudan. 

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