Exploring the impact of hepatitis B immunoglobulin and antiviral interventions to reduce vertical transmission of hepatitis B virus

Hepatitis B virus(HBV)infection is a major public health burden.In HBV endemic regions,high prevalence is also correlated with the infections acquired in infancy through perinatal transmission or early childhood exposure to HBV,the socalled mother-to-child transmission(MTCT).Children who are infected with HBV at a young age are at higher risk of developing chronic HBV infection than those infected as adults,which may lead to worse clinical outcome.To reduce the incidence of HBV MTCT,several interventions for the infants or the mothers,or both,are already carried out.This review explores the newest information and approaches available in literature regarding HBV MTCT prevalence and its challenges,especially in high HBV endemic countries.This covers HBV screening in pregnant women,prenatal intervention,infant immunoprophylaxis,and postvaccination serological testing for children.

A Novel Fractional Dengue Transmission Model in the Presence of Wolbachia Using Stochastic Based Artificial Neural Network

The purpose of this research work is to investigate the numerical solutions of the fractional dengue transmission model(FDTM)in the presence of Wolbachia using the stochastic-based Levenberg-Marquardt neural network(LM-NN)technique.The fractional dengue transmission model(FDTM)consists of 12 compartments.The human population is divided into four compartments;susceptible humans(S_(h)),exposed humans(E_(h)),infectious humans(I_(h)),and recovered humans(R_(h)).Wolbachia-infected and Wolbachia-uninfected mosquito population is also divided into four compartments:aquatic(eggs,larvae,pupae),susceptible,exposed,and infectious.We investigated three different cases of vertical transmission probability(η),namely when Wolbachia-free mosquitoes persist only(η=0.6),when both types of mosquitoes persist(η=0.8),and when Wolbachia-carrying mosquitoes persist only(η=1).The objective of this study is to investigate the effectiveness of Wolbachia in reducing dengue and presenting the numerical results by using the stochastic structure LM-NN approach with 10 hidden layers of neurons for three different cases of the fractional order derivatives(α=0.4,0.6,0.8).LM-NN approach includes a training,validation,and testing procedure to minimize the mean square error(MSE)values using the reference dataset(obtained by solving the model using the Adams-Bashforth-Moulton method(ABM).The distribution of data is 80% data for training,10% for validation,and,10% for testing purpose)results.A comprehensive investigation is accessible to observe the competence,precision,capacity,and efficiency of the suggested LM-NN approach by executing the MSE,state transitions findings,and regression analysis.The effectiveness of the LM-NN approach for solving the FDTM is demonstrated by the overlap of the findings with trustworthy measures,which achieves a precision of up to 10^(-4).

Transplacental transmission of dengue infection

We specifically addressed the persistent challenge of dengue in endemic regions,highlighting the potential seriousness of dengue infection through vertical trans-mission.Vertical dengue transmission has been well documented,particularly in hyper-endemic regions,including Ecuador.Herein,we present a neonate diagno-sed with congenital dengue and review similar cases from previously published reports.Although congenital dengue is commonly infected with severe serotypes of DENV(DENV-1 and DENV-2)infections,favorable outcomes are generally observed.

Vertical transmission of the Yq AZFc microdeletion from father to son over two or three generations in infertile Han Chinese families

This study was carried out to analyze the vertical transmission of Yq AZFc microdeletions from father to son in infertile Han Chinese families to investigate genetic factors and family background affecting fertility status.The peripheral blood of infertile males in 19 Han families was extracted and screened with modified multiplex polymerase chain reaction （PCR）. Family trees were drawn according to fertility status and clinical characteristics of the subjects. The vertical transmission of Yq AZFc microdeletions was detected in six cases of 19 investigated families （31.6%,6/19）. Although both fathers and sons showed a similar type of Yq AZFc deletion,the fathers were fertile,whereas the sons were infertile and showed severe oligozoospermia. The vertical transmission of Yq AZFc microdeletion from fertile fathers to infertile sons over generations is not rare. This has different effects on fertility status in fathers and sons in Han Chinese families. Both genetic factors and family background affect spermatogenetic phenotypes.

Efficacy and safety of tenofovir disoproxil fumarate in pregnancy for the prevention of vertical transmission of HBV infection

AIM:To evaluate the effects of tenofovir disoproxil fumarate(TDF)use during late pregnancy to reduce hepatitis B virus(HBV)transmission in highly viremic mothers.METHODS:This retrospective study included 45 pregnant patients with hepatitis B e antigen(+)chronic hepatitis B and HBV DNA levels>107copies/mL who received TDF 300 mg/d from week 18 to 27 of gestation(n=21).Untreated pregnant patients served as controls(n =24).All infants received 200 IU of hepatitis B immune globulin(HBIG)within 24 h postpartum and 20μg of recombinant HBV vaccine at 4,8,and 24 wk.Perinatal transmission rate was determined by hepatitis B surface antigen and HBV DNA results in infants at week 28.RESULTS:At week 28,none of the infants of TDFtreated mothers had immunoprophylaxis failure,whereas2(8.3%)of the infants of control mothers had immunoprophylaxis failure(P=0.022).There were no differences between the groups in terms of adverse events in mothers or congenital deformities,gestational age,height,or weight in infants.At postpartum week 28,significantly more TDF-treated mothers had levels of HBV DNA<250 copies/mL and normalized alanine aminotransferase compared with controls(62%vs none,P<0.001;82%vs 61%,P=0.012,respectively).CONCLUSION:TDF therapy during the second or third trimester reduced perinatal transmission rates of HBV and no adverse events were observed in mothers or infants.

A prospective study of vertical transmission of hepatitis C virus

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Vertically acquired hepatitis C virus infection:Correlates oftransmission and disease progression

The worldwide prevalence of hepatitis C virus(HCV)infection in children is 0.05%-0.4% in developed countries and 2%-5% in resource-limited settings, where inadequately tested blood products or un-sterile medical injections still remain important routes of infection. After the screening of blood donors, motherto-child transmission(MTCT) of HCV has become the leading cause of pediatric infection, at a rate of 5%. Maternal HIV co-infection is a significant risk factor for MTCT and anti-HIV therapy during pregnancy seemingly can reduce the transmission rate of both viruses. Conversely, a high maternal viral load is an important, but not preventable risk factor, because at present no anti-HCV treatment can be administered to pregnant women to block viral replication. Caution is needed in adopting obstetric procedures, such as amniocentesis or internal fetal monitoring, that can favor fetal exposure to HCV contaminated maternal blood, though evidence is lacking on the real risk of single obstetric practices. Mode of delivery and type of feeding do not represent significant risk factors for MTCT. Therefore, there is no reason to offer elective caesarean section or discourage breast-feeding to HCV infected parturients. Information on the natural history of vertical HCV infection is limited. The primary infection is asymptomatic in infants. At least one quarter of infected children shows a spontaneous viral clearance(SVC) that usually occurs within 6 years of life. IL-28 B polymorphims and genotype 3 infection have been associated with greater chances of SVC. In general, HCV progression is mild or moderate in children with chronic infection who grow regularly, though cases with marked liver fibrosis or hepatic failure have been described. Non-organ specific autoantibodies and cryoglobulins are frequently found in children with chronic infection, but autoimmune diseases or HCV associated extrahepatic manifestations are rare.

Vertical transmission of hepatitis C virus: Current knowledge and perspectives

Hepatitis C virus(HCV) infection is a major global health issue.Infection by the HCV can cause acute and chronic liver diseases and may lead to cirrhosis,hepatocellular carcinoma or liver failure.The World Health Organization estimates that approximately 3% of the world population have been infected with HCVand the worldwide prevalence is between 1% and 8% in pregnant women and between 0.05% and 5% in children.Following the introduction of blood product screening,vertical transmission becomes the leading cause of childhood HCV infection.The prevalence of pediatric HCV infection varies from 0.05% to 0.36% in developed countries and between 1.8% and 5% in the developing world.All children born to women with antiHCV antibodies should be checked for HCV infection.Though universal screening is controversial,selective antenatal HCV screening on high-risk populations is highly recommended and should be tested probably.Multiple risk factors were shown to increase the possibility of HCV vertical transmission,including coinfections with human immunodeficiency virus,intravenous drug use and elevated maternal HCV viral load,while breastfeeding and HCV genotypes have been studied to have little impact.At present,no clinical intervention has been clearly studied and proved to reduce the HCV vertical transmission risk.Cesarean section should not be recommended as a procedure to prevent vertical transmission,however,breastfeeding is generally not forbidden.The high prevalence of global HCV infection necessitates renewed efforts in primary prevention,including vaccine development,as well as new approaches to reduce the burden of chronic liver disease.Future researches should focus on the interruption of vertical transmission,developments of HCV vaccine and directacting antivirals in infancy and early childhood.

Vertical hepatitis C virus transmission:Main questions and answers

Hepatitis C virus(HCV) affects about 3% of the world's population and peaks in subjects aged over 40 years. Its prevalence in pregnant women is low(1%-2%) in most western countries but drastically increases in women in developing countries or with high risk behav-iors for blood-transmitted infections. Here we review clinical, prognostic and therapeutic aspects of HCV in-fection in pregnant women and their offspring infected through vertical transmission. Pregnancy-related im-mune weakness does not seem to affect the course of acute hepatitis C but can affect the progression of chronic hepatitis C. In fact, postpartum immune res-toration can exacerbate hepatic inflammation, thereby worsening the liver disease, particularly in patients with liver cirrhosis. HCV infection increases the risk of gestational diabetes in patients with excessive weight gain, premature rupture of membrane and caesarean delivery. Only 3%-5% of infants born to HCV-positive mothers have been infected by intrauterine or perinatal transmission. Maternal viral load, human immunode-ficiency virus coinfection, prolonged rupture of mem-branes, fetal exposure to maternal infected blood con-sequent to vaginal or perineal lacerations and invasive monitoring of fetus increase the risk of viral transmis-sion. Cesarean delivery and breastfeeding increases the transmission risk in HCV/human immunodeficiency virus coinfected women. The consensus is not to offer antivi-ral therapy to HCV-infected pregnant women because it is based on ribavirin(pregnancy category X) because of its embryocidal and teratogenic effects in animal spe-cies. In vertically infected children, chronic C hepatitis is often associated with minimal or mild liver disease and progression to liver cirrhosis and hepatocarcinoma is lower than in adults. Infected children may be treated after the second year of life, given the adverse effects of current antiviral agents.

Prevention of vertical transmission of hepatitis B virus infection

Hepatitis B virus(HBV)is the leading cause of chronic viral hepatitis.Annually,almost two million children younger than 5 years acquire the infection,mostly through vertical or horizontal transmission in early life.Vertical transmission of HBV is a high efficacy phenomenon ranging,in the absence of any preventive interventions,from 70%to 90%for hepatitis e antigen positive mothers and from 10%to 40%for hepatitis e antigen-negative mothers.Maternal viraemia is a preeminent risk factor for vertical transmission of HBV.Maternal screening is the first step to prevent vertical transmission of HBV.Hepatitis B passive and active immunoprophylaxis at birth together with antiviral treatment of highly viraemic mothers are the key strategies for global elimination of HBV infection.Strategies are needed to promote implementation of birth-dose vaccination and hepatitis B immunoglobulins in low-and middle-income countries where the prevalence of the infection is at the highest.

Vertical Price Transmission in the China's Layer Industry Chain:an Application of FDL Approach

This paper examines the vertical price relationship between upstream and downstream products in China＇s layer industry chain by estimating elasticity coefficients of the price transmission. We use cointegration tests, error correction models and finite distributed lag models to analyze vertical price shifts between corn, layer feed, egg-laying chicken and egg prices. With monthly data from 1994 to 2010, our results show that various prices in China＇s layer industry chain are well integrated. In addition, our results indicate that both long-run and short-run price relationships between upstream and downstream products in layer industry chain exist and the long-run equilibrium, to a certain extent, may eliminate the short-run dynamics price deviation. We also found that the influence of corn and feed prices on egg prices is still more remarkable than egg-laying chicken prices. Our findings imply that governments should pay more attention to corn and layer feed prices in order to stabilize egg prices under the conditions of market integration.

Global dynamics behaviors for new delay SEIR epidemic disease model with vertical transmission and pulse vaccination

A robust SEIR epidemic disease model with a profitless delay and vertical transmission is formulated, and the dynamics behaviors of the model under pulse vaccination are analyzed. By use of the discrete dynamical system determined by the stroboscopic map, an ‘infection-free＇ periodic solution is obtained, further, it is shown that the ‘infection-free＇ periodic solution is globally attractive when some parameters of the model are under appropriate conditions. Using the theory on delay functional and impulsive differential equation, the sufficient condition with time delay for the permanence of the system is obtained, and it is proved that time delays, pulse vaccination and vertical transmission can bring obvious effects on the dynamics behaviors of the model. The results indicate that the delay is ‘profitless’.

Vertical Transmission of Schistosoma Japonicum in the Rabbit

The aim of the present study was to confirm observations on the vertical transmission of Schistosoma japonicum in the rabbit. S. japonicum- infected pregnant rabbits were used in this study. Perfusion of mother rabbits was done 9weeks after infection in order to obtain worm bur- dens in relation to their initial cercarial dose.Anti- schistosoma specific Ig M antibodies in serum samples collected from rabbit kittens were detected by EL ISA.Our results showed that gestation period lasted the norm al2 9- 31days.All the exposed mother rabbits became infected with S. japonicum.Positive Ig M antibody OD values were detected in12 out of the6 0 kittens exam ined (2 0 .0 % ) . In group C and A,4 0 .0 % and 17.9% of the kitten were congenitally infected,re- spectively. 18.1% of the kittens born to mothers infected with a single dose of 2 0 0 cercariae per rabbit were positives;this is not significantly different from that obtained for the 6 0 0 dose group (2 2 .2 % ) .Three randomly selected Ig M+ kittens harbored between one and two adult worm s. The livers of these kittens displayed granulomatous lesions. It is concluded that congenital S. japonicum infection does occur in the rabbit and is affected by the m other stage of pregnancy and to a lesser extent by its infection load.

Asymptomatic Genital Infection of Human Papillomavirus in Pregnant Women and the Vertical Transmission Route

To further investigate the vertical transmission route of human papillomavirus (HPV) and the indication for the choice of mode of delivery, the infective status of 152 asymptomatic pregnant wemen and the maternal-fetal transmission were studied. By using general primers in polymerase chain reaction (GP-PCR) combined with restriction fragment length polymorphism analysis, HPV DNA positive rate in cervical secretions and venous blood in asymptomatic pregnant women was 36.21 % and 52.78 %, respectively, and the identified genotypes were mainly HPV_16 and _18. The maternal-fetal transmission rate of HPV via genital tract as well as blood was 40.91 % and 57.89 %, respectively. It was concluded that besides the transmission route of genital tract and amniotic fluid, there was also transplacental transmission of HPV in utero. Therefore,in our opinion, it is not an absolut indication to perform a cesarean delivery for the pregnant women with HPV asymtomatic genital infection.

Blocking Effects of Spleen Vaccine on Vertical Transmission of Classical Swine Fever Virus in Sows

[ Objective] To investigate the blocking effects of spleen vaccine on vertical transmission of classical swine fever virus （CSFV） in sows. [ Method] Sows infected by CSFV were selected from three large-scale pig farms and they were randomly divided into group Ⅰ, group Ⅱ and control group. The sows in the group Ⅰ were vaccinated with CSF spleen vaccine at a 1.5 times normal dose per pig; those in the group Ⅱ were vaccinated with CSF spleen vaccine at a 2.0 times normal dose per pig; and those in the control group were vaccinated with cell vaccine at a 4.0 times normal- dose per pig. The CSF antigens of piglets were detected by enzyme-linked immunosorbent assay （ELISA）. [ Result] The antigen positive rate of piglets in the experimental group （18.5%） was significantly lower than that in the control group （48.1% ）. No significant difference was found be- tween the group Ⅰ and the group Ⅱ. [ Condmion] CSF spleen vaccine has good blocking effects on vertical transmission of CSFV in sows.

Stability Analysis of a Delayed HIV/AIDS Epidemic Model with Treatment and Vertical Transmission

A delayed HIV/AIDS epidemic model with treatment and vertical transmission is investigated. The model allows some infected individuals to move from the symptomatic phase to the asymptomatic phase;next generation of infected individuals may be infected and it will take them some time to get maturity and infect others. Mathematical analysis shows that the global dynamics of the spread of the HIV/AIDS are completely determined by the basic reproduction number R0 for our model. If R0 R0 > 1.

Overview of Studies on Vertical Price Transmission of Agro-products

Research on price transmission in vertically markets models the various price data, production index, consumer index and expectations index to proof market integration relations and estimate price transmission cycles, as well as to find out its function mechanism. Thanks to the development of market integration theory, research in this field explored well-rounded metric models. And the main research results are very closely to. To build up systematic models to input more variables based on demand and supply function, and remove the assumption of constant returns to scale of enterprises involving marketing and fully competitive market would be the development direction in this field. In this way, models draw close to the truth of economic operations.

Mathematical analysis of drug resistance in vertical transmission of HIV/AIDS

A nonlinear mathematical model of vertical transmission of HIV/AIDS is proposed to study the effects of drug resistance in the spread of the disease. The study assumes that treatment leads to the evolution of drug resistance in some pockets of the population. We use traditional methods to determine conditions for existence and stability of disease-free and endemic equilibrium points of the model. The study showed that the burden of the disease may be reduced if the reproduction number is reduced below unity and may persist if the reproduction number is raised above unity. Furthermore, evolution of drug resistance due to treatment may change the cause of the epidemic.

Global stability for delay SIR epidemic model with vertical transmission

A SIR epidemic model with delay, saturated contact rate and vertical transmission is considered. The basic reproduction number is calculated. It is shown that this number characterizes the disease transmission dynamics: if, there only exists the disease-free equilibrium which is globally asymptotically stable;if, there is a unique endemic equilibrium and the disease persists, sufficient cond- itions are obtained for the global asymptotic stability of the endemic equilibrium.

Qualitative Detection of Proviral-DNA of HIV-1 in Infants to Determine the Efficacy of Antiretroviral Therapy in the Prevention of Vertical Transmission of HIV-1 in The Gambia

The priority of The Gambia government is to eliminate maternal to child transmission of HIV and in line with this priority, the country implemented an antiretroviral therapy (ART) program. With this, all HIV infected pregnant and breastfeeding mothers and infants have access to ARV drugs. This study aims to determine the prevalence of vertical transmission of HIV among women receiving the ARV drugs. Dried blood spot samples were collected from 109 HIV-exposed infants enrolled in 13 PMTCT sites across the country. A qualitative detection of proviral-DNA of HIV-1 was performed using the RealTime Abbott PCR assay. Data from 105 mothers were analyzed using SPSS version 16.0 and association of risk factors to PCR results were analyzed using (Crosstabs) Pearson Chi-Square. The p-value of significant was set at p < 0.05. This study has found that the prevalence of vertical transmission of HIV is 0.0% (0/64) among women that received the ARV prophylaxis then started ART, 7.1% (2/28) among mothers that received HIV prophylaxis only, and 38.4% (5/13) among women who neither receive HIV-prophylaxis nor ART during pregnancy or breastfeeding. Other risk factors of vertical transmission such as late initiation of treatment, default during treatment and first born of twins were found to be significantly associated with vertical transmission p = 0.001, p = 0.022 and p = 0.000 respectively. This study has found that the early intervention of ART at the onset of pregnancy through breastfeeding can eliminates Maternal to Child transmission of HIV-1and a high risk of vertical transmission was found among women who neither receive prophylaxis nor ART. If the effectiveness of the antiretroviral therapy is maintain, The Gambia, in the near future will attain the WHO’s goal to eliminate maternal to child transmission of HIV.