Intra-uterine & Perinatal Infection

Why are pregnant women particularly vulnerable to infection?

• Hormonal and physical changes – pregnant uterus places pressure on abdominal organs which may cause renal tract dilation.

• Immunosuppressed state.

• +/- impaired glucose tolerance

3 types of infections pregnancy makes you more susceptible to

More susceptible to infection generally but especially:

• Urinary tract infections (UTI)

• If membranes ruptured – then risk of ascending infection (chorioamnionitis)

• Influenza and other viral infections tend to be more severe

Congenital infections tend to manifest as what 3 things

Growth Retardation- low birth weight

Congenital Malformations

Foetal Loss- Stillbirths

Name the organisms most responsible for congenital infections

• Rubella

• CMV

• HIV

• Toxoplasma gondii

• Treponema pallidum (syphilis)

• Parvovirus B19

• HSV

• VZV

How do perinatal (around time of birth) infections manifest

Meningitis

Septicaemia

Pneumonia

Preterm labour

Name the organisms most responsible for perinatal infections

• Neisseria gonorrhoeae

• Chlamydia trachomatis

• HSV

• Group B Streptococcus (Streptococcus agalactiae)

• E. coli

• Listeria monocytogenes

How do postnatal infections manifest

• Meningitis

• Septicaemia

• Conjunctivitis

• Pneumonitis

Name 2 organisms that cause postnatal infections that are transmitted through the umbilicus

Staphylococcus aureus, Clostridium tetani (tetanus)

Name 3 organisms that cause postnatal infections that are transmitted by person-to-person contact

Group B Streptococcus, Listeria monocytogenes, E. coli

Name 3 organisms that cause postnatal infections that are transmitted through breast milk

HIV, CMV, HBV

Name 2 organisms that cause postnatal infections that are transmitted by contact with eyes/conjunctiva

N. gonorrhoeae, C. trachomatis

Are congenital infections usually mild/moderate/severe

Often mild/no apparent maternal infection

Wide range of severity in the baby

How are congenital infections diagnosed

Serological diagnosis

Common features of congenital infections

◦ Thrombocytopenia

◦ Ear and/or eye abnormalities

◦ Rash

◦ Cerebral abnormalities

◦ Hepatosplenomegaly; hepatitis; jaundice

Name 5 congenital infections routinely screened for

• Hepatitis B

• HIV

• Syphilis

• Rubella

• +/- VZV (chicken pox)

Name 4 congenital infections not routinely screened for

• Toxoplasmosis

• Herpes group viruses e.g. CMV, HSV

• Parvovirus

Is Hepatitis B an RNA/DNA virus

DNA virus

What is the commonest mode of transmission for Hepatitis B

Vertical transmission

If hep B is acquired vertically, what % develop chronic infection with risk of cirrhosis and HCCa (Hepatocellular carcinoma)

90%

If hep B is acquired in adulthood, what % develop chronic infection with risk of cirrhosis and HCCa (Hepatocellular carcinoma)

10%

When hep B is transmitted vertically is is generally in utero or around delivery

around delivery

(In utero transmission <2%)

Which specific antigen do you screen for in Hepatitis B antenatal screening

HBV surface antigen (HBVsAg)

What happens once someone is diagnosed with Hep B in an antenatal screening

Notifiable disease

Household contacts screened & vaccinated if not immune

Hepatitis B Immunoglobulin (HBIG) ASAP after birth & vaccine at birth/0, 2, 4 & 6 months of age. (4 doses) (usually 3 doses of 6 in 1 (DTaP/IPV/Hib/Hep B)

Maternal referral for treatment

What happens if someone is found to be HIV positive in a pregnancy screening

• Treatment with anti-retroviral drugs.

• C-section delivery.

• Avoid breastfeeding in developed world. In developing countries, not breastfeeding is a greater risk to the child – encouraged

Name some interventions that can be done to avoid HIV vertical transmission

In a baby born to HIV positive mother, what Ig(s) would be detectable in the baby, how

IgG will be detectable due to maternal transfer across placenta

In a baby born to HIV positive mother, when would you expect Ig levels to be gone again

Usually 9 months, but maybe up to 15 months

Risks to a baby born to a mother with untreated syphilis in first 2 years after infection

• Foetal/Perinatal death (20%)

• Preterm delivery (20%)

• Congenital syphilis (40%)

How might a baby born to a mother with untreated syphilis present

At birth - may be asymptomatic or multi-system involvement or present much later

What type of organism is Syphilis – T. pallidum

A spirochaete

Name the screening tests for Syphilis

ELISA (+/- RPR and TPHA).

Why are high risk pregnancies rescreened in 3rd trimester

Reinfection can occur

What do you do if pregnancy screening tests positive for Syphilis

Positive results need repeat for confirmation

Get previous treatment details

Penicillin is treatment of choice.

Refer to GUM/ID service

What is another name for Rubella

German measles

Is rubella a DNA/RNA virus

RNA virus

True/False Rubella is self-limiting

True

Rubella symptoms

Rash & fever

Does rubella present more severe in adults/children

Often more severe in adults.

How is rubella transmitted (& high/low infectivity)

Droplet spread – high infectivity

A sample of what is tested for rubella

Serology / Oral secretions

Is rubella notifiable

Yes

What type of vaccine is rubella & significance of this?

Included in MMR vaccine (live vaccine – do not give in pregnancy and delay pregnancy for 1 month after giving).

During what weeks of pregnancy is there the greatest risk of transmission (what is the % risk of transmission)

1st 11 weeks

>90% risk of transmission

The 1st 11 weeks is also when contracting rubella is riskiest - why

Greatest risk of severe congenital infection affecting hearing, heart, eye and brain

Transmission % risk & risk of what problems if rubella is contracted at 16-20 weeks of pregnancy

45% transmission risk

Deafness only.

There is a risk of what problems if rubella is contracted at 20+ weeks of pregnancy

No increased adverse foetal outcome

What Ig for rubella is most important to test for in mothers - why?

IgG

IgG can cross placenta from mother

What IU/ml if IgG would lead you to offer rubella vaccination post-partum

<10 IU/ml

Why would you only offer rubella vaccination post-partum

Avoid live vaccines in pregnancy

What can you take from if a baby tests positive for Rubella IgM

IgM can’t cross placenta – if detected, means baby has been infected in-utero

If congenital rubella confirmed, urine and oral secretions are infectious for how long

Up to one year

What precautions are taken with babies with congenital rubella in hospital

Need to isolate baby if in hospital

What poses the highest risk of rubella in Ireland

Imported cases of rubella through international travel/migration

Herpes group viruses are not part of the routine screening programme. Name 3 of these viruses

VZV – varicella zoster virus

HSV – herpes simplex virus

CMV - cytomegalovirus

Are Herpes family viruses DNA/RNA

DNA

Another name for VZV – varicella zoster virus

Chickenpox

Risk with VZV (general & specific problem)

Chickenpox in pregnancy can be more severe than in non-pregnant adults

Can → pneumonia

How to treat VZV → pneumonia

If pneumonia – admit; isolate; IV aciclovir

Foetal varicella syndrome is seen in up to 2% of foetuses in what stage of pregnancy

Foetal varicella syndrome = up to 2% in 1st 20 weeks

Foetal varicella syndrome Sx

Limb deformities

Skin scarring

Chorioretinitis

If someone has had significant exposure, test blood for which VZV Ig

VZV IgG

What do you do if IgG is present/not present for VZV

If VZV IgG detected – already immune – reassure.

If VZV IgG not detected and significant exposure, PEP may be indicated

Grey = how much

Green = Tx

Describe the process for Post exposure prophylaxis (PEP) – if non-immune and significant exposure

• Management discussed with Obstetrician/Microbiologist/ID re the use of PEP & option risks/benefits discussed with woman.

• Immunoprophylaxis with oral aciclovir is as effective as VZIG. Little evidence that prophylaxis will prevent cong varicella syndrome in the first 20/40.

• Aciclovir (800mg QDS days 7-14 post-exposure) first-line option for prophylaxis; VZIG reserved if the woman is unable to take aciclovir. Aciclovir preferable in view of administration, limited VZIG supply and potential for donor-related illness from VZIG. Aciclovir not licensed in pregnancy but robust safety data to recommend its use in the setting of VZV.

• If >7 days post exposure, 7 day course of aciclovir can be started up to day 14. VZIg can be given up to 10 days post exposure but ideally <96 hours.

• Subsequent exposure to VZV: Risk assess; Repeat VZV IgG; If further PEP warranted - additional 7 day course aciclovir. If >3/52 or more after the first dose of VZIG, an additional dose may be given

Grey = how long.

Green = Tx

HSV1 Sx in primary infection & reactivation

1ry infection may be asymptomatic or severe painful ulceration of throat & mouth.

Reactivation → cold sores

HSV2 Sx in primary infection

Painful ulceration of GU (genitourinary) tract

Risks in Neonatal herpes

Can cause a severe systemic viral infection with high morbidity and mortality

When is neonatal herpes acquired

Usually acquired at, or around, delivery.

Sx of Neonatal herpes

Encephalitis

Disseminated infection – CNS, skin, eyes

Localised eye, skin or mouth disease

How would the virus reach the foetus if the primary infection is contracted in 3rd trimester

May be HSV2 or HSV1 from maternal genital tract especially if 1ry infection in 3rd trimester

How can Neonatal herpes be prevented

C-section delivery

Tx for Neonatal herpes

Aciclovir

Cytomegalovirus (CMV) is a common cause of viral infection, which can cause what Sx

Neonatal hearing loss and brain damage

How does a primary CMV infection present in mother

asymptomatic or 'flu-like illness

When in pregnancy is the greatest risk of transmission of a primary infection

1st 12 weeks

What can cause a non-primary CMV infection

Reactivation or infection with different CMV strain

Best way of preventing CMV

The most common source of infection is saliva/urine of young children so risk can be reduced by hygiene-based measures, e.g. handwashing

If screening doesn’t exist for CMV, how is anyone tested

CMV testing is usually offered only to pregnant women who develop symptoms of influenza, glandular fever or hepatitis, or routine U/S scan detects foetal anomalies

If a pregnancy woman gets a primary CMV infection in the first 12/40, what is given to reduce the risk of the baby becoming infected

Valaciclovir

All babies born to women with confirmed/suspected CMV infection should be tested for CMV how & when

In urine or saliva within the first 21 days of life

What fraction of babies born with CMV infection will have clinically detectable signs at birth

1/8

All infants with CMV infection at birth should be followed up for minimum of how long to check for what

2 years

Check hearing and brain development

How could symptomatic CMV infection at birth present

Jaundice, rash, microcephaly, hepatosplenomegaly or small for gestational age

What Tx is given for symptomatic CMV infection at birth & why?

Valganciclovir treatment can reduce hearing loss in 5/6 babies, and improve long-term brain development outcomes in some

Toxoplasmosis is also not screened for. What organism causes this (name & type)

Toxoplasma gondii - Protozoan parasite

What is the definitive host for Toxoplasma gondii

Cat

Toxoplasmosis Sx

Often asymptomatic or mild 'flu-like illness in healthy non-pregnant people

What happens with Toxoplasmosis in pregnancy

Can cross placenta & cause serious developmental abnormalities.

(At birth, 40% symptomatic; 60% asymptomatic, may have long term sequelae)

If Toxoplasmosis is diagnosed in pregnancy, when does tx for mother/baby occur

If diagnosed in pregnancy, treatment of mother during pregnancy and baby after birth may attenuate (reduce) serious damage

How to prevent transmission of Toxoplasmosis

• Wash hands before handling food.

• Thoroughly wash all fruit and vegetables.

• Thoroughly cook raw meats and ready-prepared chilled meals.

• Wear gloves and wash hands after handling soil/gardening.

• Avoid cat faeces in cat litter or soil

Parvovirus B19 signs/sx

“Slapped cheek syndrome” mostly in children

Adults can get acute arthritis

Targets RBCs → aplastic crisis esp. if immunodeficiency or haemolytic anaemia

What fraction of maternal Parvovirus B19 infections during pregnancy are transmitted across the placenta to the foetus

1/3

Risk of maternal Parvovirus B19 infections transmitting across the placenta to the foetus

Hydrops foetalis & Death (esp. in first 20/40).

If a Parvovirus B19 infection has transmitted across the placenta to the foetus

Intervention with intrauterine transfusion

Zika virus is also not screened for but how would it present

Zika is a viral infection that usually causes a mild illness that typically lasts between 2 and 7 days. 80% of people who become infected by Zika virus have no symptoms.

How is Zika virus transmitted

Zika virus is spread through the bite of a mosquito that is in certain countries and unprotected sexual contact (without a condom) with an infected partner.

How many Corona viruses are known to infect humans

7

Sx of these 4 CoVs (HKU1, NL63, OC43, and 229E)

Mild - moderate URTI

10-30% common cold

Viral pneumonia occasionally