Columbus: bacterial infections in pregnancy Flashcards
What is the term fatality rate for GBS infected neonates?
For infants infected less than 33 weeks?
What are common maternal sites of GBS infection?
And in neonates?
2%
30%
UTI, amnionitis, endometritis
Sepsis, meningitis, Pneumonia
What percentage of women have lower G.I. tract colonization of GBS?
20-25%
What are risk factors for early-onset GBS infection?
Maternal colonization GBS bacteriuria Preterm birth Intrapartum fever Prolonged PROM African-American and Hispanic women Prior GBS-affected neonate
What is the early-onset neonatal infection rate for GBS?
How is late onset neonatal GBS infection transmitted?
0.37 per 1000
Vertical or nosocomial; lower fatality rate
Antibiotics given prior to delivery reduce the early onset GBS by what percentage?
70%
What threshold of GBS bacteriuria necessitates antibiotic treatment in labor?
Greater than or equal to 10^4 CFU/mL
What is first-line treatment for GBS prophylaxis?
What regimen is recommended for penicillin allergy with low-risk of anaphylaxis?
What is recommended for penicillin allergy with high-risk of anaphylaxis?
Penicillin 5 million units IV then 2.5 million units every 4 hours
Cefazolin 2 g IV than 1 g every 8 hours
Clindamycin 900 mg IV every 8 hours or Vancomycin 1 g IV every 12 hours if clindamycin and erythromycin resistant
When is GBS prophylaxis indicated besides positive culture or bacteriuria?
Delivery less than 37 weeks
Rupture of membranes greater than or equal to 18 hours
Intrapartum fever
Intrapartum PCR positive
What is the cause of listeriosis?
What type of organism is this?
Listeria monocytogenes
Motile, non-spore forming, gram-positive Bacillus
When should GBS culture be repeated after PPROM with long latency?
Greater than 5 weeks
How is listeriosis acquired and spread to the fetus?
Unpasteurized cheese, smoked deli meats, hot dogs
Hematogenous spread with cystic placental abscesses
How does listeriosis present less than 32 weeks?
Greater than 32 weeks?
Diffuse sepsis, high mortality rate
Fetal meningitis, hydrocephalus and mental retardation; most mothers asymptomatic
How is listeriosis treated?
Ampicillin 1-2 g IV Q6 hours and gentamicin 2 mg per kilogram IV Q8 hours for one week
What is the proper way to remove a tick that is embedded?
Tweezers or string
What is the causative agent of Lyme disease?
How is it transmitted?
Spirochete Borrelia burgdorferi
Deer tick
Describe the first stage of Lyme disease.
Second stage.
Third stage
Erythema chronicum migrans or target lesion
Neurologic and cardiac manifestations such as meningitis, cranial nerve palsy, first-degree AV heart block
Joint pain especially knee, effusions, chronic neurologic damage and fatigue
What are the perinatal complications of Lyme disease?
Transplacental passage leads to infection of fetal lymphoreticular system, CNS, myocardium with septal and aortic defects described; intrauterine and neonatal demise if untreated
In Lyme disease, what is the timing of tick attachment?
Target lesion?
Serologic changes?
24-36 hours
Four days to three weeks in up to 80%
ELISA positive IgM 2-4 weeks after rash up to six months; IgG 6-8 weeks after rash with peak at six months
How is Lyme disease treated?
What medication is recommended for pregnancy?
Doxycycline 100 mg twice daily for 10-21 days; longer duration recommended for meningitis or other neurologic manifestations
Amoxicillin 500 mg every 8 hours for 21-30 days
What is posttreatment Lyme disease syndrome?
What is the prevalence?
Chronic relapsing episodes of fatigue, joint pain, myalgia lasting six months despite adequate antibiotic therapy
10-20%
What is the causative agent of toxoplasmosis?
What are the three phases of the lifecycle?
Toxoplasma gondii, intracellular parasite
Trophozoite: invasive form
Cyst: latent form found within liver and muscle
Oocyst: reproductive form in cat feces
How does toxoplasmosis typically present?
Most are asymptomatic. If symptoms occur they include fever, night sweats, malaise, myalgias, hepatosplenomegaly
Encephalitis is possible in immunocompromised individuals.
How do people become infected with toxoplasmosis?
Contact with oocysts from cat feces or contaminated soil.
How is toxoplasmosis diagnosed?
ELISA IgM titers that show a four-fold rise over three weeks indicates an acute infection. IgM may last for years.
What are the features of congenital toxoplasmosis?
What percentage developed sequelae by one year?
Chorioretinitis, hearing loss, mental retardation, petechiae, hepatosplenomegaly, ventriculomegaly, cerebral calcifications, seizures, Fetal growth restriction
85%
What is the rate of congenital toxoplasma infection by trimester?
Comment on the severity of disease by trimester.
First trimester: 15%
Second trimester: 25%
Third trimester: greater than 60%
Severity is inversely related to gestational age at infection
Ultrasound findings for congenital toxoplasmosis are rare and late appearing. How can diagnosis be confirmed?
Amniocentesis for T. gondii by PCR or PUBS for T. gondii or IgM if greater than 20 weeks
What does ACOG recommend for toxoplasmosis prevention?
Avoid undercooked meat
Wear gloves and wash hands if working in soil
Avoid cat litter boxes
What does ACOG recommend for prevention and treatment of toxoplasmosis in pregnancy?
Fetal monitoring?
For acute maternal infection, spiramycin decreases fetal transmission by 60%
For known fetal infection, pyrimethamine, sulfadiazine, folinic acid.
Fetal ultrasound every four weeks and NST weekly at 32 weeks
What is the general recommendation for spontaneous bacterial endocarditis prophylaxis in OB/GYN procedures?
Due to low risk of bacteremia routine antibiotic prophylaxis is not recommended. Patients with high-risk cardiac conditions should have enterococcus coverage if they also have an established infection that could cause bacteremia (such as chorioamnionitis or pyelonephritis)
What antibiotic regimen is recommended for infective endocarditis prophylaxis?
Amoxicillin 2 g, ampicillin 2 g or vancomycin 1000 mg plus gentamicin 1.5 mg/kg one hour before surgery
What cardiac conditions are deemed high-risk for infective endocarditis?
Prosthetic heart valves
Previous infective endocarditis
Unrepaired cyanotic congenital heart disease
Repaired congenital heart disease within 6 months
Valve disease in cardiac transplant patient
What prophylactic antibiotics are given at Meriter hospital prior to cesarean?
Cefazolin 2 g IV or 3 g for 100 kg or more
What are the benefits of prophylactic antibiotics before C-section?
Comment on the risk of NICU admission and neonatal sepsis?
60-70% reduction in endometritis
30-65% reduction in wound infection
No change in neonatal sepsis or NICU admission
Should antibiotic prophylaxis be given for third or fourth degree perineal lacerations?
Limited evidence to support routine use. Pearls of exxcellence indicates that antibiotic treatment has been shown to decrease the incidence of perineal infection following repair based on one small study with high loss to follow up
What percentage of people have MRSA colonization by rectovaginal swab? By nasal swab?
Should any additional prophylaxis be given before C-section?
10%. 2%.
Add vancomycin for documented MRSA carriers
Should antibiotic prophylaxis be given for manual placenta extraction?
No data to support or refute this practice but WHO recommends a single dose of prophylactic broad-spectrum antibiotic.
How should non-puerperal mastitis be evaluated and treated?
Must rule out inflammatory breast cancer
Biopsy indurated tissue and send for culture and pathology
What are the causative agents for puerperal mastitis?
What percentage will develop breast abscess?
Staph aureus, Streptococcus, E. coli
10%
How is simple mastitis treated?
What if MRSA is suspected?
What if there is an incomplete or failed response?
Dicloxacillin 500 mg four times daily
Clindamycin 300 mg four times daily
Consider midstream milk culture. Amoxicillin with clavulanate or vancomycin
How should suspected breast abscess be managed?
Breast ultrasound
Needle aspiration or I&D
Broad-spectrum antibiotics
What general counseling recommendations should be given for women with mastitis?
Complete full course of antibiotics due to high risk of abscess for partial treatment
Ibuprofen as needed
Continue nursing/pumping
How should candidal mastitis be treated?
What other recommendations should be made?
Fluconazole 150 mg daily for 14 days
Keep nipples clean and dry and evaluate neonate for thrush
