A seroepidemiological survey of the effect of hepatitis B vaccine and hepatitis B and C virus infections among elementary school students in Siem Reap province, Cambodia

Abstract

Aim This study aimed to survey the prevalence and incidence of hepatitis B (HBV) and hepatitis C virus (HCV) infection among elementary school students in Siem Reap province, Cambodia and to evaluate the effects of a national infant HBV vaccination program introduced in 2001. Methods Students in 3rd grade during the 2011, 2012, and 2013 academic years were enrolled in this study; at the time of the second examination, in the 2014–2015 academic year, the students were in 5th or 6th grade. The incidence and prevalence rates of HBV and HCV infection were estimated and full HBV sequences were analyzed. Results Among 248 students (107 male and 141 female) born between 1999 and 2005, five students were HBV surface antigen (HBs‐Ag) positive (2.02%), and all of them were infected with genotype C. Among them, subgenotype C1 was found in four students and, unexpectedly, complete genetic sequence identity of subgenotype C1 was found in two students from different families. The anti‐HBV core (HBc) and anti‐HBs prevalence rates were 10.89% and 16.13%, respectively. Twenty‐five students were positive for anti‐HBs and negative for both HBsAg and anti‐HBc (10.08%; estimated serological vaccination rate); this rate increased significantly with the birth year (P = 0.0229). Prevalence of anti‐HCV was 2.82%, and HCV RNA was not detected. The estimated incidence of HBV and HCV infection were both 0/1000 person‐years (PY) (95% confidence interval, 0–20.61/1000 PY and 0–14.50/1000 PY, respectively). Conclusion Hepatitis B virus full‐genome sequencing and serological analysis revealed the possibility of horizontal transmission of HBV among Cambodian schoolchildren. However, the anti‐HBc positivity rate decreased along with increasing age and estimated serological vaccination rates.

The changing epidemiology of hepatitis B and C infections in Nanoro, rural Burkina Faso: a random sampling survey

“…To detect HBV DNA, nested PCR assays with Applied Biosystems MiniAmp Plus Thermal Cycler (Thermo Fisher Scientific, Tokyo, Japan) were performed using primers obtained from Minegishi K et al work [19]. For viral load assessment, nucleic acid extracts were amplified and measured using a real-time PCR TaqMan Fast Universal PCR Master Mix (2X); Applied Biosystems, StepOne™ (Thermo Fisher Scientific, Tokyo, Japan) with primers and probe from HBV s-region gene [20,21]. Hepatis C virus RNA was also detected using nested PCR amplification with in-house designed primer set from the conserved core region gene.…”

Molecular epidemiology of hepatitis C virus in Cambodia during 2016–2017

“…In Cambodia, a Southeast Asian country, data of HCV prevalence and molecular epidemiology are poorly documented. Previous studies were performed on small sample sizes of specific populations: blood donors 14 , human immunodeficiency virus (HIV) and HCV co-infected adults 15–17 , Cambodian immigrants in foreign countries 18 , and children 19 – and with different age categories 19,20 . Consequently, an accurate prevalence of HCV in general population is unknown.…”

“…Consequently, an accurate prevalence of HCV in general population is unknown. The prevalence of HCV ranges between 2.8% and 14.7% in rural areas depending on study sites 14,19–21 and between 5.5% and 10.4% among people with HIV in hospital-based programs in Phnom Penh, the capital city of Cambodia 15–17 . In terms of HCV genotype, there is a remarkable scarcity of data for this Southeast Asian country, compared to others in the region.…”

Existence of hepatitis B virus surface protein mutations and other variants: demand for hepatitis B infection control in Cambodia

“…For full-length genome sequences, the same primers as of the previously described method were used in this study [16,17]. The amplification was carried out by nested polymerase chain reaction (Nested-PCR) using Prime STAR ® GXL polymerase (Takara Bio Inc., Shiga, Japan) and the primer set A (WA-L and WA-R and inner primers WA-L2 and WA-R2) [16]. For the missing portion of the circular HBV DNA, the extracted DNA was assigned again for the nested PCR using Prime STAR ® GXL polymerase (Takara Bio Inc., Shiga, Japan) and the primer set B (S1, S2, AS1, and AS2).…”