HSV, Rubella, GBS

Question 1

What are the causes of neonatal herpes

Answer 1

Neonatal herpes may be caused by HSV1 or HSV2 (50% for each) since either viral type can cause genital herpes in the mother:
* HSV-1: Usually causes orolabial infection, usually acquired during childhood through direct physical contact such as kissing
* HSV-2: Usually causes genital herpes, transmitted sexually

Question 2

Classification of neonatal herpes

Answer 2

• Disease localised to skin, eye and/or mouth (best prognosis- 30% of cases)
• Local central nervous system (CNS) disease (encephalitis alone- occurs in less than 2% of cases)
• Disseminated infection with multiple organ involvement.

Question 3

Prognosis of neonatal herpes

Answer 3

• Untreated/ delayed treatment in newborns can result in intellectual disability and death. Infection with HSV-2 has a poorer prognosis than HSV-1.

Question 4

Prognosis of herpes infection in pregnancy (for the mother)

Answer 4

• Maternal complications are generally similar to those occurring in the non-pregnant state; however, the incidence of disseminated HSV, although rare, is probably increased. In most reported cases, this condition occurs in the second or third trimester

Question 5

How is herepes transmitted in pregnancy

Answer 5

• Most cases of neonatal herpes occur as a result of direct contact with infected maternal secretions, postnatal infection may occur as a result of exposure to oro-labial herpes infection
• Risk of transmission is greatest in women with primary genital herpes in the third trimester, particularly within 6 weeks of delivery (baby unlikely to be born before the development of protective maternal antibodies)
• Rarely, congenital herpes may occur as a result of transplacental intrauterine infection- can result in FGR
• Increased duration of ROM increases risk of transmission, as well as SVD
• Disseminated herpes is more common in preterm infants

Question 6

How does maternal herpes infection present in pregnancy

Answer 6

• Genital herpes causes ulcerative lesions on the vulva, vagina and cervix (may be recurrent)
• Primary infection may cause systemic symptoms and urinary retention
• Disseminated herpes, which may present with encephalitis, hepatitis, disseminated skin lesions or a combination of these conditions, is rare in adults. However, it has been more commonly reported in pregnancy

Question 7

How does neonatal herpes present

Answer 7

• Neurological: microcephaly, intracranial calcification
• Cutaneous: scarring, active lesions
• Eyes: microphthalmia, optic atrophy, chorioretinitis

Question 8

Investigations for herpes infection in pregnancy

Answer 8

• Swab of genital lesions to detect HSV (may also use PCR)

Question 9

How can HSV infection be prevented in pregnancy

Answer 9

Female partners of men with genital herpes who themselves have no history of genital herpes should be strongly advised not to have sex at the time of lesional recurrence. Use of condoms throughout pregnancy may diminish the risk of acquisition. Pregnant women should be advised on the risk of acquiring HSV-1.

Question 10

Management first or second trimeste acquisition of HSV

Answer 10

• All pregnant women with first-episode genital herpes should be referred to genitourinary physicians
• Management will usually involve the use of oral (or IV for disseminated HSV) acyclovir 400mg TDS, for 5 days
• Acyclovir is not licensed for use in pregnancy but is considered safe and has not been associated with an increased incidence of birth defects
• Providing that delivery does not ensue within the next 6 weeks, the pregnancy should be managed expectantly and vaginal delivery anticipated
• Following first or second trimester acquisition, daily suppressive acyclovir 400 mg three times daily from 36 weeks of gestation reduces HSV lesions at term and hence the need for delivery by caesarean section

Question 11

Management of third trimester acquisition of HSV

Answer 11

• Treatment will usually continue with daily suppressive acyclovir 400 mg three times daily until delivery
• C-section should be the recommended mode of delivery for all women developing first episode genital herpes in the third trimester

Question 12

How should a recurrence of HSV infection be managed during pregnancy

Answer 12

A recurrent episode of genital herpes occurring during the pregnancy is not an indication for delivery by C-section (should test using IgG antibodies to confirm previous infection)
* Risk of neonatal herpes is low, even if lesions are present at the time of delivery (0-3% for vaginal delivery)
* Most recurrent episodes of genital herpes are short-lasting and resolve within 7–10 days without antiviral treatment. Supportive treatment measures using saline bathing and analgesia with standard doses of paracetamol alone will usually suffice
* Avoid artificial rupture of membranes and invasive procedures during labour if there are genital lesions

Question 13

Management of neonatal herpes

Answer 13

• In all cases, the neonatal team should be informed
• Neonates with suspected herpes infection (with or without central nervous system signs or symptoms) should have a lumbar puncture in order to obtain specimens of cerebrospinal fluid for PCR and/or culture and should be treated with intravenous acyclovir

Question 14

What is Rubella

Answer 14

A notifiable disease. A single-stranded RNA togavirus (also known as German measles) spread by droplet transmission, now very uncommon in the UK due to the MMR

Question 15

What is the prognosis of Rubella in pregnancy

Answer 15

Most cases of rubella infection are mild and resolve spontaneously within a week. However, maternal infection in non-immune women during pregnancy can cause serious complications including: miscarriage, stillbirth and congenital rubella syndrome.

Question 16

What are the potential consequences of rubella infection in pregnancy. When is the risk of these complications highest.

Answer 16

• Congenital defects include: eye defects (cataracts), hearing impairment, cardiac abnormalities (PDA), microencephaly, IUGR, autism, DM
• The severity and type of congenital defect likely to develop vary according to the stage of pregnancy when the infection occurs- before 8-10 weeks gestation there is a high likelihood of multiple defects. 90% chance of virus being passed on to foetus in early pregnancy

Question 17

How is rubella tranmitted. What is the inoulation period and when is it contagious

Answer 17

Transmission occurs through direct contact with an infected person or droplet spread from nasopharyngeal secretions
* The virus then replicates in the respiratory mucosa and local lymph nodes and is spread haematologically to the rest of the body (including placenta)
* Susceptible people will develop disease 12–23 days later. Most infectious when the rash is erupting, but patients can be contagious from up to 7 days before to 5-7 days after the rash erupts

Question 18

When is the foetus at risk of developing congenital rubella syndrome

Answer 18

• Beyond 20 weeks there have been no cases of Congenital Rubella Syndrome (CRS).
• Between 16–20 weeks there is a low chance of deafness occurring.
• Between 11–16 weeks there is a 10–20% risk of CRS, with single defects being most common.
• Before 8–10 weeks there is a 90% risk of CRS and a high likelihood of multiple defects

Question 19

Presentation of rubella in pregnancy

Answer 19

• No clinical features are specific to rubella — diagnosis must be confirmed with laboratory investigations. Infection is asymptomatic in 50%
• Rash- present in 50-80% of cases, typically starts on the face and neck before spreading down the body and becoming generalised (pink or light red, transient and maculopapular)
• Lymphadenopathy- may precede the rash and last for 2 weeks after the rash resolves. Suboccipital, postauricular and cervical lymph nodes are often affected
• Arthritis and arthralgia- 70% of women with rubella
• Non -specific symptoms
• Should have a low-threshold of suspicion for rubella in pregnant women, especially before 20 weeks

Question 20

Risk factors for rubella infection in pregnancy

Answer 20

• Incomplete immunization and no evidence of previous infection. Rubella is unlikely in people who have previously had rubella (although reinfection can occur).
• History of exposure to contacts with rubella within the last 3 weeks.
• Travel to an area endemic for rubella

Question 21

Investigations for rubella

Answer 21

• If there is any suspicion of rubella infection, immediately notify the local Health Protection Team (notifiable disease)
• ELISA in mother to test for IgM (acute infection) and IgG (past infection or vaccination) antibodies against infection
• May also test for infections with similar characteristics (PVB19)

For congenital rubella syndrome:
* USS for foetal growth restriction (A prominent feature of rubella, CMV, syphilis)
* USS for cardiothoracic, GI and eye lesion)

Question 22

Management

Answer 22

• Contact the local health protection team immediately
• There are no effective treatments to prevent CRS, however, Human normal IG can be considered in secondary care (likely after further confirmation by amniocentesis/ foetal blood sampling
• If found to be non-immune — rubella immunization should not be administered in pregnancy but may be given post-partum
• Advise on self-care measures- rest and drink adequate fluids. Paracetamol can be taken for symptomatic relief if required. Advise to stay off work and avoid contact with other pregnant women

Question 23

What is GBS, how common is infection with GBS in pregnancy

Answer 23

The Lancefield group B beta-haemolytic streptococcus infection (Streptococcus agalactiae) is the most frequent cause of severe early-onset (less than 7 days old) infection in newborn infants. It is a normal commensal of the female genital tract and can be found in the bowel flora of 20-40% of adults. There is no evidence that carriage rate is specifically affected by pregnancy

Question 24

What are the complications of GBS infection in the neonate

Answer 24

• Can lead to sepsis, pneumonia or meningitis

Question 25

Definition of early-onset GBS disease

Answer 25

An infection appearing within 7 days of a baby being born, although 90% of cases occur within 24 hours

Question 26

Incidence and prognosis of early onset GBS disease

Answer 26

0.5 in 1000 births (mortality rate of 5%)

Question 27

What are the maternal complications of GBS infection

Answer 27

Chorioamnionitis and endometritis

Question 28

Risk factors for EOGBS

Answer 28

• Having a previous baby with GBS disease
• Discovery of maternal GBS carriage through bacteriological investigation during pregnancy (e.g urine or vaginal swab)
• Preterm birth
• Prolonged rupture of membranes (an interval of 18 hours or more between rupture and delivery)
• Chorioamnionitis/ maternal intrapartum infection and pyrexia (higher than 38 degrees)

Question 29

Presentation of GBS infection

Answer 29

The mother does not usually experience symptoms as GBS is a common vaginal commensal, but GBS can lead to infection that can manifest as:
* UTI: frequency, nocturia, dysuria
* Chorioamnionitis: fevers, lower abdominal/ uterine tenderness, foul discharge, maternal and/or foetal bradycardia intrapartum
* Endometritis: fevers, lower abdominal pain, intermenstrual bleeding, foul discharge

The infant may show signs of neonatal sepsis: sudden collapse, tachypnoea, nasal flaring, poor tone, jaundice

Question 30

Investiations for GBS infection in pregnacy

Answer 30

• When testing for GBS carrier status, a swab should be taken from the lower vagina and anorectum- single swab or two different swabs can be used

Question 31

How should women who have had GBS in a previous pregnancy be counselled

Answer 31

Explain that the likelihood of maternal GBS carriage in this pregnancy is 50%:
* Discuss the options of Intrapartum antibiotic prophylaxis (IAP), or bacteriological testing (lower vaginal swab) in late pregnancy and the offer of IAP if still positive.
* If performed, bacteriological testing should be carried out at 35-37 weeks or 3-5 weeks prior to delivery

Question 32

Intrapartum management of GBS disease

Answer 32

• IAP should be offered to women with a previous baby with early- or late-onset GBS disease
• Maternal request is not an indication for bacteriological screening
• Clinicians should offer IAP to women with GBS bacteriuria identified during the current pregnancy (But NOT for vaginal or rectal GBS)
• Method of induction should not vary according to GBS carrier status and membrane sweeping is not contraindicated in carriers of GBS
• Antibiotic prophylaxis specific for GBS is not required for women undergoing planned caesarean section in the absence of labour and with intact membranes
• Women who are pyrexial (38 degrees or higher) in labour should be offered a broad-spectrum antibiotic regimen which should cover GBS in line with local microbiology sensitivities
• IV amoxicillin 2g every 6 hours is acceptable in this context
• IAP is recommended for women in confirmed preterm labour (without known GBS colonisation i.e. irrespective of status)- not recommended in preterm planned c-section with intact membranes
• For those with evidence of colonisation in the current pregnancy or in previous pregnancies, the perinatal risks associated with preterm delivery at less than 34 +0 weeks of gestation are likely to outweigh the risk of perinatal infection. For those at more than 34 +0 weeks of gestation it may be beneficial to expedite delivery if a woman is a known GBS carrier
• There is no evidence that intrapartum vaginal cleansing will reduce the risk of neonatal GBS disease

In the case of SROM at term (37+0 weeks)
* In women who are known GBS carriers- offer immediate IAP and IOL as soon as possible.
* In women where the carrier status is negative or unknown, offer IOL immediately or expectant management up to 24 hours- beyond 24 hours IOL is appropriate (as normal)

Question 33

Postpartum management of GBS disease

Answer 33

• Postnatal antibiotic prophylaxis is not recommended for asymptomatic term infants without known antenatal risk factors
• Babies with clinical signs of EOGBS disease should be treated with penicillin and gentamicin within an hour of the decision to treat
• Babies of a mother who has had previous EOGBS, should be evaluated at birth for clinical indicators of neonatal infection and have their vital signs checked at 0, 1 and 2 hours, and then 2 hourly until 12 hours
• Breastfeeding should be encouraged irrespective of GBS status

Question 34

What are some red flags for neonatal GBS infection

Answer 34

• Abnormal behaviour (inconsolable crying or listlessness)
• Unusually floppy or has develop difficulties with feeding or tolerating feeds
• Has an abnormal temperature (lower than 36 or higher than 38 degrees)
• Rapid breathing or change in skin colour

Question 35

What should be given as IAP

Answer 35

IV Benzylpenicillin 3g as a loading dose, followed by 1.5g every 4 hours until delivery
* If non-severe penicillin allergy - IV Cefuroxime 1.5 g loading dose followed by 750 mg every 8 hrs until delivery
* if the patient has a severe penicillin allergy – intravenous vancomycin 1 g every 12 hours until delivery.