Vertical Transmission Of Virus Research Articles

SARS-CoV-2 vertical transmission during the first trimester of pregnancy in asymptomatic women

ObjectiveIt is now well established that in utero vertical SARS-CoV-2 transmission can occur during the late third trimester. However, little is known about other gestational ages. Recently, an increased risk of early miscarriage was reported in SARS-CoV-2 positive pregnant women. The objective of the present study is to evaluate the putative SARS-CoV-2 vertical transmission during the first trimester of pregnancy.DesignThis is an observational study on SARS-CoV-2-positive pregnant women during the first trimester. Fetal and syncytiotrophoblastic specimens were collected by hysterosuction from seventeen SARS-CoV-2-positive pregnant women who voluntarily terminated the pregnancy between week 8 and 12. We investigated the viral vertical transmission, by the means of SARS-CoV-2 RNA detection in fetus and syncytiotrophoblast, by two different techniques.ResultsResults suggest that SARS-CoV-2 vertical transmission is indeed possible during the first trimester in asymptomatic women. While maternal viremia was never detected, roughly 30% of the fetuses and 17% of the syncytiotrophoblasts resulted to be SARS-CoV-2-positive.ConclusionIndeed, SARS-CoV-2 is able to spread to the fetus through the syncytiotrophoblast. Concerningly, this happens in asymptomatic pregnant women as well. Long-term possible detrimental consequences on fetal development still need to be assessed. This should be taken into consideration in the management of pregnant women by implementing preventive strategies.

Vertical transmission of acute respiratory syndrome viruses from mother to the foetus

Since early in month of Dec-2019, the infection of Coronavirus Disease 19 has been prevalent in Wuhan City of China and ultimately virus spread to other countries. Literature survey was carried out by using different scientific sources such as PubMed, Scopus, Google scholar etc. There is a scarcity of literature of COVID-19 happening at some stage in pregnant women and possibilities of transmission vertically are may be due to COVID-19. So, there is an alarm situation as foetus may be at risk of congenital COVID-19. Up until August 28, 2020, we investigated at the risk of COVID-19 vertical transmission to the foetus of infected women using a database of published articles and government sites. Middle East Respiratory Syndrome MERS and Severe acute Respiratory syndrome SARS were related to poor obstetrical conclusion, so there was no recognized case of ‘intrauterine transmission’ of either Middle East Respiratory Syndrome-coronavirus (MERS-CoV) or severe acute Respiratory syndromecoronavirus (SARS-CoV).

Vertical Transmission of Sindbis Virus in Culex Mosquitoes.

Simple SummaryThe transmission of vector-borne viruses requires arthropod vectors that are actively seeking for new blood-meal hosts. In regions where vectors do not blood-feed for prolonged periods, the persistence of a virus depends on alternative mechanisms of transmission, such as the transmission of a virus from an infected arthropod mother to her offspring, via so-called vertical transmission. Far less is known about this type of transmission than about transmission between vertebrate hosts, and it is often viewed as rarely occurring. Sindbis virus is one of many mosquito-borne viruses that originates in the tropics and has become introduced and established in temperate regions. In its northern range, the virus must persist through several months of winter when its mosquito vectors are inactive. In this study, we investigated the vertical transmission of Sindbis virus, both experimentally and in the field, and found evidence from the field that it does occur but with conflicting results in the experiments. This new knowledge highlights factors which are necessary for tropical viruses to establish in temperate regions.Vertical transmission (VT) is a phenomenon of vector-borne diseases where a pathogen is transferred from an infected arthropod mother to her offspring. For mosquito-borne flavi- and alphaviruses, VT is commonly viewed as rare; however, both field and experimental studies report on vertical transmission efficiency to a notably varying degree. It is likely that this reflects the different experimental methods used to test vertical transmission efficiency as well as differences between virus–vector combinations. There are very few investigations of the VT of an alphavirus in a Culex vector. Sindbis virus (SINV) is an arthritogenic alphavirus that utilizes Culex species as main vectors both in the summer transmission season and for its persistence over the winter period in northern latitudes. In this study, we investigated the vertical transmission of the SINV in Culex vectors, both in the field and in experimental settings. The detection of SINV RNA in field-collected egg rafts and emerging adults shows that vertical transmission takes place in the field. Experimentally infected females gave rise to adult offspring containing SINV RNA at emergence; however, three to four weeks after emergence none of the offspring contained SINV RNA. This study shows that vertical transmission may be connected to SINV’s ability to persist throughout northern winters and also highlights many aspects of viral replication that need further study.

Vertical and Horizontal Transmission of Cell Fusing Agent Virus in Aedes aegypti.

Cell fusing agent virus (CFAV) is an insect-specific flavivirus (ISF) found in Aedes aegypti mosquitoes. ISFs have demonstrated the ability to modulate the infection or transmission of arboviruses such as dengue, West Nile, and Zika viruses. It is thought that vertical transmission is the main route for ISF maintenance in nature. This has been observed with CFAV, but there is evidence of horizontal and venereal transmission in other ISFs. Understanding the route of transmission can inform strategies to spread ISFs to vector populations as a method of controlling pathogenic arboviruses. We crossed individually reared male and female mosquitoes from both a naturally occurring CFAV-positive Ae. aegypti colony and its negative counterpart to provide information on maternal, paternal, and horizontal transmission. RT-PCR was used to detect CFAV in individual female pupal exuviae and was 89% sensitive, but only 42% in male pupal exuviae. This is a possible way to screen individuals for infection without destroying the adults. Female-to-male horizontal transmission was not observed during this study. However, there was a 31% transmission rate from mating pairs of CFAV-positive males to negative female mosquitoes. Maternal vertical transmission was observed with a filial infection rate of 93%. The rate of paternal transmission was 85% when the female remained negative, 61% when the female acquired CFAV horizontally, and 76% overall. Maternal and paternal transmission of CFAV could allow the introduction of this virus into wild Ae. aegypti populations through male or female mosquito releases, and thus provides a potential strategy for ISF-derived arbovirus control. IMPORTANCE Insect-specific flaviviruses (ISFs), are a group of nonpathogenic flaviviruses that only infect insects. ISFs can have a high prevalence in mosquito populations, but their transmission routes are not well understood. The results of this study confirm maternal transmission of cell fusing agent virus (CFAV) and demonstrate that paternal transmission is also highly efficient. Horizontal transmission of CFAV was also observed, aided by evaluation of the pupal infection status before mating with an infected individual. This technique of detecting infection in discarded pupae exuviae has not been evaluated previously and will be a useful tool for others in the field of studying viral transmission in mosquitoes. Identifying these routes of transmission provides information about how CFAV could be maintained in wild populations of mosquitoes and can aid future studies focusing on interactions of CFAV with their hosts and other viruses that infect mosquitoes.

Pro-Inflammatory Profile of Children Exposed to Maternal Chikungunya Virus Infection during the Intrauterine Period: A One-Year Follow-Up Study.

Chikungunya virus (CHIKV) vertical transmission occurs due to maternal viremia in the prepartum. Clinical presentation in neonates can be varied; however, the consequences of intrauterine exposure on the immune response are unclear. Thus, we aimed to analyze inflammatory alterations in children exposed to maternal CHIKV infection. This is a cross-sectional study that included children exposed to maternal CHIKV infection (confirmed by RT-qPCR and/or IgM). Circulant immune mediators were analyzed by a multiplex assay. RESULTS: We included 33 children, with a mean age of 3 ± 2.9 months-old, and 19 (57.6%) were male. Only one child presented neurological alterations. CHIKV-exposed infants showed elevated levels of MIP-1α, MIP-1β, and CCL-2 (p < 0.05). Pro-inflammatory cytokines such as TNFα, IL-6, and IL-7 (p < 0.0001) were also increased. In addition, lower levels of PDGF-BB and GM-CSF were observed in the same group (p < 0.0001). Principal component (PC) analysis highlighted a distinction in the inflammatory profile between groups, where PC explained 56.6% of the alterations. Our findings suggest that maternal exposure to CHIKV can affect the circulating levels of pro-inflammatory cytokines during the infants’ first year of life. The long-term clinical consequences of these findings should be investigated.

Correlation between Pregnancy Outcome and Placental Pathology in COVID-19 Pregnant Women.

Background Vertical transmission of several viruses during pregnancy has been shown to cause adverse fetal outcomes. The question about the possibility of a similar outcome in association with SARS-CoV-2 has been raised in recently published articles. Indeed, the rate of transmission through the placenta to the fetus reported in women with COVID-19 has been shown to form a minority. The aim of this study was to explore the possible histopathological changes in the placenta of pregnant women with COVID-19 after delivery and those changes in the umbilical cord. Methods A case-control study including a total of 50 full-term pregnant women with COVID-19 and 60 control pregnant females. Histopathological evaluation of placental tissues and umbilical cords were reported. Results The main findings in the umbilical cord were increased thickness of vessels, thrombus formation, endothelins, and narrow lumen; except for the increased thickness of blood vessels, these findings were more frequently seen in women with COVID-19, in comparison with control women in a significant manner (p < 0.05). Increased thickness of blood vessels was more significantly observed in the control group compared to the COVID-19 group (p < 0.01). Findings of the placenta included avascular villi, fibrin, thrombosis, and meconium macrophage in various combinations. Except for fibrin as the sole findings, all other findings including combinations were more frequently encountered in the study group in comparison to the control group (p < 0.05). Conclusion Pregnant women with COVID-19 have significant pathological alterations in the placenta and umbilical cord. These findings reflect the capability of SARS-CoV-2 in causing immunological reactions to the placenta, either directly or indirectly, and these pathologies may be linked to the higher rate of adverse neonatal outcomes and maternal admission to the intensive care unit.

Research Note: The prevalence and vertical transmission of avian hepatitis E virus novel genotypes in Tai'an city, China

To investigate the prevalence of avian hepatitis E virus (HEV) in chickens and gather evidence of viral vertical transmission, we collected 288 cloacal swabs and 288 yolks samples from 12 farms with clinically healthy chickens in 4 different areas in Tai'an City, Shandong Province, China (i.e., Daiyue District, Xintai City, Feicheng City, and Ningyang County). We also collected 240 samples from 2 breeder farms (from each of which 30 chicks, 30 dead embryos, 30 live embryos, and 30 hatching eggs were taken). PCR detection revealed that the positive rates of cloacal swabs and yolks were 6.25% (18/288) and 4.51% (13/288), respectively. Besides, avian HEV was detected with higher positive rates in the chicks (11.67%), hatching eggs (10.00%), live embryos (13.33%), and dead embryos (26.67%) from 2 breeder farms. Sequence and genetic evolution analyses revealed that the nucleotide homology of the isolated strains was 76.4to 83.9% compared with 4 reported genotypes, but the isolated strains were located in a separate branch, indicating they were potential novel genotypes. In conclusion, those results indicate that the latent infection of avian HEV novel genotypes has been widespread in chicken farms in Tai'an City, and provide reliable evidence of the possible vertical transmission of avian HEV.

Impact of Novel Coronavirus (COVID-19) on Pregnant Women: A Review

The novel coronavirus infection (COVID-19) is a global public health emergency. Since its outbreak in Wuhan, China in December 2019, the infection has spread at an alarming rate across the globe and humans have been locked down to their countries, cities and homes. As of now, the virus has affected over 20 million people globally and has inflicted over 7 lac deaths. Nevertheless, the recovery rate is improving with each passing day and over 14 million people have recuperated so far. The statistics indicate that nobody is immune to the disease as the virus continues to spread among all age groups, newborns to the elders, and all compartments including pregnant women. However, pregnant women may be more susceptible to this infection as they are, in general, highly vulnerable to respiratory infections. There is no evidence for vertical transmission of the COVID-19 virus among pregnant women, but an increased prevalence of preterm deliveries. Besides this, the COVID-19 may alter immune response at the maternal-fetal interface and affect the well-being of mothers as well as infants. Unfortunately, there is limited evidence available in the open literature regarding coronavirus infection during pregnancy and it now appears that certain pregnant women have been infected during the present 2019-nCoV pandemic. In this perspective, we study the impact of the COVID-19 infection on vertical transmission and fetal outcomes among pregnant women.

Issue Cover

The cover image is based on the Review Article Tenofovir disoproxil fumarate therapy to prevent hepatitis B virus vertical transmission—A review of maternal and infant outcomes by Golasa Samadi Kochaksaraei et al., https://doi.org/10.1111/liv.15249.

EXPERIENCE OF COVID 19 IN PREGNANCY IN FERTILITY CENTER: A CASE SERIES

Objective: To evaluate antenatal course and obstetrics outcomes of pregnancies affected by coronavirus disease (COVID 19). A retrospective study was performed in 15 pregnant women infected by COVID 19. TheirMethods: symptoms during pregnancy, obstetric outcomes and perinatal outcomes were reviewed. The most commonResults: symptoms of pregnant women with COVID 19 infection were fever, cold and cough. All patients with mild and moderate symptoms were managed at home. 14 patients were delivered in third trimester. The incidence of preterm birth due to preterm premature rupture of membranes and preterm labor pains was 20%. One patient had severe preeclampsia with severe oligohydramnios at 20 weeks, so termination of pregnancy was done. No neonatal SARS-CoV-2 infection was detected. There were no complications detected in neonates. In this case series study, it was concluded thatConclusion: COVID-19 had no major short-term or long-term adverse effect on pregnant women and neonates. There was no vertical transmission of virus in these cases. There was slight increase of preterm premature rupture of membrane and preterm delivery rate but as same as in other viral infections. This study was conducted in fertility center and is one of the few studies done in fertility center in India.

Hepatitis B virus Vertical Transmission in Booked Pregnant Women in Abuja, Nigeria

Background: Perinatal (vertical) transmission has remained the most important route of spread of Hepatitis B Virus in many endemic areas worldwide. Determining magnitude of vertical transmission to the new born fetuses may allow for planning and modification of strategies to curtail the menace.Objectives: To determine the prevalence of vertical transmission and Sero-prevalence of Hepatitis B virus infection rate in pregnant women in Abuja, Nigeria. Materials and Methods: This was a longitudinal, cohort study involving one hundred and five (105) pregnantwomen that were serially recruited between January 2nd and March 31st, 2013 and tested for serum Hepatitis B surface antigen (HBsAg) using commercial rapid diagnostic Elisa kits. Those women that were positive for HBsAg were tested for envelope antigen(HBeAg) variant. Recruited patients were followed up till delivery. The data was analyzed using statistical package for social sciences (SPSS) version 17. P-value of &lt; 0.05 was considered as statistically significant. The results were presented as Simple per cents and chisquare was employed to test for the significance.Results: There were 8 pregnant women that were positive for HBsAg among 105 consecutive women, giving a prevalence rate of 7.6%. There was no in-utero (vertical) transmission recorded in the study population.Conclusion: The prevalence of HBsAg is relatively high but with zero pre-natal vertical transmission. Proper precautionary measures at delivery are however advocated to keep the vertical transmission at its lowest bearable status.

Consequences of Transplacental Transmission of the SARS-CoV-2 Virus: A Single-Center Experience

The issues of vertical viral transmission from mother to fetus and the potential complications caused by SARS-CoV-2 coagulopathy are still unclear. There are few literature data about the vertical transmission of SARS-CoV-2 and health outcomes in neonates born to mothers with symptomatic or asymptomatic coronavirus disease, with the existing data based on small sample sizes. This case series study consists of two newborn children (one pre-term and one term) who were born to SARS-CoV-2-positive mothers and admitted to the neonatal intensive care unit a few hours after birth. One child had cyanotic changes that affected the entire left leg and the left forearm, with multiple livid changes on the front of the chest and abdomen, the right upper arm, right thigh, neck, and face, and one child had an altered umbilical cord. The first child was treated conservatively, and the second child was treated surgically.

A mother's perspective of consent for maternal and neonatal COVID-19 testing: can we do more?

Background There is ongoing research on the effects of COVID-19 on pregnancy and whether vertical viral transmission occurs. Aims This study aimed to determine maternal opinions of COVID-19 testing for pregnant women and newborns in order to influence future clinical practice while advancing global knowledge of the impact of testing on patient experiences. Methods This service evaluation assessed the opinions of 292 pregnant women who were tested for COVID-19 along with their newborn babies using nasopharyngeal swabs and the SARS-CoV-2 reverse transcription polymerase chain reaction test between 28 April and 21 May 2020. Results Many women felt their own (60%) and their baby's (61%) swab was compulsory and did not feel sufficiently informed about the risks and benefits for themselves (43%) or their baby (52%) being tested. Some women did not understand the implications of a positive test for themselves (43%) or their baby (42%). Most participants reported they would agree to themselves (97%) and their baby (86%) being tested in future pregnancies. Conclusion Communication to pregnant women regarding the COVID-19 swabbing process is critical and requires improvement. This service evaluation highlighted where women felt under-informed. These areas should be covered in more detail for consenting women for COVID-19 testing in future.

A Novel Pathway for Porcine Epidemic Diarrhea Virus Transmission from Sows to Neonatal Piglets Mediated by Colostrum.

ABSTRACTThe mechanisms of colostrum-mediated virus transmission are difficult to elucidate because of the absence of experimental animal models and the difficulties in tissue sample collection from mothers in the peripartum period. Porcine epidemic diarrhea virus (PEDV) is a reemerging enteropathogenic coronavirus that has catastrophic impacts on the global pig industry. PEDV primarily infects neonatal piglets by multiple routes, especially 1- to 2-day-old neonatal piglets. Here, our epidemiological investigation and animal challenge experiments revealed that PEDV could be vertically transmitted from sows to neonatal piglets via colostrum, and CD3+ T cells in the colostrum play an important role in this process. The results showed that PEDV colonizing the intestinal epithelial cells (IECs) of orally immunized infected sows could be transferred to CD3+ T cells located just beneath the IECs. Next, PEDV-carrying CD3+ T cells, with the expression of integrin α4β7 and CCR10, migrate from the intestine to the mammary gland through blood circulation. Arriving in the mammary gland, PEDV-carrying CD3+ T cells could be transported across mammary epithelial cells (MECs) into the lumen (colostrum), as illustrated by an autotransfusion assay and an MECs/T coculture system. The PEDV-carrying CD3+ T cells in colostrum could be interspersed between IECs of neonatal piglets, causing intestinal infection via cell-to-cell contact. Our study demonstrates for the first time that colostrum-derived CD3+ T cells comprise a potential route for the vertical transmission of PEDV.IMPORTANCE The colostrum represents an important infection route for many viruses. Here, we demonstrate the vertical transmission of porcine epidemic diarrhea virus (PEDV) from sows to neonatal piglets via colostrum. PEDV colonizing the intestinal epithelial cells could transfer the virus to CD3+ T cells located in the sow intestine. The PEDV-carrying CD3+ T cells in the sow intestine, with the expression of integrin α4β7 and CCR10, arrive at the mammary gland through blood circulation and are transported across mammary epithelial cells into the lumen, finally leading to intestinal infection via cell-to-cell contact in neonatal piglets. Our study not only demonstrates an alternative route of PEDV infection but also provides an animal model of vertical transmission of human infectious disease.

Natural Aedes-Borne Virus Infection Detected in Male Adult Aedes aegypti (Diptera: Culicidae) Collected From Urban Settings in Mérida, Yucatán, México.

Aedes-borne viruses (ABVs) such as dengue (DENV), chikungunya (CHIKV), and Zika (ZIKV) contribute significantly to the global burden of infectious diseases, disproportionately affecting disadvantaged populations from tropical and subtropical urban areas. ABVs can be transmitted from female mosquitoes to their progeny by vertical transmission via transovarial and/or trans-egg vertical transmission and contribute to the maintenance of infected-mosquito populations year-round in endemic regions. This study describes the natural infection rate of DENV, CHIKV, and ZIKV in field-caught male Aedes (Sergentomyia) aegypti (Linnaeus) mosquitoes from Mérida, Yucatán, México, as a proxy for the occurrence of vertical virus transmission. We used indoor sequential sampling with Prokopack aspirators to collect all mosquitoes inside houses from ABV hotspots areas. Collections were performed in a DENV and CHIKV post-epidemic phase and during a period of active ZIKV transmission. We individually RT-qPCR tested all indoor collected Ae. aegypti males (1,278) followed by Sanger sequencing analysis for final confirmation. A total of 6.7% male mosquitoes were positive for ABV (CHIKV = 5.7%; DENV = 0.9%; ZIKV = 0.1%) and came from 21.0% (30/143) houses infested with males. Most ABV-positive male mosquitoes were positive for CHIKV (84.8%). The distribution of ABV-positive Ae. aegypti males was aggregated in a few households, with two houses having 11 ABV-positive males each. We found a positive association between ABV-positive males and females per house. These findings suggested the occurrence of vertical arbovirus transmission within the mosquito populations in an ABV-endemic area and, a mechanism contributing to viral maintenance and virus re-emergence among humans in post-epidemic periods.

Overall Vertical Transmission of Hepatitis C Virus, Transmission Net of Clearance, and Timing of Transmission.

It is widely accepted that the risk of hepatitis C virus (HCV) vertical transmission (VT) is 5%-6% in monoinfected women, and that 25%-40% of HCV infection clears spontaneously within 5 years. However, there is no consensus on how VT rates should be estimated, and there is a lack of information on VT rates "net" of clearance. We reanalyzed data on 1749 children in 3 prospective cohorts to obtain coherent estimates of overall VT rate and VT rates net of clearance at different ages. Clearance rates were used to impute the proportion of uninfected children who had been infected and then cleared before testing negative. The proportion of transmission early in utero, late in utero, and at delivery was estimated from data on the proportion of HCV RNA positive within 3 days of birth, and differences between elective cesarean and nonelective cesarean deliveries. Overall VT rates were 7.2% (95% credible interval [CrI], 5.6%-8.9%) in mothers who were human immunodeficiency virus (HIV) negative and 12.1% (95% CrI, 8.6%-16.8%) in HIV-coinfected women. The corresponding rates net of clearance at 5 years were 2.4% (95% CrI, 1.1%-4.1%), and 4.1% (95% CrI, 1.7%-7.3%). We estimated that 24.8% (95% CrI, 12.1%-40.8%) of infections occur early in utero, 66.0% (95% CrI, 42.5%-83.3%) later in utero, and 9.3% (95% CrI, 0.5%-30.6%) during delivery. Overall VT rates are about 24% higher than previously assumed, but the risk of infection persisting beyond age 5 years is about 38% lower. The results can inform design of trials of interventions to prevent or treat pediatric HCV infection, and strategies to manage children exposed in utero.

Zika virus vertical transmission in interferon receptor1-antagonized Rag1\u2212/\u2212 mice results in postnatal brain abnormalities and clinical disease

The mechanisms by which vertically transmitted Zika virus (ZIKV) causes postnatal brain development abnormalities and congenital disease remain poorly understood. Here, we optimized the established anti-IFNAR1 treated, Rag1−/− (AIR) mouse model of ZIKV infection to examine the consequence of vertical transmission on neonate survival and postnatal brain development. We found that modulating the infectious dose and the frequency of anti-IFNAR1 treatment of pregnant mice (termed AIRlow mice) prolonged neonatal survival allowing for pathogenesis studies of brain tissues at critical postnatal time points. Postnatal AIRlow mice all had chronic ZIKV infection in the brain that was associated with decreased cortical thickness and cerebellar volume, increased gliosis, and higher levels of cell death in many brain areas including cortex, hippocampus and cerebellum when compared to controls. Interestingly, despite active infection and brain abnormalities, the neurodevelopmental program remained active in AIRlow mice as indicated by elevated mRNA expression of critical neurodevelopmental genes in the brain and enlargement of neural-progenitor rich regions of the cerebellum at a developmental time point analogous to birth in humans. Nevertheless, around the developmental time point when the brain is fully populated by neurons, AIRlow mice developed neurologic disease associated with persistent ZIKV infection in the brain, gliosis, and increased cell death. Together, these data show that vertically transmitted ZIKV infection in the brain of postnatal AIRlow mice strongly influences brain development resulting in structural abnormalities and cell death in multiple regions of the brain.

Dengue virus transovarial transmission detection in Aedes aegypti from dengue hemorrhagic fever patients' residences in Denpasar, Bali.

Background and Aim:To effectively control dengue hemorrhagic fever (DHF), it is necessary to assess the risk of vertical virus transmission in Aedes aegypti mosquitoes. This study aimed to detect dengue virus (DENV) transovarial transmission in A. aegypti collected from DHF patients’ residences in Denpasar, Bali.Materials and Methods:A. aegypti samples were acquired by rearing A. aegypti eggs collected from ovitraps placed in the homes of DHF patients. Ovitraps were installed for 7 days and viewed using a loupe to determine whether there were Aedes spp. eggs present. An immunocytochemical method was utilized with 200 samples, and virus detection was performed using a reverse transcriptase-polymerase chain reaction (RT-PCR).Results:Of the 10 DHF patient houses fitted with ovitraps, four produced positive ovitraps from which larvae developed (house index=40%). Of the 50 ovitraps mounted in the 10 homes, 14 ovitraps were positive and contained A. aegypti eggs (ovitrap index=28%). Of these 14 positive ovitraps containing A. aegypti eggs, 10 ovitraps produced larvae. Immunocytochemical tests were conducted on A. aegypti eggs from the four houses under study. It was found that from the 200 samples collected, 197 samples could be observed, and 11 samples (5.6%) were positive for DENV antigen. RT-PCR examination conducted on mosquitoes reared from the four houses studied obtained a negative virus content result.Conclusion:This study found the presence of DENV antigen to be as high as 5.6%. This means that potential for transovarial transmission exists within DHF patients’ homes in Denpasar, Bali. Aedes control strategy in Denpasar should address this finding, in addition to the current approaches which have focused primarily on the elimination of larval breeding habitats and control of adults using insecticidal fogging during outbreaks.

Tenofovir disoproxil fumarate therapy to prevent hepatitis B virus vertical transmission-A review of maternal and infant outcomes.

Hepatitis B virus (HBV) is a global health problem. Vertical transmission of HBV from HBV surface antigen (HBsAg)-positive mothers to their infants is the most common cause of HBV infection worldwide. The use of passive-active immunoprophylaxis is >90% effective in reducing the risk of vertical transmission, but immunoprophylaxis failure can occur in infants born to mothers with high viraemia. Thus, it is recommended that pregnant women with HBV-DNA level >200 000 IU/ml receive nucleos(t)ide analogue (NA) treatment [i.e. tenofovir disoproxil fumarate (TDF), lamivudine or telbivudine] during third trimester to prevent infant immunoprophylaxis failure. TDF is recommended as the first-line therapy based on available data on efficacy, safety and resistance profile. However, maternal immunological reconstitution following parturition can increase immune-mediated flares to viral antigens that is potentially exacerbated following TDF withdrawal. In this article, we review available data on the efficacy and safety of TDF administration to prevent HBV mother-to-child transmission. We also discuss changes in maternal viral markers [i.e. HBV-DNA, HBV e antigen and HBsAg] and alanine aminotransferase during follow-up post-partum in mothers received NA to prevent HBV vertical transmission.

Vertical Virus Transmission from SARS-CoV-2-positive Mothers to Neonates: A Tertiary Care Hospital Experience

Objectives: The coronavirus disease 2019 (COVID-19) outbreak is evolving rapidly worldwide. However, little is known about the association between pregnant women with COVID-19 and its transmission to neonates. This investigation aimed to see if COVID-19 infection could be transmitted vertically into the uterus. Methods: We conducted a prospective observational study. 48 COVID-19 infected mothers were enrolled during their third trimester. A qRT-PCR assay of the nasal and oropharyngeal swab samples was performed to confirm positive for COVID-19 infection as per WHO protocol. In addition, characteristics of pregnant women with confirmed SARS -CoV-2 infection and newborns were documented. Results: Forty-eight expectant mothers, 10 (20.8%) were found symptomatic, and 38 (79.2%) were asymptomatic, with COVID-19 infection were delivered (33 cesarean section & 15 vaginal deliveries). One female child (4.1%) out of 48 newborns was initially diagnosed with COVID-19 infection based on a nucleic acid qRT-PCR. The female child showed no or negligible signs and recovered completely, whereas 47 neonates (95.9%) confirmed negative. None of the mothers or neonates died from COVID-19 related pulmonary problems. Conclusion: There is insufficient evidence on vertical virologic transmission of COVID-19 infection during the third trimester of pregnancy. Additionally, research and surveillance involving adequate testing of samples of placental tissue, breast milk, vaginal swab, amniotic fluid, and cord blood will be needed to establish the possibility of vertical transmission of infection. J Microbiol Infect Dis 2022; 12(1):1-5.