Challenges in Managing a Case of Neonatal Listeriosis in Portugal

A male neonate was born at 34 weeks due to spontaneous labor with associated fetal distress and meconium-stained amniotic fluid. The neonate presented with septic shock and congenital pneumonia shortly after birth and later neurological symptoms. Listeria monocytogenes was identified in blood samples, but with negative urine and cerebrospinal fluid cultures. The neonate required assisted ventilation for a period of 10 days and received high-dose and long-term antibiotic therapy. Despite the fact that the mother denied an infectious risk for listeriosis infection, she developed mild respiratory symptoms. Her microbiological investigation was negative, although it did not include placental samples. Vertical transmission in this case was presumed but not confirmed. The newborn was discharged asymptomatic at day 26 of life and has presented normal developmental evolution until present, at eight months old. Listeria monocytogenes is a classic but relatively rare cause of neonatal sepsis and meningitis. This case describes a clinically successfully managed case with no possible epidemiological link and illustrates the challenges in managing cases of a public health disease. In neonatal listeriosis, communication between Neonatology and Obstetrics departments, as well as with public health, is vital, and long-term follow-up is crucial to identify possible neurological sequelae.

New data on efficacy of valacyclovir in secondary prevention of maternal-fetal transmission of cytomegalovirus

OBJECTIVE

Congenital cytomegalovirus (CMV) infection is the leading cause of non-genetic hearing and neurological deficits. The aim of our study was to evaluate the efficacy and safety of valacyclovir (VCV) treatment in preventing CMV transmission to the fetus after maternal primary infection.

METHODS

This was a retrospective, multicenter study evaluating the rate of maternal-fetal CMV transmission in pregnancies with maternal primary CMV infection treated with VCV at a dosage of 8 g per day (VCV group) compared with a control group of untreated women. Each case underwent virological testing to confirm maternal primary infection and to provide accurate dating of onset of infection. The primary outcome was the presence of congenital CMV infection at birth diagnosed based on polymerase chain reaction analysis of saliva, urine and/or blood samples. The efficacy of VCV treatment was assessed using logistic regression analysis adjusted for a propensity score.

RESULTS

In total, 143 patients were included in the final analysis, of whom 59 were in the VCV group and 84 were in the untreated control group. On propensity-score-adjusted analysis, VCV treatment was significantly associated with an overall reduction in the rate of maternal-fetal CMV transmission (odds ratio, 0.40 (95% CI, 0.18-0.90); P = 0.029). The rate of maternal-fetal CMV transmission, determined at birth, in the VCV vs control group was 7% (1/14) vs 10% (1/10) after periconceptional maternal primary infection (P = 1.00), 22% (8/36) vs 41% (19/46) after first-trimester maternal primary infection (P = 0.068) and 25% (2/8) vs 52% (14/27) after second-trimester maternal primary infection (P = 0.244). When analyzing the efficacy of VCV treatment according to maternal viremia at treatment initiation, there was a trend towards greater efficacy when patients were viremia-positive (21% vs 43%; P = 0.072) compared with when they were viremia-negative (22% vs 17%; P = 0.659). Maternal side effects associated with VCV were mild and non-specific in most cases.

CONCLUSION

Our findings indicate that VCV treatment of pregnant women with primary CMV infection reduces the risk of maternal-fetal transmission of CMV and may be effective in cases with primary infection in the first and second trimesters. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

A Whole Genome Sequencing-Based Epidemiological Investigation of a Pregnancy-Related Invasive Listeriosis Case in Central Italy

Listeriosis is currently the fifth most common foodborne disease in Europe. Most cases are sporadic; however, outbreaks have also been reported. Compared to other foodborne infections, listeriosis has a modest incidence but can cause life-threatening complications, especially in elderly or immunocompromised people and pregnant women. In the latter case, the pathology can be the cause of premature birth or spontaneous abortion, especially if the fetus is affected during the first months of gestation. The causative agent of listeriosis, Listeria monocytogenes, is characterized by the innate ability to survive in the environment and in food, even in adverse conditions and for long periods. Ready-to-eat food represents the category most at risk for contracting listeriosis. This study presents the result of an investigation carried out on a case of maternal-fetal transmission of listeriosis which occurred in 2020 in central Italy and which was linked, with a retrospective approach, to other cases residing in the same city of the pregnant woman. Thanks to the use of next-generation sequencing methodologies, it was possible to identify an outbreak of infection, linked to the consumption of ready-to-eat sliced products sold in a supermarket in the investigated city.

Innate Immune Response to Viral Infections at the Maternal-Fetal Interface in Human Pregnancy

The placenta, the first and largest organ to develop after conception, not only nurtures and promotes the development of the conceptus, but, it also functions as a barrier against invading pathogens. Early phases of pregnancy are associated with expansion of specific subsets of Natural Killer cells (dNK) and macrophages (dMφ) at the maternal uterine mucosa, the basal decidua. In concert with cells of fetal origin, dNK cells, and dMφ orchestrate all steps of placenta and fetus development, and provide the first line of defense to limit vertical transmission. However, some pathogens that infect the mother can overcome this protective barrier and jeopardize the fetus health. In this review, we will discuss how members of the classical TORCH family (Toxoplasma, Other, Rubella, Cytomegalovirus, and Herpes simplex virus) and some emerging viruses (Hepatitis E virus, Zika virus, and SARS-CoV2) can afford access to the placental fortress. We will also discuss how changes in the intrauterine environment as a consequence of maternal immune cell activation contribute to placental diseases and devastating pregnancy outcomes.

Molecular Pathology Analysis of SARS-CoV-2 in Syncytiotrophoblast and Hofbauer Cells in Placenta from a Pregnant Woman and Fetus with COVID-19

A small number of neonates delivered to women with SARS-CoV-2 infection have been found to become infected through intrauterine transplacental transmission. These cases are associated with a group of unusual placental pathology abnormalities that include chronic histiocytic intervillositis, syncytiotrophoblast necrosis, and positivity of the syncytiotrophoblast for SARS-CoV-2 antigen or RNA. Hofbauer cells constitute a heterogeneous group of immunologically active macrophages that have been involved in transplacental infections that include such viral agents as Zika virus and human immunodeficiency virus. The role of Hofbauer cells in placental infection with SARS-CoV-2 and maternal-fetal transmission is unknown. This study uses molecular pathology techniques to evaluate the placenta from a neonate infected with SARS-CoV-2 via the transplacental route to determine whether Hofbauer cells have evidence of infection. We found that the placenta had chronic histiocytic intervillositis and syncytiotrophoblast necrosis, with the syncytiotrophoblast demonstrating intense positive staining for SARS-CoV-2. Immunohistochemistry using the macrophage marker CD163, SARS-CoV-2 nucleocapsid protein, and double staining for SARS-CoV-2 with RNAscope and anti-CD163 antibody, revealed that no demonstrable virus could be identified within Hofbauer cells, despite these cells closely approaching the basement membrane zone of the infected trophoblast. Unlike some other viruses, there was no evidence from this transmitting placenta for infection of Hofbauer cells with SARS-CoV-2.

A Rare Case of Congenitally Acquired Ocular Toxocariasis in A Five-Week-Old Infant

Purpose: To report a case of strabismus in a five-week-old infant, likely secondary to a rare occurrence of congenitally acquired ocular toxocariasis.Methods: Retrospective case report.Results: A five-week-old male infant with left exotropia was referred to pediatric ophthalmology and to a vitreoretinal specialist. Fundoscopic examination revealed a granuloma with associated retinal folds and tractional retinal detachment typical for ocular toxocariasis. Serology revealed positivity for Toxocara antibodies, consistent with the clinical diagnosis of ocular toxocariasis.Conclusion: Ocular toxocariasis is typically thought to be secondary to acquired Toxocara infection secondary to fecal-oral transmission. In this case of early-onset strabismus secondary to ocular toxocariasis, it is hypothesized that this is a presentation of congenitally acquired toxocariasis.

Maternal-fetal transmission of the zika virus: An intriguing interplay

In this review, we give an overview of aspects related to the congenital transmission of the Zika virus (ZIKV). Although we acknowledge that important advances in research on ZIKV pathogenesis have come from studies using animal models, particularly non-human primates, this review emphasizes studies using ex-vivo human cells and tissues as well as natural infections in pregnant women. The possible routes used by ZIKV to cross or breach the placental barrier and infect the fetal central nervous system are presented. Understanding the viral infection biology and ZIKV pathogenesis during pregnancy may guide the design of affordable antiviral strategies to benefit pregnant women in areas at risk.

Obstetric dilemma on the most appropriate management of Creutzfeldt-Jakob disease in pregnancy: seventh case presentation, literature review and new insight

Prion diseases (PDs) are fatal neurological disorders that are thought to be caused by the accumulation of an altered variant of a benign, widely expressed protein (PrPC) into a distinct pathological conformation(s) (PrPSc). The PDs are so rare but lethal pathologies that need an early diagnosis to adequately support the infected patient. A maternal-fetal transmission during pregnancy has been supposed to be on the basis of animal studies, but till now the effective vertical transmission in humans has not been proved. We present a case of infected pregnant woman with a peculiar pregnancy course and outcome. We also provided a systematic literature review to find the best obstetrical management of women affected by prionic disease during pregnancy. The available data underline the potential risk of prenatal and postnatal transmission of the disease but do not permit to define the exact molecular mechanism of transmission, the best follow-up and recommendations that are useful in both obstetrical and neonatal practice. At present awaiting for further clarifications about this topic, it is mandatory to personalize the management of this rare pregnancy complication according to the maternal-fetal well-being status.

Efficacy and safety of 1-month postpartum zidovudine-didanosine to prevent HIV-resistance mutations after intrapartum single-dose nevirapine

BACKGROUND

Intrapartum single-dose nevirapine plus third trimester maternal and infant zidovudine are essential components of programs to prevent mother-to-child transmission of human immunodeficiency virus (HIV) in resource-limited settings. The persistence of nevirapine in the plasma for 3 weeks postpartum risks selection of resistance mutations to nonnucleoside reverse-transcriptase inhibitors (NNRTIs). We hypothesized that a 1-month zidovudine-didanosine course initiated at the same time as single-dose nevirapine (sdNVP) would prevent the selection of nevirapine-resistance mutations.

METHODS

HIV-infected pregnant women in the PHPT-4 cohort with CD4 cell counts >250 cells/mm3 received antepartum zidovudine from the third trimester until delivery, sdNVP during labor, and a 1-month zidovudine-didanosine course after delivery. These women were matched on the basis of baseline HIV load, CD4 cell count, and duration of antepartum zidovudine to women who received sdNVP in the PHPT-2 trial (control subjects). Consensus sequencing and the more sensitive oligonucleotide ligation assay were performed on samples obtained on postpartum days 7-10, 37-45, and 120 (if the HIV load was >500 copies/mL) to detect K103N/Y181C/G190A mutations.

RESULTS

The 222 PHPT-4 subjects did not differ from matched control subjects in baseline characteristics except for age. The combined group median CD4 cell count was 421 cells/mm3 (interquartile range [IQR], 322-549 cells/mm3), the median HIV load was 3.45 log10 copies/mL (IQR, 2.79-4.00 log10 copies/mL), and the median duration of zidovudine prophylaxis was 10.4 weeks (IQR, 9.1-11.4 weeks). Using consensus sequencing, major NNRTI resistance mutations were detected after delivery in 0% of PHPT-4 subjects and 10.4% of PHPT-2 controls. The oligonucleotide ligation assay detected resistance in 1.8% of PHPT-4 subjects and 18.9% of controls. Major NNRTI resistance mutations were detected by either method in 1.8% of PHPT-4 subjects and 20.7% of controls (P < .001).

CONCLUSIONS

A 1-month postpartum course of zidovudine plus didanosine prevented the selection of the vast majority of NNRTI resistance mutations.