Exam 2 Flashcards
newborn screening
Series of blood tests performed on a neonate with the goal of early identification and treatment of disease.
- Individual tests for specific diseases
- Tandem mass spec
- Genetic probes
Hearing screen
Pulse oximetry screening
Note: it is continually evolving
history of newborn screenings
varies by state; 2000 congress mandated increased federal involvement to correct disparities
- 1961: PKU first screen began in MA
features of any screening test
High sensitivity
Disease with severity which would warrant early detection
Cheap, easy and fast
Definitive test is available
Early detection can change the course of the illness
Treatment available: historically a requirement, now controversial.
sensitivity
probability that a person who truly has a disease will have a positive test. This is a “true positive”
- inversely related to specificity
specificity
probability that a person who really does not have the disease will have a negative test. This is a “true negative.”
- inversely related to sensitivity
false negative
person who tests as negative but who is actually positive
- results in delayed detection of disease
false positive
person who tests as positive but who is actually negative.
- results in unnecessary testing and therapeutics
positive predictive value
likelihood that a person has the disease given a positive test result
negative predictive value
the likelihood that a person does not have the disease given a negative test result
process of newborn screening
HHS (federal) now mandates what to screen for and gives states time to comply; trying to make more uniform among states
- all state use public funds
- CO: tests are paid by fees required by and collected by the state (covered by insurance and medicaid)
Blood tests performed at the State Department of Public Health and Environment (CDPHE)
newborn screening in CO
initial and second blood spot tests for newborns required by law
- some things do not show up as early (endocrine disorders and hypothyroidism)
- CO also gets WY samples
what was included on the standard screen prior to 2006 (when mass spec was added)
Phenylketonuria
Congenital Hypothyroidism
Hemoglobinopathies
Congenital Adrenal Hyperplasia
Galactosemia
Cystic Fibrosis
Biotinidase Deficiency
B.A.E.R. (hearing test)
Note: top 4 on second NBS as well
tests that use drug blood spot samples
Phenylketonuria
Congenital Hypothyroidism
Hemoglobinopathies (Sickle Cell Disease)
Cystic fibrosis
expanded metabolic screen - added in 2006 (mass spec)
With any given sample can detect up to 40 disorders
- Colorado reports on only 23 disorders (those for which are recommended by March of Dimes, for which there is treatment)
- MCADD
Primarily disorders of organic, amino and fatty acid metabolism
Potential for additional diseases
what’s new in blood spot screening?
SCID
Bart’s Hemoglobin
Potential for spinal muscular atrophy screen
Pompay’s Disease: glycogen storage disease
phenylketonuria
First and classic congenital disease identified by newborn screen
Disorder of amino acid metabolism; caused by an enzyme deficiency
Occurs in 1 in 10-15,000 live births
between 1979 and 2003
Prevalence Rate: 0.01% or 27,200 people in USA
Untreated, causes developmental delay and often, severe cognitive impairment
PKU - untreated
Symptoms of PKU include neurodevelopmental problems:
- Developmental delay to severe cognitive impairment
- Seizures
- Autism
- Hyperactivity
- Aggressive behavior
Hair and skin changes incl. hypo pigmentation (melanoma missing)
PKU - treated
Tx: diet restriction; elimination of specific AA
Children can live healthy life and be developmentally normal
Current recommendation is lifelong diet
NOTE: Children of mom with PKU off diet during pregnancy at risk for congenital heart disease
hypothyroidism
Most common true positive test
- Incidence is 1 in 3600 to 5000 births
Screen for T4, if abnormal, check TSH
- Timing is important since all newborns have a TSH spike after delivery
- Check as close to or after 24 hours
Main reason why second screen was added in 1996
hypothyroidism - treated and untreated
untreated:
- causes “cretinism” (severely stunted physical and mental growth)
- cognitive impairment, growth and neurologic abnormalities, fatigue, skin changes, coarse hair, large tongue
Treated with thyroid hormone for life: normal IQ, good health
sickle cell disease (hemogloinopathies)
primarily a RBC disease but since blood flow is sluggish, spleen gets infarcted early in life and affects WBCs too
Sx: Painful crises Aplastic crises Predisposition to infection Tendency toward infarction Bony changes associated with high blood cell turnover
Incidence of Sickle Cell Disease is 1 in 500 African Americans
hemogloinopathies (sickle cell) screen
Screening Test is isoelectric focusing, then electrophoresis
Confirmatory Test: Hemoglobin Electrophoresis (not fast enough for screening test - this is a diagnostic test)
sickle cell treatment
Early immunization against “encapsulated organisms,” (pneumococcus and H.flu) - likely to loose spleen
Penicillin prophylaxis
Early treatment of crises - painful (pain meds)
Attention toward hydration (helps with thick blood)
Avoid triggers such as infection, hypoxia (such as altitude)
Genetic counseling of parents
cystic fibrosis
Disorder of membrane transport of ions (sodium and chloride)
Presents with:
- Chronic lung disease (secretions can’t be cleared and act as plugs)
- Malabsorption/ malnutrition (secretions are thick and block pancreatic function)
cystic fibrosis treatment
Tx:
Managed, not cured
- new medication: Kalydeco (genetic intervention med resolved symptoms in 4% - one strain)
Antibiotics, preventive and therapeutic
Bronchodilators
Exogenous pancreatic enzymes
Attention to nutrition
Life expectancy now 40 years
cystic fibrosis diagnosis
Screen measures immunoreactive trypsinogen (1st and 2nd screen)
Definitive test is sweat chloride (older - not babies)
Genetic testing for specific mutation
M.C.A.D.D (Medium chain acyl-CoA dehydrogenase deficiency)
metabolic disease detected as part of mass spec test
- disorder of fatty acid oxidation that impairs the body’s ability to break down medium-chainfatty acids into acetyl-CoA
M.C.A.D.D. - symptoms and treatment
Times of stress and fasting: cause hypoglycemia and shock
Treatment: avoid fasting & dehydration and administer carnitine (plays a crucial role in energy production, as it is responsible for transporting fatty acids (acetyl choline?) to the mitochondria)
SCID - Severe Combined Immune Deficiency (“bubble boy disease”)
Most debilitating human lymphoid deficiency disease, impairs the differentiation of both T and B lymphocytes
Infants are highly susceptible to recurring infections of viruses, fungi and bacteria
Invariably die within 2yr of birth
SCID - testing and treatment
Test is a genetic probe
- some inconsistency yet in the test
- results sent to National Jewish Lab for confirmatory test, a second genetic marker
Treatment: bone marrow transplant
Bart’s Hemoglobin
Normal adult hemoglobin, Hbg A, has 2 alpha and 2 beta strands - Bart’s hemoglobin is a tetramer of 4 beta strands
Genetic probe used for screening test; hemoglobin electrophoresis confirmatory test
Found in alpha-thalassemia: severity based on # of genes missing (silent carrier v. hydrous fatalis and incompatible with life b/c RBC cannot carry O2)
Found in hemoglobin H disease: RBCs have high binding of O2 so they don’t release it to tissues as well - anemia
What two diseases can be protective against malaria?
sickle cell disease and alpha-thalassemia
- worldwide distribution is same as malaria belt
SMA (spinal muscular atrophy) - candidate for future screening
2ndmost frequently observed autosomal recessive lethal disorder
Clinical presentation ranges from a perinatal lethal to adult onset disease.
- Type I lethal in first year of life
New treatment options and a clearer understanding of the natural history have made SMA a candidate for prospective screening
timing of newborn screening test
1st screen 24 to 48 hours
- need several feeds to diagnose galactosemia
- wait until after TSH spike
- normal values on CF and CAH tests vary according to age at time of test
2nd screen 8 to 14 days (range 3 to 30 days)
How is newborn screening performed?
Blood is drawn from baby’s heel and allowed to dry on filter paper
Sent to Colorado Dept. of Public Health and Environment where individual tests are run
Results sent to hospital, PCP, specialty follow-up clinics and definitive tests arranged with families
newborn screening beyond blood spot
hearing screening
pulse oximetry for critical congenital heart disease
congenital hearing loss
American Academy of Pediatrics: recommend that hearing loss in infants be identified prior to 6 months of age - better prognosis for speech and cognitive abilities
BEAR: Brainstem auditory evoked response measures brainwave response to broadband click
- best at 2 wks but newborns usually get screen b/f leave hospital
pulse ox screening for C.C.H.D. (critical congenital heart disease - needs tx in 1st month of life)
Method:
- Performed after 24 hours
- Place probe on right hand (pre-ductal) and one foot.
- Room air saturation less than 95% requires further workup
- Definitive test is echocardiogram
Lesions identified:
- Tetralogy of Fallot
- Transposition of Arteries
- Truncus Arteriosis
- Tricuspid Atresia
- TAPVR
- Pulmonic Stenosis
- Hypoplastic Left Heart
- Coarctation of the Aorta
NOTE: will not pick up CHDs that do not cause cyanosis!!
malformation
complete or partial absence or abnormal formation of a structure caused by environmental or genetic factors which interfere with development
Most originate during the period of organogenesis, the 3rd to 8th weeks of gestation.
- ex. Congenital heart defect
MOST common cause of infant mortality in the U.S. (more than prematurity and SIDS)
Can be minor or major (see below)
syndrome
groups of anomalies occurring together with a common cause
association
groups of anomalies occurring together more often than chance alone would allow but cause is unknown
sequence
one primary defect causes the next, which causes the next
Example: Pieere Robin sequence:
- small chin causes tongue to be pushed up and back (glossoptosis)
- position of tongue prevents normal closure of palate, causing cleft palate
- results in obstruction of airway and feeding difficulties
deformation
body part which was forming normally but was acted upon by environment to be distorted; most often musculoskeletal and fixable
- ex. clubfoot
disruption
body part was forming normally when an event occurs that changes it dramatically and irreversibly– often amniotic bands or vascular accident
- often not fixable (more disruptive than deformation)
minor malformations
Occur in less than 4% of population; no major intrinsic medical significance
- 70% found on face or hands
- ex. syndactyly (fingers connected)
Significance: more minor anomalies = more likely to have major anomaly
Note: 3 minor anomalies = 20% inc. major anomaly
transverse palmar crease
Single, uninterrupted horizontal crease on palm
- previously called “simian crease”
Occurs in 45% of babes with Down Syndrome
4% of Caucasians (minor anomaly)
16% of Chinese (normal variant)
major malformation
congenital defect of surgical, medical or functional significance
- ex. omphalocele (intestines protrude from stomach) or congenital heart disease (Tetralogy of Fallot)
types of genetic defects
chromosomal disorders:
- abnormalities of number (e.g. Trisomy (3 copies of 1) v. triploidy (3 copies of all))
- abnormalities of structure (e.g. Deletions or duplications of portions of chromosome)
Single gene disorders
- deletions
- duplications
- substitutions
autosomal dominant
autosomal recessive
X-linked
genomic defects
Genomics is a subset of genetics in which we look at the turning on or off of specific genes
- can be caused by environmental factors
- explains how normal tissues vary from organ to organ
- also explains how teratogens can effect the expression of an individual’s genetic makeup
prenatal diagnosis of genetic defects - two techniques
Two techniques:
- amniocentesis
- chorionic villus sampling
Can be used for: - biochemical screening - genetic screening Karyotype FISH probe
amniocentesis
Under ultrasound guidance, a spinal needle is inserted through the maternal abdominal wall and uterine wall, into a pocket of amniotic fluid (contains cells from skin and kidney)
Risks: greater in first trimester than second
- fetal loss
- damage to fetal structures
- leakage of amniotic fluid
chorionic villus sampling
best performed at 11-13 weeks (adv: can do earlier than amniocentesis; if later would just do amnio)
- Requires ultrasound guidance
- approach may be trans-vaginal or trans-abdominal (depending upon location of the placenta)
- Needle biopsies a portion of the chorion
Risks: 2-3% risk of fetal loss, very low if any fetal abnormalities if after 10 weeks
diagnosis of genetic diseases
history physical exam laboratory - Karyotyping - FISH probe - Microarray (genomic)
Why make diagnosis of a syndrome in a neonate?
External signs give clues to serious, internal malformations
Enables provider to help family plan early interventions for expected issues
Genetic counseling; incl. likelihood of recurrence
Helps family to deal with uncertainty / get support
karyotyping - definition and indications
Visual inspection of chromosomes and their banding (ID’s all types of specific abnormalities)
Indications:
- Confirmation of a known syndrome
- Infants with multiple congenital anomalies
- Child with developmental delays and morphologic changes
- Ambiguous genitalia
- Still born infant with malformation (5-15% of babies will have a chromosomal abnormality)
Advantage: can see structure of chromosomes
Disadvantage: needs to grow in culture - takes a week
FISH Probe
Fluorescent In Situ Hybridization
- DNA probe + label
- Hybridize with sample cells
- Fluorescent detector
Disadvantage: Asks a specific question; ie. You have to have the disorder in mind when selecting which probe to use
- helpful for genital ambiguity
Advantage: results in 24 hours
microarray
mainstay in genetic analysis!
Microarray analysis involves breaking open a cell, isolating its genetic contents, identifying all the genes that are turned on in that particular cell, and generating a list of those genes.
A DNA micorarray allows scientists to perform an experiment on thousands of genes at the same time.
Each spot on a microarray contains multiple identical strands of DNA.
The DNA sequence on each spot is unique.
Each spot represents one gene.
Thousands of spots are arrayed in orderly rows and columns on a solid surface (usually glass).
The precise location and sequence of each spot is recorded in a computer database.
Microarrays can be the size of a microscope slide, or even smaller.
Trisomy 21 - Down Syndrome
Babies are born with three copies of chromosome 21
- complete: 100% of cells involved
- mosaic: varying percentage of cells involved
NOTE: % of cells is proportional to severity of symptoms
Incidence: 1:600- 1000; MOST common syndrome in man
clinical feature of down syndrome at birth
Hypotonia - tongue protrudes, more due to tone than size - hyperflexibility of joints Typical facies - microcephaly - up slanting palpebral fissures - inner epicanthal folds Typical features of hands and feet - transverse palmar crease - sandal toe / flat feet
hidden features of down syndrome
40% have congenital heart disease (endocardial cushion defect, VSD)
Skeletal abnormalities (atlanto-axial subluxation, hip problems)
66% hearing loss (at birth or later)
Hypothyroidism
White blood cell abnormalities (susceptibility to infection
Increased risk of leukemia)
diagnosis of down syndrome
Prenatal "quad screen": - dec. alpha-fetoprotein (AFP) - Inc. Human gonadotropin (hCG) - Dec. Unconjugated estriol (uE3) - Inc. Inhibin A NOTE: detects 85%
Prenatal ultrasound:
- increased nuchal width
Amniocentesis for karyotyping:
- encouraged in moms over 35
Genetic testing:
- FISH probe – looking specifically for chromosome 21; fast results
- however, does not tell you what type which is important for additional children from mom (Robertsonian translocation – much higher likelyhood in next sibling); also does not provide mosaic - Karyotype (from tissue culture) – this looks for everything but takes a week
“Quad” Screen
4 things tested: AFP, HCG, uE3, Inhibin
Neural tube defect (NTD):
-AFP up (rest normal)
Trisomy 21:
- AFP and uE3 down
- HCG and inhibit up
Trisomy 18
- all down
Turner’s Syndrome
chromosomal abnormality
- XO - females only!
Clinical features:
- Short stature
- Lack of secondary sex characteristics
- Shield chest / Webbed neck
- Wide carrying angle of arms
- Normal intellect (problems with math)
Unseen problems:
- Cardiac disease (coarctation of aorta, aortic valve anomalies)
- Infertility/lack of sexual development
- Renal disease
Prader-Willi Syndrome
chromosomal abnormality
- deletion of a portion of a chromosome
Clinical presentation at birth:
- Severe hypotonia
- Poor feeding
- Micropenis
- Small hands and feet
Symptoms later:
- Short stature
- Mild to moderate mental retardation
- Food related behavior issues
achondroplasia
Example of a single gene mutation
Passed on in an autosomal dominant fashion
What you see (midget)
Large head
Short stature
Bony abnormalities: curvatures of spine, short hands, abnormally formed pelvis
Normal intelligence and fertility
autosomal recessive disorders
Occur if both parents, though clinically normal, carry the same gene
When combined present with the disease in question
Increased likelihood if parents are related or in small, closed communities
Many diseases, including sickle cell disease, cystic fibrosis, Crigler-Naajar
X-linked disease
Gene for trait is carried by mother on the X chromosome
- expressed in male children only
- classic examples are hemophilia, Duchenne’s muscular dystrophy and red-green color-blindness
teratogens
agent or factor that causes a malformation
- thalidomide (drug for morning sickness): babies with flipper limbs
- fetal alcohol syndrome: typical facies (smooth philtrum), microcephaly; developmental delay, behavior problems
Viruses - Main Issues
Important cause of prenatal and neonatal morbidity and mortality
Frequency of viral infections in fetus and newborn may be as much as 6 to 8% (compared to 1 to 2% for bacterial disease)
More likely than bacteria to cross the placenta and cause disease in fetus
congenital infection
acquired in utero
can result in malformations, fetal loss, prematurity, IUGR, neurological sequellae
natal infections
acquired at the time of birth
- infection did not cross membranes or placenta
wide variety of outcomes from asymptomatic disease to chronic disease or death
postnatal infection
acquired during the neonatal period
vertical transmission
the transfer of a disease, condition, or trait from one generation to the next either genetically or congenitally
Eg. Passing on an inherited trait (sickle cell disease)
Eg. Passing on an infection (early onset GBS infection) (either during pregnancy or during delivery)
horizontal transmission
the spread of an infectious agent from one individual to another, usually through contact with bodily excretions or fluids, such as sputum or blood, that contain the agent.
Eg. Spreading the common cold or spreading avian flu
Eg. Infant developing late onset GBS sepsis from his mother.
effect of material immune response on fetus
When mother is infected - immune system first makes IgM
- large molecule
- does not cross the placenta
- spike in IgM indicates current infection
As the immune response continues, maternal antibody is primarily IgG
- small molecule
- freely crosses placenta (especially during the third trimester)
- indicates convalescent of past infection
Term baby is essentially born with a copy of his mom’s IgG which persists for 4 to 6 mos
- why premature babies are more prone to infection
effect of viral infection varies with trimester of pregnancy
1st trimester: viral infections act as teratogens (period of organogenesis)
2nd trimester: baby gets infection and immunity
3rd trimester: baby can pick up infection without antibody (if come to delivery)
congenital viral infections - what happens when mom gets virus while pregnant?
most maternal infection are self-limiting and have no effect on fetus (Influenza, RSV, rhinovirus, Norwalk)
maternal viremia (virus in blood) - usually placenta protects fetus
some viruses cross placenta and cause:
- replication and infection of placenta
- damage to vessels of placenta so it is “leaky”
- infection of maternal leukocytes which sneak through inflamed placenta
common viral pathogens - TORCH
Toxoplasmosis Other- primarily syphilis Rubella- aka “German measles” Cytomegalovirus 3 H's: - Herpes - Hepatitis B & C - HIV
Note: There is no such thing as a “Torch Titer”- provider needs to consider each possible infection and order specific antibody titers separately
toxoplasmosis - not a virus at all
Caused by an intracellular protozoan parasite
Most natural infections are acquired by ingesting undercooked meat or food contaminated by cat feces
Cat - definitive host
Severity of fetal disease is inversely proportional to gestational age
- 1st trimester: fetal death or baby with severe neurologic (calcified lesions in brain) or eye disease (calcifications on retina); also see ASYMMETRIC IUGR
- 2nd or 3rd: mild or subclinical disease
syphilis (“other”) - not a virus at all
Sexually transmitted infection caused by Treponema pallidum
In adult, 4 stages:
- Primary: ulcerative lesion on genitals, non-painful and easily missed
- Secondary: systemic illness with fever, sore throat, headache and diffuse rash
- Latent: treponemes present but without symptoms
- Tertiary syphilisL neurologic and cardiac symtoms
more recent mom’s infection, the more likely the transmission to fetus; (i.e. 100% transmission in primary and secondary syphilis infection;
after secondary, i.e. during latent phase, infection rate drops)
Baby more likely infected if mom is infected during second or third trimester
- if baby gets in 1st trimester - full blown congenital syphilis (bad!)
syphilis - congenital infection
May result in stillbirth, hydrops fetalis, prematurity, IUGR, microcephaly, blistering rash
Or, baby may be asymptomatic at birth, develop characteristic symptoms in first 3 months:
- Hepatomegaly, splenomagaly, skeletal & dental abnormalities ()Hutchinson teeth), anemia, snuffles, saddle nose
Treat with PENICILLIN
Untreated, will develop neurosyphilis and bony changes
congenital syphilis
we do not see a lot of it here, but screen for it since it can be devastating and is preventable with PENICILLIN
rubella
Classic example of viral teratogen if infection occurs during the first 8 weeks of pregnancy
Symptoms: heart defects, cataracts, cognitive impairment, hearing loss, IUGR, blueberry muffin rash
- these are malformations (occur early)
Infection in third trimester: causes myocarditis (pathology of an already formed structure - deformation)
NOTE: there is an effective vaccine - so rare in US
- WE STILL SEE IT IN OTHER PARTS OF WORLD!
congenital rubella - familiar rash
“Blueberry muffin rash” - consists of raised purplish bumps on the skin which reflect extramedulary hematopoiesis (RBC formation on the skin; outside of the bone marrow)
NOTE: also see with congenital CMV
CMV (cytomegalovirus)
MOST common cause of intrauterine infection in US (1% of all neonates infected)
Mom is asymptomatic, as are most babes
Early childhood infections are common and mild - often spread in daycare settings (25% of population has CMV antibody)
NOTE (1st trimester): 20-30% risk of fetal loss if occurs during first trimester; other bad effects
congenital CMV - symptoms at birth
Symptoms are most severe when they occur in first trimester:
- Prematurity
- Corioretinopathy
- Hepatic failure
- Microcephaly (i.e., OFC (head circumference) less than 5%tile)
“Blueberry muffin” appearance (petechiae & purpura)
blueberry muffin rash
Usually on trunk
Can be seen in rubella, CMV, congenital leukemia, neuroblasoma, etc.
- any intrauterine condition in which there is severe anemia
Magenta coloured papulonodular lesions suggestive of dermal hematopoiesis (RBC formation)
CMV - long term symptoms
MOST COMMON cause of congenitally-acquired sensoirneural hearing loss
Intracranial calcifications Cerebral palsy Seizures Cognitive impairment Dental defects
CMV diagnosis
Urine specimen is best source for culture (though virus present in other body fluids also)
viral infections acquired during time of delivery: all of the H’s
HIV
Hepatitis B
Hepatitis C
Herpes Simplex virus
HIV (Human Immunodeficiency Virus)
virus responsible for AIDS
Routine testing for HIV is recommended for all pregnant women
RISK OF TRANSMISSION of HIV from untreated mom to baby is 25%
TREAT!
- antiretroviral drugs (ATZ) (not teratogenic to the developing fetus)
HIV positive mom - how to treat
Mom with low titers (good t cell count):
- can delivery vaginally; begin AZT tx to baby
- reduced risk of HIV to baby down to 1%
Mom with high titers: - vaginal v. c-section AZT during labor and delivery - baby gets multi-drug therapy - 2% likelihood of infection in newborn
CONTACT CHIP program - follow mom and baby once born
HIV and breastfeeding
Depends on where in world (HIV can pass through breast milk and cause newborn infection.)
In “first world,” better to use formula
In developing world, particularly Africa, better to continue to breast feed (likelihood of newborn death due to diarrheal illness outweighs death due to HIV)
HBV (hepatitis B)
Picked up at time of delivery; does not dross placenta
Babies present with a variety of signs and symptoms, including:
- CHRONIC INFECTION (90%)
- Clinical hepatitis with jaundice
- Fatal fulminant hepatitis
- Chronic hepatitis - Predisposition for hepatocellular CA (carcinoma).
Note: More than 90% of perinatally infected infants will develop chronic infection whereas only approximately 10% of infected adults do
HBV positive mom - management
All pregnant women are screened for HBV as part of prenatal labs
- Immediate bath
- Hep B vaccine
- HBIG (Hepatitis B Immune Globulin)
note: Breastfeeding poses no threat to baby -BREASTFEED
95% EFFECTIVE in preventing HBV infection in baby!
HCV - hepatitis C
Not part of routine prenatal screening
Signs and symptoms of hep C virus are indistinguishable from Hep B and Hep A
Acute disease is mild; children have low chance of chronic disease (opposite Hep B - HBV)
management for baby of HCV positive mom:
- test bay at 18 months (after maternal antibody gone)
- BREASTFEEDING OK
herpes simplex virus (HSV)
HSV-2 is more commonly the cause of neonatal infection than HSV-1
most often transmitted during birth through an infected maternal genital tract
Risk to babe
- 33-50% if mom’s primary infection
- 5% if result of reactivation shedding
Neonatal herpes infections are severe
- High morbidity and mortality rates
Consider diagnosis in neonates with fever, irritability, abnormal CSF findings and seizures
HSV - manifestations
Manifestations
- 1/3 disseminated disease involving multiple organs (sepsis): presents in 1st week
note: vesicular rash will kill - must catch!
- 1/3 localized CNS disease: presents in 2nd or 3rd week
- 1/3 localized to skin, eyes and mouth: presents in 2nd week
HSV at delivery
active lesions: many OBs elect C-section
AVOID USING FETAL SCALP ELECTRODE (common site for introduction of infection)
Do NOT RUPTURE MEMBRANES, if possible
Care of newborn at risk for HSV (due to maternal lesions)
isolation
cultures from many areas
treatment:
- controversial if asymptomatic
- ACYCLOVIR if has any symptoms
Parvovirus B19 (aka Fifth disease)
Causes mild, self-limited illness with typical rash in young children
- “slapped cheeks”
- lacy rash on extensor surfaces of joints
Contagious before rash appears; typically a preschool disease
Like many viruses, causes bone marrow suppression
varicella (aka chicken pox)
Caused by Herpes Varicella Zoster virus
Like all herpesviruses, characterized by an acute infection with recurrences (shingles)
Initial infection is “chicken pox”
Lesions at different stages (unlike small pox)
NOTE: vaccine now exists (1995)
effect of varicella virus on fetus and newborn
First trimester: serious but not common (limb atrophy, CNS, eye manifestations)
Second trimester: unapparent infection
Varicella infection occurring 5 days before to 2 days after birth: can be fatal since no IgG
More then 5 days before delivery in 3rd trimester: no problem b/c maternal antibody
bacteremia
The presence of bacteria in the bloodstream
can be a transient, self-limited phenomenon, cleared by immune system
can “seed” other sites such as bone, lung, meninges
can progress to sepsis
sepsis
Bacteremia coupled with inadequate perfusion and end-organ involvement
- decreased blood flow causing damage to important organs
Two types of neonatal sepsis
Early-onset sepsis (EOS): Sepsis which occurs in a neonate within the first 3 days of life
- vertical transmission
Late-onset sepsis (LOS): Sepsis which occurs after the first 3 days until 2 to 3 months of life (definitions vary)
- horizontal transmission