Hepatitis B in Senegal: A Successful Infant Vaccination Program but Urgent Need to Scale Up Screening and Treatment (ANRS 12356 AmBASS survey)

Abstract

Senegal introduced the infant hepatitis B virus (HBV) vaccination in 2004 and recently committed to eliminating hepatitis B by 2030. Updated epidemiological data are needed to provide information on the progress being made and to develop new interventions. We estimated the prevalence of hepatitis B surface antigen (HBsAg) in children and adults living in rural Senegal and assessed hepatitis B treatment eligibility. A cross‐sectional population‐based serosurvey of HBsAg was conducted in 2018‐2019 in a large sample (n = 3,118) of residents living in the Niakhar area (Fatick region, Senegal). Individuals positive for HBsAg subsequently underwent clinical and biological assessments. Data were weighted for age and sex and calibrated to be representative of the area’s population. Among the 3,118 participants, 206 were HBsAg positive (prevalence, 6.9%; 95% confidence interval [CI], 5.6‐8.1). Prevalence varied markedly according to age group in individuals aged 0‐4, 5‐14, 15‐34, and ≥35 years as follows: 0.0% (95% CI, 0.00‐0.01); 1.5% (95% CI, 0.0‐2.3); 12.4% (95% CI, 9.1‐15.6); and 8.8% (95% CI, 6.1‐11.5), respectively. Of those subsequently assessed, 50.9% (95% CI, 41.8‐60.0) had active HBV infection; 4 (2.9%; 95% CI, 0.9‐9.4) were eligible for hepatitis B treatment. Conclusion: In this first population‐based serosurvey targeting children and adults in rural Senegal, HBsAg prevalence was very low in the former, meeting the World Health Organization’s (WHO) < 1% HBsAg 2020 target; however, it was high in young adults (15‐34 years old) born before the HBV vaccine was introduced in 2004. To reach national and WHO hepatitis elimination goals, general population testing (particularly for adolescents and young adults), care, and treatment scale‐up need to be implemented.

Prevalence and geo-clinicodemographic factors associated with hepatitis B vaccination among healthcare workers in five developing countries

“…A combined hepatitis B vaccine given at 6, 10, and 14 weeks of age as part of National Immunization Schedule were introduced in Nepal, Senegal, Malawi, Afghanistan, and Haiti in 2002 [31,32], 2002 [33], 2004 [34], 2006 [35], and 2012 [36,37] respectively. However, the birth dose was introduced only in 2014 in Afghanistan [35], while Senegal introduced the monovalent birth-dose vaccine in 2016 [34]. Yet, the Senegalese government lacks vaccination programme for high risk population such as HCWs [31,32].…”

Applying the health capability profile to empirically study chronic hepatitis B in rural Senegal: a social justice mixed-methods study protocol

“…In total 3118 participants representative of the Niakhar HDSS population were recruited, among which 1505 were born before September 2003 (hereafter adults), and 206 tested positive for CHB (a 7.1% CHB prevalence in the general population; 12.6% in the adult population). 52 …”

“… 12 Nowadays, liver disease secondary to viral hepatitis remains one of the leading cause of cancer, 13 particularly among adult Senegalese men and women who were born before the successful implementation of the vaccination programme. 14 …”

Predicting health services utilization using a score of perceived barriers to medical care: evidence from rural Senegal

“…The score was computed with con rmatory factor analysis [33] in the dataset of the ANRS12356 AmBASS survey, which was conducted in the Niakhar HDSS in 2018-2019 and featured a sample representative of the general population living in the area [34,35].…”