Sexual activity and hepatitis B and C virus infection among young adults after introduction of a vaccination program in an area of high endemicity.
BACKGROUND
In areas where hepatitis is endemic, little is known about the sexual transmission of HBV after introduction of an HBV vaccination program.


METHODS
We used a self-administered questionnaire and serological tests for HBsAg, anti-HBs, anti-HBc, and anti-HCV to examine the role of sexual activity, as well as sociodemographic status, lifestyle habits, and a history of vaccinations, transfusions, and surgery, in the transmission of HBV and HCV in Korea. The subjects were 865 female and 541 male university students (median age, 19 years; age range, 16-25).


RESULTS
Overall seropositivity was 8.1% for HBsAg, 69.3% for anti-HBs, 21.3% for anti-HBc, and 0.4% for anti-HCV. Regarding HBV, 8% of the subjects were chronic carriers or had recently been infected, 22.8% were never exposed and nonvaccinated, 16.6% were exposed noncarriers, and 52.7% had most likely been vaccinated. We found a significant association between HBsAg seropositivity and history of sexual intercourse (Odds Ratio, 1.8; 95% CI, 1.1-2.8). Students without serologic evidence of immunization against HBV were more likely to have become HBsAg-positive after becoming sexually active.


CONCLUSIONS
Our findings suggest that sexual transmission does occur among adolescents and young adults who have not been vaccinated, whereas vaccination protects individuals from becoming an HBV carrier after becoming sexually active.
Lim
Min Kyung
MK
National Cancer Control Research Institute, National Cancer Center, Goyang, Republic of Korea.
Franceschi
Silvia
S
Vaccarella
Salvatore
S
Ju
Young-Hee
YH
Oh
Jin-Kyoung
JK
Kong
Hyun-Joo
HJ
Kim
Dong-Il
DI
Kim
Byoung-Gwon
BG
Kim
Jung-Il
JI
Jung
Kap-Yeol
KY
Lee
Dong-Soon
DS
Shin
Hai-Rim
HR
D000293:Adolescent; D005260:Female; D006509:Hepatitis B / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission*; D006510:Hepatitis B Antibodies / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000097:blood; D006526:Hepatitis C / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission*; D006801:Humans; D007723:Korea / Q000453:epidemiology; D008019:Life Style; D008297:Male; D032541:Mass Vaccination; D012725:Sexual Behavior / Q000706:statistics & numerical data*; D015229:Sexually Transmitted Diseases, Viral / Q000453:epidemiology; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D014761:Viral Hepatitis Vaccines; D055815:Young Adult
D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D014761:Viral Hepatitis Vaccines