infections sepsis and pregnancy Flashcards
what infections can cause miscarriage?
chlamydiosis ( transmission by inhalation - farm animals, can cause still birth or abortion) Listeria monocytogenes (from animals or contaminated food, mild flu like symptoms, may cause abortion or premature birth)
what infections can affect the unborn baby?
rubella chicken pox Parvo virus CMV Zika virus Syphilis Toxoplasmosis (perinatal infections are responsible for 2-3% of all congenital anomalies)
what is rubella and what are the symptoms?
mild disease - caused by togavirus
incubation period 14-21 days
infectious about 1 week before symptoms appear
droplet transmission
fever malaise mild conjunctivitis
transitory rash - unreliable clinical diagnosis
what problems can rubella cause if caught <13 weeks?
severe foetal damage in up to 90% of cases
Cataracts & other eye defects
Deafness
Cardiac anomalies
Microcephaly
Growth retardation
Inflammatory lesions of brain, liver, lungs, bone marrow.
what problems can occur if rubella is caught after 13 weeks?
mainly associated with hearing impairment
what happens if rubella caught after 16 and 20 weeks?
Anomalies rare after 16 weeks and no increased risk of anomaly after 20.
what is cytomegalovirus?
Member of the herpes family
Malaise, fever, lymphadenopathy.
Transmitted in body fluids including saliva, urine & blood.
Remains latent in the host after primary infection & may reactivate.
Transmission at birth or from breast feeding extremely unlikely to cause damage to the baby.
50% adults immune
when and what are the risk of CMV during pregnancy?
Primary CMV in first trimester risk of transplacental infection is about 40%
Of these 5-15% are symptomatic at birth. Multiple manifestations including microcephaly, other neurological abnormalities, growth restriction mental retardation.
Of these 20-30% will die and 80% survivors have serious disabilities.
Of those with no symptoms at birth 5-15% will go on to develop serious sequelae including hearing loss, visual impairment & pschyomotor delay.
By third trimester risk of transmission is higher but risk of fetal injury is very low.
Secondary infection in the mother - low risk to fetus
Most commonly acquired from own or other children eg child care workers
how can CMV be prevented?
No vaccine
Advice of good hand hygiene
Diagnosis of infection in mother by serology – following reported contact OR
More commonly following the identification of an anomaly in the fetus by ultrasound
Infection in fetus by amniocentesis
Unclear which babies will be affected
Urine / saliva swab from baby at birth - PCR for DNA- follow up if infected
what is zika virus?
Recent epidemic in South America but exists across Africa, S & SE Asia & Pacific
Mosquito transmission
Recent spread to new aera with low population immunity
Microcephaly +?
Travel advise
Serial scanning if infection identified
what is parvo virus B19?
what are problems of it during pregnancy?
slapped cheek
Droplet spread
Infects rapidly dividing cells
Characteristic rash in children
Adults often asymptomatic
50 – 60% adults immune
Diagnosis as with CMV following reported contact or when symptoms identified in the fetus on scan
Attacks red blood cells -> fetal anaemia
Infection in the first 20 weeks may result in miscarriage/ intrauterine death (9% risk)
OR hydrops fetalis (about 3%)
Not associated with fetal anomaly, but may rarely.
Consequences usually occur 3 – 5 weeks after maternal infection.
Intrauterine transfusion after 20 weeks
what is chickenpox
Presentation – characteristic vesicular rash, fever & malaise.
Clinical diagnosis highly specific.
Incubation period 2 – 3 weeks
Infectious from 48 hours before rash until lesions are dry, about 5 days after rash erupts.
Spread by direct contact / respiratory droplets.
> 90% pregnant population immune.
Affects 3 in every 1000 pregnancies.
Affects fetus, neonate & mother
what are the risks of chicken pox to mothers
Excess morbidity associated with infection in adults including pneumonia, hepatitis , encephalitis and occasionally mortality.
Up to 10% of pregnant women with C Pox will get pneumonia
Increased risk in later pregnancy, smokers, h/o chronic lung disease or immunosuppression
what are the risks of chickenpox to fetus?
Risk of anomally before 20 weeks.
Fetal Varicella Syndrome has been described where C. Pox has occurred between 3 and 28 weeks of pregnancy.
Risk is thought to be about 2% between 13 to 20 weeks gestation, probably only around 0.5 – 1 % in first trimester
Very rare after 20 weeks
Immunoglobulin for non-immune mother following contact
what are the risks to neonate of chickenpox
Varicella infection of the newborn (congenital varicella)
If maternal infection at term .
Most likely to cause severe infant infection if mother develops the rash 7 days before to 7 days after delivery.
Allow 5 – 7 days after onset of rash for maternal antibodies to transfer to fetus if planning delivery.
what are shingles and are they harmful to fetus?
Shingles occurs in people who have already had chicken pox – reactivation of the virus.
As mother will have antibodies will not have risk to baby
