Lecture 37 - Clinical infections - childhood and pregnancy Flashcards
Infections during pregnancy may cause
miscarriage congenital anomalies Fetal hydrops Fetal death preterm delivery preterm rupture of the membranes
-Maternal antibodies cross the placenta and give passive immunity to the foetus
Route of acquisition of cytomegalovirus
respiratory droplet. secretions
Route of acquisition of Parvovirus B19
respiratory droplet. secretions
Route of acquisition of Toxoplasmosis
Ingestion of oocytes
Route of acquisition of Syphilis (blood)
Sexual
Route of acquisition of Varicella Zoster Virus
respiratory droplet/secretions
Route of acquisition of rubella
Nasopharyngeal secretions
Route of acquisition of Zika virus
Mosquito bite
Neonatal infections acquired during passage through birth canal
Group B Streptococcus Herpes simplex virus (HSV) Gonorrhoea Chlamydia HIV Hep B
NICE CG62
Antenatal care for uncomplicated pregnancies
Women should be offered routine screening for asymptomatic bacteriuria by midstream urine culture early in pregnancy.
Identification and treatment of asymptomatic bacteriuria reduces the risk of pyelonephritis.
Asymptomatic bacteriuria in pregnancy
Symptomatic UTI in pregnancy is frequently preceded by asymptomatic bacteriuria
Prevalence is around 5%
Untreated, at least 30% of women with ASB will develop acute pyelonephritis
Screening for ASB is considered to be a cost effective approach to preventing pyelonephritis
Why is Screening for Group B Streptococci not recommended in UK
Until it is clear that antenatal screening for GBS carriage does more good than harm and that the benefits are cost-effective, the National Screening Committee does not recommend routine screening in the UK
Prevention of Early-onset Neonatal Group B Streptococcal Disease
Intrapartum antibiotic prophylaxis (IAP) offered to:
Women with a previous baby with neonatal GBS disease
Women with GBS in current pregnancy
Women who are pyrexial in labour should be offered broad-spectrum antibiotics including an antibiotic for prevention of neonatal EOGBS disease
UTI during pregnancy
Screening for bacteriuria is indicated in pregnancy
Asymptomatic bacteriuria - no symptoms of UTI and 2 samples containing > 105 same organisms
Bacteriuria can develop into symptomatic UTI if untreated
Continuing bacteriuria is associated with premature delivery and increased perinatal mortality
Antimicrobial prescribing in pregnancy and puerperium
The potential to cause harm to the embryo/foetus/neonate must be considered
All antimicrobials cross the placenta to some extent
Virtually all antimicrobials appear in breast milk if given in therapeutic amounts to breast feeding women
Safe antimicrobials in pregnancy
Penicillins Cephalosporins
Some antimicrobials considered unsafe in pregnancy
Chloramphenicol Tetracycline Fluoroquinolones (e.g. ciprofloxacin) Trimethoprim-sulphamethoxazole
Intra-amniotic infections
Affects 1-2% term pregnancies
Affects 20-25% pregnancies with pre-term labour
major cause of perinatal morbidity and mortality
“chorioamnionitis” refers to inflammation of umbilical cord, amniotic membranes, placenta
Risk factors for intra-amniotic infections
Most common after prolonged rupture of membranes
Other risk factors include:amniocentesis, cordocentesis, cervical cerclage multiple vaginal examinations, ?BV
Pathogenesis of intra-amniotic infections
Bacteria present in the vagina cause infection by ascending through the cervix
Haematogenous (via blood ) infection is rare e.g. Listeria monocytogenes
Causative organisms of intra-amniotic infections
Group B Streptococcus
enterococci
Escherichia coli
Management of intra-amniotic infections
antimicrobials and delivery of the foetus
antimicrobials should be administered at the time of diagnosis (not after delivery)
Puerperal endometritis
infection of the womb during puerperium affects ~5% of pregnancies
puerperal sepsis remains a major cause of maternal death
Risk factors for puerperal endometritis
caesarean section, prolonged labour, prolonged rupture of membranes, multiple vaginal examinations
Clinical features of puerperal endometritis
fever (38.5oC in first 24 h post delivery or >38.0o for 4 hours, 24 h+ after delivery) uterine tenderness purulent, foul-smelling lochia increased white cell count general malaise, abdominal pain
puerperal endometritis causative organisms
Escherichia coli
Beta-haemolytic streptococci
Anaerobes
Diagnosis of puerperal endometritis
the role of transvaginal endometrial swabs is controversial
Treatment for puerperal endometritis
Broad-spectrum intravenous antimicrobials - continued until the patient has been apyrexial for 48 hours.
Early onset sepsis
Early-onset neonatal sepsis (usually within 72 hours) is a major cause of mortality and morbidity in newborn babies.
High mortality, particularly in premature and low birth weight babies.
Death: 1 in 4 babies who develop it, even when they are given antibiotics.
Typical to have multisystem involvement/pneumonia
Higher mortality, particularly those infections evident within first 24 hours
Cause of Early onset sepsis
organisms from the maternal genital tract
Cause of late onset sepsis
Coagulase-negative staphylococci Staphylococcus aureus Escherichia coli Klebsiella spp. Enterobacter spp Pseudomonas spp. Candida spp.
Why are children more susceptible to infections
Young infants
Children with special health care needs
Children with impaired immune systems
Children with long standing prosthetic devices
As children age, the incidence of illness decreases from 12 per year to 4 per year by the time the child is 5 years old
90% of infections are mild, self-limited, and require no treatment
What are the upper respiratory tract infections in children
Common cold
Acute tonsillitis
Acute otitis media
What is a sore throat
any of various inflammations of the tonsils, pharynx, or larynx characterized by pain in swallowing
70-80% of the time is viral
Group A beta-haemolytic Streptococcus (20-30%)
Symptoms of otitis media
Unusual Irritability Difficulty Sleeping Tugging or Pulling At One Or Both Ears Fever Fluid Draining From The Ear Loss Of Balance Unresponsiveness To Quiet Sounds or Other Signs Of Hearing difficulty
Prevalence of LRTI’s in children
30–40 cases per 1000 children per year in the UK;
(a GP will see, on average, 1-2 cases per year)
Every year, pneumonia contributes to 750,000 – 1.2 million neonatal deaths worldwide
Includes pneumonia, acute bronchitis & bronchiolitis
Respiratory viruses remain the leading cause in children under 5years
What is the major cause of acute respiratory infections in children?
Respiratory synctial virus (63%)
Streptococcus pneumoniae (8%)
Adenovirus (7%)
Bronchiolitis
a seasonal viral illness characterized by fever, nasal discharge, and dry, wheezy cough. On examination there are fine inspiratory crackles and/or high-pitched expiratory wheeze”
Causes of bronchiolitis
Respiratory Syncytial Virus (RSV) Metapneumovirus Adenovirus Para-influenza virus Influenza Rhinovirus
Common pathogens causing pneumonia in Newborn
Group B Strep Gram -ve bacilli Listeria monocytogenes Herpes simplex Cytomegalovirus Rubella
Common pathogens causing pneumonia in 1-3 month year olds
Chlamydia trachomatis
Respiratory Synctial virus
other respiratory viruses
Common pathogens causing pneumonia in 3-12 month year olds
Respiratory Synctial virus Other respiratory viruses Strep pneumoniae Haemophilius influenzae Chlamydia trachomatis Mycoplasma pneumoniae
Common pathogens causing pneumonia in 2-5 year olds
Respiratory viruses Strep pneumoniae Haemophilius influenzae Mycoplasms pneumoniae Chlamydia pneumoniae
Common pathogens causing pneumonia in 5-18 year olds
Mycoplasma pneumoniae strep pneumoniae Chlamydia pneumoniae Haemophilius influenzae Influenza viruses A and B Adenoviruses Other respiratory viruses
Presentation of pneumonia
Acute febrile illness, possibly preceded by typical viral URTI.
Symptoms of pneumonia
Breathlessness (poor feeding)
Irritability
Sleeplessness
Cough, chest or abdominal pain in older patients
Audible wheezing is rare in LRTI but can occur
Pertussis
Usually affect children before vaccine available, recent resurgence noted
Clinical illness in 3 stages
Catarrhal phase, Paroxysmal phase, Convalescent phase
Catarrhal phase of Pertussis
Cold-like (coryza, conjunctival irritation, occasionally a slight cough)
7-10 days
Paroxysmal phase of pertussis
Long duration (2-6 weeks); No fever
a series of rapid, forced expirations, followed by gasping inhalation the typical whooping sound
Post-tussive vomiting common
Very young infants may present with apnea or cyanosis in the absence of cough
Convalescent phase of pertussis
Characterized by:
Gradual recovery
Less persistent, paroxysmal coughs that disappear in 2-3 weeks
Paroxysms often recur with subsequent respiratory infections for many months after the onset of pertussis.
cause of pertussis
Highly communicable acute respiratory infection caused by B. pertussis
Transmission of pertussis
Person-to-person transmission through aerosolised respiratory droplets
Humans are the sole reservoir
Diagnosis of pertussis
Culture and PCR in early stages
Serology if illness
more than 3 weeks
Meningitis in children
Newborn & Infants: non-specific clinical presentation
Fever
Irritability
Lethargy
Poor feeding
High pitched cry, bulging anterior fontanelle
Convulsions, opisthotonus
Aetiology of meningitis in neonates
Group B Strep, E Coli, Listeria monosytogenes
Aetiology of meningitis in more than 1 - 5 years
Streptococcus pneumoniae, Neisseria meningitidis
Viral meningitis
Most common infection of CNS especially in <1yr
Enteroviruses (commonest, meningitis occurring in 50% of children <3mth ), HSV, Influenza, EBV, adenovirus, CMV
Mononuclear lymphocytes in CSF
Symptomatic treatment CP
UTI’s in children
Up to 7% of girls and 2% of boys experience a symptomatic culture-proven UTI prior to 6 years of age.
Of febrile neonates, up to 7% have UTIs.
Most UTIs in children are from ascending bacteria
E. coli (60-80%), Proteus, Klebsiella, Enterococcus, and Staphylococcus saprophyticus
The overall prevalence of UTI is approximately 5% in febrile infants but varies widely by race and sex.
Caucasian children had a two- to fourfold higher prevalence of UTI as compared to African-American children
Females have a two- to fourfold higher prevalence of UTI than do circumcised males
Symptoms of uti’s in children
Classic UTI symptoms in older children
Dysuria, frequency, urgency, small-volume voids, lower abdominal pain.
Infants with UTIs have nonspecific symptoms
Fever, irritability, vomiting, poor appetite
Urine sampling
A clean catch sample should be obtained
If not possible, use non invasive method i.e. Urine collection pad
Do not use cotton wool balls, gauze or sanitary towels.
If non invasive method not possible
Use catheter sample or suprapubic aspiratio
Follow up for UTI’s in children
Those who have recurrent UTI or abnormal imaging results should be assessed by paediatric specialist
Those who do not require imaging do not need specialist assessment
Asymptomatic bacteriuria does not require follow up
Antibiotic prophylaxis should not be routinely recommended in infants and children following first-time UTI
Meningococcoemia
MORTALITY 5-10% (90% if DIC)
MORBIDITY 10% (Deafness, neurological problems, amputations)
Peak incidence < 4yrs
Immunisation programme includes Men C
60% of bacterial meningitis in UK due to Men B
Fever, non-specific malaise, lethargy, vomiting, meningism, resp distress, irritability, seizures
Maculopapular rash common early in disease
Petechial rash seen in 50-60%
Meningococcoemia cause
Staphylococcus aureus or Strep pyogenes
Symptoms of Meningococcoemia
Classically ruptured vesicles with honey-coloured crusting May be bullous More common in pre-existing skin disease Very contagious, rapid spread Commonly starts around face/mouth
Treatment for Meningococcoemia
Topical antibiotics or oral Flucloxacillin
Advice re nursery/school
Scarlet fever
Gp A beta-haemolytic Streptococcus 2-4 days post-Streptococcal pharyngitis Fever, headache, sore throat, unwell Flushed face with circumoral pallor Rash may extend to whole body Rough ‘sandpaper’ skin Desquamation after 5/7, particularly soles and palms School age children White strawberry tongue Dx Throat swab, ASO titres Rx Penicillin 10/7
Cause of scarlet fever
Staphylococcus aureus or Strep pyogenes
Classically ruptured vesicles with honey-coloured crusting
May be bullous
More common in pre-existing skin disease
Very contagious, rapid spread
Commonly starts around face/mouth
Rx. Topical antibiotics or oral Flucloxacillin
Advice re nursery/school
What is chicken pox and its causes
Is a contagious disease caused by a virus
Member of the herpes virus family
Chickenpox is considered by many experts to be a relatively harmless childhood disease.
Symptoms of chicken pox
Fever
runny nose
sore throat
itchy skin rash
rash and disease usually disappear after one or 2 weeks
disease confers permanent immunity - will not get it again
Complications in adults who did not have chicken pox as a child or in youngsters with already weakened immune systems
