L20 Infections (gestational, after)

Maternal Immune system has 2 main roles
1. Don’t kill the foetus
• Foetus is ‘❌’ therefore maternal immune system is ❌ so that the foreign tissue is not killed
2. Protect the foetus & newborn
• Protect foetus from infections in utero (❌ infections)
• Transfer maternal ❌ to newborn

Maternal Immune system
• Increase in ❌ of cells of the innate immune system, including NK cells
• Cytokine production modified
• ❌ antigen presentation at early stages
• Increasing ❌ – augments Th2/❌ responses
• Progesterone has a ❌ effect at later stages on acquired responses
Result of this…
• Increased ❌ where cellular responses are important
• Increased ❌ due to altered physiology in pregnancy eg cardiopulmonary changes

Transfer of maternal immunity
Newborn has:
• an ❌ immune system - immune system in the foetus is tolerogenic and ❌, so
doesn't try to kill mother.
• is immunologically naïve - no ❌, every infection is new – will get sick
• no/underdeveloped microflora

• Newborn infants and children < 2 are highly ❌ to infection, particularly ❌ infections.
• This can result in very serious disease - infections must be taken seriously and treated quickly.

Maternal ❌ can cross the placenta and accounts for the high levels present in the foetus. Baby born at 20 weeks ~ ❌. Breast milk contains ❌ (& leukocytes) - transferred to neonate. Baby can produce only limited amounts of antibody, only ❌ for first 6 months. At ❌ months all maternal IgG is gone.

• GBS (group B streptococcus infection) is the most ❌ infection of neonates, ❌ transmission from mum during labor/delivery can occur
• Infection in neonates – ❌ pathology with 20-30% mortality in ❌ infants, 2-3% in full-term
• NZ has gone for a ❌ approach (rather then universal screening)
• All newborns must be observed for ❌ hour as per MoH guidelines
• If risk factors for GBS extend to at least ❌ hours

TORCH(Z) = Microbes associated with congenital infections.
T - ❌
O - ❌
R - ❌
C - ❌
H - ❌
Z - Zika?

CMV - Treatment
• 6 months of ❌ for newborns with ❌ symptomatic disease
• No evidence base for treating ❌ children
• Requirement for new anti-virals with less ❌

Rubella
• Togaviridae, enveloped ❌ strand RNA virus, worldwide distribution
• Transmission - respiratory via ❌, fetal (infection rate ❌ as pregnancy progresses)
• Highly ❌
• Originally thought to be a benign disease until birth defects were linked to disease early in pregnancy

• Post-natal infection
- Fever, aching, ❌ lymph nodes, cough, ❌ throat. Self- ❌.

• Congenital infection
- infection in the first ❌ weeks results in fetal damage in 85% of infants
- immediate symptoms: cataracts, ❌ abnormalities, deafness
- delayed symptoms - ❌ impairment, ❌ disorders, diabetes

• Treatment - treat ❌

• Prevention - Live vaccine (❌), 90-97% effective

Varicella-Zoster Virus
- enveloped ds DNA virus
- highly ❌, airborn ❌
- 3 diseases - congenital varicella syndrome (❌), chickenpox (❌), shingles (herpes zoster - ❌)
- major complication is ❌ of rash
- treatment - lotions to stop ❌, immunoglobulin or nucleotide analogues for at risk groups

- congential disease in 1-2 trimester - very ❌, deformed ❌, low birth ❌, scarring, ❌ defects.
- 3 trimester - mother develops rash < ❌ before delivery - disseminated & fulminant disease, ❌% mortality.
- prevention: vaccine.

Post natal infections - mother:
• Risk of any infection ❌% after vaginal delivery and ❌% after caesarean section
• Mild ❌ infections most common, anti-microbials in 1/3 of cases
• Infections associated with ❌ of breast feeding

Mastitis
• inflammation of the breast, may be due to ❌
• common – ❌% of lactating women, usually ❌ in lactation, 3-11% will develop an ❌
• usually ❌
• 70% cases ❌
Signs & Symptoms
• Local – breast ❌, engorgement, inflammation, heat, nipple ❌ (abscess – lump, necrosis)
• Systemic - fever, malaise
Treat:
- Support mum & baby (hydrated, growing – continue breast feeding), analgesia, antimicrobials?