Seroprevalence and factors associated with hepatitis B infection among the hill tribe adult population in Thailand: a cross-sectional study
BMC INFECTIOUS DISEASES
Authors: Upala, Panupong; Apidechkul, Tawatchai; Tamornpark, Ratipark; Chomchoei, Chalitar; Yeemard, Fartima
Abstract
BackgroundHepatitis B virus (HBV) infection is one of the greatest public health burdens, particularly for people living with several barriers to access to health care services, such as the hill tribe adult population in Thailand. People aged 25years and over who are out of the target population for HBV immunization under the national Expanded Program on Immunization (EPI) are at risk of HBV infection. The study aimed to estimate the prevalence and determine the factors associated with HBV infection among hill tribe adults aged 25years and over living in Chiang Rai Province, Thailand.MethodsA cross-sectional study design was used to collect information on hill tribe adults aged 25years and over living in 36 selected hill tribe villages in Chiang Rai Province. All people living in the selected villages who met the criteria were invited to participate in the study. A validated questionnaire and a 5-mL blood specimen were used as research instruments. Hepatitis B surface antigen (HBsAg), antibody to hepatitis B surface (anti-HBs), and antibody to hepatitis B core (anti-HBc) were detected by using the Wondfo Test Kit(@), which has high sensitivity and specificity. Logistic regression was used to detect the associations between variables at the significance level of alpha =0.05.ResultsA total of 1491 individuals were recruited into the analysis; 60.8% were females, 81.3% were aged between 30 and 60years, and 86.0% were married. The majority were illiterate (54.9%), were Buddhist (55.7%), worked in agricultural sectors (87.3%), and had an annual income of less than 50,000 baht per year (72.9%). The overall prevalence of hepatitis B infection was 26.6%; 7.6% were positive for HBsAg, 19.2% were positive for anti-HBs, and 18.9% were positive for anti-HBc. In the multivariate analysis, three variables were found to be associated with hepatitis B infection: those who were in the Yao and Lisu tribes had a 1.64-fold (95% CI=1.08-2.49) and a 1.93-fold (95% CI=1.10-3.31) greater chance, respectively, of HBV infection than did those in the Karen tribe; those who were Christian had a 1.41-fold (95% CI=1.06-1.87) greater chance of HBV infection than did those who were Buddhist; and those who did not use alcohol had a 1.29-fold (95% CI=1.01-1.65) greater chance of HBV infection than did those who used alcohol.ConclusionsIt is necessary to develop and implement effective public health interventions among hill tribe adult populations who are not part of the EPI-targeted population, particularly Christians, those in the Lisu and Yao tribes, and those who do not use alcohol, to reduce the HBV infection rate, save lives and reduce medical expenses.
Seroprevalence of chronic hepatitis B virus infection and immunity to measles, rubella, tetanus and diphtheria among schoolchildren aged 6-7 years old in the Solomon Islands, 2016
VACCINE
Authors: Breakwell, Lucy; Anga, Jenniffer; Cooley, Gretchen; Ropiti, Laura; Gwyn, Sarah; Wannemuehler, Kathleen; Woodring, Joseph; Ogaoga, Divinal; Martin, Diana; Patel, Minal; Tohme, Rania A.
Abstract
The Western Pacific Region (WPR) established a goal to decrease chronic hepatitis B virus (HBV) infection among children to <1% and to achieve >= 95% hepatitis B vaccine birth dose (HepB-BD) and >= 95% three-dose (HepB3) coverage by 2017. In 2016, we conducted a national serosurvey in the Solomon Islands among 6-7-year-old school children to assess progress towards the control goal and immunity to measles, rubella, tetanus and diphtheria. Eighty schools were selected systematically proportional to their 6-7-year-old population; all 6-7-year-olds were enrolled. We collected basic demographic information and vaccination history. Children were tested for HBV surface antigen (HBsAg) using a rapid test, and for immunity to measles, rubella, tetanus, and diphtheria using a multiplex bead assay. In total, 1,249 out of 1,492 children (84%) were enrolled, among whom 1,169 (94%) underwent HBsAg testing and 1,156 (93%) provided dried blood spots. Almost 80% (n = 982) of enrolled children had vaccination cards, among whom 59% (n = 584) received a timely HepB-BD (within 24 hours of birth), 95% (n = 932) received HepB3, and >90% received vaccines for diphtheria, tetanus, and measles (rubella vaccine was not available at the time). HBsAg prevalence was 3.1% (95% confidence interval (CI): 2.0%-4.9%), with 55% of identified cases from one province. Among 982 children with vaccination cards, HBsAg prevalence was higher among children who had not received a timely HepB-BD and at least two HepB doses compared to those who had (4% vs. 2%). Of 1,156 tested children, immunoprotection estimates were 99% (95% CI: 98%-99%) for measles, 99% (95% CI: 97%-100%) for rubella, 85% (95% CI: 83%-87%) for tetanus, and 51% (95% CI: 47%-55%) for diphtheria. Improving timely HepB-BD coverage and maintaining high HepB3 coverage could help Solomon Islands reach the regional HBV control goal. Low immunity to tetanus and diphtheria suggests the need to introduce booster doses to ensure long-term protection. Published by Elsevier Ltd.