Strategies for the prevention of neonatal infection with herpes simplex virus: a decision analysis

[Update on the treatment of genital herpes]

Genital herpes is a chronic infection characterized by periodic reactivation. It can produce symptomatic disease in the host although asymptomatic viral excretion can also occur. It is currently the main cause of genital ulceration and an important public health problem that has substantial clinical, psychological, and economic repercussions. This review analyzes the currently available therapeutic options and regimens, which are based mainly on systemic use of antiviral agents such as aciclovir, valacyclovir, and famciclovir. In addition, special emphasis is placed on the prevention and management of this infection in specific situations, such as pregnant, pediatric, and immunocompromised patients.

Agreement of decision analyses and subsequent clinical studies in infectious diseases

PURPOSE

Decision analysis techniques can compare management strategies when there are insufficient data from clinical studies to guide decision making. We compared the outcomes of decision analyses and subsequent clinical studies in the infectious disease literature to assess the validity of the conclusions of the decision analyses.

METHODS

A search strategy to identify decision analyses in infectious disease topics published from 1990 to 2005 was developed and performed using PubMed. Abstracts of all identified articles were reviewed, and infectious disease-related decision analyses were retained. Subsequent clinical trials and observational studies that corresponded to these decision analyses were identified using prespecified search strategies. Clinical studies were considered a match for the decision analysis if they assessed the same patient population, intervention, and outcome. Agreement or disagreement between the conclusions of the decision analysis and clinical study were determined by author review.

RESULTS

The initial PubMed search yielded 318 references. Forty decision analyses pertaining to 29 infectious disease topics were identified. Of the 40, 16 (40%) from 13 infectious disease topics had matching clinical studies. In 12 of 16 (75%), conclusions of at least 1 clinical study agreed with those of the decision analysis. Three of the 4 decision analyses in which conclusions disagreed were from the same topic (management of febrile children).

CONCLUSIONS

There was substantial agreement between the conclusions of decision analyses and clinical studies in infectious diseases, supporting the validity of decision analysis and its utility in guiding management decisions.

Cost-effectiveness of herpes simplex virus type 2 serologic testing and antiviral therapy in pregnancy

OBJECTIVE

The purpose of this study was to determine whether serologic testing for herpes simplex virus type 2 (HSV-2) in pregnant women and their partners is cost-effective.

STUDY DESIGN

A decision analysis model was developed to investigate the cost-effectiveness of providing type-specific serologic testing at week 15 of pregnancy for all women unaware of their HSV-2 status, and offering antiviral suppressive therapy from week 36 until delivery to all seropositive women. This scenario was compared with current care, in which only a minority of women diagnosed with genital herpes (GH) receives antiviral suppressive therapy (AST). In a third scenario, testing is offered to partners of pregnant women who test seronegative, and antiviral suppressive therapy is offered to the partners who test seropositive.

RESULTS

Compared with current care, offering testing and antiviral suppressive therapy to 100,000 pregnant women resulted in an incremental cost of $3.1 million, 15.7 fewer cases of neonatal herpes, 186 fewer cesarean deliveries, and an incremental cost per quality-adjusted life- year gained (QALY) of $18,680. Offering testing and suppressive therapy to both the pregnant women and their partners resulted in an increased cost of $8.6 million, 16.8 fewer cases of neonatal herpes, 192 fewer cesarean deliveries, and an incremental cost per QALY of $48,946 compared with no testing.

CONCLUSION

Compared with commonly accepted benchmarks for cost-effectiveness (<$50,000/QALY), type-specific HSV-2 serologic testing of pregnant women may be a cost-effective strategy.

Neonatal genital herpes simplex virus type 1 infection after Jewish ritual circumcision: modern medicine and religious tradition

OBJECTIVE

Genital neonatal herpes simplex virus type 1 (HSV-1) infection was observed in a series of neonates after traditional Jewish ritual circumcision. The objective of this study was to describe neonate genital HSV-1 infection after ritual circumcision and investigate the association between genital HSV-1 after circumcision and the practice of the traditional circumcision.

METHODS

Eight neonates with genital HSV-1 infection after ritual circumcision were identified.

RESULTS

The average interval from circumcision to clinical manifestations was 7.25 +/- 2.5 days. In all cases, the traditional circumciser (the mohel) had performed the ancient custom of orally suctioning the blood after cutting the foreskin (oral metzitzah), which is currently practiced by only a minority of mohels. Six infants received intravenous acyclovir therapy. Four infants had recurrent episodes of genital HSV infection, and 1 developed HSV encephalitis with neurologic sequelae. All four mohels tested for HSV antibodies were seropositive.

CONCLUSION

Ritual Jewish circumcision that includes metzitzah with direct oral-genital contact carries a serious risk for transmission of HSV from mohels to neonates, which can be complicated by protracted or severe infection. Oral metzitzah after ritual circumcision may be hazardous to the neonate.

Effect of serologic status and cesarean delivery on transmission rates of herpes simplex virus from mother to infant

CONTEXT

Neonatal herpes most commonly results from fetal exposure to infected maternal genital secretions at the time of delivery. The risk of transmission from mother to infant as it relates to maternal herpes simplex virus (HSV) serologic status and exposure to HSV in the maternal genital tract at the time of labor has not been quantified. Furthermore, no data exist on whether cesarean delivery, the standard of care for women with genital herpes lesions at the time of delivery, reduces HSV transmission.

OBJECTIVE

To determine the effects of viral shedding, maternal HSV serologic status, and delivery route on the risk of transmission of HSV from mother to infant.

DESIGN

Prospective cohort of pregnant women enrolled between January 1982 and December 1999.

SETTINGS

A university medical center, a US Army medical center, and 5 community hospitals in Washington State.

PATIENTS

A total of 58 362 pregnant women, of whom 40 023 had HSV cultures obtained from the cervix and external genitalia and 31 663 had serum samples tested for HSV.

MAIN OUTCOME MEASURE

Rates of neonatal HSV infection.

RESULTS

Among the 202 women from whom HSV was isolated at the time of labor, 10 (5%) had neonates with HSV infection (odds ratio [OR], 346; 95% confidence interval [CI], 125-956 for neonatal herpes when HSV was isolated vs not isolated). Cesarean delivery significantly reduced the HSV transmission rate among women from whom HSV was isolated (1 [1.2%] of 85 cesarean vs 9 [7.7%] of 117 vaginal; OR, 0.14; 95% CI, 0.02-1.08; P =.047). Other risk factors for neonatal HSV included first-episode infection (OR, 33.1; 95% CI, 6.5-168), HSV isolation from the cervix (OR, 32.6; 95% CI, 4.1-260), HSV-1 vs HSV-2 isolation at the time of labor (OR, 16.5; 95% CI, 4.1-65), invasive monitoring (OR, 6.8; 95% CI, 1.4-32), delivery before 38 weeks (OR, 4.4; 95% CI, 1.2-16), and maternal age less than 21 years (OR, 4.1; 95% CI, 1.1-15). Neonatal HSV infection rates per 100 000 live births were 54 (95% CI, 19.8-118) among HSV-seronegative women, 26 (95% CI, 9.3-56) among women who were HSV-1-seropositive only, and 22 (95% CI, 4.4-64) among all HSV-2-seropositive women.

CONCLUSION

Neonatal HSV infection rates can be reduced by preventing maternal acquisition of genital HSV-1 and HSV-2 infection near term. It can also be reduced by cesarean delivery and limiting the use of invasive monitors among women shedding HSV at the time of labor.

10: Herpes simplex and varicella-zoster virus infections

Any new patient with suspected genital herpes should have diagnostic testing with virus identification. Type-specific serological tests that distinguish between antibodies for type 1 and type 2 herpes simplex virus (HSV) may be useful to determine previous exposure but cannot be used to diagnose recurrences of genital herpes. Initial episodes of genital herpes usually require antiviral therapy, while recurrences may be treated with continuous antiviral suppression (if frequent) or episodic therapy; patient counselling and education (including how to recognise lesions) are essential. Topical or systemic therapy is available for initial and recurrent non-genital herpes simplex. Primary varicella infection (chickenpox) and herpes zoster (shingles) are usually diagnosed clinically, but can be confirmed by detection of varicella-zoster virus antigens or nucleic acid from swabs of lesions or by antibody tests. Antiviral therapy should be considered in chickenpox if disease is complicated or the patient is immunocompromised. In herpes zoster, antiviral therapy should be given within 72 hours of onset to patients aged over 50 years or with severe pain or neurological abnormalities to reduce the likelihood and duration of postherpetic neuralgia. The availability of effective antiviral therapy makes early diagnosis vital

HSV-2 specific serology should not be offered routinely to antenatal patients

The proposal to introduce antenatal screening for HSV has no evidence for a public or individual health benefit; indeed, it has the potential to increase anxiety for patients, with a minimal likelihood of reducing the risk of neonatal herpes infection. Antenatal screening of an essentially healthy population of women must be validated in settings of different rates of neonatal HSV infection and the purposes and limitations of screening clearly outlined. Identification of pregnant women at risk of acquiring genital herpes in pregnancy is also dependent upon being able to obtain the serostatus of the male sexual partner which will reduce the practical application of the test if both patient and partners need to be screened. We recommend that efforts to improve on the currently established mechanisms for reducing the morbidity of neonatal herpes, namely early diagnosis and prompt treatment, must take priority for resources over new and unevaluated screening programmes, such as routine testing of antenatal patients.

Management of women with recurrent genital herpes in pregnancy in Australia

OBJECTIVE

To document clinical practice for the management of recurrent genital herpes in pregnant women in Australia.

DESIGN AND PARTICIPANTS

A questionnaire to all doctors associated with the Royal Australian College of Obstetricians and Gynaecologists.

MAIN OUTCOME MEASURES

Policies for antenatal herpes screening, circumstances in which delivery by caesarean section was considered appropriate, and the use of aciclovir during pregnancy. The results were analysed by college status, sex, and whether the doctor worked in a public or private facility.

RESULTS

2855 (67.3%) obstetricians returned questionnaires. 696 (34.3%) stated that their hospital had a policy for managing recurrent genital herpes in pregnancy: 44.5% examined the genitalia and 33.8% took cultures during pregnancy. Fellows were more likely to examine the genitalia (87% v 37%, p < 0.001), and more likely to perform antenatal viral cultures than members (75% v 30%, p < 0.001). Doctors working at private hospitals were significantly more likely to take viral cultures than doctors in public hospitals (39% v 33% p < 0.05). Doctors were asked to consider five scenarios and judge whether caesarean section would be appropriate. 96% considered that a caesarean section was appropriate in women with active herpes at the onset of labour. In the case of a recurrence of genital HSV at the time of presentation with ruptured membranes longer than 4 hours, diplomats (79%) were significantly more likely to recommend a caesarean section than fellows (64%), members (63%), or trainees (49%) (all p < or = 0.001). Where there were positive viral cultures before the onset of labour fellows (45%) were more likely than members (29%) (p = 0.005), males (62%) were more likely than females (55%) (p = 0.03), and doctors working in private hospitals (69%) were more likely than those in the public sector (54%) (p < 0.001) to recommend caesarean section.

CONCLUSION

There is considerable divergence of opinion regarding the appropriate management of recurrent genital herpes in pregnancy. The implementation of management guidelines would provide consistency of care.

Neonatal herpes simplex virus infection in the British Isles

This study was set up to estimate the incidence of neonatal herpes simplex virus (HSV) infection in the British Isles, and to document the outcome of neonatal infection. Paediatricians reported cases of neonatal HSV through the active reporting scheme of the British Paediatric Association Surveillance Unit. Over a 5 1/2 year period (1986-91) 76 infants with neonatal HSV infection were reported, an incidence of recognised infection in the British Isles of 1.65/100000 livebirths. Twenty-five infants had HSV-1 infection, 24 HSV-2 and in 27 virus type was unknown. Twenty-seven had disseminated infection, 23 herpes encephalitis and 26 localised infection. Nineteen infants (25%) died in the neonatal period, and a further 25 (33%) have subsequently died or have long-term sequelae. At least half of the infants had been discharged home before symptoms became apparent. For 21 women there was evidence of a maternal genital herpes infection at some time, but this was reported or diagnosed retrospectively after neonatal HSV was suspected in 19 cases, and antenatally in only two. Neonatal HSV is rare in the British Isles and routine antenatal screening for genital herpes infection during pregnancy is not justified. A high proportion of infected infants present with non-specific signs and symptoms and without mucocutaneous involvement; furthermore, there is rarely a history of maternal infection. As early diagnosis and prompt treatment is essential, there must be a high level of awareness of the serious nature of neonatal HSV infection.

The management of recurrent genital herpes infection in pregnancy: a postal survey of obstetric practice

OBJECTIVE

To determine clinical practice amongst obstetricians in the UK in the antepartum and intrapartum management of pregnant women with recurrent genital herpes infection.

METHODS

All Members and Fellows of the Royal College of Obstetricians and Gynaecologists resident in the UK were sent a questionnaire requesting information concerning their management of pregnant women with recurrent genital herpes infection.

RESULTS

There was a 76% response rate to the questionnaire. Of the 1201 obstetricians who responded, only 369 (31%) admitted to having a formal policy governing the management of herpes in pregnancy within their unit. However, regular screening was advocated by 718 (60%), of whom 463 (64%) performed regular antenatal swabs for viral culture. At the time of presentation in labour 974 obstetricians (81%) routinely examined the genitals for evidence of a recurrence. When asked in what circumstances caesarean section would be considered an appropriate method of delivery in women with genital herpes infection, 1107 (92%) felt that visible active lesions at the time of labour was sufficient. However, when the membranes had been ruptured for more than four hours in the presence of genital lesions, only 678 (56%) considered this an indication for caesarean section. Caesarean section was more likely to be considered appropriate in this situation by obstetricians who performed antenatal screening (chi 2 = 30.38, P < 0.0001). Five hundred and ninety-six obstetricians (50%) felt that a positive viral culture obtained at antenatal screening from the most recent occasion prior to presentation in labour was an indication for caesarean section, although of this group 192 (32%) said they did not perform antenatal screening by viral culture. The reporting of a recurrence by the patient without visible evidence of disease was considered an appropriate indication for caesarean section by 438 respondents (36%). Maternal request for caesarean section regardless of recurrences at delivery was considered an acceptable indication for operative delivery by 745 obstetricians (62%).

CONCLUSIONS

1. There seems to be little agreement amongst obstetricians in the UK regarding the management of recurrent genital herpes infection in pregnancy. 2. The management possibilities are reviewed and suggestions are made for a more cohesive approach to the problem.

The role of obstetric interventions in the prevention of pediatric human immunodeficiency virus infection

By the end of the decade 10 million children will be infected with human immunodeficiency virus. Several potential means of preventing vertical transmission of human immunodeficiency virus are under study. Although the perinatal use of antiretroviral agents can prevent some of these infections, those agents are neither uniformly effective nor universally available. A significant portion of vertical transmission may be an intrapartum phenomenon, potentially amenable to obstetric interventions, such as cesarean section or vaginal virucides. The utility of these obstetric interventions will be determined in large part by the timing of vertical transmission. This work reviews the evidence that human immunodeficiency virus can be transmitted during the intrapartum period and critically reviews the data supporting a role for obstetric interventions. Finally, we outline the necessary elements for the conduct of a conclusive efficacy trial and delineate a mechanism to arrive at a definitive standard of care in the absence or anticipation of a trial.

Herpes simplex virus infection of the fetus and newborn

Although infrequent, untreated neonatal herpes results in death in half the cases and neurologic sequelae in three quarters of the survivors. Neonatal infection is usually acquired from maternal genital herpes, which is asymptomatic or unrecognized in 60% to 80% of women. The greatest risk of neonatal infection occurs when the mother has primary genital herpes involving the cervix at delivery, and the infant is premature and delivered with instrumentation (eg, scalp electrodes). More than 80% of neonates with herpes will have typical herpetic lesions of the skin, eye, or mouth, and most of the remainder will have either encephalitis or a sepsis syndrome with pneumonitis and hepatitis and negative bacterial cultures. Because herpes can mimic other neonatal infections, laboratory diagnosis is important, using cultures of the virus from lesions, peripheral blood white cells, or CSF. Treatment with intravenous acyclovir does reduce mortality and neurologic sequelae, but outcome is still guarded in babies with disseminated disease or encephalitis. Prevention focuses on caesarean section in women with active lesions at the time of impending delivery and avoidance of postnatal exposure. Further studies are needed to determine whether maternal screening (eg, HSV-2 type specific antibodies and vaginal cultures in selected women at delivery) will be cost effective in preventing neonatal herpes.

Genital herpes and pregnancy--preventive measures

Genital herpes is particularly dangerous during pregnancy because of the risk of neonatal infection. This is discussed in four situations of genital herpes associated with pregnancy. Choosing the most appropriate method of delivery, i.e. carrying the least risk of transmission from mother to baby, is based on our knowledge of the natural history of genital herpes infection, the risk to the newborn (estimated from epidemiological studies), and, lastly, the possible preventive measures available.

Herpes simplex virus type 2 antibody in patients attending antenatal or STD clinics

OBJECTIVE

To determine the prevalence of antibody to herpes simplex virus type 2 (HSV-2) in patients attending a general public antenatal clinic and three public sexually transmitted disease (STD) clinics in Sydney.

BACKGROUND

Highly specific tests for herpes simplex type 2 antibody, using the glycoprotein G2, have been recently introduced, allowing determination of past asymptomatic infection. Overseas studies have confirmed the long held suspicion that asymptomatic infection is more common than clinical genital herpes. The seroprevalence of HSV-2 in antenatal and STD clinic patients varies markedly in different countries. These are the first data available for Australia by means of this highly specific test.

DESIGN

Cross-sectional study of seroprevalence in these two patient groups. Sera used in the antenatal study were those submitted for routine antenatal screening for viral markers.

PARTICIPANTS

Two hundred and twenty-nine consecutive patients attending the Westmead Hospital antenatal clinics, and 107 consecutive patients attending three public STD clinics.

HYPOTHESES

That Australian populations show a relatively high prevalence of past asymptomatic infection with HSV-2; and that higher rates of infection will be found in patients attending STD clinics and with past or current histories of STDs.

MAIN OUTCOME MEASURES

Comparison of HSV-2 seroprevalence between antenatal clinic patients and STD clinic patients; and associations of HSV-2 antibody with age, sex, occupation, country of birth, a history of current or past STDs and antibody to HSV-1.

RESULTS

Antibody to HSV-2 was found in 14.5% of antenatal clinic patients and 40% of STD clinic patients. None of the antenatal patients and less than half of the seropositive STD clinic patients reported clinical genital herpes. Associations with age, socioeconomic status and previous HSV-1 infection were less marked than in studies from the United States. Female STD clinic patients had a significantly higher seroprevalence than males and three times the seroprevalence of age-matched antenatal clinic patients. The correlation between HSV-2 antibody and current gonorrhoea was more marked than that between HSV-2 and other STDs.

CONCLUSION

Asymptomatic infection with HSV-2 is quite common in Australian antenatal patients and more common in patients with STDs, who have higher rates of sexual exposure.

Herpes simplex virus infection in pregnancy

Genital infections in pregnancy caused by herpes simplex virus types 1 and 2 are a difficult management problem. Both primary and recurrent genital herpes can range from severe, extensive ulceration to asymptomatic virus shedding. Although neonatal herpes is a well recognized complication of symptomatic maternal primary genital infection at the time of delivery, most cases are associated with asymptomatic virus shedding and absence of a history of genital herpes. Neonatal herpes may also be acquired in utero and in the postnatal period. The diagnosis of herpes simplex infection is made most reliably by virus isolation or antigen detection from samples obtained from clinically apparent lesions. Serology is useful for diagnosing primary herpes, and newer serological techniques allow the detection of HSV-2 specific antibodies. Strategies to prevent neonatal herpes are limited by the failure of currently available diagnostic tests to rapidly detect women in labour who are at risk of transmitting herpes, by the absence of proven antenatal screening tests for HSV, and by transmission of herpes to neonates from asymptomatic mothers. The most useful current strategy is careful examination of the vulva and cervix for herpes lesions in women coming to labour. Caesarean section is indicated in women with clinically apparent genital herpes at delivery. Effective and safe antiviral agents are available for treatment of maternal and neonatal herpes.

Neonatal herpes simplex: Royal Women's Hospital 10-year experience with management guidelines for herpes in pregnancy

In the 10-year period 1982-1991 inclusive, 6 cases of neonatal herpes simplex were diagnosed at the Royal Women's Hospital, Melbourne (1 disseminated, 1 pneumonitis, 4 cutaneous [1 with central nervous system involvement]), resulting in an incidence of 1 in 11,000 livebirths for this population. Three cases were due to HSV 1 and 3 to HSV 2. In no case did the mother have a recent or past history of overt genital herpes infection. Two cases were acquired in utero, an uncommonly recognized form of infection. A favourable long-term outcome occurred in 2 of 4 cases in which diagnosis was prompt and antiviral therapy was instituted rapidly. Routine antenatal screening in the last trimester of pregnant women with a history of genital herpes before pregnancy is not advised, because the results have been shown to be unreliable in predicting viral shedding and hence the infants' risk of exposure to virus at delivery. A protocol for management of herpes in pregnancy is included.

Herpes simplex virus infection in pregnancy and its management

Neonatal herpes simplex virus (HSV) infection is considered to be rare in the UK, affecting less than 3 per 100,000 live births, but the true incidence is probably higher due to under-reporting. In contrast, neonatal HSV infection is more common in the USA affecting 1 per 7500 live births overall. Infection in neonates is frequently serious and may be fatal.