Pregnancy & Childhood Infections Flashcards
What are the problems with infections during pregnancy?
Pregnancy does not alter resistance to infection
some infections during pregnancy are more severe and can affect the foetus
What may infections in pregnancy cause?
- Miscarriage
- congenital abnormalities
- fetal hydrops
- fetal death
- preterm delivery
- preterm rupture of the membranes
What is meant by “fetal hydrops”?
A serious fetal condition defined as an abnormal accumulation of fluid in two or more fetal compartments
this includes Ascites, pleural effusion, pericardial effusion and skin oedema
How can the foetus receive immunity?
Maternal antibodies cross the placenta and give passive immunity to the foetus
What is a key message during antenatal counselling?
Avoid exposure to infections during pregnancy
i.e. vaccination (pertussis vaccine b/w 16 - 32 weeks)
What screening is offered during pregnancy?
- Screening for HIV and syphilis and hepatitis B occurs early in pregnancy (by 10 weeks)
- it is reoffered before 20 weeks
- Hepatitis B, HIV and syphilis can all be passed from mother to baby during pregnancy and birth
- early detection aids specialist appointment and interventions/treatment to reduce the risk of transmission
Why is screening for rubella in pregnancy no longer offered?
Screening for rubella in pregnancy is no longer offered
rubella is now very rare in the UK because of the high uptake of the MMR vaccine
What is meant by the TORCH acronym for infections that can be transmitted from mother to baby during pregnancy (in utero)?
- Toxoplasmosis
- Others (syphilis, HIV, Coxsackie virus, Hepatitis B, Varicella zoster)
- Rubella
- Cytomegalovirus
- Herpes simplex virus
How are the following pathogens acquired?
How are they transmitted to the baby?
- Cytomegalovirus - respiratory droplets / secretions
- Parvovirus B19 - respiratory droplets / secretions
- toxoplasmosis - ingestion of oocytes
- syphilis - sexually transmitted
- varicella zoster virus - respiratory droplets / secretions
- rubella - nasopharyngeal secretions
- zika virus - mosquito bite
What do most of the TORCH infections cause?
They cause mild maternal morbidity, but have serious fetal consequences:
- abortion
- stillbirth
- prematurity
- IUGR
- congenital malformations - microcephaly, intracranial calcifications
What is IUGR?
Intrauterine growth restriction
this is a condition in which an unborn baby is smaller than it should be because it is not growing at a normal rate inside the womb
What are other perinatal infections?
- Group B streptococcus
- listeriosis
- gonorrhoea
- chlamydia
- influenza
- human immunodeficiency virus
- hepatits b virus
HIV and HBV virus can be passed in utero and postnatal via breast milk
What are the risks associated with transplacental passage of the influenza virus?
Teratogenesis has not been confirmed
premature delivery may occur (as in any febrile maternal illness), increasing the perinatal morbidity and mortality
the clinical syndrome in the mother is self-limited unless pneumonia occurs and the newborn manifests as any form of sepsis
What is meant by the “perinatal period”?
The period immediately before and after birth
usually starts at the 20th - 28th week of gestation and ends 1 - 4 weeks after birth
Why is screening for Group B Streptococci not recommended in the UK?
Until it is clear that antenatal screening for GBS carriage does more good than harm and that the benefits are cost-effective, routine screening is not recommended
What is the likelihood of maternal GBS carriage in current pregnancy if a mother has had previous GBS carriage?
What 3 options does the mother have in this situation?
If there is history of previous GBS carriage, likelihood of maternal GBS carriage in current pregnancy is 50%
3 choices are:
- To NOT have intra-partum antibiotics
- To have intra-partum antibiotics
- Screening at 35-37 weeks and offer antibiotics to those who have GBS colonisation
When are intrapartum antibiotics administered?
Intra-partum refers to the time period between onset of labour and the delivery of the placenta
What is chorioamnionitis?
How many pregnancies are affected by this?
Inflammation of the umbilical cord, amniotic membranes / fluid and placenta
it is a major cause of perinatal morbidity and mortality
affects 1-2% of term pregnancies and 20-25% of pregnancies with pre-term labour
What are the symptoms of chorioamnionitis?
- Maternal fever
- uterine tenderness
- tachycardia
- purulent / foul amniotic fluid
obstetric complications + adverse outcomes for the neonate:
- sepsis
- pneumonia
- long term neurodevelopment disability
what usually causes chorioamnionitis?
What is it associated with?
It is inflammation of the fetal membranes (amnion / chorion) due to a bacterial infection
it typically results from bacteria ascending from the vagina into the uterus
it is most often associated with prolonged labour
What are the risk factors for intra-amniotic infections?
- Most common after prolonged rupture of membranes
- amniocentesis / cordocentesis
- cervical cerclage
- multiple vaginal examinations
- bacterial vaginosis
What is the pathogenesis of intra-amniotic infections like?
Bacteria present in the vagina cause infection by ascending through the cervix
Haematogenous (via blood) infection is rare e.g. Listeria monocytogenes
What organisms can cause intra-amniotic infections?
- Group B Streptococcus
- Escherichia coli
- Genital Mycoplasma (Mycoplasma hominis & Ureaplasma urealyticum)
it is caused by polymicrobial infections
What is involved in the management of intra-amniotic infections?
Intrapartum antimicrobials and delivery of the foetus
antimicrobials should be administered at the time of diagnosis (not after delivery)
What is puerperal endometritis?
A uterine infection (lining of the womb) during puerperium which affects 5% of pregnancies
It is typically caused by bacteria ascending from the lower genital or GI tract
it can occur up to 6 weeks following birth
What is the major risk associated with puerperal endometritis?
Puerperal sepsis is a major cause of maternal death
it can cause sepsis, pelvic abscesses and peritonitis in the mother
What are the risk factors for puerperal endometritis?
- Caesarean section
- prolonged labour
- prolonged rupture of membranes
- multiple vaginal examinations
what are the clinical features of puerperal endometritis?
- Fever - 38.5C in first 24h post-delivery or >38.0C for 4 hours 24+ hours after delivery
- uterine tenderness
- purulent, foul-smelling lochia
- increased white cell count
- general malaise, abdominal pain
What are the causative organisms for puerperal endometritis?
The causative organisms are frequently mixed:
- Escherichia coli
- Beta-haemolytic Streptococci (Group B)
- anaerobes
What is involved in the diagnosis and treatment of puerperal endometritis?
Diagnosis:
- the role of transvaginal endometrial swabs is controversial
treatment:
- broad spectrum intravenous antimicrobials
- these are continued until the patient has been apyrexial for 48h
- for polymicrobial infections, clindamycin + gentamicin are used
What are the most common infections in children?
Neonatal sepsis
Common childhood infections - respiratory tract infections, UTIs, meningitis
Rashes associated with systemic disease
What are the main causes of maternal and neonatal mortality?
Maternal mortality:
- haemorrhage
- indirect causes
- hypertension
- sepsis
- other direct causes
- abortion
- embolism
neonatal mortality:
- complications from preterm birth
- intrapartum related
- sepsis / meningitis
- pneumonia
- congeital
- other
- tetanus
- diarrhoea
What are the risks associated with early onset sepsis (EOS) in neonates?
When does this start?
early-onset neonatal sepsis (usually within 72 hours) is a major cause of mortality and morbidity in new-born babies
high mortality, particularly in premature and low birth weight babies
death occurs in 1 in 4 babies that develop it, even when they are given antibiotics
What causes early onset sepsis in neonates?
Under what circumstance does it have higher mortality?
It is caused by organisms from the maternal genital tract
typical to have multisystem involvement / pneumonia
higher mortality, particularly in infections that are evident within the first 24 hours
What are the major causative pathogens of neonatal late-onset sepsis?
- Coagulase negative staphylococci
- staphylococcus aureus
- escherichia coli
- klebsiella spp.
- enterobacter spp.
- pseudomonas spp.
- candida spp.
What are the commonest symptoms reported in early education settings?
- Respiratory symptoms
- fever
- gastroenteritis
- earache
- rash
In which groups of children are infections more common?
Why are infections more common in children?
Affected groups:
- young infants
- children with special health care needs / impaired immune systems
- children with long-standing prosthetic devices
Why are infections common?
- frequent hand-to-mouth behaviours
- still learning appropriate hygiene skills e.g. washing hands, covering coughs
- some children are not fully immunised
- children have close physical contact
What are the vast majority of infections in children?
90% of infections are mild, self-limited and require no treatment
What are the 3 main upper respiratory tract infections in children?
- Common cold
- acute tonisillitis
- acute otitis media
What is a “sore throat”?
What causes it?
Any of various inflammations of the tonsils, pharynx or larynx, characterised by pain on swallowing
70-80% of cases are viral
20-30% of cases are caused by Group A beta-haemolytic Streptococcus
What is otitis media?
What are the typical symptoms?
Inflammation of the middle ear +/- presence of middle ear effusion
- unusual irritability
- difficulty sleeping
- tugging or pulling at one or both ears
- fever
- fluid draining from the ear
- loss of balance
- unresponsive to quiet
- sounds or other signs of hearing difficulty
What are the bacteria that cause acute otitis media?
- Streptococcus pneumoniae
- haemophilus influenzae
- M. Catarrhalis
- streptococcus pyogenes
- staphylococcus aureus
What are the most common lower respiratory tract infections in children?
- Pneumonia
- acute bronchitis
- bronchiolititis
respiratory viruses are the leading cause in children under 5 years
What are the most common organisms which cause acute respiratory infections in children?
- Respiratory syncytial virus
- mycoplasma pneumoniae
- streptococcus pneumoniae
- adenovirus
- haemophilius influenzae
- influenza A and B
- haemophilus parainfluenzae
H. Influenzae is now quite rare due to immunisation
What is the definition of bronchiolitis?
Inflammation of the bronchioles / small airways in children younger than 2 years (usually 3-6 months of age)
it is a seasonal viral illness characterised by fever, nasal discharge and dry, wheezy cough
on examination there are fine inspiratory crackles and/or high-pitched expiratory wheeze
What are the causes of bronchiolitis?
- Respiratory syncytial virus (RSV)
- metapneumovirus
- adenovirus
- para-influenza virus
- influenza
- rhinovirus
What are the bacterial and viral pathogens which cause pneumonia in neonates?
Bacterial pathogens:
- group B streptococcus
- gram negative bacilli ( E. coli, K. Pneumoniae, Proteus spp.)
- staphylococcus aureus
Viral pathogens:
- RSV
- herpes simplex virus
- cytomegalovirus
- adenovirus
What are the main pathogens which cause pneumonia in children aged 1-3 months?
Bacterial pathogens:
- s. Pneumoniae
- h. Influenzae type B
viral pathogens:
- RSV
other:
- C. Trachomatis
What are the main pathogens which cause pneumonia in children aged 4 months - 5 years?
Bacterial pathogens:
- s. Pneumoniae
- h. Influenzae type b
viral pathogens:
- parainfluenza virus 1 and 3
- adenovirus
- influenza virus A and B
What are the pathogens that cause pneumonia in children aged 5 years and older?
Bacterial pathogens:
- s. Pneumoniae
others:
- M. Pneumoniae
- C. Pneumoniae
What is the presentation of pneumonia in children?
Acute febrile illness, possibly preceded by typical viral upper respiratory tract infection
younger children rarely cough and may present with grunting tachypnoea and chest retractions
What are the symptoms of pneumonia in children?
- Breathlessness (poor feeding)
- irritability
- sleeplessness
- cough, chest or abdominal pain in older patients
- audible wheezing is rare in LRTI, but can occur
What is pertussis (whooping cough)?
A highly contagious respiratory disease caused by Bordetella pertussis bacteria
it is known for uncontrollable, violent coughing which often makes it hard to breathe
What are the 3 stages of clinical illness in pertussis?
Catarrhal phase:
- cold-like - coryza, conjunctival irritation, occasional slight cough
- lasts 7-10 days
Paroxysmal phase:
- long duration (2-6 weeks) with no fever
- series of rapid, forced expirations followed by gasping inhalation (whooping sound)
- post-tussive vomiting
- very young infants may present with apnea or cyanosis in the absence of cough
convalescent phase
How is pertussis transmitted?
How is it diagnosed?
It is transmitted person-to-person through aerosolised respiratory droplets
humans are the sole reservoir
Diagnosis:
- culture & PCR in early stages
- serology if illness > 3 weeks
How does meningitis present in children?
There is a non-specific clinical presentation in newborn & infants
- fever
- irritability
- lethargy
- poor feeding
- high pitched cry, bulging AF
- convulsions, opisthotonus
What organisms cause meningitis in neonates and young children?
Neonates:
- Group B streptococcus
- escherichia coli
- Listeria monocytogenes
> 1 month - 5 years:
- Streptococcus pneumoniae
- Neisseria meningitidis
What is viral meningitis?
What is it caused by?
It is the most common infection of the CNS especially in < 1 year
caused by enteroviruses, HSV, influenza, EBV, adenovirus and CMV
there are mononuclear lymphocytes in CSF
What is the morbidity and mortality involved in meningococcemia?
Mortality - 5-10% (90% if DIC)
Morbidity - 10% (deafness, neurological problems, amputations)
Peak incidence < 4 years
What are the symptoms of meningococcaemia?
- Fever
- non-specific malaise
- lethargy
- vomiting
- meningism
- respiratory distress
- irritability
- seizures
- maculopapular rash common in early disease
what is meningococcaemia?
A severe form of blood poisoning that affects the entire body
the hallmark sign of meningococcaemia is a rash that does not fade under pressure
the rash can appear anywhere on the body due to damaged blood vessels allowing blood to leak into the skin
