Download Perinatal infections - Lisa C. Cirello, RN

Perinatal infections
Bacterial
Background
Bacterial infections are not associated with
problems related to organogenesis.
Maternal immunosuppression during
pregnancy can make the course of these
infections worse.
Bacterial infections are associated with poor
pregnancy outcomes such as preterm birth,
low birth weight, and stillbirth
Bacterial infections to be discussed
Group A Streptococcus
Listeriosis
Gonorrhea
Chlamydia
Genital Mycoplasma, ureaplasma
Group B Streptococcus
Group A Streptococcus
Background
Group A Streptococcus causes a wide variety of
diseases:
Bacterial pharyngitis
Impetigo
Scarlet fever
Necrotizing fascititis
Streptococcal toxic shock syndrome
The most common etiologic agent is
Streptococcus pyogenes.
Background cont.
Streptococcus pyogenes is divided into serotypes
based on the type of M protein present on the
bacteria.
In addition to M proteins the other significant
virulence factor is streptococcal phylogenic
exotoxins (SPE).
SPE acts as a superantigen. Causing a more
significant infection.
These streptococcal bacteria may be recovered
from skin or mucous membranes of asymptomatic
colonized patients.
Background cont.
The bacteria enter the body through the skin, mucosa,
pharynx, and vagina.
The infections can be suppurative or nonsuppurative.
During pregnancy, the most significant infections caused
by Group A streptococcus are:
Bacteremia without an obvious source of infection
Endometritis
Streptococcal toxic shock syndrome
Necrotizing fasciitis
All of these diseases are more common during the
postpartum period.
Diagnosis
Group A streptococcus can be easily cultured from
infected sites.
However, in clinical situations caused by the more
virulent forms of Group A streptococcus treatment
needs to be started before the bacteria will grow in
culture.
Fever is the most common presenting sign.
20% of patients will have “flu-like” symptoms.
Diagnosis cont.
Signs of possible necrotizing fasciitis:
Sudden onset of severe pain at the incision site
that is out of proportion to the physical findings.
A thin ,watery, nonmalodorous discharge.
In order to confirm the diagnosis the wound must
be opened and debrided.
Sudden onset of hypotension and shock, think
about Streptococcus toxic shock syndrome.
Fetal risks
Maternal Group A Streptococcus disease can be associated
with stillbirth.
Neonatal invasive Group A streptococcus disease has been
reported. The mortality rate is 30%. 50% of these infants
are infected within 1 week of birth. This suggests vertical
transmission from an infected mother.
Neonatal Group A streptococcus disease presents as:
Omphalitis
Cellulitis
Menengitis
Sepsis
Fasciitis
Management
Most patients present in the immediate
postpartum period.
Broad spectrum antibiotics should be
utilized in the treatment of fever within the
first 24-48 hours of delivery.
A cephalosporin or broad spectrum
penicillin would be appropriate.
Listeriosis
Background
The organism casing the infection is Listeria
monocytogenes.
The most common infective sources are:
Soft cheese
Other milk products
Deli meats
Outcomes of pregnancies infected with
listeria vary
Background cont.
There is a high incidence of spontaneous
abortion and stillbirth in pregnancies
complicated by listeriosis.
The worst prognosis occurred in
pregnancies where the mother developed
meningitis.
Diagnosis
Listeriosis presents with “flu-like” symptoms.
The average duration of symptoms prior to
diagnosis is 6 days.
29% of patients are asymptomatic
Rarely listeriosis may cause meningitis and sepsis.
Listeria can be grown in routine culture media.
Diagnosis depends on a high degree of clinical
suspicion.
Fetal risks
Transmission to the fetus is either through ascending
infection from the vagina or transplacental secondary to
maternal bacteremia.
Neonatal listeriosis presents as:
Respiratory distress
Fever
Neurologic symptoms
Skin rash
Asymptomatic
Similar to Group B strep there is early onset and late onset
disease in the neonate.
Management
The primary management is prevention.
In pregnant women infected with listeria the
primary therapy is Ampicillin 2 grams IV qid for
10-14 days.
In penicillin allergic women Bactrim 20
mg/kg/day IV divided into 4 daily doses.
Other second line therapeutic agents are
vancomycin, erythromycin, or carbapenems.
Cephalosporins are not effective against listeria.
Prevention
Do not eat hot dogs, luncheon meats, or deli meats unless
they are reheated until steaming hot.
Do not eat soft cheeses such as feta, brie, camembert, blue
cheese and Mexican style “queso blanco fresco.”Hard
cheese or soft pasteurized cheeses are safe.
Do not eat refrigerated pate or meat spreads.
Do not eat refrigerated smoked seafood unless it is an
ingredient in a cooked dish.
Do not drink raw (unpasteurized) milk or eat foods that
contain unpasteurized milk.
Gonorrhea
Background
Gonorrhea is caused by the bacteria Neisseria
gonorrhea.
The prevalence in pregnancy varies depending on
the population from, 0.5%-7.4%.
Risk factors include:
Multiple sexual partners
Young age
Nonwhite race
Low socioeconomic status
unmarried
Diagnosis
Up to 80% of women with gonoccocal infections of the cervix are
asymptomatic.
Gonoccocal cervicitis is associated with:
PPROM
Preterm labor
Chorioamnionitis
Endometritis
Acute salpingitis may rarely occur in the first trimester but is unlikely
to occur after the first trimester because the pregnancy prevents
ascending infection.
Disseminated gonococcal infection can also occur in pregnancy.
Diagnosis is made by DNA assay or culture.
Fetal risks
The main risks to the fetus are secondary to
complications in the mother causing preterm
delivery.
Infants delivered to mothers acutely infected with
gonorrhea are at risk for gonococcal ophthalmia
nonatorum.
40% of infants who do not receive ocular
prophylaxis are at risk for ophthalmologic
complications when the mother is infected.
Management
Uncomplicated gonorrhea infections:
Cefixime 400mg PO in a single dose
Ceftriaxone 125mg IM in single dose
Spectinomycin 2 gm IM in single dose
Disseminated gonococcal infection hospitalization with
parenteral antibiotics:
Ceftriaxone 1 gm IM or IV qd
Ceftizoxime 1 gm IV tid
Cefotzxime 1 gm IV tid
Parenteral antibiotics are continued until symptoms
resolve.
Chlamydia
Background
Chlamydial infection is caused by the organism Chlamydia
trachomatis.
The prevalence of infection in pregnant women ranges
from 2-37%, with the average estimate of 5-7%.
Risk factors for cervical infection with chlamydia include:
Young age
Unmarried mothers
Multiple sexual partners
Previous history of sexually transmitted diseases.
Diagnosis
The majority of infected women are
asymptomatic.
The diagnosis is made by culture or DNA
detection.
The urine or cervical secretions can be used for
testing.
Because of the risk of preterm delivery in infected
mothers screening and treatment in pregnancy is
indicated.
Fetal risks
The major risk to the fetus is related to early
delivery due to maternal infection.
50-60% of neonates delivered vaginally to
women with chlamydial cervicitis will be
colonized with chlamydia.
This colonization can cause conjunctivitis
and pneumonia in the newborn.
Management
The treatment of chlamydial cervicitis in
pregnancy includes:
Azithromycin 1 gram PO in one dose
Erythromcin ethylsuccinate 800mg PO qid for 7
days
Erythromycin base 500mg PO qid for 7 days
Alternative therapy is Amoxicillin 500mg PO tid
for 7 days
The sexual partners should be tested and treated.
Genital mycoplasma and
ureaplasma
Background
The cervicitis in this disease entity is caused
by Mycoplasma hominis and Ureaplasma
urealyticum.
These organisms have been associated with:
Septic abortion
Postpartum endomyometritis
Preterm labor
Chorioamnionitis
Diagnosis
Culture of cervical secretions in infected
women.
Routine culture and treatment for these
bacteria is controversial.
Fetal risks
The risk to the fetus is related to preterm
delivery and the complications of
prematurity and low birth weight.
Management
Routine screening and treatment for these
bacteria is controversial.
Ureaplasma is sensitive to erythromycin.
Mycoplasma is resistant to erythromycin
but sensitive to clindamycin.
Group B Streptococcus (GBS)
Background
In the 1970’s GBS emerged as the leading
cause of neonatal morbidity and mortality in
the USA.
In the early 1980’s clinical trials showed
that IV antibiotics given during labor to “at
risk” women could prevent early onset
disease in the newborns.
Background cont.
In the 1990’s the first guidelines were
issued by the CDC, ACOG, AAP. These
guidelines recommended one of 2
approaches:
A risk based approach
A culture based screening approach
In 2002 these guidelines were updated to
the ones we use today.
Differences between the 1996 and
2002 guidelines
Recommendation of universal prenatal culturebased screening for the vagina and rectal GBS
colonization of all pregnant women at 35-37
weeks’ gestation.
Updated prophylaxis regimens for women with
penicillin allergy.
Detailed instruction on prenatal specimen
collection and expanded methods of
GBS culture processing, including instructions on
susceptibility testing.
MMWR.51(RR-11):1-23,2002
Differences cont
Recommendations against routine intrapartum
antibiotic prophylaxis for GBS-colonized women
undergoing planned cesarean deliveries who have
not begun labor or had ROM.
A suggested algorithm for management of
patients with threatened preterm delivery .
An updated algorithm for management of
newborns exposed to intrapartum antibiotic
prophylaxis.
MMWR,51(RR-11);1-23.2002.
Similarities between the 1996 and
2002 guidelines
Penicillin remains the first-line agent for
intrapartum antibiotic prophylaxis, with ampicillin
an acceptable alternative.
Women whose culture results are unknown at the
time of delivery should be managed according to
the risk-based approach; the obstetric risk factors
remain unchanged:
Delivery <37 weeks gestation
Duration of membranes rupture >18 hours
Temperature>100.4°F
MMWR.51(RR-11);1-23.2002
Similarities cont.
Women with negative vaginal and rectal GBS screening
within 5 weeks of delivery do not require intrapartum
antimicrobial prophylaxis for GBS even if obstetric risk
factors develop.
\Women with GBS bacteriuria in any concentration during
their current pregnancy or who previously gave birth to an
infant with GBS disease should receive intrapartum
antimicrobial prophylaxis.
In the absence of GBS urinary tract infection,
antimicrobial agents should not be used before the
intrapartum period to treat asymptomatic GBS
colonization.
MMWR 51(RR-11);1-23.2002.
GBS colonization
Natural reservoir is gastrointestinal tract.
10-30% of pregnant women are colonized
with GBS in the vagina or rectum.
Maternal colonization is the major risk
factor for early-onset disease in infants.
Vertical transmission primarily occurs after
the onset of labor or ROM.
Additional risk factors for early
onset GBS disease
Gestational age <37 completed weeks
Longer duration of ROM
Intraamniotic infection
Young maternal age
Black race
Hispanic race
Algorithm for universal screening
Resistance to GBS
To date there is no confirmed resistance to Penicillin or
ampicillin.
Penicillin is the drug of choice with ampicillin an
acceptable alternative (at Overlook we use Ampicillin as
the agent of choice)
Resistance to other agents in penicillin allergic women:
Erythromycin-7-25%
Clindamycin-3-15%
Vancomycin use should be reserved for known resistant
strains to the other 2 agents listed above
Recommended intrapartum
antibiotic prophylaxis
Algorithm for threatened preterm
delivery
Algorithm for management of
newborns exposed to antibiotics