Perinatal infections

Question 1

Describe how a swab is taken and sent for culture of Group B Streptococcus (GBS) to provide the highest rate of detection of colonisation. (3)

Answer 1

Vaginal swab - self swab (don’t use speculum) 2cm into vagina
Don’t touch cotton bud end
Then insert swab into anus- 1cm
Swab at 35-37/40
• Place in sterile medium tube of selective enrichment broth, label, send with form requesting GBS culture with pt name, NHI, details and gestation.
• Should be processed as soon as possible.

Question 2

Describe and evaluate two different strategies for the prevention of early onset neonatal GBS disease. (8 marks)

Answer 2

. Universal Screening
- All women are screening with LVS/anogenital swab for GBS at 35-37 weeks gestation.
- If GBS positive on swab:
o IAP (intrapartum antibiotic prophylaxis) is given
o Recommend immediate IOL if SROM at term
- If GBS negative on swab:
o No IAP required
- Exceptions:
o No IAP required for elective C/S with intact membranes even if GBS positive (but swab should still be done in case of SROM prior to elective date)
o Women with previous affected baby with GBS sepsis or GBS bacturia in current pregnancy should not be swabbed as should receive IAP regardless as result

    Benefits:	

• Studies have shown decreased rates of early onset GBS sepsis in neonates, RR 0.46 (although decrease in mortality not shown)
• Will pick up more women colonised with GBS
• Likely cost effective

Disadvantages:

• More expensive
• More labour intensive
• Medicalisation of pregnancy and labour
• Need for greater resources to facilitate immediate IOL for SROM at term
• Some women will be given antibiotics unecessarily
• Antibiotic allergies can occur
• Some women will be missed e.g. late bookers/unbooked women

. Risk Based Screenng
- No routine swabs for GBS
- Women should be given IAP if:
o Previous GBS infected neonate
o Previous GBS bacturia (any colony count) in this pregnancy
o GBS on swabs done for another reason in the pregnancy (unless has had LV at 35-37 weeks which is negative)
o Ruptured membranes >18hrs
o Maternal fever >38 degrees or clinical chorioamnionitis
o Preterm labour <37 weeks gestation

     Advantages:

• Cheaper
• Fewer unnecessary antibiotics given
• Fewer cases of anaphylaxis/allergic reaction
• Can apply to any woman who presents in labour
• Although less effective, still low EOGBS rate

    Disadvantages:

• May miss some GBS postive women
• Less effective at protecting against EOGBS

Question 3

Discuss the antibiotics used for intrapartum chemoprophylaxis of early onset neonatal GBS disease. (4 marks)

Answer 3

IV antibiotics should be given in labour if GBS positive or risk factors for EOGBS infection.
Aim for at least 4 hours prior to delivery, so give when in active labour until delivery.

Suggested regime from ASID: (however other local guidelines may differ)
- 1st line – benzylpenicillin 3g IV loading dose then 1.8g IV q4 hourly (penicillin preferred over amoxicillin as narrower spectrum of cover)
- Penicillin hypersensitivity without history of anaphylaxis:
o Cefazolin 2g IV loading dose then 1g q8hrly
- Penicillin or cephalosporin allergy at risk of anaphylaxis:
o Clindamycin 600mg IV q8hrly (ask for sensitivities at time of sending swab if penicillin allergic as 20% clindamycin resistance of GBS), OR
o Vancomycin 1g IV q12hrly
o (Erythromycin no longer an acceptable alternative - resistance rates of 30%).

• If signs of maternal sepsis broaden antibiotic cover to:
  o Amoxycillin 2g IV q6hrly, PLUS
  o Gentamicin 4-6mg/kg IV daily, PLUS
  o Metronidazole 500mg IV q12hrly

If delivered by elective pre rupture of membranes C/S – not required.

Question 4

3. Regarding GBS:
   a) maternal carriage is 50%
   b) neonatal sepsis is rare if the mother is clinically well
   c) 10% of babies born of carrier mothers are sick
   d) if isolated from amniotic fluid with PPROM should give antibiotics and deliver
   e) treat and wait

Answer 4

D
Colonisation of the genital tract with GBS occurs in ~ 20% of women
Early onset GBS occurs at a rate of 1-2% per 1000 live births (although declining)
The later in pregnancy that culture are performed, the better the correlation with culture results at delivery (particularly within 5 weeks of delivery)
Detection of GBS is increased by up to 25% by collecting an anorectal swab in addition to a vaginal swab.
90% of neonates with early onset GBS have onset of signs within 12 hrs of birth (suggesting intrauterine transmission) so intrapartum antibiotic prophylaxis is the most effective means of prevention.
Rate of maternal anaphylaxis to penicillin is estimated at 1 in 100,000
Alternatives to penicillin
o clindamycin 600mg IV 8h
o erythromycin 500mg IV 6h
Duration of intrapartum prophylaxis is inversely proportional to the percentage of babies colonised with GBS

Question 5

4. What organism causes chancroid?
   a) Calymmatobacterium granulomatis
   b) Haemophilus Ducreyi
   c) Gardnerella vaginalis
   d) Chlamydia trachomatis
   e) Calymmatobacterium donovae

Answer 5

B

Chancroid
o Haemophilus Ducreyi
o Base may have grey or yellow exudate
o Painful
o Detection – gram stain or PCR
o Treatment – Azithromycin 1gm stat or ceftriaxone 250mg IM
o 50% inguinal adenopathy – often painful

Question 6

5. What organism causes Donovanosis?
   a) Calymmatobacterium granulomatosis
   b) Haemophilus Ducreyi
   c) Gardnerella vaginalis
   d) Chlamydia trachomatis
   e) Calymmatobacterium donovae

Answer 6

Answer a
Donovanosis / Granuloma Inguinale
o Calymmatobacterium granulomatosis
o Usually painless
o Diagnosed on Wright stain for Donovan bodies
o Treatment – azithromycin 1gm orally once a week for 4/52

Question 7

6. What causes LGV (lymphogranuloma venereum)?
   a) Calymmatobacterium granulomatis
   b) Haemophilus Ducreyi
   c) Gardnerella vaginalis
   d) Chlamydia trachomatis
   e) Calymmatobacterium donovae

Answer 7

Answer d
LGV
o	Chlamydia trachomatis L1-L3
o	Adenopathy – matted clusters
o	Treatment – doxycycline 100bd for 21 days or azithromycin 1g stat

Question 8

7. Your 16w patient has a Mantoux reaction of 16mm. She is asymptomatic and CXR is normal. What is the best management?
   a) Vaccinate with BCG
   b) Reassure and review postnatally
   c) Isoniazid 300mg daily for 6 months
   d) Isoniazid 300mg daily for 12 months
   e) Rifampicin 100 mg daily for 12 months

Answer 8

Answer b
A positive test is presumptive evidence of current or prior infection or prior BCG vaccination.
If recent close contact with an active case or with known or suspected HIV infection – 5mm or more of induration is considered positive, other problems >10mm, all others (low risk) >15mm.
Patients with a positive test should be evaluated with a CXR
For management see Prologs question 42
If no recent exposure then isoniazid 300 mg daily for 6 months post-natally

Question 9

8. PID with temp. 39 degrees and bilateral pelvic tenderness. Chlamydia on swabs. Best therapy:
   * **
   a) IM Cephalothin and PO doxy
   b) PO doxy alone
   c) IV cefoxitin and PO doxy
   d) IV clindamycin
   e) IV penicillin + erythromycin

Answer 9

c) IV cefoxitin and PO doxy

Question 10

9. All of the following statements about HSV II are true except:
   * **
   a) infection with HSV I confers some immunity from HSV II
   b) treatment with acyclovir significantly reduces recrudescence
   c) genital herpes is mostly HSV II
   d) recrudescence occurs in the first 6 months

Answer 10

B

Question 11

11. In an acute tubo-ovarian mass, most common culture is:
    * **
    a) group b strep
    b) gonococcus
    c) Chlamydia
    d) Anaerobes
    e) E.coli

Answer 11

D

Question 12

What are the risk factors for acquiring primary HSVII in pregnancy?

Answer 12

• Unprotected sexual intercourse with infected partner, especially if active lesions at the time
• Young adults have highest risk of new infection

Question 13

What is the risk of vertical transmission of HSVII in a woman who acquires primary infection in late gestation?

Answer 13

~50%

Question 14

What is the risk of vertical transmission of HSVII in a woman who has an active recurrence of HSVII at the time of labour?

Answer 14

1-3%

Question 15

What is the risk of vertical transmission of HSVII in a woman who has a recurrence of HSBVII with no lesions at the time of labour?

Answer 15

<0.01%

Question 16

How would you reduce vertical transmission of HSVII?

Answer 16

• If first episode within 6 weeks of delivery:
o Recommend elective C/S
o If SROM prior recommend urgent C/S, but may not confer additional benefit if SROM >4 hrs
o Paediatric assessment of neonate and prophylactic acyclovir

• If recurrent infection, consider suppressive acyclovir from 36/40 gestation
o If lesions present at time of delivery (do speculum exam):
 Counsel about mode of delivery – can have vaginal birth if wishes, as low risk (1-3% of vertical transmission)
 Avoid FSE/FBS/ARM/instrumental
o If no lesions at time of delivery:
 Reassure vaginal birth safest
 Avoid FSE/FBS/ARM/instrumental

Question 17

Explain the characteristics of Listeria monocytogenes that account for this rare infection being 20 times more common in pregnant women than in the general population. (2 marks)

Answer 17

• Cell-mediated infection is a primary host defence against listeria – a gram positive bacillus.
• Reduced cell-mediated immunity in pregnancy leads to higher susceptibility.
• Listeria has a low virulence in general population.

Question 18

Justify the food safety advice given to pregnant women to prevent listeria infection. (4 marks)

Answer 18

• Avoidance of foods that could contain listeria:

• Unpasteurised milk/soft cheeses – pasterurisation kills listeria
• Uncooked meat/fish – cooking kills listeria
• Pre-prepared salads – may have become cross-contaminated with listeria and have time to replicate

• Safe food handling

• Cook food thoroughly – kills listeria
• Rinse fruits/veges well – remove listeria from surface (the bacteria is found in soil)
• Store ‘high risk’ foods away from ‘safe’ foods – avoid cross-contamination

Question 19

A 30 year old primigravid presents at 28 weeks having consumed a product that has recently been recalled because of contamination with listeria. She is extremely anxious for her health and that of her baby.

b. Formulate a detailed response for this patient to address these concerns:

Clinical features (3 marks) 
Perinatal effects (3 marks) 
Management (3 marks)

Answer 19

Clinical features - enquire and educate about these:
• Fever, flu-like illness, general malaise, abdominal/loin pain, back ache, diarrhoea, sore throat, conjunctivitis.
• If severe – ARDS, meningitis, encephalitis, septicaemia. May be asymptomatic (approx. 1/3).

Perinatal effects:
• Transmission is highest in 3rd trimester and has 40-50% mortality for fetus.
• Miscarriage/IUFD, perinatal mortality, PPROM, PTL, chorioamnionitis, meconium stained liquor. Neonatal – pneumonia, meningitis. However, may also have no affect.

Management:

1. Admit to hospital for observation and supportive management.
2. Maternal diagnosis – blood cultures and gram stain and cultures of genital tract (serology unhelpful)
3. Antibiotics – PO amoxycillin/ampicillin if mild. IV amoxycillin/ampicillin and gentamicin if severe (not sensitive to cephalosporins). Duration of 14 days.
4. Consider delivery after steroids if severe (weigh risks of infection vs risks of permaturity).
5. Notifiable disease to Public Health services.

Question 20

List specific groups of women at an increased risk of acquiring Parvovirus B19 infection in pregnancy (1 mark)

Answer 20

• Women with children affected at home (50% risk if susceptible, compared to exposure in general community of 20%)
• Women working in daycares or schools who are in contact with children who may be affected (20-30% risk if susceptible)

Question 21

In women who have Parvovirus B19 infection during pregnancy:

i) Explain the pathogenesis of fetal disease (2 marks)

Answer 21

• Affects erythroid precursors, where it is cytotoxic, which can result in severe anaemia, which in turn can cause cardiac failure and contribute to hydrops
• Infects hepatic cells causing hypoalbuminaemia and myocardial cells causing cardiomyopathy, which contributes to hydrops
• May infect megakaryocytes which can cause thrombocytopenia

Question 22

In women who have Parvovirus B19 infection during pregnancy:

ii) Outline the potential fetal clinical sequelae including likelihood of occurrence (4 marks)

Answer 22

• Fetal anaemia 10-25%, can resolve spontaneously
• Non-immune hydrops 3-12%
• IUFD may occur without hydrops 5-10% (highest risk 2nd trimester)
• Rarely myocarditits, fetal arrhythmia, brain injury

Question 23

A 27 year old G2P1 who is now 17 weeks pregnant has been referred to you by her GP because she has recently been exposed to a confirmed diagnosis of “slapped cheek syndrome” (Parvovirus B19 infection). She has no symptoms and has not yet had any tests performed.

c. Outline and justify your approach to this women.
i) To diagnose or refute maternal parvovirus infection (4 marks)

Answer 23

• Maternal serology:
o IgG +ve, IgM –ve = immune, reassure, no action required
o IgG -ve, Ig M–ve = susceptible
 Repeat IgG 2-4 weeks after exposure/symptoms
• –ve, reassure not recent infection, no action required however remains susceptible
• +ve confirms recent infection
o IgG –ve, IgM +ve = ? recent infection
 Repeat IgG 2-4 weeks after exposure/symptoms
• -ve then the IgM was false positive, reassure not recent infection, no action required, however remains susceptible
• +ve confirms recent infection
o IgG +ve, IgM +ve = recent infection

• +/- newer diagnostic techniques such as IgG avidity and epitope-type specificity assays may be more sensitive and specific however not widely available

Question 24

A 27 year old G2P1 who is now 17 weeks pregnant has been referred to you by her GP because she has recently been exposed to a confirmed diagnosis of “slapped cheek syndrome” (Parvovirus B19 infection). She has no symptoms and has not yet had any tests performed.

c. Outline and justify your approach to this women.
ii) To manage proven parvovirus infection in pregnancy (4 marks)

Answer 24

Maternal:
• Monitor FBC due to risk of anaemia if immunocompromised or has hereditary blood disease
• Monitor for risk of Mirror Syndrome secondary to hydrops if this develops (preeclampsia like syndrome)
• Otherwise reassurance, no intervention for mother required

Fetus:
• No intervention is available to prevent fetal infection or damage
• Termination is not indicated because of low risk of fetal damage
• Ultrasound should be performed at 1-2 weekly intervals for 12 weeks to detect fetal anaemia or hydrops including Doppler assessment MCA PSV
o If fetal anaemia detected refer to specialist experience in fetal ultrasound, blood sampling and IUT. 84% of fetuses with severe hydrops will survive if treated with IUT. Long term sequelae is rare.
o If no fetal abnormality after 30 weeks then no further action required

Overall candidates showed poor knowledge of Parvovirus B19, one of the five common childhood exanthemas. Maternal infection in the first 20 weeks can cause fetal anaemia with the potential cause of fetal harm through miscarriage or hydrops in up to 15% of these pregnancies. There is no vaccination available, so serological immune status of both Parvovirus B19 IgG and IgM is used to assess the risk to or infective status of a pregnant woman. Management of an acute infection includes weekly ultrasound assessment to diagnose fetal anaemia by raised MCA PSV or the presence of hydrops. If anaemia is detected, referral to a fetal medicine unit is indicated for fetal blood transfusion. There is no preventative therapy. Long term sequelae are rare.

Question 25

What advice do you give with regards to avoiding toxoplasmosis infection in pregnancy?

Answer 25

• Avoid raw or undercooked meat
• Wash raw vegetables
• Wash hands after gardening
• Wash hands after contact with cats or their faeces; minimise contact with kittens

Question 26

What are the signs of fetal infection (Toxo) on USS?

Answer 26

• IUGR
• Brain and hepatic calcifications
• Hydrocephalus
• Ascites
• Splenomegaly

Question 27

How would you manage maternal infection (TOXO) at 25/40?

Answer 27

• Confirm infection with maternal serology (IgG, IgM and if both positive do IgG avidity, if low then likely recent infection)
• Consider treatment of mother at diagnosis (depending on gestation and certainty of diagnosis). Treat mother with pyrimethamine, sulfadiazine & folinic acid until delivery to reduce the risk of vertical transmission (although efficacy not confirmed in RCTs)
• Referral for tertiary MFM unit to confirm diagnosis in infant and provide counselling
o USS assessment and surveillence
o Amniocentesis at 18-20/40 or >4 weeks post maternal infection for toxo PCR (50-60% sensitivity >21 weeks)
• Consider TOP if USS abnormal
• Paediatric review of neonate

Question 28

How do you diagnose maternal (Toxo)infection?

Answer 28

Symptoms:
•	Usually sub-clinical
•	Malaise
•	Fever
•	Lymphadenopathy

Serology:
•	Documented seroconversion
•	IgG pos + IgM pos, however IgM can remain positive for months/years therefore the following tests are more specific for ‘recent’ infection;
o	IgM high pos
o	IgA pos
o	Low IgG avidity
o	Rising IgG titre

Question 29

What are the fetal effects from toxoplasmosis infection?

Answer 29

Congenital toxoplasmosis:
•	Micro/hydrocephalus
•	Intracranial calcification
•	Cataracts
•	Seizures
•	Pneumonia
•	Hepatosplenomaegaly
•	Thrombocytopaenia
•	Lymphadenopathy
•	Chorioretinitis
•	Mental retardation

Proportion of infant infected and severity depends on when maternal infection occurred and if treated:
• 1st trimester;
o Fetal infection = low risk (4-15%)
o High risk of damage if infected (34-85%), likely to be severe
• 2nd trimester;
o Fetal infection = intermediate risk (25-44%)
o Intermediate risk of damage if infected (18-33%), likely to be less severe
• 3rd trimester;
o Fetal infection = high risk (30-75%)
o Low risk of damage if infected (4-17%), usually asymptomatic at birth

High incidence of long-term sequalae (eg. chorioretinitis) in untreated infants even if asymptomatic at term.

Question 30

A woman who is 18 weeks pregnant has been exposed to chickenpox.

What history and investigations would you obtain? (2 marks)

Answer 30

History:
• Had chickenpox as a child or had vaccination?
• When was she exposed?
• What were the symptoms of the person she was exposed to – infectious from 48 hours prior to rash until lesions crusted over
• Duration of exposure and type of contact (household contact, same room, face-to-face?)
• Has she had any symptoms – fever, mylagia, rash?
• PMHx, meds, allergies, smoker.

Investigations:
• Maternal varicella zoster serology - IgG and IgM

Question 31

How would you manage her exposure risk (to varicella)? (4 marks)

Answer 31

• If history of childhood chickenpox – 97-99% predictive of IgG seropositivity – reassure
• If IgG positive – reassure, confirms not susceptible
• If IgG negative then is susceptible– give VZIG – most effective within 96h but still effective up to 10 days after signficant exposure (household contact, same room for 1 hour, face-to-face for at least 5 mins)
• Counsel and consent (human blood product)
• If >96h from exposure then ASID recommends no VZIG but consider oral aciclovir post-exposure prophylaxis if at risk (2nd half of pregnancy, underlying lung disease, immunocompromised, smoker)
• Educate on signs and symptoms of chickenpox and advise to seek medical attention promptly if develops (preferably GP or ED to minimise exposure to other pregnant women)

Question 32

2 weeks later she develops a moderately severe chicken pox infection.

c. List the maternal signs and risks of chicken pox infection. (2 marks)

Answer 32

Maternal signs:

• Prodrome - fever, malaise, mylagia, lymphadenopathy
• Then - pruritic rash that arranges into crops and becomes vesicular – lesions eventually burst and crust over

Risks – Disseminated chickenpox:

• Varicella pneumonia
• Varicella encephalitis
• Hepatitis
• Increased mortality in pregnancy

Question 33

d. Justify the circumstances under which you would give oral or parenteral treatment to the mother (3 marks) (for chickenpox)

Answer 33

Aciclovir can be commenced if <24 hours sicne onset of rash to reduce the severity/duration of symptoms (Not known to decrease risk of transmission or treat FVS.)
• If no complications: oral dosing 800mg 5 times per day
• If complications (respiratory symptoms, haemorrhagic rash or bleeding, new pocks developing >6 days, persistent fever >6days or neurological symptoms) or immunocompromised: IV dosing 10mg/kg/dose 8 hourly

Question 34

What would you explain to the mother about the fetal risk and its management? (4 marks) (for chicken pox)

Answer 34

Fetal risk:
• Overall risk of fetal varicella syndrome (FVS) is low
• Risk depends on gestation – highest risk is 12-28 weeks but is still only 1.4%
• FVS manifested by:
o Skin scarring in dermatomal disribution
o Low birth weight, prematurity
o Eyes – cataracts, microphthalmia
o Limb hypoplasia
o CNS – microcephaly, low IQ, sphincter dysfunction,
o 30% early mortality

Management:
• VZIG and acyclovir do not reduce the risk of development of FVS once the mother has chicken pox
• MFM referral, detailed tertiary USS and counselling
• Signs may not show on USS for 5 weeks post infection
• Consider amnio for VZV PCR if abnormalities on USS – helpful if negative (reassuring), if positive does not correlate with severity of outcome
• If signs present – offer TOP
• If continuing pregnancy – serial growth USS for possible development of IUGR
• Neonatal review for serology, neuro and ophthalmology at birth

Question 35

What things increase the risk of vertical transmission of HIV?

Answer 35

The probability of mother to child transmission of HIV can be reduced from 30% to < 1% with appropriate management. Interventions to reduce vertical transmission include:
• Antiretroviral therapy to mother (antepartum +/- intrapartum) and baby (postpartum) – use of ARVs significantly reduces the rate of vertical transmission.
• Elective caesarean section if viral load not fully suppressed
• Caution with invasive obstetric procedures (eg. amniocentesis, fetal scalp monitoring, fetal scalp blood sampling, episiotomy)
• Formula feeding (avoiding breastfeeding) - Some mothers will decide to breastfeed and ideally this decision has been made some time prior to delivery and there has been time for an informed discussion with the woman, the LMC, the neonatologist, the ID HIV CNS and the ID physician.

Question 36

What the the principles of antenatal management of a women with HIV?

Answer 36

Antenatal Management
MDT approach – Infectious disease specialist, obstetrician, physician, Midwife who is used to looking after HIV +ve women, Neonatologist Anaesthetist, also inform GP

Needs :
Usual Booking bloods and susceptibility to other infections ( Rubella, Syphillis, HBV, including Hep C ( increase risk of transmission if HIV+ve and HCV +ve ), Toxo, CMV, HZV, HSV
Screen for other STI – swabs for chlamydia, gonorrhea, trichomonas
Cervical smear

Baseline blood for monitoring of HIV, then every 1-2months then again at 36 weeks

• CD4 count
• HIV RNA Viral levels – aim for < 50 copies /ml
• LFT’s
• Lactate
• Monthly MSU

MSS1 or MSS2 screening
- if high risk – for NIPT as higher sensitivity and specificity
- Amniocentesis and CVS will increase risk of vertical transmission
GTT – screen for diabetes

Serial Growth USS every 3-4 weeks

Question 37

Outline the intrapartum management of a women with HIV and her fetus

Answer 37

Mode of delivery is dependant on Viral load
If viral load < 50copies /ml or undetectable
- can have vaginal delivery
- No need for intrapartum zidovudine
- Avoid prolonged rom, FBS or FSE
Staff: Gloves, apron and eye protection
If viral load >50 – 400 copies/ml
- Can consider intrapartum zidovudine in labour until cord clamping and cs 38-39 weeks

If viral load > 400
For elective Caesar at 38-39 weeks with intrapartum zidovudine

Question 38

Outline the management of the fetus postpartum (HIV)

Answer 38

Neonate
- needs paeds review
- Early cord clamping and wash baby immediately post delivery before Vit K
- Test neonate with HIV viral culture and PCR ( HIV RNA or DNA ) post delivery, 6 weeks, 3 months then HIV antibody test at 18months
- antibody testing not useful as maternal antibodies can be present up to 18/12 post partum
- anti retroviral prophylaxis regimen dependant on high > 2% risk or low risk of MTCT < 2%
o Low risk
 AZT stat dose then zidovudine for 4 weeks, no need for pneumocystitis prophylaxis
o High risk
 HAART and Pneumocystitis prophylaxis
Maternal
No breast feeding – to reduce MTCT
Discuss contraception
Continue HAART
Follow up with Infectious disease specialist for long term health

Question 39

38yr old thai G4P3, HIV Ag +ve (Ab positive)

- outline the issues/counselling and management antenatally

Answer 39

Counselling:
Counsel patient in sensitive culturally appropriate manner with interpreter if needed, emphasize confidentiality.
Have a HIV specialist nurse present.
Give written information.
Allow time for consult with no distractions eg have phone off.

Take full history and examination ( Hep C, risk factors for HIV )

Explain screening test positive – need confirmation test with HIV1/HIV2 differentiation immunoassay or western blot , if low risk then risk of false positive.

Discuss implications of disease long term – chronic disease, no cure, needs HAART to reduce disease progression to AIDS and risk of immunosuppression. Increased susceptibility to infection.

Transmission risk via sexual contact, parenteral, and perinatal and prevention of spread.

Implications in pregnancy - No teratogenic. LBW, PTB and risk of vertical transmission can be reduced from 20% to < 1% with treatment ( HAART, +/-CS, No breast feeding . HAART safe in pregnancy and benefit outweigh risks.
Pregnancy implications on HIV – minimal, no effect on disease progression.
Treatment side effects – HAART can cause nausea and vomiting and lethargy. Rare toxicity – lactic acidosis, hepatitis, peripheral neuropathy, pancreatitis.

Question 40

GDM and PET with HIV

Answer 40

GDM & PET: Glucose impairment and pre-eclampsia have been associated with HAART. Both should be managed in accordance with normal obstetric practice.

Question 41

Preterm birth and HIV

Answer 41

Preterm labour: Preterm birth has been identified as a risk for vertical transmission. An HIV positive woman presenting with threatened preterm labour and intact membranes should have triple swabs taken for microbiology. Betamethasone should be administered in keeping with normal obstetric practice. There is no evidence for benefit from use of tocolytics in women with HIV infection. Since women with an unsuppressed viral load are at increased risk of sepsis, tocolysis should be avoided. For women with fully suppressed viral load on HAART the decision to treat with tocolytics should be discussed with the consultant on call. It would be reasonable not to use tocolysis in this setting.

Question 42

PROM and HIV 34-37/40

Answer 42

PPROM at 34-37/40: In the event of PPROM after 34 weeks gestation birth should be expedited without delay. Triple swabs should be taken for microbiology and intravenous antibiotics should be prescribed in labour in accordance with the local guidelines on antibiotic prophylaxis in labour. For those women with no other obstetric complication on HAART with a fully suppressed viral load and intending to birth vaginally then induction of labour is the management of choice.

Question 43

PPROM and HIV <34/40

Answer 43

PPROM <34/40: In the event of preterm pre-labour rupture of membranes before 34 weeks gestation the decision to expedite birth will depend on various factors:
• If the mother has an undetectable viral load and is on HAART and if there is no evidence of infection on triple swabs or blood parameters, then the benefits of prolonging gestation probably outweigh any increased risks of vertical transmission. The woman should be managed in the usual way with two doses of betamethasone and ten days of oral erythromycin.
• Birth should be expedited if there is any evidence of infection or at 34 weeks gestation.
• If the woman is not on HAART or has a viral load more than 40 copies per mL, then consideration should be given to earlier birth, which unless there are obvious signs of infection may be delayed until two doses of betamethasone have been given. The woman’s care should be discussed with the Infectious Diseases Consultant on call regarding antiretrovirals during labour and for the infant following birth.
Suspected chorioamnionitis: The risks of chorioamnionitis to both mother and baby are increased in the presence of HIV. Therefore there should be a low threshold for administration of broad spectrum intravenous antibiotics where chorioamnionitis is suspected.

Question 44

Mode of delivery HIV

Answer 44

• A full discussion regarding the mode of birth should take place with each woman. A clear plan must be documented in the notes.
• Women whose viral load is less than 40 copies/mL or not detected (fully suppressed) may safely choose a vaginal birth. Caesarean section does not offer additional benefit to reduce vertical transmission of HIV and should be used for usual obstetric indications- in fact c-section carries higher risk to women with HIV. - —- There is no data at present to suggest that spontaneous rupture of membranes in labour increases the risk of vertical transmission for women who have a fully suppressed viral load and are on HAART.
• Other co-morbidities including chorioamnionitis and preterm labour are associated with an increase in the risk of vertical transmission and this should be considered when making management decisions. - —

Elective Caesarean section is recommended if the viral load is not fully suppressed or if the woman is not on HAART.

• Invasive procedures including use of fetal scalp electrodes and fetal pH sampling, episiotomy and assisted vaginal delivery appear safe in women with a completely suppressed viral load. However, the decision to perform them should be made on a case by case basis.

Question 45

Intrapartum care for HIV positive women

Answer 45

• Women who are on antenatal combination antiretroviral treatment should continue this regimen as much as possible during the intrapartum period, to provide maximal virologic effect and to minimize the chance of drug resistance developing.
• Intravenous zidovudine during the intrapartum period should be discussed and recommended to all HIV-infected pregnant women with detectable viral loads. For those women with a fully suppressed viral load and are on HAART this may not be necessary

Question 46

Postpartum care for HIV positive women

Answer 46

• Confidentiality is paramount. Check the level of disclosure required by the woman.
• Women with HIV may be at higher risk of postnatal infection. Regular observations of pulse, blood pressure and temperature should be performed at least four times a day.
• Offer cabergoline (Dostinex® 1 mg for suppression of lactation within first 24 hours unless the woman has decided to breastfeed.
• All maternal medications including antiretrovirals should be continued post-partum at the usual dose times.
• In some women, antiretroviral medication may be stopped postpartum, but would be continued in those women who require antiretrovirals for their own health. - In addition a woman who decides to breastfeed should remain on anti-retroviral therapy. Contraceptive advice should be given.

Question 47

Management of the baby postnatally in HIV positive women

Answer 47

• Universal precautions should be adhered to and it is recommended that the baby is handled with gloves until bathed in warm water.
• ‘Skin to skin’ procedures • If the woman has an undetectable viral load and on HAART treatment, then ‘skin to skin’ contact with the mother should be offered as soon as possible after the birth.
• The baby should then be bathed at a suitable time following this period of skin to skin.
• It is important for baby to have a bath prior to any intramuscular injections or heel pricks.

• If the woman has an unknown or high viral load then the baby should be bathed immediately after birth prior to skin to skin.

Feeding guidelines National recommendations are that all breastfeeding (including colostrum) should be avoided (MOH: Feeding your baby when you are HIV positive, 2 May 2016). If the mother decides to breastfeed despite advice then she should continue ARVs.

• Within 6 hours of birth the infant should be administered zidovudine suspension for 4 weeks as per Neonatal Drug Profile Guidelines.
• BCG is contra-indicated until the infant is confirmed to be HIV negative. Other vaccinations are safe and highly recommended as per the immunisation schedule.

Question 48

ARV treatment in pregnancy

Answer 48

Women not on treatment pre-pregnancy: Any HIV-infected woman who meets standard criteria for initiation of antiretroviral therapy should receive potent combination antiretroviral therapy, generally consisting of two nucleoside reverse transcriptase inhibitors (NRTIs) plus a reverse transcriptase inhibitor (NNRTI) or protease inhibitor (PI), with continuation of therapy post-partum. This should be started as soon as possible, including in the 1st trimester, as the potential benefits to the mother outweigh the potential fetal risks.

For all women who do not require antiretroviral treatment for their own health, antiretroviral therapy should be discussed and recommended for the prevention of mother to child transmission. This should be commenced after the 1st trimester and by the 26th week of pregnancy, to allow time for antiretroviral effect and allow alteration of medication if side-effects occur.

Question 49

AIDS defining illnesses

Answer 49

PCP, cerebral toxoplasmosis, CMV, TB, Kaposi’s sarcoma, Non-hodgkin’s lymphoma, candidiasis (of lower resp tract not just mouth), Cryptococcus.

Question 50

Toxoplasmosis:

Answer 50

• From infected cat faeces with toxoplasma gondii. - —– Women would be largely asymptomatic but it can cause longer term symptoms like glandular fever such as swollen glands and lymph nodes.
• Most people will have it before pregnancy and therefore be immune.
• 85% of congenitally infected infants appear normal at birth.
• Maternal infection in first trimester less likely to infect fetus (10%) but if it does the damage is more severe. —- Mid or late trimester infection more likely to infect fetus (30-50%) but the effects are milder.
• Congenital defects include: hydrocephalus, calcifications of the brain, or retinochoroiditis.
• If mother is infected- consider treating with Abx (spiramycin). Then consider fetal imaging/amnio for T PCR in amniotic fluid in 2nd trimester.
• Counsel regarding risks as per trimester. Offer termination depending on scenario. Once neonate born- needs serology, clinical examination and discussion with paediatric team.

Question 51

Cytomegalovirus:

Answer 51

• Most common viral infection of TORCH screen, leading cause of congenital infections and incidence 0.5-0.7%.
• Passed between humans in saliva etc.
• Often gives mild ‘flu-like’ symptoms or similar to glandular fever with tiredness, sore throat, swollen glands and fever.
• Women at highest risk are those around young children.

Question 52

Risk of congenital infection with CMV

Answer 52

• primary infection in 30%, long term sequelae 50% if symptomatic, 10-15% if not.
• Risk of congenital infection with reinfection/reactivation is 1%.
• Overall long term risk of sequelae in an affected child is 10-20%.

Question 53

Effects of CMV on fetus

Answer 53

These can include hearing loss, vision loss, small head size, cerebral palsy, developmental delay or intellectual disability, and in rare cases, death. Most infants are asymptomatic but may have later deafness or learning disability.

Question 54

Investigation of CMV in pregnancy:

Answer 54

• IgG – and IgM -: no evidence of past or current infection
• IgG +ve and IgM –ve: evidence of past infection not current
• IgG – and IgM +: repeat in 2/52 if no change in IgG then possible recent infection
• IgG + and IgM + :Test CMV specific avidity- negative or intermediate then suggestive of recent infection. If high then suggestive of past infection.
If recent infection with CMV is confirmed then proceed to fetal testing.

Non-invasive: USS or MRI.

Invasive- amniocentesis, ideally after 6/52 of infection but before 21/40.

Question 55

Features of fetal CMV infection

Answer 55

Features associated with symptomatic congenital CMV infection include: Microcephaly Hydrocephalus (ventricular dilation) Intrauterine growth retardation (IUGR) Ascites Intracranial calcification Pleural or pericardial effusions Oligo or polyhydramnios Hydrops fetalis Hepatomegaly Abdominal calcification Pseudomeconium ileus Hyperechogenic bowel.

Caution is advised in interpretation of findings as presence of signs not always predictive of degree of fetal damage. The sensitivity of fetal ultrasound is difficult to evaluate from the literature, with an overall estimate of ~30–50% sensitivity for detecting symptomatic congenitally infected infants.

Question 56

Amniocentesis CMV

Answer 56

Sensitivity is increased by waiting ≥ 6 weeks after maternal infection • Diagnosis by amniocentesis testing (PCR and culture) is poor, ~ 45% sensitive if taken < 20 weeks and 80-100% sensitive if taken ≥ 21 weeks gestation. Specificity approaches 100%. Diagnosis is best achieved by a combination of fetal ultrasound + amniocentesis (for PCR) • Positive results cannot predict degree of fetal damage • Quantitative PCR may identify infected fetuses at risk of symptomatic disease but not reliably.

Termination of pregnancy is an option by informed choice if congenital CMV is confirmed in-utero, with the knowledge that a positive PCR is not predictive of fetal damage