Neonatal herpes simplex: clinical findings and outcome in relation to type of maternal infection

Leveraging biotin-based proximity labeling to identify cellular factors governing early alphaherpesvirus infection

Neurotropic alphaherpesviruses, including herpes simplex virus type 1 and pseudorabies virus, establish a lifelong presence within the peripheral nervous system of their mammalian hosts. Upon entering cells, two conserved tegument proteins, pUL36 and pUL37, traffic DNA-containing capsids to nuclei. These proteins support long-distance retrograde axonal transport and invasion of the nervous system in vivo. To better understand how pUL36 and pUL37 function, recombinant viral particles carrying BioID2 fused to these proteins were produced to biotinylate cellular proteins in their proximity (<10 nm) during infection. Eighty-six high-confidence host proteins were identified by mass spectrometry and subsequently targeted by CRISPR-Cas9 gene editing to assess their contributions to early infection. Proteins were identified that both supported and antagonized infection in immortalized human epithelial cells. The latter included zyxin, a protein that localizes to focal adhesions and regulates actin cytoskeletal dynamics. Zyxin knockout cells were hyper-permissive to infection and could be rescued with even modest expression of GFP-zyxin. These results provide a resource for studies of the virus-cell interface and identify zyxin as a novel deterrent to alphaherpesvirus infection.IMPORTANCENeuroinvasive alphaherpesviruses are highly prevalent with many members found across mammals [e.g., herpes simplex virus type 1 (HSV-1) in humans and pseudorabies virus in pigs]. HSV-1 causes a range of clinical manifestations from cold sores to blindness and encephalitis. There are no vaccines or curative therapies available for HSV-1. A fundamental feature of these viruses is their establishment of lifelong infection of the nervous system in their respective hosts. This outcome is possible due to a potent neuroinvasive property that is coordinated by two proteins: pUL36 and pUL37. In this study, we explore the cellular protein network in proximity to pUL36 and pUL37 during infection and examine the impact of knocking down the expression of these proteins upon infection.

Prevention and management of neonatal herpes simplex virus infections

Human herpes simplex virus (HSV) infection in neonates can result in devastating outcomes, including mortality and significant morbidity. All infants are potentially at risk for neonatal HSV infection. This position statement reviews epidemiology, transmission and risk factors, with a focus on intrapartum infection. It considers diagnosis and prognosis according to infection category, along with testing modalities and limitations. Recommendations for managing newborns known to have been exposed intrapartum to HSV are based on expert opinion because a randomized trial to compare management options is not feasible. Guidance is provided for the empirical management of infants with suspected clinical sepsis, including those who do not respond to antibacterial therapy. The present statement replaces a 2006 position statement by the Canadian Paediatric Society.

Value of herpes simplex virus type-specific serology: a case report

Genital herpes, usually caused by herpes simplex virus type 2 (HSV-2), is one of the most common sexually transmitted diseases in humans. By contrast, intrauterine HSV-2 infections have been described rarely in the literature. Our report describes a case of neonate who was delivered after 30+2 gestational weeks by cesarean section. He presented with a respiratory distress syndrome resulting in broncho-pulmonary dysplasia. At the age of 6 weeks, a chorioretinal scar was detected. During the 4th month of age, the infant developed recurrent HSV-2 infection with nasal lesions. The retrospective type-specific serologic diagnosis revealed previous HSV-2 infection of the mother resulting in prenatal HSV-2 infection of the infant. In conclusion, intrauterine HSV-2 infections may be underrepresented since they may not be associated with severe congenital malformations and the diagnosis requires the use of HSV type-specific serologic methods not widely applied in microbiological laboratories.

Neonatal herpes simplex virus infection

Herpes simplex virus (HSV) infection in the neonate is a rare event with severe consequences for the child even if adequately treated with antiviral drugs. Mothers with primary genital herpes infections late in pregnancy or at delivery have a high risk of transferring the infection to the child, while the risk of transfer in mothers with recurrent genital infections is only a few percent. Neonatal herpes localized in skin-eye-mouth has no mortality and morbidity after antiviral treatment. In neonatal disseminated and central nervous system disease, early treatment is a predictor for better outcome. The morbidity in survivors is high; after herpes encephalitis, only one-third of children have normal development. While awaiting vaccines or reliable predictors for prevention of neonatal herpes, clinical awareness of primary maternal herpes during pregnancy and recommendations for prophylactic treatment are important tools. For pediatricians the differential diagnosis of a child aged two to four weeks with seizures, neonatal herpes encephalitis must be considered and either excluded or treated. Neurological follow-up and training programs to minimize the consequences of a disability are important clinical aspects.

Neuropsychologic outcomes in children with neonatal herpes encephalitis

Neonatal herpes simplex virus infection with involvement of the central nervous system is a serious disease with high morbidity, even with acyclovir therapy. The disability includes cerebral palsy and different aspects of cognitive dysfunction which are of utmost importance for the child's future habilitation. We conducted a descriptive cohort study to define neuropsychologic outcomes and determine the relationship between neonatal neuroimaging and neuropsychologic outcomes. Among 267,690 children born in the Stockholm area over 12 years (1989-2000), 14 were diagnosed with neonatal herpes including central nervous system involvement. Nine children were neuropsychologically evaluated. Neonatal herpes virus infection had an even greater impact on cognitive function, speech ability, and attention deficit than anticipated. Relapse leading to deterioration was demonstrated in one child. Social skills were influenced to a lesser degree. Neurodevelopmental outcomes of the children were not well-correlated with extent of cerebral damage as visualized by computed tomography at 7-28 days after onset of signs. Neuropsychologic assessment is essential in the habilitation of the child, and a prerequisite for the evaluation of new treatments and for the assessment of deterioration of cerebral function related to relapses.

Neonatal herpes simplex virus infections in Canada: results of a 3-year national prospective study

OBJECTIVE

The goal was to determine incidence, determinants, and morbidity and mortality rates of neonatal herpes simplex virus infections in Canada.

METHODS

From October 1, 2000, to September 30, 2003, reports of neonatal herpes simplex virus infection were solicited actively from all Canadian pediatricians and pediatric subspecialists on a monthly basis.

RESULTS

Fifty-eight cases of neonatal herpes simplex virus were reported (5.9 cases per 100,000 live births). Cesarean section was performed in 24.6% of cases, 28.1% of patients were born prematurely, 28.6% had birth weights of < 2500 g, and 7.5% had Apgar scores of < 7 at 5 minutes of life. Mothers < 20 years of age and those reporting Aboriginal ethnicity were affected disproportionately; 40% of mothers had no history of genital herpes before delivery, and intrapartum genital lesions were present in only 1 of 58 cases. Of cases with known herpes simplex virus type, 62.5% were herpes simplex virus-1. Localized infections accounted for 59.6% of cases, whereas disseminated disease and central nervous system disease were reported for 17.5% and 22.8%, respectively. Localized infections were more likely to be herpes simplex virus-1 and disseminated and central nervous system infections herpes simplex virus-2. Nine of 58 cases were fatal. All cases with known treatment information (n = 55) were treated with intravenously administered acyclovir.

CONCLUSIONS

This is the first study to examine the national incidence of neonatal herpes simplex virus in Canada. Many women had no genital herpes simplex virus history before delivery, and the majority of cases were herpes simplex virus-1, which has implications for prenatal screening and vaccine/drug development. Follow-up monitoring of case subjects is being performed annually for 3 years, to be completed in October 2006.

Detection of herpes simplex virus DNA in dried blood spots making a retrospective diagnosis possible

BACKGROUND

Herpes simplex virus (HSV) infections in neonates are associated with life-threatening disease. Early diagnosis and treatment with antiviral therapy has decreased the morbidity, mortality and long-term sequelae in surviving children. The aim of the study was to investigate if herpes simplex virus DNA detection in dried blood spots on filter papers (Guthrie cards) sampled for screening of metabolic diseases may contribute to early diagnosis of neonatal HSV infection and enable pre-emptive therapy.

METHODS

For detection of HSV-1 and -2 DNA, two different DNA extraction methods were evaluated. A minimal essential medium (MEM) extraction method was found superior and was used in combination with detection of HSV-1 and -2 DNA by PCR in dried blood spots from children with verified neonatal HSV infection. Cards from 28 children were included. The onset of illness varied from day 0 to 42 days and was the result of different types of maternal infection (27 cases) and an external source (one case).

RESULTS

HSV DNA was detected in seven of the 28 Guthrie cards, two were HSV-1 and five were HSV-2 DNA positive. Positive dried blood spot cards were sampled within the interval 5 days before, to 6 days after onset of neonatal herpes. In cases of late onset CNS disease, viremia, was not demonstrable at the age of 3-5 days, the time period when the blood spot cards are normally sampled.

CONCLUSION

Viremia, the prerequisite for demonstrating HSV DNA in dried blood spot cards preceded the onset of illness by up to 5 days and lasted at least up to 6 days thereafter. Analysis of HSV DNA in dried blood spot cards may be of value in the diagnostic arsenal for early onset of neonatal herpes and also have a role in the follow up of a child exposed at delivery. As the majority of the later onset neonatal herpes encephalitis cases are missed, a large-scale neonatal screening does not seem appropriate.

Herpes simplex virus epidemiology and ocular importance

PURPOSE

To review the changing epidemiology of herpes simplex disease and correlate it with the epidemiology of ocular herpes simplex disease.

METHOD

A review of pertinent reports in the world literature about the epidemiology of herpes simplex and specifically about ocular herpes simplex.

RESULTS

In developed countries, many individuals are reaching adolescence and adulthood without prior herpesvirus infection. Herpes simplex genital infection is increasing at a rapid rate in sexually active adolescents and adults, with about one in six adults now infected in the United States. Similar statistics are confirmatory worldwide in developed countries. Active herpes simplex infection is a risk factor for acquisition of human immunodeficiency virus. The Herpetic Eye Disease Study, as well as prior studies from Moorfields Eye Hospital and the Mayo Clinic in Rochester, Minnesota, provides us with the epidemiology of ocular herpes simplex. Recent studies suggest an older age of onset and perhaps overall more severe ocular disease as compared with the older literature.

CONCLUSIONS

Herpes simplex is a significant health concern at present with genital infections increasing in epidemic proportions. This is also reflected in a rise in the incidence of neonatal herpes. Herpes simplex virus type 1 (HSV-1) infection is being acquired for the first time in an older age group. A significant and increasing proportion of genital herpes is caused by HSV-1. Serologic studies are no longer as useful in distinguishing orofacial herpes from genital herpes. More acute retinal necrosis syndrome cases are associated with HSV-2. Speculation about the future of ocular herpes is made based on this changing epidemiology.

Neonatal herpes prevention: a minor public health problem in some communities

BACKGROUND

Neonatal herpes is a condition with high morbidity and mortality. The greatest risk occurs when the mother acquires herpes simplex virus (HSV) towards the end of pregnancy. A study from Seattle has suggested that the risk of acquisition of HSV during pregnancy was 3.7%. In Australia, HSV-2 infection is less common in pregnant women than in the United States. Consequently we conducted a study to establish HSV seroprevalence and the rate of HSV seroconversion in this population.

METHODS

The study was conducted at Westmead Hospital, Sydney, between June 1995 and April 1998. Women completed a questionnaire covering risk factors for the acquisition of genital herpes. A serum sample during pregnancy and a specimen of cord blood were obtained and tested for antibodies to HSV-2 using a type specific indirect enzyme linked immunosorbent assay (ELISA). Equivocal results were resolved by western blot. A subset of the paired sera was tested for antibodies to HSV-1. The data were analysed using SPSS.

RESULTS

326 of the 2616 (12.5%) women were HSV-2 seropositive. Three women (0.15%) acquired HSV-2 infection during pregnancy. None of the three babies of these mothers developed neonatal herpes. 416 maternal cord pairs were tested for HSV-1 antibodies and 330 (79.3%) were positive. No HSV-1 seroconversions occurred.

CONCLUSIONS

In this population, HSV acquisition was uncommon (0.34% per year) and neonatal herpes was rare. A cost effective analysis suggested that type specific serology to screen pregnant women and their partners in low prevalence communities was not cost effective.

Neonatal herpes simplex virus infections: HSV DNA in cerebrospinal fluid and serum

AIM

To investigate the diagnostic potential of herpes simplex virus (HSV) DNA in cerebrospinal fluid and serum; to correlate the findings with outcome in the child and with type of maternal infection.

METHODS

Cerebrospinal fluid and serum specimens from 36 children with verified neonatal HSV infections, diagnosed between 1973 and 1996, were examined using the polymerase chain reaction technique (PCR).

RESULTS

In 21 children for whom both cerebrospinal fluid and sera were available, HSV DNA was found in one or both specimens in 19 (90%). Overall, HSV DNA was found in the cerebrospinal fluid of 74% of 27 children, and in the sera of 20 out of 30 children (67%). In two children HSV DNA was not demonstrable in either serum or cerebrospinal fluid. In sequential specimens from four children, the persistence of HSV DNA after the end of intravenous treatment was associated with a poor prognosis.

CONCLUSIONS

These findings indicate that HSV DNA detection in CSF and serum is highly sensitive for the diagnosis of neonatal HSV infections but does not replace the detection of virus in other locations using virus isolation and antigen detection.

Disseminated herpes simplex virus infection in a neonate

The emergency department (ED) evaluation of the neonate with sepsis or symptoms suggesting sepsis usually includes a complete blood count, catheterized urinalysis with culture, blood cultures, cerebrospinal fluid analysis and culture, and possibly a chest radiograph. Admission for observation for neonates at high risk for sepsis is universal. Depending on the patient's presentation and the preference of the admitting physician, intravenous antibiotics are started. Typically, ampicillin and either an aminoglycoside or cefotaxime are chosen because they cover the likely pathogens in this age group, ie, group B streptococci, Escherichia coli and other gram-negative enterics, and Listeria monocytogenes. Coverage for viral infection, most notably herpes simplex virus (HSV), is only rarely instituted in the ED and is usually considered if the patient has obvious ulcerative lesions or if the mother has known HSV infection. Unfortunately, antiviral therapy with acyclovir or vidaribine has to be started in the early stages of infection to be effective. If antiviral therapy is started after viral entry into cells, morbidity is severe and mortality approaches 80%. Neonates who survive are usually severely disabled. Broadening the indications for initiating antiviral therapy to include the neonate whose mother has any history of a sexually transmitted disease may prevent the sequelae of untreated or inadequately treated HSV infection. A case is reported of an 8-day-old girl who developed disseminated HSV infection and died as a result of hepatic failure.