Seroepidemiologic Study of Spermatozoal Transmission of Hepatitis B Virus (HBV)
Condition: Hepatitis B
MeSH terms: Hepatitis A; Hepatitis B; Hepatitis
Study type: Observational

Summary: 
      Animal experiments demonstrated that father might transmit HBV vertically via male germ line,
      however, whether it is really existed in human remains to be determined. Since HBV is a
      blood-borne virus, the unvaccinated pregnant women would be at risk for HBV exposure if their
      fetuses carried the virus from fathers. If women had been vaccinated for HBV before
      conception, what would happen to a maternal immune system if her fetus carried HBV from
      spermatozoa? However, the literature on transmission of HBV by spermatozoa in vivo is rare,
      the viral replicating status and fetal immune response in uterus are unknown. The aim of
      study was to detect father-to-fetus transmission of hepatitis B virus (HBV) in uterus.
    

Detailed description: 
      Transmission of hepatitis B virus (HBV) from mother-to-infant is the predominant route in
      most high prevalence areas such as China. However, father-to-child transmission also plays
      another important role in the prevalence of hepatitis B. Children infected with HBV from
      their carrier fathers would be horizontally by postnatal intimate contact or vertically via
      male germ line. The latter is considered an intrauterine infection, however, whether it is
      really existed in human remains to be determined.

      In past decades, several experiments reported there presences of integrated HBV DNA in human
      spermatozoal chromosomes. Studies on embryos hybridized with mammalian ova and human
      spermatozoa were also confirmed that sperm-integrated HBV DNA can replicate and express the
      HBV protein in two-cell' hybrid embryos. All above findings demonstrated that father might
      transmit HBV to fetus by spermatozoa in theory.

      Since HBV is a blood-borne virus, the unvaccinated pregnant women would be at risk for HBV
      exposure if their fetuses carried the virus from fathers. On other hand, maternal antibodies
      can pass through the placenta and enter the fetal circulation freely. If women had been
      vaccinated for HBV before conception, thus some attractive questions are raised that what
      would happen to a maternal immune system if her fetus carried HBV from spermatozoa? Would the
      fetus be passive immunized by hepatitis B immunoglobulin leaked from maternal circulation?
      However, the literature on transmission of HBV by spermatozoa in vivo is rare, the viral
      replicating status and fetal immune response in uterus are unknown. Only one study had
      detected HBV DNA and serological makers on eight aborted fetuses suspected with HBV
      transmission via spermatozoa, but it is a small sample study and the maternal serological
      status is uncertain.

      Specimens applied for evaluating intrauterine infection include amniotic fluids, placental
      tissue and neonatal peripheral blood. Because postnatal sample is inevitably to be
      contaminated by maternal blood during delivery, it would be useless to determine the time
      when the infection was occurred (before or during the partum). A better alternative is
      detecting fetal infection before the partum by prenatal diagnostic technique. Comparing to
      the postnatal specimens, intrauterine specimens obtained from amniocentesis or cordocentesis
      can minimize the contamination of maternal blood. It is also a safety technique and the risk
      of nosocomial infection caused by invasive procedures is very low. The aim of this study was
      to investigate the fetal hepatitis B seroepidemiology by prenatal diagnostic technique and to
      find the evidence of HBV vertical transmission via spermatozoa.
    

Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        The research consisted of the pregnant women who visited for prenatal diagnosis during the
        January 2008 and June 2010.
      
Biospecimen description: 
      whole blood, serum,amniotic fluid