Prevention of neonatal herpes

Abstract

Neonatal herpes can occur when the neonate is exposed to herpes simplex virus in the maternal genital tract during labour. Attack rates are highest when the mother has a newly acquired infection and, therefore, does not have antibodies to protect the neonate. Even with early therapy, there is significant morbidity and mortality associated with neonatal herpes, suggesting that preventing neonatal herpes simplex virus exposure or early recognition of exposure is important. The incidence of neonatal herpes has not declined despite national guidelines for prevention. This suggests that the prevention guidelines need to be re-addressed.Keywords Herpes, neonate, prevention.Please cite this paper as: Gardella C, Brown Z. Prevention of neonatal herpes. BJOG 2011;118:187-192. Epidemiology of genital herpesBased on serological data from a large National Health and Nutrition Examination Survey (NHANES), 22% of pregnant women in the USA are infected with herpes simplex virus 2 (HSV-2), 63% are HSV-1 seropositive, 13% have both HSV-1 and HSV-2, and 28% are seronegative. 1 In the general population, for the first time since the 1976 inception of NHANES, the seroprevalence of HSV-2 has decreased; overall, the age-adjusted HSV-2 seroprevalence was 17% in 1999-2004, compared with 21% in 1988-94, a relative decrease of 19% between the two study periods. Among those infected with HSV-2, the percentage who reported being diagnosed was 14.3% in 1999-2004 and 9.9% in 1988-94, suggesting that more providers are aware of genital herpes, and able to make appropriate diagnoses. 2 However, the vast majority of people infected with HSV-2 remain undiagnosed and, therefore, untreated and able to spread the infection. Between 75% and 90% of HSV-2-infected people are not aware of having the infection. [3][4][5][6] This is important because most sexual transmission of HSV occurs during episodes of subclinical reactivation among persons with unrecognized infection. 4,7-10 Virtually all HSV-2 seropositive people have intermittent shedding from the genital mucosa, and most have mild (and hence unrecognized and undiagnosed) disease. 5 In the absence of symptoms, HSV-2 can be detected in the genital tract, by viral culture, on 3% of days for the first year after initial infection, then on 1% of days for the next 2 years. HSV-2 DNA can be detected by polymerase chain reaction testing 15-20% of days. 11,12 Recent data suggest that HSV reactivation may occur much more frequently than previously understood, and may be characterised by frequent short bursts of viral shedding that do not correlate with symptoms. 13 As HSV-2 seroprevalence decreased, HSV-1 seroprevalence in the USA increased to 62% in 1988-94 from 57.7% in 1999-2004. 2 Among persons infected with HSV-1 but not HSV-2, a higher percentage reported a diagnosis of genital herpes in 1999-2004 compared with 1988-94 (1.8% versus 0.4%). 2 HSV-1 has emerged as a major cause of genital herpes among college-age populations, in which up to 80% of new cases of genital HSV were caused by HSV-1. [14][1...

Herpes Simplex Virus Infection in Pregnancy

“…In this case there may not be sufficient time for the development of maternal IgG and their passage to the fetus, and the risk of neonatal infection is 30 to 50% [34]. …”

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

“…In this scenario, we consider that pregnant women with asymptomatic viral shedding can transmit the virus to the newborn, as previously reported in other studies. 10,11,18 The presence of the virus in the blood nourishing the fetus during pregnancy is facilitated by its occurrence in the placenta, which is a tissue shown to be permissive to HSV infection in vitro. 23,26 There are few studies investigating HSV vertical transmission using the cord blood as a target tissue.…”

“…3 During the asymptomatic virus shedding, the virus can be transmitted to the partner or even to the newborn during labor. [10][11][12] The infant can become infected during pregnancy, labor or in the postnatal period. 12 Congenital infections, not resulting in miscarriage, may affect the infant in several ways, including skin or eye lesions (cataracts, chorioretinitis or microphthalmia), neurological calcifications, microcephaly, seizures, delayed growth, and psychomotor developmental problems.…”

Association of Depressed Mood With Herpes Simplex Virus-2 Immunoglobulin-G Levels in Pregnancy

“…The frequency of genital herpes varies greatly by race and ethnicity in pregnant women but most infected women are asymptomatic [38, 42]. The greatest risk during pregnancy of HSV-2 infection is neonatal infection acquired during birth when there is contact with viruses shed from the cells lining the birth canal [43]. Nearly 85 % of HSV-2 transmission from mother to fetus occurs during delivery, while 5 % is caused by intrauterine infection.…”