Infections Flashcards

1
Q

For women with toxoplasmosis, is there an association between the risk of infection and gestation age?

A

Yes.
- The risk of fetus acquiring infection INCREASES with advancing gestational age.
- the risk of fetus being affected/damaged DECREASES with increasing GA.

In other words a younger/less developed fetus is less likely to contract toxo, but if it does it is likely to be more severely affected.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Fetal risks associated with toxo?

A

Spontaneous T1 losses
IUGR
Microcephaly
Hydrocephalus
Intracranial calcification
Chorioretinitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the most common congenital viral infection in pregnancy?

A

CMV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

T/F. Neonatal CMV can be detected from a urine culture?

A

True, as CMV is excreted in urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Can CMV occur if the mother is immune prior to pregnancy?

A

Yes, because both primary and reactivated infection can infect the neonate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

A patient has a negative VDRL and a positive FTA-Abs, interpret these results.

A
  • Consistent with treated syphilis or newly contracted syphilis
  • when syphilis is contacted, the FTA-Abs becomes positive before the VDRL, hence it could indicate early infection.
  • after the patient is treated, the VDRL becomes negative, but the FTA-Abs remains positive.
  • so VDRL will be positive in untreated secondary/latent/tertiary syphilis
  • TPHA (Treponema Pallidum Haemagglutination) tests also remain positive after treatment.

VDRL/RPR= rapid plasma reagin
FTA-Abs= fluorescent treponemal antibody- absorption test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which tests for syphilis remain positive after adequate treatment?

A
  1. TPHA (Treponema Pallidum Haemagglutination) tests and
  2. FTA-Abs (fluorescent treponemal antibody- absorption) tests
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Is a boy with Fifth’s disease contagious?

A

Assuming he has the slapped cheek rash, then NO.
—-because the virus disappears from the serum and respiratory droplets about 5 days prior to onset of the rash.

  • Rash occurs approx 17-18 days after infection.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

T/F. A patient with clinical signs of Fifths disease is no longer contagious?

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How long does it take for IgM to be detectable after parvovirus exposure? How long does it persist? When should testing be repeated if pt was initially IgG neg?

A

3 days

  • usually persists up to 6 mths
  • repeat testing in 2-3wks, depending on time of exposure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Management of parvovirus positive mother?

A

Serial u/s scans for early identification of hydrops

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Pt presents in TI with fever and vesicular, generalised rash for 3 days. No respiratory/neurological signs. What is ur advice?

A
  • This patient has likely contracted a Varicella infection
    -Oral acyclovir 800mg po five times daily for 7 days.
    —to prevent development of severe complications (hepatitis, encephalitis, pneumonia)
  • acetaminophen for the fever
  • advise to self isolate and stay away from patients at high risk of getting the infection (babies, other pregnant women, known immunocompromised persons).
  • I would not administered Varicella immunoglobulin, as she presented after the rash appeared and it has no therapeutic benefit at this point.
  • as the infection is contracted early in pregnancy (<28weeks), the risk of fetal infection (fetal Varicella syndrome) is very low.
  • infection in the first trimester does NOT increase her risk of miscarriage.
  • she would be referred to a maternal fetal medicine/MFM specialist at 5 weeks post infection or between 16-20 weeks gestation.
    —-they will perform a detailed u/s to assess for evidence of fetal anomalies and they will also counsel her about the risks to the fetus.
    -Her delivery would be vaginal unless there is an obstetric indication.
  • the paediatricians would be informed of this patient and any fetalncomplications that developed due to the infection [Fetal Varicella syndrome which may require nursery admission].
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Give a brief overview of Hep C

A
  • Hepatitis C is an RNA- viral infection that causes acute and chronic hepatitis.
  • 80% develop chronic HCV, of which 20% develop progressive cirrhosis over 1-3decades (10-30yrs).
  • Risk of progressive liver disease is LOWER when:
    —- age <40yrs
    —- non-alcohol drinkers
  • Prevalence 0.3%-0.5%

-Transmission is via blood mainly seen with IV drug users but also with blood transfusion.
It is the commonest cause of post transfusion hepatitis and it is not commonly transmitted via intercourse.
- <5% of long term sexual partners become infected.
- there is no vaccine to prevent transmission

  • Risk of vertical transmission is 3%-5% (uncommon) but risk increases if viruses contracted in T3.
    —-increases to 20% with HIV confection
    -Vertical transmission is dependent on the viral RNA load.
  • chronic HCV does not affect the the rates of transmission.
  • treatment with interferon alpha and ribavirin are Contraindicated in pregnancy.
  • other newer antivirals (Sofosbuvir, ledipasvir) show no evidence of harm in animal models.
    —both are taken orally, are well tolerated and highly effective.

Intrapartum - reduce transmission:
No fetal scalp electrode/fetal blood sampling
No AROM until delivery of Presenting part
Timing of delivery and mode of delivery impacted by hiv co-infection - will be dependent on HIV viral load at 36 weeks
—otherwise, vaginal delivery at term if no obstetric contraindications

  • breastfeed postpartum as transmission in breast milk is uncommon.
    -Test neonate for infection - look for HCV RNA in 2 serum samples taken at least 3 months apart w/in the first year Or a positive test for antibodies at 18mths
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does detection of HCV antibodies in the mother imply?

A

Persistent infection, NOT immunity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the s/es of interferon therapy for HCV? What percentage are asymptomatic?

A

Nonspecific symptoms:
Flu-like illness 80%
Fatigue 50%
Depression 25%
Haematological 10%

15% - asymptomatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the maternal risks of Varicella infection?

A

HEP-D:
Hepatitis
Encephalopathy
Pneumonia
Death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

T/F. Acute hepatitis is a rare event in pregnancy?

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

VZIG can be given for how many days post exposure?

A

10 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the postmortem protocol for maternal sepsis (as per the Saving lives and improving mother’s care report 2014)?

A
  1. Thorough examination and histological sampling of all organs, including bone marrow.
  2. Examine and sample placenta if available.
  3. Information on the status of the fetus
  4. Blood cultures as soon as possible after death
    —- taken from heart/neck veins, NOT from below the umbilicus and BEFORE the body is opened.
    ——-if not possible, take a sample of spleen parenchyma for culture.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

T/F. Parvovirus infection is self-limiting?

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the treatment for hydrops due to fetal paroviral infection?

A
  • Intrauterine fetal blood transfusion
    —– to correct the fetal anaemia and resolve the hydrops
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Neonatal mortality rate of Listeria infection in pregnancy?

A

22%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How is MTCT of Hepatitis B prevented?

A
  1. hep-B specific Immunoglobulin
    —provides immediate protection
  2. hep-B vaccine
    —–to develop lifelong immunity
  • These reduce vertical transmission by 90%
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Maternal Varicella infection with seroconversion before 28weeks. What are the concerns?

A
  • small increased risk of foetal Varicella syndrome
  • characteristics:
    ▪︎scaring along dermatomes
    ▪︎limb hypoplasia
    ▪︎eye defects (micropthalmia chorioretinitis, cataracts)
    ▪︎neurological abnormalities (microcephaly, cortical atrophy, mental restriction, bowel/ureteric dysfunction).
25
Q

Primary infection of herpes vs recurrence is likely caused by which strain?

A
  • Primary infection is 50% HSV1 & 50% HVS2
  • Recurrence is usually due to HSV2
26
Q

T/F. Most women infected with Herpes have subclinical or latent infection?

A

True

27
Q

When is the risk of herpes transmission to the fetus highest?

A

If she develops primary genital herpes in the third trimester, within 6 weeks of delivery.
—- BCUZ the baby is likely to be born before the development of protective maternal antibodies.

28
Q

T/F. Disseminated herpes is more common in preterm infants and occurs almost exclusively due to primary infection in the mother.

A

True

29
Q

What is the concern about recurrent herpes at the time of delivery?

A

Recurrent herpes is associated with a VERY LOW RISK of neonatal herpes

  • Recurrent herpes at the time of delivery is usually asymptomatic and may go unrecognized.
  • can cause localised neonatal herpes: local CNS disease and skin, eyes and mouth infection
30
Q

Symptoms of maternal herpes infection?

A
  • flu-like symptoms (fever, myalgia)
  • meningitis is possible
  • inguinal lymphadenopathy
  • genital vesicles - rapidly ulcerate
    ——ulcers are painful, last 10-12 days
  • vaginal ulcers
  • cervicitis
  • vaginal discharge
  • urethra usu involved = dysuria +/- urinary retention
  • perianal ulcers +/- proctitis symptoms
  • extra-genital lesions on buttocks/ thighs
31
Q

Which organism is associated with postabortal and postpartum fever. It lacks a cell wall and therefore cannot retain Gram stain.

A

Mycoplasma hominis

  • mycoplasma hominis and ureaplasma supp don’t have a cell wall and don’t stain with gram stain.
  • They are from the genitourinary tract and are assoc with preterm labour, PPROm, low birth weight, neonatal conjunctivitis and resp disease.
32
Q

Which organism is associated with buboes?

A

Buboes= draining abscesses are causes by haemophilus ducreyi which causes Chancroid

  • Chancroid are painful ulcers which sharply defined borders, grey base and bleeds easily when scraped.
  • LNs are enlarged and may break through the skin, causing draining abscesses/buboes.
33
Q

Describe the cardinal features of trichomonas vaginalis?

A
  • green-frothy discharge, but can be any colour
  • malodourous in 50%
  • vulval or vaginal itching
  • vaginitis or cervicitis on speculum
    ——- punctuate haemorrhages/ strawberry cervix in 2%
  • ph >4.5
  • wet mount: flagellated protocol

-Tx: Metronidazole 2g po stat or Metronidazole 400mg po bd x 5/7

  • Cure rate: 95% with partner notification and treatment.
  • Test of cure is not necessary of pt is complaliant with treatment
34
Q

Who should be offered IAP against Group B strep in labour?

A

A patient who:
1. Had GBS in a prev pregnancy
2. Had a baby with GBS infection
3. Had GBS bacteruria in this pregnancy
4. Had genital/rectal swab positive for GBS
5. Is in preterm labour (<37+0)
6. Has a fever of >38°C

35
Q

What is the risk of GBS in the current pregnancy if mother had GBS in a previous pregnancy? What advice RE testing would you give her?

A

50%

  • Can have IAP or
  • bacteriological testing at 35-37weeks (2-3wks before expected delivery) —and IAP if still positive.
36
Q

Is GBS infection a contraindication to membrane sweeping?

A

No

37
Q

Is antibiotic prophylaxis for GBS required for women receiving csection?

A

No, provided she is not in labour and her membranes are intact
— because the risk of neonatal EOGBS disease is extremely low.

38
Q

Known GBS carrier presents at term with SROM. Labour is not established.
1. How would u manage?
2. How would your management differ if her GBS status was unknown/negative?

A
  1. Immediately start IAP and induce labour.
    —-because of the increased risk of neonatal early onset GBS disease with prolonged ROM.
  2. Offer immediate induction of labour OR expectant management up to 24 hours. Beyond 24hrs IOL is appropriate.
39
Q

Should all pregnant women be screened for GBS? Justify your answer.

A

No.
1. Many women are carriers of the bacteria and deliver their baby safely.
—–2. Therefore, screening in late pregnancy does NOT predict/help illucidate who will develop GBS infection.
3. 5-7% of women who are negative for GBs at 35-37 weeks will be positive at delivery.
4. Most babies severely affected from GBS are born prematurely and before the time for screening.
5. Giving all carriers antibiotic treatment they do not need can increase risk to mother and fetus

40
Q

How would you manage a pt who was incidentally found to have GBS incidentally on HVS?

A

Offer IAP during labour

41
Q

T/F. Method of induction is influenced by GBS carrier status.

A

False. Ensure to offer IAP once labour is established.

42
Q

Pt in labour with temp >38°C, with unknown GBS status. Next step?

A
  • Broad spectrum antibiotics that will cover GBS
    —- broad spectrum instead of pen g to cover chorioamnionitis
    ——–Amoxicillin 2g iv qid OR
    ——–Cefuroxime 1.5g iv qid

—- Intrapartum pyrexia of 38°C and above is assoc with an increased risk of neonatal EOGBS disease (5.3/1000 vs background risk of 0.6/1000)

Remember!:
—Pyrexia in labour is an indication to treat for GBS!!!

-

43
Q

Should IAP be given to all women with:
1. Preterm prelabour rupture of membranes
2. Preterm labour?

A
  1. No, because there is no evidence to suggest that treating GBS before labour is beneficial. IAP is required once in labour.
    - give Emycin 250mg po qid x10/7 or until labour is established OR
    - penicillin if allergic
  2. Yes as the risk of GBS infection is higher with preterm delivery AND risk of mortality from infection is higher in preterm babies:
    —-20-30% versus 2-3% (term babies)
44
Q

What antibiotic is used for IAP?

A

Benzylpenicillin
- 3g iv stat after onset of labour
- 1.5g 4hrly until delivery

Or if allergic:
- Cefuroxime 1.5g stat
- 750mg q8hrly (tds)

Or for severe allergy:
Vancomycin 1g iv q12hrly

45
Q

Pt declines IAP. Next step?

A

Counsel mother about risk of neonatal EOGBS disease.
- baby will need close monitoring after birth
- discourage from seeking early discharge after birth

46
Q

Antiviral treatment for Hep B? Indications for treatment?

A
  1. Tenofovir - preferred for monotherapy
  2. Lamivudine - reduces risk of cirrhosis/liver ca

▪︎Indications:
1. Active disease/cirrhosis
2. In T3 if mother has high viral load, to decrease risk of perinatal transmission

47
Q

Can patients receiving antiviral therapy for Hep B breastfeed?

A

No. Advise mother not to if receiving therapy postpartum

48
Q

Pt 38wks. For iol at 39 wks. Confirmed chickenpox and currently on acyclovir. Next step?

A

Delay delivery by 7 to i) allow transfer of maternal antibodies to fetus and ii) decrease risk of Varicella Infection of the Newborn- can result in severe infection.

49
Q

Neonate born within 7 days of maternal chickenpox infection. Next step?

A

Give VZIG with or without acyclovir prophylaxis

50
Q

Can a patient with active chickenpox lesions close to the nipple breastfeed?

A

NO. WAIT until they have crusted over.
Baby should have received VZIG +/- acyclovir.

51
Q

Causes of Varicella Infection of the newborn?

A
  1. Maternal Varicella infection within 7 days of delivery
  2. Postpartum exposure/breastfeeding with active lesions
  3. Postpartum from another person with chickenpox/shingles
52
Q

Antibiotic dose for IAP for GBS?

A

No fever present?
▪︎Penicillin G/ Benzylpenicillin 3g IV stat then 1.5g q4hrly until delivery
OR
▪︎Cefuroxime 1.5g loading dose then 750mg IV q8hrly/tds until delivery
(Clindamycin is assoc with increased resistance)
OR (if severe beta lactam allergy)
▪︎Vancomycin 1g IV q12hrly

Fever present?
- indicates chorioamnionitis, therefore give broad spec antibx:
▪︎Amoxicillin 2g iv qid/ q6hrly OR
▪︎Cefuroxime 1.5g IV qid

53
Q

What is the treatment regime for postpartum endometritis?

A

IV clindamycin 900mg tds/q8hrly
IV gentamicin 1.5mg/kg tds OR
5mg/kg od

  • both give broad spectrum coverage
  • give until afebrile for 48hrs
  • if no improvement or enterococcal infection is suspected add:
    Ampicillin 1g qid/q6hrly
  • oral antibiotics after iv meds is NOT necessary
54
Q

What predisposes a pt to postpartum endometritis/risk factors?

A

1.Caesarean delivery - particularly unscheduled delivery
- hence antibiotics should be given within 60mins of surgery
2. Vaginal infection/bacterial colonization during labour and delivery.
- BV, group B strep, STIs, chorioamnionitis
3. Prolonged ROM or labour
4. Insertion of foreign objects into the vagina
-multiple VEs, invasive maternal/fetal monitoring, manual removal of placenta
5. Operative vaginal delivery
6.Maternal factors - obesity, DM, HIV

55
Q

T/F. For postpartum endometritis endometrial and blood cultures must always be done.

A

False. Endometrial and blood cultures are not routinely done.

Infection is usually polymicrobial (aerobic + anaerobic bacteria translocated from the cervix & vagina during labour and delivery)

56
Q

T/F. Endometritis is a cx directed diagnosis.

A

False. Endometritis is a clinical diagnosis.

Clinical features:
Unexplained Fever
Postpartum pain
Uterine/fundal tenderness

57
Q

What is the most common Postpartum infection?

A

Postpartum endometritis

58
Q

What is acute endometritis that is unrelated to pregnancy called? What are the causes?

A

PID

Causes:
- STDs
- BV causing organisms

59
Q

Risl

A