Necrotizing Enterocolitis: Progress, Problems, and Prospects
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Transcript Necrotizing Enterocolitis: Progress, Problems, and Prospects
Three Common Neonatal
Infections: 2013
Roger G. Faix, M.D.
The University of Utah
Primary Children’s Medical Center
Intermountain Medical Center
Importance of Cytomegalovirus
(CMV)
Frequent pathogen in all human populations
70-80%
of US adults are seropositive
Up to 100% in the developing world
Importance
Transmission usually involves prolonged
intimate contact with infected body fluid
Infection ≠ Disease – usually asymptomatic
in immunocompetent subjects
Among immunocompromised, CMV is a
leading cause of morbidity and mortality
Cytomegalovirus CPE In Vivo
CMV
One
of at least 8 human herpesviruses
DNA
genetic material
Latency – lifelong potential dormancy
Persistence – may shed virus for years
Reactivation- latent virus may become
actively shed again
Importance
Congenital infection (acquired in utero,
present at birth): 0.5 – 2.5% of liveborns,
(10,000-50,000/year in US)
Natal infection (acquired during passage
through infected birth canal): 10-35% of
liveborns; detectable after 3 weeks
Post-natal infection (acquired after birth):
up to 100% in some populations; breast
milk, day care, contact with infected fluid
Importance
Natal
and postnatal infections usually
are asymptomatic in newborns, but
VLBWs
may develop sepsis-like
condition and other syndromes
May cause significant disease if subject
later immunocompromised
May serve as a source for transmission to
high risk individuals
Importance of Congenital CMV
Major
cause of morbidity and death for
embryo, fetus, and neonate
Wide array of potential responsible
agents for congenital infection important to identify which responsible
CMV most common cause of
congenital infection in US by far
Congenital CMV Infection
Congenital CMV Infection
Congenital CMV Infection
Potential
for intervention
Limitations of therapy
Effective
therapy may arrest further
injury, BUT
May not reverse injury that already
occurred
May not immediately stop injury
Congenital Cytomegalovirus (CMV)
Mother usually asymptomatic
Transmission from mother to fetus
hematogenous or transamniotic
Father may be source of infection or
multiple other sources
DNA analysis useful for epidemiologic
investigations
Congenital Cytomegalovirus
(CMV)
With
congenital CMV infection,
symptomatic disease occurs in 5-10%
With symptomatic presentation, 90+%
will have severe neurodevelopmental
sequelae (100% if microcephaly or
intracranial destructive lesions)
Symptomatic Presentation
Abnormal head size
CNS lesions
Calcifications
Organomegaly
Adenopathy
Petechiae
‘Blueberry muffin’
Symmetric IUGR
Hydrops
Anemia
Bony/dental lesions
Deafness
Chorioretinitis
Numerous others
Congenital CMV
Congenital CMV
Congenital Cytomegalovirus
(CMV)
With
congenital CMV infection, 90%+
are usually asymptomatic at birth
10-15%
of these may develop later
sequelae, usually relatively mild
• Hearing loss (SNHL)
• Enamel hypoplasia
• Seizure disorders
• Learning disorders
Congenital CMV: Hearing Loss
>20 dB (Fowler et al, 1999)
40
Hearing loss,%
35
30
25
20
15
10
5
0
0
6
12
18
24
30
36
42
48
54
Months since birth
Symptomatic
Asymptomatic
60
66
72
What Determines Presentation?
Maternal infection – primary or recurrent
Gestational timing of infection
Maternal organism load
Other factors to be determined
Congenital Cytomegalovirus (CMV)
Primary infection
1-4% of seroneg
Congenital infection
40%
Symptomatic
5-15%
Normal
10%
Sequelae
90% (severe)
Asymptomatic
85-95%
Sequelae
5-15%
mild-mod
Normal
85-95%
Effect of GA at primary CMV
infection on transmission and disease
Outcome
4-22 wk GA
16-27 wk GA
23-40 wk GA
Total
Maternal
primary CMV
33
10
26
69
Fetal infection
17 (51%)
6 (60%)
12 (46%)
35 (51%)
Symptomatic
congenital
2 (12%)
1 (16%)
0 (0%)
3/37* (8%)
Severe sequelae
5 (29%)
0 (0%)
0 (0%)
5/37* (13%)
*32 of original 69 were terminated or otherwise lost before birth
Congenital CMV
Much lower risk in mother who is
seropositive at start of pregnancy, BUT
absolute number of those who are
seropositive is so much greater that absolute
number of resultant infants with
symptomatic CMV is significant
Up to 40% of those with symptomatic
congenital CMV result from mothers who
were seropositive at start of pregnancy
Diagnosis of Congenital CMV
Many
other pathogens may cause
congenital disease that mimic CMV
It is important to determine the
presence/absence of these organisms
Some
are amenable to specific therapy
Many are associated with very different
sequelae and care needs
Diagnosis of Congenital CMV
Viral
culture (urine, saliva) up to age 3
weeks – congenital detected more
quickly due to high viral load
PCR up to 3 weeks of age OR blood
spot from newborn screen
Diagnosis of Congenital CMV
TORCH
IgG-
titers - very limited utility
specific usually transplacental
IgM-specific antibody – diagnostic if + in
first 3 weeks; does not exclude if
negative
Treatment of Congenital CMV
Treat
signs/symptoms as detected
Longitudinal assessment for SNHL
Ganciclovir (GCV)
IV
6 weeks; CVC requirement
50% thrombocytopenia, neutropenia
Does ↓frequency and severity of SNHL
Sparse data re: other CMV issues
Chorioretinitis usually treated
Quantity of CMV in urine with 42
days of GCV (Whitley, 1997)
6
pfu log10
5
4
3
2
1
0
0
7
14
21
28
Study days
8 mg/kg
12 mg/kg
35
42
49
Treatment of Congenital CMV
– oral prodrug
converted to GCV upon absorption;
sparse neonatal data, but what there is
appears promising
Problems with all
Valganciclovir
Not
eradicate latency
Viral infection recurs once stop
Not reverse established injury
Utah State Law – 2013 Session
All newborn infants who fail hearing screen
must undergo testing for congenital CMV
Parents of all infants found to be positive,
must be offered counseling re: treatment,
consequences
Prevention of Congenital CMV
Infection
control and universal
precautions remain critical
At
home, school, hospital, all settings
High potential (not always avoidable) for
contacting infected fluids of
asymptomatic, actively shedding
individuals
Early-onset GBS (EOGBS) in
the Era of Intrapartum
Antibiotic Prophylaxis IAP)
GBS
Although
dramatic decreases in
frequency since adoption of universal
screening and IAP, still #1 cause of
early-onset sepsis in term infants in US
Frequent cause of mortality (5-10% of
affected) and morbidity
EOGBS and ECMO
Suspicion aroused, if no IAP
and…
No antenatal culture
Culture obtained, but results unavailable
History GBS UTI
History maternal chorioamnionitis
History prior infant with EOGBS
Unexplained POL
ROM >18 hours
Suspicion aroused, if IAP given
but…
Negative culture may be false-negative
IAP with erythromycin or clindamycin may
be ineffective
IAP with penicillin or cefazolin may be
ineffective if given <4 hrs prior to delivery
EOGBS – Presenting Signs
Temp Instability
Respiratory distress
Neutropenia
Thrombocytopenia
Hypoperfusion
Hypoglycemia
Pneumonia
PPHN
Focal erythema
Arthritis
Meningitis
Others
Treatment for EOGBS
Supportive
Culture
Blood
CSF
Focal
areas
Empirical treatment
Ampicillin
and Gentamicin
If +, covert to PCN G – 400,000U/kg/d
Treatment for EOGBS
Follow-up culture to assure sterilization
Duration
7-10
after sterilization, if + blood only
14-21 after sterilization, if CSF+
14+ after resolution of sequestered focus
RSV
Respiratory syncytial virus (RSV)
Paramyxovirus:
RNA, many strains
Mother or other contacts (family,
healthcare staff) symptomatic or mild
URI
Spread by contact with respiratory
droplets, not aerosol
RSV and ECMO
Respiratory syncytial virus (RSV)
Neonatal signs: rhinorrhea, wheezing,
pneumonia, lethargy, irritability, apnea; in
preterms, absent or minimal respiratory
signs is not unusual
Diagnosis
culture/PCR
IFA
or EIA of NP swab (only 80-90%
sensitive)
Respiratory syncytial virus (RSV)
Prevention:
RSVIg (IM or IV)
Controversial
based on cost-benefit
analyses, lack of data re: mortality and
need for vent
Nonetheless recommended by AAP in
select circumstances and widely used,
including SLC
Respiratory syncytial virus (RSV)
Infection control:
Careful
attention to handwashing
Minimizing hand-eye contact
Barrier precautions
Discouraging visiting by infected family, work
by infected staff
Respiratory syncytial virus (RSV)
Treatment
Supportive
Careful
attention to upper airway toilet
Bronchodilators controversial (racemic epi-,
albuterol, DXM)
Ribavirin very controversial