Infections at the maternal-fetal interface: an overview of pathogenesis and defence.

Infections are a major threat to human reproductive health, and infections in pregnancy can cause prematurity or stillbirth, or can be vertically transmitted to the fetus leading to congenital infection and severe disease. The acronym 'TORCH' (Toxoplasma gondii, other, rubella virus, cytomegalovirus, herpes simplex virus) refers to pathogens directly associated with the development of congenital disease and includes diverse bacteria, viruses and parasites. The placenta restricts vertical transmission during pregnancy and has evolved robust mechanisms of microbial defence. However, microorganisms that cause congenital disease have likely evolved diverse mechanisms to bypass these defences. In this Review, we discuss how TORCH pathogens access the intra-amniotic space and overcome the placental defences that protect against microbial vertical transmission.

Release of HSV-1 Cell-Free Virions: Mechanisms, Regulation, and Likely Role in Human-Human Transmission.

Herpes simplex virus type 1, or HSV-1, is a widespread human pathogen that replicates in epithelial cells of the body surface and then establishes latent infection in peripheral neurons. When HSV-1 replicates, viral progeny must be efficiently released to spread infection to new target cells. Viral spread occurs via two major routes. In cell-cell spread, progeny virions are delivered directly to cellular junctions, where they infect adjacent cells. In cell-free release, progeny virions are released into the extracellular milieu, potentially allowing the infection of distant cells. Cell-cell spread of HSV-1 has been well studied and is known to be important for in vivo infection and pathogenesis. In contrast, HSV-1 cell-free release has received less attention, and its significance to viral biology is unclear. Here, I review the mechanisms and regulation of HSV-1 cell-free virion release. Based on knowledge accrued in other herpesviral systems, I argue that HSV-1 cell-free release is likely to be tightly regulated in vivo. Specifically, I hypothesize that this process is generally suppressed as the virus replicates within the body, but activated to high levels at sites of viral reactivation, such as the oral mucosa and skin, in order to promote efficient transmission of HSV-1 to new human hosts.

Cell-to-cell transmission of HSV1 in human keratinocytes in the absence of the major entry receptor, nectin1.

Herpes simplex virus 1 (HSV1) infects the stratified epithelia of the epidermis, oral or genital mucosa, where the main cell type is the keratinocyte. Here we have used nTERT human keratinocytes to generate a CRISPR-Cas9 knockout (KO) of the primary candidate HSV1 receptor, nectin1, resulting in a cell line that is refractory to HSV1 entry. Nonetheless, a small population of KO cells was able to support infection which was not blocked by a nectin1 antibody and hence was not a consequence of residual nectin1 expression. Strikingly at later times, the population of cells originally resistant to HSV1 infection had also become infected. Appearance of this later population was blocked by inhibition of virus genome replication, or infection with a ΔUL34 virus defective in capsid export to the cytoplasm. Moreover, newly formed GFP-tagged capsids were detected in cells surrounding the initial infected cell, suggesting that virus was spreading following replication in the original susceptible cells. Additional siRNA depletion of the second major HSV1 receptor HVEM, or PTP1B, a cellular factor shown elsewhere to be involved in cell-to-cell transmission, had no effect on virus spread in the absence of nectin1. Neutralizing human serum also failed to block virus transmission in nectin1 KO cells, which was dependent on the receptor binding protein glycoprotein D and the cell-to-cell spread glycoproteins gI and gE, indicating that virus was spreading by direct cell-to-cell transmission. In line with these results, both HSV1 and HSV2 formed plaques on nectin1 KO cells, albeit at a reduced titre, confirming that once the original cell population was infected, the virus could spread into all other cells in the monolayer. We conclude that although nectin1 is required for extracellular entry in to the majority of human keratinocytes, it is dispensable for direct cell-to-cell transmission.

Seroprevalence of Chlamydia trachomatis, herpes simplex 2, Epstein-Barr virus, hepatitis C and associated factors among a cohort of men ages 18-70 years from three countries.

OBJECTIVES: To estimate the seroprevalence of Chlamydia trachomatis (CT), herpes simplex type-2 (HSV2), hepatitis C (HCV), Epstein-Barr virus (EBV) and nine human papilloma virus (HPV) types, and investigated factors associated with the seropositivity among men from three countries (Brazil, Mexico and U.S). METHODS: Archived serum specimens collected at enrollment for n = 600 men were tested for antibodies against CT, HSV2, HCV, EBV, and 9-valent HPV vaccine types (6/11/16/18/31/33/45/52/58) using multiplex serologic assays. Socio-demographic, lifestyle and sexual behavior data at enrollment were collected through a questionnaire. RESULTS: Overall, 39.3% of the men were seropositive for CT, 25.4% for HSV2, 1.3% for HCV, 97.3% for EBV, 14.0% for at least one of the seven oncogenic HPV (types: 16/18/31/33/45/52/58), and 17.4% for HPV 6/11. In the unadjusted models, age, race, smoking, sexual behavior variables, and seropositivity for high-risk HPV were significantly associated with the seropositivity for CT. In multivariable analyses, self-reported black race, higher numbers of lifetime female/male sexual partners, current smoking, and seropositivity to high-risk HPV were significantly associated with increased odds of CT seropositivity. Odds of HSV2 seroprevalence were elevated among older men and those seropositive for high risk HPV. CONCLUSION: Exposure to STIs is common among men. Prevention and screening programs should target high-risk groups to reduce the disease burden among men, and to interrupt the disease transmission to sexual partners.

Management of Viral Complications of Pregnancy: Pharmacotherapy to Reduce Vertical Transmission.

Viral infections are common complications of pregnancy. Although some infections have maternal sequelae, many viral infections can be perinatally transmitted to cause congenital or chronic infection in fetuses or infants. Treatments of such infections are geared toward reducing maternal symptoms and complications and toward preventing maternal-to-child transmission of viruses. The authors review updates in the treatment of herpes simplex virus, cytomegalovirus, hepatitis B and C viruses, human immunodeficiency virus, and COVID-19 during pregnancy.

Ginkgolic Acid Inhibits Herpes Simplex Virus Type 1 Skin Infection and Prevents Zosteriform Spread in Mice.

Herpes simplex virus type 1 (HSV-1) causes a lifelong latent infection with an estimated global prevalence of 66%. Primary and recurrent HSV infections are characterized by a tingling sensation, followed by an eruption of vesicles, which can cause painful erosions. Commonly used antiviral drugs against HSV infection are nucleoside analogues including acyclovir (ACV), famciclovir, and valacyclovir. Although these nucleoside analogues reduce morbidity and mortality in immunocompetent individuals, ACV-resistant HSV strains (ACVR-HSV) have been isolated from immunocompromised patients. Thus, ACVR-HSV infection poses a critical emerging public health concern. Recently, we reported that ginkgolic acid (GA) inhibits HSV-1 by disrupting viral structure, blocking fusion, and inhibiting viral protein synthesis. Additionally, we showed GA affords a broad spectrum of fusion inhibition of all three classes of fusion proteins, including those of HIV, Ebola, influenza A and Epstein Barr viruses. Here we report GA's antiviral activity against HSV-1 skin infection in BALB/cJ mice. GA-treated mice demonstrated a significantly reduced mortality rate and decreased infection scores compared to controls treated with dimethylsulfoxide (DMSO)-vehicle. Furthermore, GA efficiently inhibited ACVR-HSV-1 strain 17+ in vitro and in vivo. Since GA's mechanism of action includes virucidal activity and fusion inhibition, it is expected to work alone or synergistically with other anti-viral drugs, and we anticipate it to be effective against additional cutaneous and potentially systemic viral infections.

HSV-associated proctitis presenting without perianal lesions: why testing and empirical treatment may be important.

A man in his late 30s presented with a several-day history of rectal pain, discharge and bleeding associated with systemic upset. Sexual history revealed receptive anal sex with several male partners in the 2 weeks preceding his clinic visit. Examination of the perianal area was unremarkable. Proctoscopy showed evidence of non-ulcerative proctitis. Microscopy for Gram stain showed pus cells plus extracellular Gram-negative diplococci. The patient was treated for presumptive gonorrhoea and chlamydial infection with ceftriaxone, azithromycin and doxycycline. The patient failed to improve with this treatment regimen. Rectal swab results at 48 hours confirmed the causative agent to be herpes simplex virus (HSV) type 2. The patient was recalled and treated successfully with valaciclovir. This case serves as a useful reminder to clinicians to consider HSV in the differential diagnosis of sexually transmitted proctitis, in the absence of perianal or anorectal ulceration.

HSV-1 and Zika Virus but Not SARS-CoV-2 Replicate in the Human Cornea and Are Restricted by Corneal Type III Interferon.

Here, we report our studies of immune-mediated regulation of Zika virus (ZIKV), herpes simplex virus 1 (HSV-1), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in the human cornea. We find that ZIKV can be transmitted via corneal transplantation in mice. However, in human corneal explants, we report that ZIKV does not replicate efficiently and that SARS-CoV-2 does not replicate at all. Additionally, we demonstrate that type III interferon (IFN-λ) and its receptor (IFNλR1) are expressed in the corneal epithelium. Treatment of human corneal explants with IFN-λ, and treatment of mice with IFN-λ eye drops, upregulates antiviral interferon-stimulated genes. In human corneal explants, blockade of IFNλR1 enhances replication of ZIKV and HSV-1 but not SARS-CoV-2. In addition to an antiviral role for IFNλR1 in the cornea, our results suggest that the human cornea does not support SARS-CoV-2 infection despite expression of ACE2, a SARS-CoV-2 receptor, in the human corneal epithelium.

Premature Rupture of Membranes with Concurrent Viral Infection.

Treatment of viral infections is geared toward ameliorating maternal symptoms and minimizing perinatal transmission. Multidisciplinary teams often are required to manage sequelae due to viral diseases in patients with preterm premature rupture of membranes (PPROM). although data are scarce regarding the antepartum management of common viruses in PPROM, essential principles may be extrapolated from national guidelines and studies in gravid patients. The well-established risks of prematurity are weighed against the often unclear risks of vertical transmission.

Impact of COVID-19 and other viruses on reproductive health.

Male infertility is linked to some viral infections including human papillomavirus (HPV), herpes simplex viruses (HSV) and human immunodeficiency viruses (HIVs). Almost nothing is known about severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) effect on fertility. The possible risk factors of coronavirus disease 2019 (COVID-19) infection on fertility comes from the abundance of angiotensin-Converting Enzyme-2 (ACE2), receptor entry of the virus, on testes, a reduction in important sex hormone ratios and COVID-19-associated fever. Recent studies have shown a gender difference for COVID-19 rates and comorbidity. In this review, we will discuss the potential effect of COVID-19 on male fertility and talk about what needs to be done by the scientific community to tackle our limited understanding of the disease. On the other side, we will focus on what is known so far about the risk of COVID-19 on pregnancy, neonatal health and the vertical transfer of the virus between mothers and their neonates. Finally, because reproduction is a human right and infertility is considered a health disease, we will discuss how assisted reproductive clinics can cope with the pandemic and what guidelines they should follow to minimise the risk of viral transmission.

High Incidence of Herpes Simplex Virus-1 in Cord Blood and Placenta Infection of Women in Southern Brazil.

OBJECTIVE: Estimate the prevalence of human herpesvirus type 1 HSV-1 DNA in placental samples, its incidence in umbilical cord blood of newborns and the associated risk factors. METHODS: Placental biopsies and umbilical cord blood were analyzed, totaling 480 samples, from asymptomatic parturients and their newborns at a University Hospital. Nested polymerase chain reaction (PCR) and gene sequencing were used to identify the virus; odds ratio (OR) and relative risk (RR) were performed to compare risk factors associated with this condition. RESULTS: The prevalence of HSV-1 DNA in placental samples was 37.5%, and the incidence in cord blood was 27.5%. Hematogenous transplacental route was identified in 61.4% from HSV-1+ samples of umbilical cord blood paired with the placental tissue. No evidence of the virus was observed in the remaining 38.6% of placental tissues, suggesting an ascendant infection from the genital tract, without replication in the placental tissue, resulting in intra-amniotic infection and vertical transmission, seen by the virus in the cord blood. The lack of condom use increased the risk of finding HSV-1 in the placenta and umbilical cord blood. CONCLUSION: The occurrence of HSV-1 DNA in the placenta and in cord blood found suggests vertical transmission from asymptomatic pregnant women to the fetus.

OBJETIVO: Estimar a prevalência do DNA do vírus herpes humano 1 (HSV-1) em amostras de placenta, sua incidência no sangue do cordão umbilical de recém-nascidos e fatores de risco associados. MéTODOS: Biópsias de placenta e de sangue de cordão umbilical foram analisadas, totalizando 480 amostras de parturientes assintomáticas e seus recém-nascidos em um hospital universitário. Reação de cadeia de polimerase (RCP) nested e sequenciamento gênico foram usados para identificar o vírus; odds ratio (OR) e risco relativo (RR) foram realizados para comparar os fatores de risco associados à essa condição. RESULTADOS: A prevalência do DNA do HSV-1 em amostras de placenta foi de 37,5%, e a incidência no sangue do cordão foi de 27,5%. A via transplacentária hematogênica foi identificada em 61,4% das amostras de HSV-1 + do sangue do cordão umbilical, pareadas com o tecido placentário. Nenhuma evidência do vírus foi observada nos restantes 38,6% dos tecidos placentários, sugerindo uma infecção ascendente do trato genital. A falta de uso do preservativo aumentou o risco de encontrar o HSV-1 na placenta e no sangue do cordão umbilical. CONCLUSãO: A ocorrência de DNA do HSV-1 na placenta e no sangue do cordão umbilical sugere uma transmissão vertical de gestantes assintomáticas para o feto.

Recent Out-of-Africa Migration of Human Herpes Simplex Viruses.

Herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) are ubiquitous human pathogens. Both viruses evolved from simplex viruses infecting African primates and they are thus thought to have left Africa during early human migrations. We analyzed the population structure of HSV-1 and HSV-2 circulating strains. Results indicated that HSV-1 populations have limited geographic structure and the most evident clustering by geography is likely due to recent bottlenecks. For HSV-2, the only level of population structure is accounted for by the so-called "worldwide" and "African" lineages. Analysis of ancestry components and nucleotide diversity, however, did not support the view that the worldwide lineage followed early humans during out-of-Africa dispersal. Although phylogeographic analysis confirmed an African origin for both viruses, molecular dating with a method that corrects for the time-dependent rate phenomenon indicated that HSV-1 and HSV-2 migrated from Africa in relatively recent times. In particular, we estimated that the HSV-2 worldwide lineage left the continent in the 18th century, which corresponds to the height of the transatlantic slave trade, possibly explaining the high prevalence of HSV-2 in the Americas (second highest after Africa). The limited geographic clustering of HSV-1 makes it difficult to date its exit from Africa. The split between the basal clade, containing mostly African sequences, and all other strains was dated at ∼5,000 years ago. Our data do not imply that herpes simplex viruses did not infect early humans but show that the worldwide distribution of circulating strains is the result of relatively recent events.

High incidence of herpes simplex virus-1 in cord blood and placenta infection of women in southern Brazil / Alta incidência do vírus herpes simplex 1 em sangue de cordão e infecção na placenta de mulheres no sul do Brasil

Abstract Objective Estimate the prevalence of human herpesvirus type 1 HSV-1 DNA in placental samples, its incidence in umbilical cord blood of newborns and the associated risk factors. Methods Placental biopsies and umbilical cord blood were analyzed, totaling 480 samples, from asymptomatic parturients and their newborns at a University Hospital. Nested polymerase chain reaction (PCR) and gene sequencingwere used to identify the virus; odds ratio (OR) and relative risk (RR) were performed to compare risk factors associated with this condition. Results The prevalence of HSV-1 DNA in placental samples was 37.5%, and the incidence in cord blood was 27.5%. Hematogenous transplacental route was identified in 61.4% from HSV-1+ samples of umbilical cord blood paired with the placental tissue. No evidence of the virus was observed in the remaining 38.6% of placental tissues, suggesting an ascendant infection from the genital tract, without replication in the placental tissue, resulting in intra-amniotic infection and vertical transmission, seen by the virus in the cord blood. The lack of condom use increased the risk of finding HSV-1 in the placenta and umbilical cord blood. Conclusion The occurrence of HSV-1 DNA in the placenta and in cord blood found suggests vertical transmission from asymptomatic pregnant women to the fetus.

Resumo Objetivo Estimar a prevalência do DNA do vírus herpes humano 1 (HSV-1) em amostras de placenta, sua incidência no sangue do cordão umbilical de recém-nascidos e fatores de risco associados. Métodos Biópsias de placenta e de sangue de cordão umbilical foram analisadas, totalizando 480 amostras de parturientes assintomáticas e seus recém-nascidos emum hospital universitário. Reação de cadeia de polimerase (RCP) nested e sequenciamento gênico foram usados para identificar o vírus; odds ratio (OR) e risco relativo (RR) foram realizados para comparar os fatores de risco associados à essa condição. Resultados A prevalência do DNA do HSV-1 em amostras de placenta foi de 37,5%, e a incidência no sangue do cordão foi de 27,5%. A via transplacentária hematogênica foi identificada em 61,4% das amostras de HSV-1+do sangue do cordão umbilical, pareadas com o tecido placentário. Nenhuma evidência do vírus foi observada nos restantes 38,6% dos tecidos placentários, sugerindo uma infecção ascendente do trato genital. A falta de uso do preservativo aumentou o risco de encontrar o HSV-1 na placenta e no sangue do cordão umbilical. Conclusão A ocorrência de DNA do HSV-1 na placenta e no sangue do cordão umbilical sugere uma transmissão vertical de gestantes assintomáticas para o feto.

Maternal and neonatal infections of herpes simplex virus-1 and cytomegalovirus in Saudi Arabia.

It is common practice to screen for human cytomegalovirus (CMV) and herpes simplex virus (HSV) among women with infertility problems, recurrent abortion or exhibiting intrauterine growth restriction during pregnancy. Nonetheless, limited information exists about the incidence of these viruses in Saudi Arabia. The IgG and IgM antibodies of 761 women and 85 of neonates who showed intrauterine growth retardation (IUGR) were reviewed against cytomegalovirus and herpes simplex virus-1. Tests were repeated only for those with positive results. Recent infection of herpes simplex virus-1 and cytomegalovirus was evidenced by the presence of IgM in the female patients: incidence was 1.1% and 1.3% respectively. None of the neonates showed positive IgM for cytomegalovirus, but a single case showed a positive result for herpes simplex virus-1 IgM. Among the female patients, however, the presence of IgG indicated previous exposure to cytomegalovirus in 92% of cases and herpes simplex virus in 80.8%. It was concluded that although previous exposure to CMV and HSV-1 were found in high percentages in women experiencing infertility problems but did not appear to be associated with neonates exhibiting intrauterine growth retardation.

Oral Transmission of Sexually Transmissable Infections: A Narrative Review.

Over the last few decades, behavioral changes in sexual practices have made oral transmission of traditional sexually transmissible infections increasingly recognized. Patients harboring a sexually transmissible infection may first present lesions on the oral cavity, as these may be visible and interfere with basic functions such as speech or swallowing. Moreover, the oral cavity may function as a reservoir for future spread of these infections. In order to successfully control this problem, a greater focus on oral sex should be persued, along with promotion of the use of condom and education on safe oral sex practices. Furthermore, examination of the oral cavity should is essential when evaluating any patient suspected of harboring a sexually transmissible infection. In this article, oral transmission of several viral and bacterial infections is reviewed, including human papillomavirus infection, genital herpes, syphilis and gonorrhea, among others.

Com as alterações comportamentais nas práticas sexuais verificadas nas últimas décadas, a transmissão oral de infeções sexualmente transmissíveis tem vindo a ser progressivamente mais reconhecida. As lesões na cavidade oral podem ser visíveis ou interferir com funções básicas como a fala ou deglutição, sendo por isso o motivo de apresentação de muitos destes doentes. Além disso, a cavidade oral pode funcionar como um reservatório para a disseminação futura dessas infecções. Para um controlo adequado deste problema, deve ser prestada uma maior atenção às práticas de sexo oral, à promoção do uso do preservativo e à educação relativamente a práticas sexuais seguras. Por outro lado, o exame da cavidade oral deve ser parte integrante da avaliação de qualquer indivíduo com suspeita de uma infecção sexualmente transmissível. Neste artigo, a transmissão oral de várias infeções virais e bacterianas é revista, nomeadamente a infeção pelo vírus do papiloma humano, herpes genital, sífilis e gonorreia, entre outras.

Genetic and phenotypic intrastrain variation in herpes simplex virus type 1 Glasgow strain 17 syn+-derived viruses.

The Glasgow s17 syn+ strain of herpes simplex virus 1 (HSV1) is arguably the best characterized strain and has provided the reference sequence for HSV1 genetic studies. Here we show that our original s17 syn+ stock was a mixed population from which we have isolated a minor variant that, unlike other strains in the laboratory, fails to be efficiently released from infected cells and spreads predominantly by direct cell-to-cell transmission. Analysis of other s17-derived viruses that had been isolated elsewhere revealed a number with the same release phenotype. Second-generation sequencing of 8 plaque-purified s17-derived viruses revealed sequences that vary by 50 single-nucleotide polymorphisms (SNPs), including approximately 10 coding SNPs. This compared to interstrain variations of around 800 SNPs in strain Sc16, of which a quarter were coding changes. Amongst the variations found within s17, we identified 13 variants of glycoprotein C within the original stock of virus that were predominantly a consequence of altered homopolymeric runs of C residues. Characterization of seven isolates coding for different forms of gC indicated that all were expressed, despite six of them lacking a transmembrane domain. While the release phenotype did not correlate directly with any of these identified gC variations, further demonstration that nine clinical isolates of HSV1 also fail to spread through extracellular release raises the possibility that propagation in tissue culture had altered the HSV1 s17 transmission phenotype. Hence, the s17 intrastrain variation identified here offers an excellent model for understanding both HSV1 transmission and tissue culture adaptation.

A unique class of lignin derivatives displays broad anti-HIV activity by interacting with the viral envelope.

In Gordts et al. (2015), we have shown that lignosulfonic acid, a commercially available lignin derivative, possesses broad antiviral activity against human immunodeficiency virus (HIV) and Herpes simplex virus (HSV) by preventing viral entry into susceptible target cells. Because of the interesting safety profile as potential microbicide, we now determined the antiviral activity of a series of lignosulfonates in order to understand better which molecular features can contribute to their antiviral activity. Here, 24 structurally different lignosulfonates were evaluated for their capacity to inhibit HIV and HSV transmission and replication in various cellular assays. These derivatives differ in origin (hardwood or softwood), counter-ion used during sulphite processing (Na+, Ca2+, or NH4+), sulphur content, carboxylic acid percentage, and molecular weight fraction, which allowed to determine structure-activity relationships. We demonstrate that the broad antiviral activity of lignosulfonates is mainly dependent on their molecular weight and that their mechanism of action is based on interactions with the viral envelope glycoproteins. This makes the lignosulfonates a potential low-cost microbicide that protects women from sexual HIV and HSV transmission and thus prevents life-long infection.