预防乙型肝炎病毒母婴传播的随机对照研究

目的探讨乙肝免疫球蛋白（HBIG）预防乙型肝炎病毒（HBV）母婴垂直传播的效果。方法以2001年1月至2005年5月在台州医院产科初次进行妊娠健康检查,HBsAg测定阳性或HBsAg、HBeAg均阳性孕妇作为研究对象,共279例。将单纯HBsAg阳性孕妇与HBsAg、HBeAg双阳性孕妇分别应用随机数表方法随机分组,分别为单阳注射组（n=80）、单阳对照组（n=60）、双阳注射组（n=79）、双阳对照组（n=60）。单阳注射组、双阳注射组于妊娠加周开始肌肉注射HBIG 200U,每4周注射1次,直至临产。两对照组不注射HBIG。4组孕妇所产婴儿,除常规接种乙肝疫苗外,均于出生后16h内和2周肌肉注射HBIG。然后随访并测定婴儿HBsAg。结果单阳注射组、单阳对照组、双阳注射组、双阳对照组所生婴儿HBsAg感染率分别为3％、13％、10％、32％。单阳注射组与单阳对照组之间（x^2=6．07,P〈0．05）,以及双阳注射组与双阳对照组之间婴儿HBsAg感染率（x^2=10．11,P〈0．01）均有统计学意义,注射HBIG组,对单纯HBsAg阳性孕妇及HBsAg、HBeAg双阳性孕妇,出生婴儿HBsAg感染率均显著低于对照组;单阳注射组与双阳注射组之间婴儿HBsAg感染率差异亦有统计学意义,说明HBIG对单纯HBsAg阳性孕妇预防效果优于HBsAg、HBeAg双阳性孕妇。结论HBIG能有效预防母婴传播,降低HBV感染率。因此,妊娠妇女应及时进行健康检查,发现HBV感染阳性,及时采取注射HBIG等有效措施,以促进优生优育。     

乙型肝炎高危儿免疫预防效果及乙肝病毒母婴传播影响因素分析

目的 分析乙型肝炎病毒(HBV)母婴传播影响因素及乙肝高危儿免疫预防的效果,为儿童乙肝防治提供科学依据。方法 回顾性调查539例HBsAg阳性产妇及其6个月至5岁的乙肝高危儿551例,并检测乙肝高危儿的乙肝标志物,分析乙肝病毒母婴传播的影响因素。结果 乙肝疫苗接种率为100%,96.6%联合注射了乙肝疫苗和乙肝免疫球蛋白(HBIG)。各年龄段乙肝高危儿的HBsAg阳性率差异无统计学意义;HBsAb阳性率随年龄增长逐步下降 (P<0.01)。高危儿母亲为HBsAg、HBeAg双阳性者较单纯HBsAg阳性的乙肝感染率高 (15.1% vs 0.2%,P<0.01)。单纯接种乙肝疫苗的高危儿乙肝感染率 (28.6%)高于联合免疫注射者 (2.8%),P<0.01。结论 乙肝高危儿HBsAb阳性率随年龄增高逐渐下降。母亲HBsAg、HBeAg双阳性和出生未联合免疫注射是乙肝病毒母婴传播的危险因素。     

Combined Passive and Active Immunization for Preventing Perinatal Transmission of Hepatitis B Virus Carrier State

With the intravenous and intramuscular injection of HBIG followed by repeated vaccinations, of 223 infants born to HBeAg-positive HBV carrier mothers, 215 infants were prevented from developing HBV carrier state during a follow-up period of longer than 12 months. The protective efficacy rate was 95.6%. During this study, four infants developed HBs antigenemia before the completion of the immunoprophylaxis schedule, and five after the completion of the schedule. Possible preventive methods for these infants for the ultimate prevention of persistent HBV infection are discussed.     

Role of hepatitis B immunoglobulin in infants born to hepatitis B e antigen-negative carrier mothers in Taiwan

BACKGROUND: The efficacy of hepatitis B immunoglobulin (HBIG) in infants of hepatitis B e antigen (HBeAg)-negative hepatitis B surface antigen (HBsAg) carrier mothers in Taiwan is not clear. OBJECTIVE: To describe the responses of infants born to HBeAg-negative carrier mothers receiving HBIG combined with hepatitis B vaccine. METHODS: Term babies born to HBeAg-negative carrier mothers were assigned based on chart number to 1 of the 2 treatment groups. Group A infants (n = 94) received 0.5 ml (145 IU) of HBIG within 24 h of birth and 3 subsequent doses of recombinant hepatitis B virus (HBV) vaccine at 3 to 5 days, 1 month and 6 months of age. Group B infants (n = 122) received 3 doses of vaccines only. Infants (n = 19) born to HBeAg-positive carrier mothers were treated like those in Group A and are referred to as Group C. Sera obtained from infants at 2 and 7 months of age were tested for hepatitis B virus (HBV) markers. RESULTS: There were 2 (1%; one in Group A and one in Group B) subclinical breakthrough hepatitis B infections among studied infants. One (5%) child of Group C had asymptomatic HBV infection at the age of 7 months and became a chronic carrier. The rate of protective anti-hepatitis B surface antibody (anti-HBs) titers achieved (>10 mIU/ml) by 2 months of age was significantly higher in Group A than that in Group B (98% vs. 57%, P < 0.001). However, it was not different by 7 months of age. Infants (Group A) immunized with HBIG and vaccine had a significantly higher geometric mean titer (GMT, milli-International Units/ml) of anti-HBs than those (Group B) with vaccines only at 2 months of age (P < 0.001). Conversely at 7 months of age, the GMT of anti-HBs was significantly higher in infants who received vaccine only (P = 0.001). CONCLUSIONS: A protective level of antibodies was achieved earlier in those infants receiving both passive and active immunizations. However, infants receiving active immunizations alone achieved a higher GMT at 7 months of age. There was no clear benefit of passive-active vs.active immunization alone for chronic HBV infection in infants of HBsAg-positive, HBeAg-negative mothers.     

Combined immunoprophylaxis in the prevention of perinatal transmission of hepatitis B and hepatitis D virus infections in Saudi children.

The efficacy of the combined immunoprophylaxis approach (passive plus active immunization) was evaluated in babies born to 52 HBsAg-carrier Saudi mothers, of whom seven (13.5%) were HBeAg-positive and seven were anti-HDV-positive. Newborns were given 100 IU of hepatitis B immune globulin (HBIG) from the Hepuman Berna-Swiss Serum and Vaccine Institute, Berne, and hepatitis B vaccine (5 micrograms) within 12 hours of birth, and the vaccine was given again at 1 and 6 months of age (5 micrograms/injection). After 18 months of follow-up, all but one baby had protective levels of antibody to HBsAg and none of the babies born to anti-HDV-positive carrier mothers showed evidence of HDV infection. These results show that the combined immunoprophylaxis approach is quite successful in protecting against perinatal transmission of HBV and HDV in the Saudi population. Furthermore, early vaccination against HBV will also protect against HDV infection later in life.     

National Project on the Prevention of Mother-to-Infant Infection by Hepatitis B Virus in Japan

In Japan, a nationwide prevention program against mother-to-infant infection by hepatitis B virus (HBV) started in 1985. This program consists of double screenings of pregnant women and prophylactic treatment to the infants born to both hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) positive mothers. These infants are treated with two injections of hepatitis B immune globulin (HBIG) and at least three injections of plasma derived hepatitis B vaccine. We sent questionnaires about the numbers of each procedure or examination during nine months of investigation period to each local government in 1986 and 1987. 93.4% pregnant women had the chance to be examined for HBsAg, and the positive rate was 1.4 to 1.5%. The HBeAg positive rate in HBsAg positive was 23 to 26%. The HBsAg positive rate in neonates and in infants before two months were 3% and 2% respectively. Some problems may arise, because 27 to 30% of infants need the fourth vaccination in some restricted areas.     

Prevention of perinatal transmission of the hepatitis B virus. Outcome of infants in a community prevention program.

OBJECTIVE. To assess the outcome of infants born to hepatitis B surface antigen (HBsAg)-positive mothers who received prenatal and infant care in a large, public health care system. DESIGN. Follow-up of a cohort of infants born to HBsAg-positive mothers. SETTING. Large, urban hospital providing prenatal care and obstetric services to county health departments. PARTICIPANTS. Forty-two infants born to HBsAg-positive women. INTERVENTIONS. Prenatal testing of women and immunoprophylaxis of infants with hepatitis B immune globulin at birth and hepatitis B vaccine at birth and ages 1 and 6 months. RESULTS. All 42 infants received hepatitis B immune globulin and the first dose of vaccine. Of forty-one infants (98%) who received the second dose of vaccine, 37 received it by age 4 months. Thirty-two infants (76%) completed the three-dose vaccine series by age 12 months, and 34 infants (81%) completed the series by age 18 months. The rate of completion of the hepatitis B vaccine series was comparable to that of infants receiving the third dose of diphtheria-pertussis-tetanus vaccine. Of 26 infants who completed the hepatitis B vaccine series and had follow-up serologic testing, 24 (92%) had adequate levels of antibody to HBsAg. Only one infant who did not complete the vaccine series had serologic evidence of hepatitis B virus infection. No infant was HBsAg-positive. CONCLUSIONS. Public programs serving urban populations can effectively deliver hepatitis B immunoprophylaxis to infants born to HBsAg-positive mothers.     

Antibody response to postexposure prophylaxis in infants born to hepatitis B surface antigen-positive women

BACKGROUND: Annually 20,000 infants are born to hepatitis B surface antigen (HBsAg)-positive US women. Without prophylaxis 30% risk chronic hepatitis B virus infection, and 25% of those risk dying from resulting liver cirrhosis or liver cancer as adults. METHODS: We attempted to interview each HBsAg-positive pregnant woman reported to the health department between 1992 and 1997, to provide their infants with immunoprophylaxis at birth and in the clinic or home and to serotest at 9 to 15 months of age. RESULTS: Of 879 women reported, 92% enrolled; 787 delivered 796 live infants; 91% of infants received hepatitis B immunoglobulin; 98, 95 and 89% received hepatitis B vaccine (HepB) Doses 1, 2 and 3, respectively; and 80% were serotested. Of these 2.2% were HBsAg-positive and 97% had antibody to HBsAg (anti-HBs) of > or =10 mIU/ml. Anti-HBs concentrations measured in 504 infants were 10 to 99 mIU/ml (25%), 100 to 999 mIU/ml (43%) and > or =1000 mIU/ml (29%). Serotesting was less likely among infants of mothers <20 years of age [odds ratio (OR) 2.5]; white, non-Hispanic (OR 2.8); or with a household income of <$15,000/year (OR 2.0). Lower antibody titers were found when serotesting at 4 to 12 months than at <4 months after HepB-3 (OR 1.8 to 4.4), with HepB-3 receipt <6 months after HepB-2 (OR 2.5) and when household income was <$15,000/year (OR 2.1). CONCLUSIONS: Centralized case management with home visits resulted in high rates of complete immunoprophylaxis and postvaccination testing among infants born to HBsAg-positive women. Perinatal immunoprophylaxis was immunogenic under routine public health use, with higher anti-HBs titers occurring in infants tested <4 months postvaccination. Because infants in households with low income had higher rates of nonprotective antibody responses, they may benefit from extra efforts to ensure that serotesting is conducted postvaccination.     

Hepatitis B virus infection

Hepatitis B virus (HBV) infection is a worldwide health problem and may cause acute, fulminant, chronic hepatitis, liver cirrhosis, or hepatocelullar carcinoma (HCC). Infection with HBV in infancy or early childhood may lead to a high rate of persistent infection (25-90%), while the rates are lower if infection occurs during adulthood (5-10%). In most endemic areas, infection occurs mainly during early childhood and mother-to-infant transmission accounts for approximately 50% of the chronic infection cases. Hepatitis B during pregnancy does not increase maternal mortality or morbidity or the risk of fetal complications. Approximately 90% of the infants of HBsAg carrier mothers with positive hepatitis B e-antigen (HBeAg) will become carriers if no immunoprophylaxis is given. Transplacental HBeAg may induce a specific non-responsiveness of helper T cells and HBcAg. Spontaneous HBeAg seroconversion to anti-HBe may develop with time but liver damage may occur during the process of the immune clearance of HBV and HBeAg. Mother-to-infant transmission of HBV from HBeAg negative but HBsAg positive mothers is the most important cause of acute or fulminant hepatitis B in infancy. Although antiviral agents are available to treat and avoid the complications of chronic hepatitis B, prevention of HBV infection is the best way for control. Screening for maternal HBsAg with/without HBeAg, followed by three to four doses of HBV vaccine in infancy and hepatitis B immunoglobulin (HBIG) within 24h of birth is the most effective way to prevent HBV infection. In areas with a low prevalence of HBV infection or with limited resources, omitting maternal screening but giving three doses of HBV vaccine universally in infancy can also produce good protective efficacy. The first universal HBV immunisation programme in the world was launched in Taiwan 22 years ago. HBV infection rates, chronicity rates, incidence of HCC and incidence of fulminant hepatitis in children have been effectively reduced.     

Horizontal transmission of hepatitis B virus infection to United States-born children of Hmong refugees.

There is evidence that hepatitis B virus (HBV) transmission continues among Southeast Asian refugees after resettlement. To determine the prevalence of HBV infection (hepatitis B surface antigen [HBsAg] positive or core antibody positive) and modes of transmission in Hmong refugee households in Wisconsin, results of serologic tests were reviewed for 429 US-born children not previously vaccinated with hepatitis B vaccine and 754 of their Asian-born household members. The prevalence of HBV infection was 14% (62/429) among all US-born children, 30% (21/69) among children whose mothers were HBsAg-positive, and 11% (41/360) among children whose mothers were HBsAg-negative. Among children whose mothers were HBsAg-negative, the prevalence of HBV infection increased with increasing age (chi 2 test for trend = 5.6, P = .02) and was related to the household presence of HBsAg-positive sibling(s) (relative risk = 4.0; 95% confidence interval = 1.5, 9.3; P less than .001). Of the 62 infected children, 13 (21%) lived in households with no HBsAg-positive household members. US-born children of Hmong refugees apparently acquire HBV infection through both horizontal and perinatal transmission. These findings emphasize the importance of routinely integrating hepatitis B vaccine doses into the childhood vaccination schedule for all infants whose parents are from areas where HBV infection is highly endemic. In addition, the findings support the need for pediatricians to consider vaccinating older children (up to age 7 years) whose parents are from HBV-endemic areas.     

�и���ǰ����������������������͸��׻�����������Ч����ϵ���о�

目的探讨采用乙型肝炎免疫球蛋白(HBIG)阻断孕妇乙型肝炎病毒(HBV)感染对新生儿乙型肝炎(简称乙肝)基因疫苗免疫效果的影响。方法对55例HBV标志物阳性孕妇于产前28周、32周和36周分别给予HBIG200IU免疫阻断作为阻断组;31例HBV标志物阳性孕妇未给予HBIG免疫阻断作为未阻断组;同期选择HBV标志物阴性孕妇42例作为对照组。对三组新生儿分别给予乙肝基因疫苗的免疫接种,并分别于1个月、2个月、7个月和12个月龄采集外周血检测HBV标志物及丙氨酸转氨酶(ALT)。结果阻断组、未阻断组和对照组新生儿免疫保护率分别为87.3%(48/55)、77.4%(24/31)和97.6%(41/42);未阻断组与对照组间比较具有统计学意义(P<0.01);对“大三阳”孕妇的阻断效果最好,新生儿抗HBs阳转率从33.3%上升到71.4%。结论对HBV感染孕妇采用HBIG免疫阻断,可以降低宫内感染及母婴传播的发生率;分娩时孕妇HBV感染状态对新生儿抗HBs阳转率可能产生一定程度的影响。     

Lack of evidence for transplacental transmission of HBV infection by HBsAg-carrier mothers

The possibility of transplacental transmission of HBV infection was investigated in 54 HBsAg-carrier Saudi mothers and their newborns. Controls were 60 Saudi mothers with previous exposure to HBV, and their newborns. Thirteen cord blood samples were HBsAg-positive by ELISA, including three from mothers with previous exposure to HBV, compared with one sample which was HBsAg- and HBeAg-positive and three samples which were only HBeAg-positive. Eight of the 13 cord blood samples which were HBsAg-positive by ELISA were haemolysed sera and were found to be HBsAg-negative by RIA and RPHA. None of the infants' sera, taken within 1-4 days of delivery, was positive for HBsAg or IgM anti-HBc. These results indicate that HBV markers in cord blood are either false-positive or due to contamination by maternal blood rather than an indication of in utero infection.     

Prospective study of mother-to-infant transmission of hepatitis C virus

BACKGROUND: Mother-to-infant transmission of hepatitis C virus (HCV) could become the main route of HCV infection in the future because there are no methods available to prevent vertical infection. The aim of this study was to determine the incidence of mother-to-infant transmission in infants born to mothers who tested positive for anti-HCV antibodies and to elucidate associated risk factors for transmission. METHODS: Screening was conducted for 16,800 pregnant women with an anti-HCV antibodies test, and 154 mothers were positive. From the positive group 141 mothers were enrolled in the study and their 147 infants were followed from birth for serum alanine aminotransferase activity, anti-HCV antibodies and HCV RNA. HIV infection was tested in 73 of 141 mothers, all of whom were negative. RESULTS: Thirty-three infants were dropped from the study because they were followed for <6 months or were not tested adequately. Of the 114 infants finally evaluated 9 (7.8%) had detectable HCV RNA. The transmission rate was not influenced by the mode of delivery [vaginal delivery, 8 of 90 vs. cesarean section, 1 of 24 (P = 0.396)] or by the type of feeding [9 of 98 for breast-fed infants vs. 0 of 16 for formula-fed infants (P = 0.243)]. All infected infants were born to mothers who had HCV viremia at the delivery (P = 0.040) and to those with a high viral load (P = 0.019). CONCLUSIONS: Our prospective study showed that the transmission rate of mother-to-infant HCV infection was 7.8% in anti-HCV antibody-positive mothers. Risk was related to the presence of maternal HCV viremia at delivery and a high viral load in the mothers.     

乙型肝炎病毒母婴传播影响因素探讨

目的：探讨乙型肝炎病毒(HBV)母婴传播的影响因素,寻求降低婴儿HBV感染率的方法。方法：HBV携带及慢性乙型肝炎孕妇共635例,分别比较不同血HBV DNA滴度,不同分娩方式（剖宫产或自然分娩）,以及不同肝功能状态孕妇所生婴儿出生时及3月龄时HBV的感染率。新生儿生后12 h内肌注乙肝免疫球蛋白200 U 及重组酵母乙肝疫苗10 μg;生后即刻显示血清HBV感染存在者,14 d时再肌注乙肝免疫球蛋白200 U。结果：孕妇高滴度组（HBV DNA>105拷贝/mL）所生新生儿出生时（14.4% vs 4.1%,P<0.01）与3月龄时（4.7% vs 0,P<0.01）HBV感染率均高于低滴度组（HBV DNA ≤105拷贝/mL）。两组新生儿3月龄时HBV感染率均低于出生时（P<0.05）。自然分娩的孕妇其婴儿出生时HBV感染率明显高于剖宫产组（P<0.01）,但3月龄时,两组感染率接近。HBV携带孕妇所生婴儿出生时HBV感染率明显高于慢性乙型肝炎孕妇所生婴儿（P<0.01）,但3月龄时两组婴儿HBV感染率亦接近。结论：孕妇血清HBV DNA水平与新生儿HBV宫内感染密切相关,故降低孕妇血清HBV DNA水平可能成为减少新生儿HBV感染的一种有效途径。在乙肝免疫球蛋白及重组酵母乙肝疫苗的双重保护下,孕妇的分娩方式与肝功能状态对HBV母婴传播无影响。     

Factors associated with immunoprophylaxis failure against vertical transmission of hepatitis B virus

In spite of adequate immunoprophylaxis, perinatal transmission of hepatitis B virus (HBV) has not been completely eliminated. This study evaluated the factors associated with the failure of HBV immunoprophylaxis. The study participants were 144 children who were born to HBsAg-seropositive mothers of known HBeAg status and they had received HB immune globulin and HB vaccine within 24 hours after birth followed by two further administrations of HB vaccine as recommended. Seventeen of the children (11.8%) suffered immunoprophylaxis failure, defined by HBsAg-seropositivity. The rate of HBV immunoprophylaxis failure was 12%, 0%, 21%, 0%, and 27% among the children born to HBsAg-seropositive, HBeAg-seronegative, HBeAg-seropositive, undetectable HBV DNA, and detectable HBV DNA mothers, respectively. The failure of HBV immunoprophylaxis was significantly associated with maternal HBeAg-seropositivity and HBV DNA seropositivity. To identify those children at high risk of HBV immunoprophylaxis failure, maternal HBeAg and HBV DNA need to be assessed prior to childbirth.     

Prevention of perinatal acquisition of hepatitis B virus carriage using vaccine: preliminary report of a randomized, double-blind placebo-controlled and comparative trial

Hepatitis B is a serious disease of global significance. In developing countries, hepatitis B virus (HBV) infection and its sequelae rank among the public health problems of highest priority. Infants born to mothers who are chronic carriers of HBV are at particularly high risk of acquiring infection and becoming chronic HBV carriers. The efficacy of hepatitis B vaccine alone in preventing the transmission of HBV to infants born to HBV carrier mothers was determined in a double-blind placebo-controlled trial. Infants received plasma-derived vaccine at birth, 1 month, and 6 months of age. Of 180 infants born to hepatitis B surface antigen (HBsAg)-positive mothers, equal numbers received National Institute of Allergy and Infectious Disease (NIAID) vaccine, Beijing Institute of Vaccine and Serum (BIVS) vaccine, and placebo. The cumulative seroconversion to the vaccines at 1 year of age was 95% and 75%, respectively. Vaccine efficacy as measured by the prevention of HBsAg-positive events was 88% for the NIAID vaccine and 51% for the BIVS vaccine. Vaccine efficacy was similar among infants born to hepatitis Be antigen-positive mothers. Because of the low efficacy of the BIVS vaccine, an additional group of 28 infants was given vaccine and hepatitis B immune globulin at birth. The resulting efficacy was 83%. The results of this trial indicate that hepatitis B vaccine alone can substantially reduce perinatally acquired HBV infection and the resulting chronic carrier state.     

Significance of measurement of pre-S2 antigen for the prevention of vertical transmission of hepatitis B virus in infants born to HBsAg carrier mothers

Terazawa S, Kondo N, Orii T. Significance of measurement of pre-S2 antigen for the prevention of vertical transmission of hepatitis B virus in infants born to HBsAg carrier mothers. Acta Pædiatr 1994;83:30–4. Stockholm. ISSN 0803–5253
The significance of pre-S2 antigen (pre-S2 Ag) as a marker of hepatitis B virus (HBV) infection, especially in infants born to HBsAg carrier mothers who are HBeAg-negative or HBeAg-positive, was evaluated. Pre-S2 Ag was measured by enzyme immunoassay. HBsAg carrier mothers who were HBeAg-negative and HBeAb-positive were divided into two groups: group A, mothers whose infants were not infected with HBV ( n = 10) and group B, mothers whose infants were infected with HBV ( n = 13). Absorption rates of pre-S2 Ag in group A and B were 0.09 k 0.04 and 1.36 ± 0.95, respectively. The values for pre-S2 Ag in group B were significantly higher than those in group A. Values for pre-S2 Ag among HBsAg carrier mothers who were HBeAg-positive and HBeAb-negative were also measured by reversc passive hemagglutination. In the same way, HBsAg carrier mothers who were HBeAg-positive and HBeAb-negativc were divided into two groups: group C, mothers whose infants did not become HBsAg carriers ( n = 15) and group D, mothers whose infants became HBsAg carriers (n = 11). The titers of pre-S2 Ag (reverse passive hemagglutination) in group C and D were 2^{5.75 ± 1.68} and 2^10.45±^1.69, respectively. The values for pre-S2 Ag in group D were significantly higher than those in group C. The values for pre-S2 Ag as markers of infectivity became higher with increasing amounts of HBV-DNA. Therefore, our results show that measurement of pre-S2 Ag in HBsAg carrier mothers who are HBeAg or HBeAb-positive is useful in the detection of high-risk groups of vertical transmission of HBV.     

Secular trends of HBeAg prevalence among HBsAg-positive delivery mothers in a hepatitis B endemic area

A high prevalence of HBeAg among HBsAg-positive mothers at the time of delivery results in a high prevalence of hepatitis B vertical transmission. From 1990 to 1995, 896 pregnant HBsAg-positive women, including 411 (46 per cent) HBeAg-positive subjects, were enrolled in our study to analyse the secular change in HBeAg prevalence. Their mean age, number of pregnancies and parity were 29.5 +/- 4.1 years, 2.0 +/- 1.2, and 0.6 +/- 0.7, respectively. The prevalence rates of HBeAg were 48, 54, 49, 47, 40, and 40 per cent among the subjects enrolled in 1990, 1991, 1992, 1993, 1994, and 1995, respectively. In univariate analyses, prevalence of HBeAg decreased by the calendar year of pregnancy (p = 0.01), and also by age (p < 0.00001), number of pregnancies (p < 0.0001) and parity (p < 0.0002). After adjusting for age in multiple logistic regression, the calendar year of pregnancy was still the independent variable, while gravida and parity became insignificant. The odd ratios (95 per cent confidence interval) of HBeAg negative-seroconversion in the equations were 1.09 (1.00-1.19) per calendar year and 1.14 (1.10-1.18) per year of age. Our results have shown a secular decrease in HBeAg-prevalence among pregnant HBsAg-positive women in Taiwan.     

Demonstration of mother-to-infant transmission ofStaphylococcus aureus by pulsed-field gel electrophoresis

We assessed mother-to-infant transmission ofStaphylococcus aureus. Anterior nares swabs of 466 pregnant women, vaginal swabs of 305 of these women and anterior nares swabs of 305 6-day-old infants were examined for the presence ofS. aureus. The results showed that 7.5% of the vaginal swabs from the pregnant women and 10.1% of the anterior nares swabs from the infants were positive forS. aureus. Six of the 466 pregnant women (1.3%) and 12 of the 305 infants (3.9%) carried methicillin-resistantS. aureus (MRSA) in the anterior nares site, but none of the vaginal specimens were positive for MRSA. Analysis ofSmaI digested chromosomal DNA analysis using pulsed-field gel electrophoresis (PFGE) showed that methicillin-sensitiveS. aureus (MSSA) strains obtained from four pairs of pregnant women and their infants were completely identical, which strongly suggesting mother-to-infant transmission ofS. aureus.Conclusion This study elucidated the prevalence ofS. aureus carriage among pregnant women and newborn infants. Mother-to-infant infection ofS. aureus was demonstrated phenotypically and genetically. PFGE is a useful tool to detect infection routes including mother-to-infant-infection.     

乙型肝炎病毒宫内感染对新生儿外周血细胞因子干扰素γ和白介素4的影响

目的 探讨乙型肝炎病毒(HBV)侵犯新生儿外周血单个核细胞(PBMC)后,对新生儿免疫功能的影响,了解其免疫失败发生的机理.方法 聚合酶链反应法(PCR)检测67对乙型肝炎表面抗原(HBsAg)、乙型肝炎e抗原(HBeAg)阳性孕妇及其新生儿血清和PBMC的HBV DNA.根据新生儿PBMC中HBV DNA分成阴性和阳性组,将新生儿的PBMC分别在植物血凝素(PHA)和纯化HBsAg刺激下进行体外细胞培养,检测培养上清液中干扰素-γ(IFN-γ)、白介素-4(IL-=4)的分泌含量.结果 (1)35例母亲PBMC HBV DNA阳性者其新生儿15例为阳性,母亲与患儿PBMC HBV DNA阳性,差异有显著统计学意义(P＜0.01).(2)新生儿PBMC内HBV DNA阳性组与阴性组比较,纯化HBsAg刺激时,阳性组IFN-γ的分泌量较阴性组低(P＜0.01),IL-4含量显示PBMC HBV DNA阳性组高于阴性组(P＜0.05),PHA刺激时,两组IFN-γ、IL-4含量差异无统计学意义(P＞0.05).结论 PBMC内的HBV DNA可能是HBV母婴垂直传播的一条重要途径;宫内新生儿PBMC感染HBV,IFN-γ特异性反应低下,而IL-4特异性反应增强,细胞调节失衡,可能是新生儿免疫失败和易于免疫耐受的一个重要原因.