Perinatal infections

1. Perinatal infections Bacterial

2. 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

3. Bacterial infections to be discussed • Group A Streptococcus • Listeriosis • Gonorrhea • Chlamydia • Genital Mycoplasma, ureaplasma • Group B Streptococcus

4. Group A Streptococcus

5. 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.

6. 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.

7. 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.

8. 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.

9. 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.

11. 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

12. 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.

13. Listeriosis

14. 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

15. 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.

16. 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.

17. 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.

18. 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.

19. 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.

20. Gonorrhea

21. 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

22. 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.

23. 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.

24. 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.

25. Chlamydia

26. 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.

27. 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.

28. 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.

29. 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.

30. Genital mycoplasma and ureaplasma

31. 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

32. Diagnosis • Culture of cervical secretions in infected women. • Routine culture and treatment for these bacteria is controversial.

33. Fetal risks • The risk to the fetus is related to preterm delivery and the complications of prematurity and low birth weight.

34. Management • Routine screening and treatment for these bacteria is controversial. • Ureaplasma is sensitive to erythromycin. • Mycoplasma is resistant to erythromycin but sensitive to clindamycin.

35. Group B Streptococcus (GBS)

36. 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.

37. 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.

38. Differences between the 1996 and 2002 guidelines • Recommendation of universal prenatal culture-based 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

39. 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.

40. 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

41. 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.

42. 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.

43. 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

44. Algorithm for universal screening

45. 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

46. Recommended intrapartum antibiotic prophylaxis

47. Algorithm for threatened preterm delivery

48. Algorithm for management of newborns exposed to antibiotics