Infectious Diseases Flashcards
What are the characteristics of Rubella?
- RNA toga virus
- transmitted by droplets
- MMR vaccination decreased its incidence
- if lady got infected in first trimester < 12 weeks there is a 90% risk of congenital infection
- if lady got infected at end of second trimester the risk is < 25 %
What is the maternal presentation of rubella?
- 50% asymptomatic
- febrile rash
What are the symptoms of Congenital Rubella syndrome?
- sensorineural hearing loss
- cataract & blindness
- congenital heart disease (VSD)
- encephalitis
- endocrine problems
How is infection with Rubella managed during pregnancy?
Depending on gestational age
- if infected < 16 weeks -> termination
- If after 16 weeks -> reassure
How is diagnosis of Rubella made during pregnancy?
- IgM antibody after 4 - 5 weeks from onset of symptoms
- antibodies can last up to 2 weeks
- in baby -> ultrasound
What are the characteristics of toxoplasmosis?
- parasite found in cat feces, soil, & uncooked meat
- transmitted by ingestion
- asymptomatic infection of glandular-like fever illness
What is the transmission risk versus fetal damage percentage?
- in first trimester -> transmission 10% but damage is 85%
- in third trimester -> transmission is 85% but damage is 10%
What are the signs of congenital toxoplasmosis infection?
- ventriculomegaly
- microcephaly
- chorioretinitis
- cerebral calcifications
How is toxoplasmosis diagnosed?
- Sabin Feldman dye test
- ELISA -> IgM looking for rising titer
- if suspected by US -> amniocentesis then PCR
How is toxoplasmosis treated during pregnancy?
- Spiramycine for 3 weeks (2 - 3 g/d)
- termination is ultrasound features are secondary to toxoplasmosis
What is the cause for Syphilis infection?
- Spirochete bacteria -> treponema pallidum
- sexually transmitted -> screen at booking
What are the maternal presentations for syphilis?
Primary
- localized disease
- painless genital ulcer with indurated border
Secondary
- from 6 weeks to 6 months
- maculopapular rash or lesions in the mucous membranes & condylomata lata
Untreated Primary & secondary
- 70 - 100% transmission to baby
- 25% still birth
Tertiary
- if untreated
- 20% cardiovascular tertiary syphilis
- 10% neurosyphilis
What are the complications of syphilis transmission to baby?
- stillbirth
- fetal growth restriction
- fetal nonimmune hydrops
- maculopapular rash
- anemia & hepatosplenomegaly
- preterm birth
- neonatal death
What are the diagnostic tests for syphilis?
For Screening
- VDRL
- RPR
For Confirmation
- Enzyme immunoassay (EIA)
- T. Pallidum hemagglutination assay
- fluorescent treponema antibody absorbed test (FTA-abs)
How is syphilis managed during pregnancy?
Parental Penicillin for mother
- start in the hospital to manage Jarish-Herxheimer reaction
- if mother is not treated -> baby should be treated to avoid seizures & developmental delay after birth
What are the characteristics of herpes simplex virus?
- DNA virus
- HSV2 in genital infections
- STD
- high neonatal mortality & morbidity
What is the presentation of HSV in mother?
- painful genital ulcers in vulva, vagina, & cervix
- could cause systemic symptoms -> urinary retention
What are the types of neonatal herpes?
Acquired during labour from contact with lesion
1- Localized -> skin, eye, & mouth
2- Localized to CNS -> encephalitis
3- Disseminated -> high death rate
What are the risk factors that may lead to transmission of HSV to baby?
- mode of delivery -> vaginal
- interventions during labour -> fetal scalp sampling
- if infection was acquired within 6 weeks of delivery
- presence of maternal transplacental antibodies
What are the measures that should be taken to reduce risk of transmission of HSV during pregnancy?
Third Trimester
- acyclovir 400mg 3 times a day
- plan elective C section if EDD is within 6 weeks
First & Second Trimesters
- daily suppressive acyclovir from 36 weeks gestation
- if mother will have vaginal delivery -> intrapartum IV acyclovir
Recurrent Infection
- daily suppressive acyclovir + no need for C section
- inform neonatologist
What are the signs of congenital CMV in ultrasound examination?
- growth restriction
- microcephaly
- ventriculomegaly
- ascites
- hydrops
- intracranial calcifications
How is CMV diagnosed during pregnancy?
- antibodies in seronegative mother
- if suspected by US -> PCR through amniocentesis
How is congenital CMV infection managed?
Termination of pregnancy
What are the characteristics of HIV?
- RNA retrovirus
- transmitted by: sexual intercourse, blood, IV needles
- vertical transmission during 3rd trimester, delivery, or breastfeeding
What are the tests used for screening of HIV?
Screening done at booking
- ELISA
- Western Blot test
If lady is at risk
- screen again at 3rd trimester
If lady presents in labour unbooked
- rapid test
How is HIV transmission risk reduced?
Depends on 3 factors
- maternal plasma viral load, OB factors, infant feeding
Reducing transmission from 25-30% to 2%
1- preconception all ART
2- antepartum ART
3- intrapartum continuation of oral ART + IV zidovudine
4- delivery by C section if high viral load
5- avoid breast feeding
How is the type of delivery decided in patient with HIV?
Planned vaginal
- if 1000 copies/ml or less at 39 weeks
- avoid amniotomy, fetal scalp electrode, instrumental delivery
Planned C section at 38 weeks
- if > 1000 copies/ml
- hepatitis C confection
What are the post delivery interventions that should be done to prevent transmission of HIV?
- early cord clamping
- early bathing of baby
- in PPH -> avoid methylergonovine
- oral ART 4-6 weeks for neonate Zidovudine
- PCR for the baby:
1- at birth
2- at 3 weeks
3- at 6 weeks
4- at 6 months
What are the characteristics of HBV?
- DNA virus
- transmitted via blood, saliva, seminal fluid, IV drug users
- risk of transmission reaches 90% if Hbe Ag is positive as well as HBs Ag
How is transmission of HBV from mother to child reduced?
1- give neonate Ig immediately after delivery to reduce transmission risk by 95%
2- give hepatitis B vaccine at birth, at 1 month, & 6 months
3- Tenofovir for mothers with viral load of 1 000 000 to 100 000 000 & is safe in pregnancy
4- If mother is not immune & is high risk -> HBV vaccine can be given during pregnancy
What are the risk factors for HBV?
- chronic liver disease
- drug abuser
- occupational exposure
- household contact
- HIV & HCV coinfection
- HBV infected partner
