MINISTRY OF EDUCATION &TRAINING THAI NGUYEN UNIVERSITY NONG THI TUYEN THE PROPORTION OF MOTHER TO CHILD TRANSMISSION OF HBsAg CARRIER MOTHERS AND THE IMMUNE RESPONSE TO HEPATITIS B VACCINE IN INFANTS IN DINH HOA DISTRICT - THAI NGUYEN Speciality: Internal Digestion Code: 62.72.01.43 SUMMARY OF DOCTORAL THESIS Thai Nguyen - 2019 The dissertation was completed in: Thai Nguyen University of Medicine &Pharmacy Thai Nguyen University Scientific Supervisors: Assoc Prof, PhD Duong Hong Thai Assoc Prof, PhD Tran Viet Tu Opponent 1: Opponent 2: Opponent 3: The dissertation will be defended at the Dissertation Committee In National Level held in Thai Nguyen University of Medicine & Phrmacy Time … date …… month……year 20…… The information from this dissertation can be found at: - National Library ; - Learning Resource Center - Thai Nguyen University - Library of Thai Nguyen University of Medicine &Pharmacy LIST OF REPORTED WORKS RELATED TO THESIS Nong Thi Tuyen, Phung Thi Tuyet Nga, Duong Hong Thai, Hoang Anh Tuan (2016),“ Clinical and paraclinical features of prenant women with HbsAg (+) at Dinh Hoa district in Thai Nguyen province”, Viet Nam Medical Journal, No special /449 (2016), pp.188-194 Nong Thi Tuyen, Duong Hong Thai, Tran Viet Tu (2018), “Assessment of immune response after hepatitis B vaccine injection in infants born to mothers with HBsAg (+)”, Viet Nam Medical Journal, No 2/472 (2018), pp 71-75 Nong Thi Tuyen, Duong Hong Thai, Tran Viet Tu (2018),“Study on prevalence of HBV in pregnant women and infants with mothers with HBsAg (+) infants in Dinh Hoa district – Thai Nguyen province”, Viet Nam Medical Journal, No 2/472 (2018), pp.115-118 INTRODUCTION Viral hepatitis is a common and dangerous infectious disease group Hepatitis virus infection, especially Hepatitis B virus (HBV) is a global health problem According to World Health Organization (WHO), there are approximately 240 million chronic HBV carriers worldwide and 650000 people die each year due to hepatitis B, mainly from chronic complications such as liver cirrhosis and hepatocellular carcinoma (HCC) 20 to 30% people with chronic hapatitis B develop these complications The are common routes of HBV infection: blood transfusion, sexual transmission and vertical transmission from mother to child Vertical transmission is mostly observed in people with high HBV DNA load or HBeAg positive In countries with high prevalence of HBsAg (>8%) before the implementation of Expanded program on immunization (EPI), HBV infection is mostly through vertical transmission or household transmission Perinatal transmission is also present in countries with lower HBV prevalence where pregnant women are not examined regularly and HBV vaccinated In Vietnam, domestic plasma-derived hepatitis B vaccine was first introduced in the Expanded program on immunization for infants under years old in some provinces in 1997 By the end of 2001, approximately 370.000 infants had been vaccinated against hepatitis B, accounted for 25% of infants under years old in the country The first dose of hepatitis B vaccine within first 24 hours after birth are recommended for all infants according to WHO However, there are still mother-to-child transmission despite of adequate hepatitis B vaccination Immune response in infants depends on many factors, but hepatitis B vaccination are still the most important measure to prevent vertical transmission In Vietnam, there have been not many studies on the effectiveness of Gene HBvax and Quinvaxem vaccine in infants under years old Their effectiveness in infants born to HBsAg(+) mothers also needs to study more thoroughly as these two vaccine are used extensively in the Expanded program on immunization Dinh Hoa is a mountainous district of Thai Nguyen province People in this district are almost from ethnic minorities who have poor living condition and inadequate knowledge about disease prevention including the prevention of HBV vertical transmission In addition, the current prevention of HBV vertical transmission include only the use of those two vaccine in EPI without any other measure Because of those reasons, we conduct the study "Assess the proportion of mother-to-child transmission of HBsAg carrier mothers and the immune response to hepatitis B vaccine in infants in Dinh Hoa district - Thai Nguyen" for the following purposes: To determine the prevalence of HBsAg(+) in pregnant women in Dinh Hoa district - Thai Nguyen during the years 2015 - 2017 To determine the proportion of HBsAg(+) in infants born to HBsAg(+) mothers in Dinh Hoa district - Thai Nguyen To assess the post-vaccination immune response after administering vaccine Gene HBvax and Quinvaxem in infants born to HBsAg(+) mothers STRUCTURE OF DISSERTATION The key part of the dissertation is 131 pages, including the following parts: Introduction: pages Chapter Literature review: 39 pages Chapter Subjects and method: 25 pages Chapter Results: 24 pages Chapter Discussion: 38 pages Conclusions and recommendations:3 pages The dissertation has 130 references, including 25 Vietnamese and 105 documents in English The dissertation includes 35 tables and charts, pictures.The appendix includes subappendices with 12 pages Chapter 1: LITERATURE REVIEW 1.1 Overview of Hepatitis B virus In 1964, Blumberg S.M was found antigen Australia in Australia aborginical that were transmitted many time blood After that, scientists proved Australia antigen that was surface HBV antigen, international signal was HBsAg (Hepatitis B surface antigen) After 11 years, in 1975, Dane discoveried little corns by electromicroscopy that had 42nm diameter, they were called Dane corns Afterwards, scientists carried out many studies for HBV and determined Dane corns were completed virus corns 1.1.1 Structure of Hepatitis B virus HBV belongs to Hepadnaviridae, are virus affinity to liver that AND structure is composed by 3.200 couple of acid nucleotids, weight of molecule are x 106 dalton 1.1.2 Genome of Hepatitis B virus HBV genotypes caused heterogenerous in clinical signs and therapy responses in patient with chronic hepatitis B in another area over the world Up-to-now, there were 10 genotypes of HBV (A-J) that were determined and some another sub-genotypes These genotypes were determined by separating to whole of HBV genotype family and distributing distincted geography 1.2 Transmission of Hepatitis B virus Mode of transmission of HBV are as following: 1.2.1 Transmission by blood transfusion Before 60s in XX century, because there were not tests of HBV screening for blood donors, HBV infected proportion of blood receiver was over 30%, and patients that had to recurrent blood transmission (such as patient with Hemophilia) catched up to 60% infecting HBsAg(+) Since 1970, after blood transmission, HBV prevalence decreased clearly for using HBV screening in serum 1.2.2 Mother to child transmission Mother to child transmission is a important epidemic characteristic in area of high HBV prevalence including Vietnam The transmission can occur in foetus period, in and after delivery So that, beside of expand vaccination for kids we had to care about vaccination for reproducing women 1.2.3 Sexual transmission HBsAg was found in sperm, secreting fluid form vagina, blood from menopause HBV infiltrated the body into minimal scratching trace by intercourse HBV transmission can occur homosexual intercourse and sexual intercourse 1.2.4 Intra-familial transmission According to Hà Thị Minh Thi et al showed that prevalence of people with positive HBsAg in the family having at least a person with HBV catched up to 47.8% 1.3 Clinical manifestations of Hepatitis B 1.3.1.Clinical presentation Chronic Hepatitis B is hepatitis being made by situation of long lasting infected HBV Duration of infected HBV is at least months and these patients have chronic inflamation and necrosis in liver Chronic Hepatitis B is divided two sorts being positive and negative HBeAg 1.3.2 Laboratory tests * AST/ ALT increased high continuously or intermittently in Chronic Hepatitis B * Other tests of liver function also changed if liver was injuried such as high bilirubin, low albumine, low prothrombine * Blood cell count: anaemia, low white blood count, decreasing plalete Ultrasound: maybe cirrhosis image Liver biopsy: maybe injuried liver on histopathology * There were markers of HBV 1.4 Hepatitis B, pregnancy and newborn infants: 1.4.1 Hepatitis B in pregnancy Characteristics of acute Hepatitis B in pregnant women: ro ret clinical sign was jaudice, especially biliruibin icterus with itching Pregnancy was not increasing of infected HBV 1.4.2 Pregnancy outcomes of hepatitis B Affecting to infected acute hepatitis B in pregnant women and foetus were abortion, prematurity, stillbirths, acute hepatitis in infant, cirrhosis but it was not made congenital defects 1.4.3 Hepatitis B in newborn infants Hepatitis B in newborn infants usually was serious and included three sorts such as urgent, acute, semi-acute disease 1.5 Hepatitis B vaccine 1.5.1 First-generation hapatitis B vaccine The First-generation hepatitis B vaccine was produced from plasma of people with chronic HBsAg The vaccine was found the first time in France and the USA and was used broadly from 1981 to 1982 1.5.2 Second-generation hapatitis B vaccine The second-generation hapatitis B vaccine was studied at the end of 70s In 1986 this vaccine was proceduced the first time in the USA There was a vaccine recombination ADN that displayed S genotype to code for surface antigen HBsAg on cellulars of yeast, or biocellular of mammals to start-up HBsAg synthetic process 1.5.3 Third-generation hapatitis B vaccine The third-generation hapatitis B vaccine was a vaccine of origin of S, Pre S1 and S2 genotype of HBV, its immune response making better There were two surface protein including Pre S1 and Pre S2 that had important role to stimulate T-help making anti-HBs 1.6 Immune response to hepatitis B vaccine in infants under years old 1.6.1 The implementation of hepatitis B vaccination in Vietnam national program on immunization On 18th August 1997, The Prime Minister officially approved to allow developing hepatitis B vaccine in national expand vaccination program Pilot deployment of hepatitis B vaccine was applied in Hà Nội city and Hồ Chí Minh city In 2003, 100% villages in the nation carried our hepatitis B vaccine for 1.500.113 infants under years old 1.6.2 Hepatitis B vaccination schedule Today, almost of cases, we used hepatitis B vaccination schedule as following - - or - - - 12 10 * Post-vaccination immune response in infants born to HBsAg positive mothers - HBsAg marker in infants under months old: Being divided two groups as following: Positive and negative HBsAg Umbilical cord blood test by ELISA for 6-month-old infants who were injected enough HBV vaccine in Center of Hematology, Thai Nguyen central hospital - Anti HBs marker in infants under months old: Being divided three groups as following: Anti HBs < 10(mIU/ml); From 10 to 100(mIU/ml); Anti HBs > 100(mIU/ml) Umbilical cord blood test by ECLIA for 6-month-old infants, in Center of Hematology, Thai Nguyen central hospital 2.5 Data collection techniques 2.5.1 Clinical examination All pregnant mother who give birth in deparment of obstetrics, in Dinh Hoa general hospital were examinated, taken note study and medical record by author or doctor in here The mothers with toxaemia pregnancy, pregnant diabetes were excluded the study As soon as being delivery, infants were exminated carefully The infans had unusual signs such as congetinal defect, congenital heart defect, circulator and breathing failure were excluded the study 2.5.2 Hepatitis B vaccination - Neonatas that were selected in the study were injected one Gene Hbvax vaccine by mid-wife, taking note to HBV vaccination book in Department of Obstetrics, in Dinh Hoa general hospital - The infants in the study were injected st, 2nd, 3rd Quinvaxem vaccine in turn at 2-month-old, 3-month old and 4-month-old time at medical station where the infants lived 2.5.3 Laboratory tests 2.5.3.1 For mothers: HBsAg test (quick test); anti HCV test (quick test); anti HIV test (quick test); HbsAg test (ELISA); HBeAg (quick test); HBV DNA test 2.5.3.2 For infants: HbsAg test (ELISA) at neonatas by umbilical cord blood; HbsAg test (ELISA) by vein in –month-old infant; anti HBs test by ECLIA in 6–month-old infant 11 2.5.4 Data analysis: The data were entered into pre- designed data templates using Epidata software and analysed using SPSS 20.0 2.6 Definition of variables: 2.6.1 Chronic hepatitis B Chronic hepatitis B was necrosis and chronic in liver that was caused by HBV and long lasting over months Chronic hepatitis B was divided two group that Chronic hepatitis B with positive HbeAg and negative HBeAg 2.6.2 Immune response To distribute post-vaccination results: + Infants having Hepatitis B post-vaccination: the infant with HBsAg(+) at 6-month old + Infant having non-hepatitis B post-vaccination: the infant with HBsAg(-) at 6-month old + Infants were achieved successful post-vaccination results: the infants with HBsAg(-) and level of anti HBs in plasma ≥ 10 mIU/ml at 6-month-old + Infants were had unsuccessful post-vaccination results: the infants with HBsAg(+) or HBsAg(-) and level of anti HBs in plasma < 10 mIU/ml at 6-month-old + Infants having immune respond under protecting: the infants with anti HBs level < 10 mIU/ml at 6-month-old + Infants having weak immune respond: the infants with anti HBs being from ≥ 10 mIU/ml to ≤ 100 mIU/ml at 6-month-old + Infants having good immune respond: the infants with anti HBs ≥ 100 mIU/ml at 6-month-old 2.6.3 Dependent variable * Level of anti HBs in infants after injecting Gene – HBvax and Quinvaxem vaccine: The level of anti HBs at 2,3,4 –month-old was quantity variable Anti HBs was measured by mIU/ml and minimal level was 10 mIU/ml * HbsAg infants after injecting Gene – HBvax and Quinvaxem vaccine: qualitative variable were positive and negative 2.6.4 Independent variable - Neonatal HBV vaccine (Gene – HBvax) and Quinvaxem vaccine were independent variable 12 - HBV DNA load: was divided two degrees as following that HBV DNA: ≥ 3x102 coppies/ml and HBV DNA: < 3x102coppies/ml 2.7 Materials in research - Thermostat (PCR) Mastercycler of Germany, at Department of Microbiology Thai Nguyen University of Medicine and Pharmacy - ARCHITECT PLUS machine of the United States, at Blood Transfusion Center, Thai Nguyen Central Hospital - Vaccine Gene HBvax and Quinvaxem 2.8 Ethical approval We only selected infants that had their mother with HBsAg(+) and they agreed spontanously after being talked careful consultant for objective study, schedule of the study, their rights and responsibility They can be out of the study any time and were kept secret individual for all objects 2.9 Limitations of the thesis No 6-month infant blood was obtained from children of HBsAg mothers (-) to compare immune responses Chapter 3: RESULTS 3.1 General characteristics of the subjects: Table 3.1 Age of the pregnant women Age group Frequency Percent (%) < 18 0.9 18 - 35 106 96.4 > 35 2.7 Mean age (X  SD) 26.36  4.54 *Comment: Age of pregant women in the study was from 16 to 38 years old In which proportion of 18-to-35 year-old group was the highest (96.4%) Mean age was 26.36  4.54 years old Table 3.3 Ethnicity of the subjects Ethnic group Frequency Percent (%) Kinh 17 15.5 Tay 55 50.0 San chi 21 19.1 Nung 4.5 13 Others 12 10.9 Total 110 100.0 * Comment: Tay group accounted for the highest in the women of the study up to 50.0%, proprotion of San group only was 19.1%, Kinh group was 15.5% Besides, there were other ethnic group such as Nung, Dao, Thai, Muong Table 3.6 Mode of delivery Mode of delivery Frequency Percent (%) Normal labour 6.4 Vaginal delivery with episiotomy 62 56.4 C – section 41 37.2 Total 110 100.0 * Comment: Pregnant women in the study were had vaginal delivery with episiotomy accounted for 56.4% (meant 62/110 cases) The women with C-section were 41/110 cases, accounted for 37.2% Normal labour had the lowest proportion that was 6.4% (7/110 cases) Table 3.7 Gender of infants Gender Frequency Percent % Male 63 57.3 Female 47 42.7 Total 110 100.0 * Comment: In 110 infants males were 63 people (57.3%) and females were 47 people (42.7%) Table 3.8 Birthweight of infants Birthweight (gr) Frequency (n) Percent (%) 2500 - < 3000 42 38.2 3000 - < 3500 44 40.0 ≥ 3500 24 21.8 Total 110 100.0 3131.64 ± 395.73 Mean birthweight ( X  SD) * Comment: No infant had birthweight under 2500grams Proportion of infants that weighed from 3000grams to under 3500grams was the highest (40.0%) Mean infant-birthweight was 3131.64 ± 395.73 grams 14 3.2 Prevalence of HBsAg in pregnant women in Dinh Hoa district, Thai Nguyen Table 3.9 Prevalence of HBsAg in pregnant women who give birth at Dinh Hoa general hospital Pregnant women Frequency Percent (%) HBsAg(+) 239 6.3 HBsAg(-) 3579 93.7 Total 3818 100.0 * Comment: There were 239/ 3818 pregantn women with positive HbsAg, accounted for 6.3 % Table 3.11 HBeAg test result in HBsAg-positive pregnant women HBeAg test result Frequency (n) Percent (%) HBeAg(+) 40 36.4 HBeAg(-) 70 63.6 Total 110 100.0 * Comment: Number of woment with positive HbeAg were 40/110 cases (36.4 %) Table 3.12 HBV DNA load in HBsAg-positive pregnant women HBV DNA load in mother Frequency (n) Percent (%) < 3x102 (copies/ml) 45 40.9 From x10 to < 10 11 10.0 (copies/ml) From 103 to < 104 (copies/ml) 8.2 From 10 to < 10 (copies/ml) 1.8 From 10 to < 10 (copies/ml) 4.5 > 106 (copies/ml) 38 34.6 Total 110 100.0 * Comment: Number of woment with HBV DNA > 10 copies/ml were 38/110 cases (34.6%) Number of woment with HBV DNA < 3x102 copies/ml were 45/110 case (40.9%) Table 3.13 Relationship between HBV DNA load and HBeAg in HBsAg-positive pregnant women (n=110) HBeAg(+) HBeAg(-) 15 HBeAg Frequency Percent Frequency Percent (n) (%) (n) (%) HBV DNA ≥ 3x10 38 95.0 27 38.6 copies/ml < 3x102 5.0 43 61.4 copies/ml Total 40 100.0 70 100.0 p, OR,CI p 0.05; OR = 1.8; CI (0.817 – 3.964) * Comment: Women with positive HBeAg(+) were no affection to transmit HBV to infant by Umbilical cord blood, insignificant with p > 0.05 Table 3.18 Prevalence of HBsAg(+) umbilical cord blood in the infected HBV mother with HBV DNA > 3x102 copies/ml Umbilical HBsAg(+) HBsAg(-) cord Frequency Percent Frequency Percent Blood HBV (n) (%) (n) (%) DNA Mother ≥ 3x102 32 71.1 33 50.8 copies/ml < 3x102 13 28.9 32 49.2 copies/ml Total 45 100.0 65 100.0 p, OR, CI p < 0.05; OR = 2.39; CI (1.065 – 5.352) * Comment: The mother with HBV DNA ≥ 3x10 copies/ml had tranmitted HBV from mother to infant by umbilical cord blood was 2.39 times compared with the other mother with HBV DNA < 3x10 copies/ml The difference was singnificant with p < 0.05; OR = 2.39; CI (1.065 – 5.352) Table 3.21 Relationship between maternal age group and HBV transmission to infants through umbilibal cord blood (n=110) 17 Umbilibal cord Blood Maternal age ≤ 26 years HBsAg(+) HBsAg(-) Frequency (n) Percent (%) Frequency (n) Percent (%) 30 66.7 27 41.5 > 26 years 15 33.3 38 58.5 Total 45 100,0 65 100,0 P, OR, CI p < 0.05; OR = 2.82; CI (1.275 – 6.216) * Comment: The under 26-year-old women with infected HBV had transmitted HBV to infant was 2.82 times compared with the other women in the study The difference was significant with p < 0.05, 95%CI (1.275 – 6.216) 3.4 Post-vaccination immune response in infants born to HBsAg positive mothers Table 3.22 HBsAg test results in infants under months old Test results HBsAg(+) HBsAg(-) Total Frequency 44 58 102 Percent (%) 43.1 56.9 100.0 * Comment: In which 102 infants, there were 44 infants (43.1%) had in 6month-old infant with positive HBsAg Table 3.23 Relationship between post-vaccination anti HBs levels and HBsAg in infants under months old HBsAg HBsAg(+) HBsAg(-) months old Anti HBs level (mIU/ml) < 10 10 - 100 > 100 Frequency (n) Percent (%) Frequency (n) Percent (%) 22 13 50.0 29.5 20.5 28 23 12.1 48.3 39.6 18 Total Mean concentration of anti HBs, p 44 100.0 58 218.58 ± 134.28; p < 0.001 100.0 * Comment: Level of anti HBs in plasma in post-vaccination children had a closed relationship to level of their HBsAg in plasma The difference was significant with p < 0.001 Table 3.25 Relationship between maternal HBe and HBsAg in 6-month-old infants after vaccination HBsAg in 6HBsAg(+) HBsAg(-) month-old infants Frequency Percent Frequency Percent Maternal (n) (%) (n) (%) HBeAg HBeAg(+) 21 47.7 18 31.0 HBeAg(-) 23 52.3 40 69.0 Total 44 100.0 58 100.0 p, OR,CI p > 0.05; OR = 2.03; CI (0.901 – 4.570) *Comment: Maternal HBeAg was affected to transmit HBV to children after vaccination The difference was insignificant with p > 0.05 Table 3.26 Relationship between maternal HBV DNA load and HBsAg in 6-month-old infants after vaccination HBsAg in 6HBsAg(+) HBsAg(-) month-old Infant s Frequenc Percent Frequenc Percent Maternal y (n) (%) y (n) (%) HBV DNA (copies/ml) ≥ 3x102 32 72.7 30 51.7 19 < 3x102 12 27.3 28 48.3 Total 44 100.0 58 100.0 p, OR,CI p < 0.05; OR = 2.49; CI (1.075 – 5.765) * Comment: The infected HBV mother with positive HBV DNA transmitted to HBV to infants as high as 2.49 times compared with the mother with negative HBV DNA The difference was significant with p < 0.05; OR = 2.49; CI (1.075 – 5.765) Table 3.32 Relationship between maternal HBV DNA load and immunization result in 6-month-old infants 6-monthUnsuccessful Successful old infants immunization immunization Frequenc Percent Frequenc Percent Maternal y (n) (%) y (n) (%) HBV DNA ≥ 3x102 35 68.6 27 52.9 copies/ml < 3X102 16 31.4 24 47.1 copies/ml Total 51 100.0 51 100.0 p,OR, CI p > 0.05; OR = 1.94; CI (0.876 – 4.36) * Comment: In maternal HBV DNA load ≥ 3x102 copies/ml, the 6month-old infant was unsuccessful immunization as high as 1.94 times compared with the other maternal The difference was insignificant with p > 0.05 Chapter 4: DISCUSSION 4.1 General characteristics of the subjects According to the table 3.1, 110 hepatitis B infection mothers mostly was in the age of 18-35 years old (96.4%), the youngest and the oldest was 16 and 38 years old The average age of pregnancy was 26.364.54 20 In the table 3.3, most of subjects was ethnic minority, Tay was the dominant (49.1%) Others was San Chi, Dao, Nung, Thai, Muong, Hoa It was easy to give the advice and prevention technique for them In table 3.6, 55.5% woman with episiotomy 38.2% woman had cesar, 6.4% with normal labor There was no case with forceps There was no relation between the method of labor and the risk of HBV infection in the previous research However, there was some recommendation of avoiding the lesion In 110 cases, there was no case had complication In table 3.7, in 110 newborn babies, there was 57.3% (63/110) boys, and 42.7% (47/110) girls This results was also the same with others studies in Vietnam Table 3.8 showed that there was no baby weighted under 2500 g, mostly from 2500 to 3500 g, 24 babies weighted over 3500 g Other studies showed the lighter babies had low antibody level 4.2 The prevalence of HBsAg in pregnant woman in Dinh Hoa district, Thai Nguyen Table 3.9 showed that there was 239 in 3818 pregnant woman from April, 2015 to June, 2017 with HBsAg (+) took 6.3%, lower than Chu Thi Thu Ha study at Hospital of Gynecology Ha Noi (12%), Nguyen Thi Tuyet Nga (12.59%), higher than Nguyen Van Hien (0.16%) These differences might be caused by the high mountain area Table 3.11 showed 36.4% woman with HBsAg (+), lower than Chu Thi Thu Ha (40.5%), Purusotam Raj Shedain in Nepal high mountain with HBV positive and HBeAg positive (40%) It was also higher than Phi Duc Long in Ha Noi and Thai Binh (26.7%) Table 3.12 showed that the HBV DNA (-) woman was 45 cases (40.9%), 38 woman (34.6%) with HBV DNA > 10 copies/ml It could raise the concern among the chronic HBV, the high level one was young (16 years old) This study also showed the woman ≤ 26 had higher virus level than > 26 year-old individuals Table 3.13 showed the close relation between HBV DNA level and HBeAg in pregnant HBV infection woman (p 500 mIU/ml It showed good outcome of Gene Hbvax and Quinvaxem if prescribed for babies under year old because of antibody level > 1000 mIU/ml After 6months, 51 babies successfully vaccinated Table 3.25 showed that 21/44 babies with HBsAg (+) had mothers with HBeAg (-), 23/44 babies with HbsAg (+) had mothers with HBeAg (-) (p>0.05) This result was different with the others, normally there was a correlation between HBV infected mothers HBeAg (+) and babies with HBsAg (+) after vaccination Table 3.26 showed the observation of months babies recevied full vacinnation who had mother with HBV DNA (+) was 32 cases (72.7%) HBV infected mothers with HBV DNA (-) spread to her baby was 12 cases (27.3%) Mothers with HBV DNA (+) had 2.49 times risk of baby infection than HBV DNA (-) ones In this research, some mothers with HBeAg (-) but HBV DNA (+) From Tablle 3.30, in 44 babies HBsAg(+), there was 22 babies had anti HBs < 10 mIU/ml (50%), 22 babies with HBs > 10 mIU/ml Babies with anti HBs < 10 mIU/ml had higher risk of HBsAg (+) (7.29 times) than the other, p 0.05 The full vacinnated baby had to have HBsAg (-) and anti HBs > 10 mIU/ml In this study, months babies with HBsAg (-) but anti HBs < 10 mIU/ml was defined as non response 23 CONCLUSION Studying in 3818 pregnant women in Dinh Hoa general hospital from April 2015 to June 2017, to assess prevalence of having HBsAg in women, in 110 infants born to HBsAg positive mothers, post-vaccination immune response in 102 one-year-old infants to HBsAg positive mothers, the results showed: Prevalence of HBsAg in pregnant women and their newborn infants - Pregnant women having HBsAg(+) were 239/3818 cases, accounted for 6.3% - Number of pregnant women having the first catching HBV (unknown duration of infection) were 63/110 cases, accounted for 57.3% - Number of pregnant women infecting HBV with HBeAg(+) were 40/110 cases, accounted for 36.4% - Number of pregnant women infecting HBV that having HBV DNA ≥ 3x102 copies / ml were 65/110 cases, accounted for 59.1% in which 38 cases (34.6%) having HBV DNA > 106 copies / ml Prevalence of HBsAg in infants born to HBsAg positive mothers in Dinh Hoa district, Thai Nguyen - Number of infants with HBsAg(+) in umbilical cord blood were 45/ 100 case, accounted for 40.9% - There was no relationship between pregnant women having HBeAg(+) and transmission HBV to infant by umbilical cord blood - Pregnant women infecting HBV having HBV DNA ≥ 3x102 copies / ml had infected HBV to 32 infants that was as high as 2.39 times in the women catching HBV DNA < 3x10 copies / ml, significantly p < 0.05 - Pregnant women being ≤ 26 years old increased risk transmission HBV to infant by umbilical cord blood 2.82 times than pregnant women > 26 years old The difference was significant with p< 0.05 and 95%CI: 1.275 – 6.216 24 Post-vaccination immune response in infants born to HBsAg positive mothers -There were 44/102 cases with HbsAg (+), accounted for 43.1% after 6-month HBsAg vaccination - After vaccination, there were 51 cases (50.0%) having anti HBs > 10 mIU/ml and negative with HBsAg And 51 cases (50.0%) were not immune response in which having positive with HBsAg and/ or anti HBs < 10 mIU/ml - There was no relationship HBeAg in pregnant women with HBsAg transmission in infant after vaccination - Number of HBV DNA in pregnant women was one of risk factor to level of anti HBs in infant after vaccination The difference was significant with p < 0.05 RECOMMENDATION - We should screen pre-delivery to know pregnant women having HBV If we discover pregnant women infecting HBV, we should carry out HBV DNA test to prevent infected HBV from the mother to infants by the mother had to use anti-HBV therapy in triesmeter pregnancy - Infants were born from pregnant women having HBsAg(+)/HBV DNA ≥ 3x102copies/ml can not post-vaccination immune response, we need to combine many other preventing therapy (such as using HBIG in infant) and HBV vaccination to prevent transmissing HBV from the mother to infant ... children with positive HBsAg (40.9%) Table 3.17 Prevalence of newborn infants with HBsAg- positive umbilical cord blood born to mother with HBsAg( +) and HBeAg(+) Umbilical HBsAg( +) HBsAg( -) cord Frequenc... of HbsAg in newborn babies with HBsAg positive mothers in Dinh Hoa district, Thai Nguyen province Table 3.16 defined the proportion of newborn babies with HBV infection by HBsAg (ELISA) of umbilical... mothers with HBeAg (-) but HBV DNA (+) From Tablle 3.30, in 44 babies HBsAg( +), there was 22 babies had anti HBs < 10 mIU/ml (50%), 22 babies with HBs > 10 mIU/ml Babies with anti HBs < 10 mIU/ml