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.

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.

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.

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.

Management and Outcome of Pregnant Women with HIV Acquired by Vertical Transmission

The majority of children with perinatally acquired human immunodeficiency virus (HIV) do not survive beyond childhood but this is changing due to the benefit of antiretroviral therapy for the perinatally infected cohort, so affected children are now approaching the age to be mothers. The aim of this article is to evaluate the outcomes of pregnant women with HIV acquired by vertical transmission in our centre and encourage the results obtained in “Thirty Years Later: Pregnancies in Female Perinatally Infected with Human Immunodeficiency Virus-1”, a review article published in this journal in 2012 [2]. We report 6 patients with eight pregnancies with HIV acquired by vertical transmission. They delivered a total of nine newborns between 2004 and 2013. In any case, mother-to-child transmission was reported. The management of pregnant women with HIV acquired by vertical transmission is complicated, since the patients are the most of the cases young and the compliance to the treatment may be poor. The prematurity was the more frequent complication and the cesarean section was the more frequent form of ending. In our case series, mother-to-child transmission was absent.

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.

Microdeletions and vertical transmission of the Y-chromosome azoospermia factor region

Spermatogenesis is regulated by several Y chromosome-specific genes located in a specific region of the long arm of the Y chromosome,the azoospermia factor region(AZF).AZF microdeletions are the main structural chromosomal abnormalities that cause male infertility.Assisted reproductive technology(ART)has been used to overcome natural fertilization barriers,allowing infertile couples to have children.However,these techniques increase the risk of vertical transmission of genetic defects.Despite widespread awareness of AZF microdeletions,the occurrence of de novo deletions and overexpression,as well as the expansion of AZF microdeletion vertical transmission,remains unknown.This review summarizes the mechanism of AZF microdeletion and the function of the candidate genes in the AZF region and their corresponding clinical phenotypes.Moreover,vertical transmission cases of AZF microdeletions,the impact of vertical inheritance on male fertility,and the prospective direction of research in this field are also outlined.

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).

Mechanisms and Prevention of Vertical Transmission in Chronic Viral Hepatitis

Vertical transmission (VT) is the primary route of transmission of viral hepatitis in children.The rate of VT ranges from 1-28% with hepatitis B virus (HBV) and 3-15% with hepatitis C virus (HCV).VT for both viruses can occur during the intrauterine or peripartum period.VT of HBV primarily occurs by intrauterine transmission (IUT).Hepatitis B surface antigen is unable to cross the placenta and,therefore,relies on processes like transplacental leakage,placental infection,cellular transmission by peripheral blood mononuclear cells,and germline transmission.HCV can also infect the fetus by IUT.Both viruses also have the potential for transmission during delivery,when there is increase chance of maternal-fetal blood exposure.HBV and HCV share some common risk factors for VT,including maternal viral load,human immunodeficiency virus co-infection and neonatal sex.Prevention of VT differs greatly between HBV and HCV.There are several alternatives for prevention of HBV VT,including antiviral medications during the third trimester of pregnancy and HBV vaccine,as well as hepatitis B immunoglobulin administration to infants post-partum.In contrast,there are no preventative interventions available for HCV.Despite these differences,the key to prevention with both viruses is screening women prior to and during pregnancy.

Mathematics of dengue transmission dynamics:Roles of vector vertical transmission and temperature fluctuations

A new deterministic model is designed and used to gain insight into the effect of seasonal variations in temperature and vector vertical transmission on the transmission dynamics of dengue disease.The model,which incorporates(among many other features)the dynamics of the immature dengue-competent mosquitoes,vertical transmission in the vector population,density-dependent larval mortality and temperature effects,is rigorously analysed and simulated using data relevant to the disease dynamics in Chiang Mai province of Thailand.The non-trivial disease-free equilibrium of the model is shown to be globallyasymptotically stable when the associated basic reproduction number of the model is less than unity.Numerical simulations of the model,using data relevant to the disease dynamics in the Chiang Mai province of Thailand,show that vertical transmission in the vector population has only marginal impact on the disease dynamics,and that the effect of vertical transmission is temperature-dependent(in particular,the effect of vertical transmission on the disease dynamics increases for values of the mean monthly temperature in the range[16-28]℃,and decreases with increasing mean monthly temperature thereafter).It is further shown that dengue burden(as measured in terms of disease incidence)is maximized when the mean monthly temperature is in the range[26-28]℃(and dengue burden decreases for mean monthly temperature values above 28℃).Thus,this study suggests that anti-dengue control efforts should be intensified during the period when this temperature range is recorded in the Chiang Mai province(this occurs between June and August).

Vertical transmission of hepatitis B virus:propositions and future directions

Chronic hepatitis B virus(HBV)infection due to vertical transmission remains a critical concern with regards to eliminating HBV infection.Implementation of hepatitis B vaccine,the foundation to prevent perinatal and horizontal transmission,has reduced the prevalence of HBV by>80%.In countries where the hepatitis B immune globulin(HBIG)is available,such as China and the United States,the administration of HBIG and hepatitis B vaccine to the infants of mothers who are positive for hepatitis B surface antigen has become a standard practice and is effective in preventing vertical transmission.Accumulating evidence on the efficacy and safety of antiviral prophylaxis during pregnancy indicates the probability of attaining the goal of the World Health Organization to eliminate hepatitis by 2030.In this review,we discuss the transmission routes,diagnostic criteria,and preventive strategies for vertical transmission.A preventive program that includes screening before pregnancy,antiviral prophylaxis during pregnancy,and postpartum immunoprophylaxis provides“perfect strategies”to eliminate vertical transmission.However,there is still a notable gap between“perfect strategies”and real-world application,including insufficient coverage of timely birth dose vaccine and the efficacy and necessity of HBIG,especially in mothers who are negative for hepatitis B envelope antigen.In particular,there is a clear need for a comprehensive long-term safety profile of antiviral prophylaxis.Therefore,feasible and cost-effective preventive strategies need to be determined across regions.Access also needs to be scaled up to meet the demands for prophylaxis and prevalence targets.

Semen extracellular vesicles mediate vertical transmission of subgroup J avian leukosis virus

Subgroup J avian leukosis virus(ALV-J) is a highly oncogenic retrovirus that has been devastating the global poultry industry since the late 1990s. The major infection model of ALV-J is vertical transmission, which is responsible for the congenital infection of progeny from generation to generation. Increasing evidence has suggested that extracellular vesicles(EVs) derived from virus-infected cells or biological fluids have been thought to be vehicles of transmission for viruses. However, the role of EVs in infection and transmission of ALV-J remains obscure. In the present study, semen extracellular vesicles(SE) were isolated and purified from ALV-J-infected rooster seminal plasma(SE-ALV-J), which was shown to contain ALV-J genomic RNA and partial viral proteins, as determined by RNA sequencing, reverse transcription-quantitative PCR and Western blotting. Furthermore, SE-ALV-J was proved to be able to transmit ALV-J infection to host cells and establish productive infection.More importantly, artificial insemination experiments showed that SE-ALV-J transmitted ALV-J infection to SPF hens, and subsequently mediated vertical transmission of ALV-J from the SPF hens to the progeny chicks. Taken together, the results of the present study suggested that ALV-J utilized host semen extracellular vesicles as a novel means for vertical transmission, enhancing our understanding on mechanisms underlying ALV-J transmission.

Mathematical model of Zika virus with vertical transmission

Zika is a flavivirus transmitted to humans through either the bites of infected Aedes mosquitoes or sexual transmission.Zika has been linked to congenital anomalies such as microcephaly.In this paper,we analyze a new system of ordinary differential equations which incorporates human vertical transmission of Zika virus,the birth of babies with microcephaly and asymptomatically infected individuals.The Zika model is locally and globally asymptotically stable when the basic reproduction number is less than unity.Our model shows that asymptomatic individuals amplify the disease burden in the community,and the most important parameters for ZIKV spread are the death rate of mosquitoes,the mosquito biting rate,the mosquito recruitment rate,and the transmission per contact to mosquitoes and to adult humans.Scenario exploration indicates that personal-protection is a more effective control strategy than mosquito-reduction strategy.It also shows that delaying conception reduces the number of microcephaly cases,although this does little to prevent Zika transmission in the broader community.However,by coupling aggressive vector control and personal protection use,it is possible to reduce both microcephaly and Zika transmission.2000 Mathematics Subject Classifications:92B05,93A30,93C15.

Isolation and Progeny Transmission of Non-Temperature-Sensitive MS-H Vaccine Strains of Mycoplasma synoviae from Temperature-Sensitive MS-H-Vaccinated Laying Breeder Hens

This pilot study reports the vertical transmission and reverse thermosensitivity of the MS-H vaccine strain of Mycoplasma synoviae (MS) by RAPD in commercial breeders and their progeny. At two weeks of age, breeders were vaccinated with the ts+ MS-H strain. At 9 weeks of age, an outbreak of infectious synovitis (IS) was detected in the progeny. Tracheal swab samples were collected from breeders at 24, 39, 48, and 70 weeks of age. At 9 weeks, pullets swab from the elbow joints were collected. RAPD was performed on the isolates at 39.5°C, and the same ts- MS-H strains were identified in the breeder hens and their progeny. Tracheal swabs from breeder hens were negative to MS isolation at 37°C and 39.5°C at 24- and 39-weeks. MS isolation was recovered from tracheal swabs from 9/10 and 10/10 breeders at 48- and 70- week. At 9 weeks of age in the progeny, MS was isolated from tracheal swabs of 10/10 from non-IS pullets. MS was isolated from 9/10 joints samples. The isolates from breeder hens and their progeny showed non-significant differences in five antimycoplasmic MIC100 values;otherwise, enrofloxacin presented a significant difference in MIC100 value (p < 0.05). This investigation demonstrated the reversal of the thermosensitivity, pathogenicity, and vertical transmission of the MS-H strain. Consequently, it is crucial to contemplate the danger of reversing pathogenicity and transmission to progeny when applying the MS-H vaccine strain.

Risk Factors and Prevalence of Mother to New-Born Transmission of Carbapenemase Producing Enterobacteriaceae in Two Hospitals in Yaounde, Cameroon

Background: In African countries, where the burden of neonatal sepsis is the highest, the spread of Carbapenemases Producing Enterobacteriaceae (CPE) in the community, potentially contributing to neonatal mortality, is a public health concern. The transmission routes are not well defined, particularly the possible key role played by pregnant women. The aim of this study was to understand the neonatal acquisition of CPE in Yaounde, Cameroon. Methods: A transversal analytical study was conducted in an urban area. Maternal stool samples during delivery and the first stool from their new-born were collected and cultured to isolate Enterobacteria. After isolation, characterization using API20E identification system, and antibiotic susceptibility testing were performed according to the Antibiogram Committee of the French Society of Microbiology. Carbapenemases detection was done on each carbapenem-resistant strain using the Modified Hodge Test (MHT) and their classification using the synergy tests with different inhibitors. Results: Out of the 55 CPE isolates identified, Escherichia coli was the most encountered bacteria both in mothers (n = 18, 50.00%) and infants (n = 11, 57.89%). Class B and D carbapenemases were found both in mothers and infants. The estimated prevalence of vertical transmission in our study, was 10% (n = 12). Logistic regression showed that CPE carriage in mothers and CPE acquisition in their new-borns were independently associated with the presence of greenish amniotic fluid (OR = 7.33, p 0.0001 in mothers and OR = 4.09, p = 0.0086 in new-borns). Conclusion: Our results highlight the non-negligeable role played by pregnant women in the neonatal acquisition of CPE.

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.

The Dynamic Behavior of a Discrete Vertical and Horizontal Transmitted Disease Model under Constant Vaccination

In this paper, a class of discrete vertical and horizontal transmitted disease model under constant vaccination is researched. Under the hypothesis of population being constant size, the model is transformed into a planar map and its equilibrium points and the corresponding eigenvalues are solved out. By discussing the influence of coefficient parameters on the eigenvalues, the hyperbolicity of equilibrium points is determined. By getting the equations of flows on center manifold, the direction and stability of the transcritical bifurcation and flip bifurcation are discussed.