Pregnancy Infections

jmanderson's version from 2015-12-12 16:49

Pregnancy Infection Routes and most common organisms


Question Answer
Route of infecting the baby In uterotransplacental
Routes of infecting the baby During child birthAscending infection/colonizing bacteria gets on/in baby during delivery
Routes of infecting the baby Neonatalchildhood diseases
Gestational Infections routeInfections disseminate from mother in utero
Gestational infections organismstoxoplasma, Rubella virus, HCMV, Treponema pallidum, HIV, listeria monocytogens, “Others” (Hep B, VZV, mycobacterium leprae, parvovirus B19)
Most common infections assoc. w/ congenital anomaliesTORCH infections -> Toxoplasmosis, Other (syphilis, varicella-zoster, parvovirus B19), Rubella, Cytomegalovirus (CMV), and Herpes
Perinatal/Ascending Infections colonization bugsListeria (Sepsis->Death), GBS, Mycoplasma Hominis
MOST COMMON cause of conjunctivitisChlamydia t
Neonatal infections bugsGBS/GNB, HSV, Staph, C. tetani
Mastitis bug and Sxmost commonly due to staph a => breast pain, inflammation, fever/chills
Can cause septicemia, pneumonia, or meningitis due to cross infection in nursery-GBS/GNB
Attending adults with whitlow (lesion on finger) or cold soresHSV infection
Neonate nose colonized during this period (1-2 weeks after birth) and can enter nipple during feeding causing breast abscess-Staphlococcal infections
Poor hygiene/contaminated instruments causes umbilical stump to be infectedNEONATAL TETANUS (C. tetani)

morphology and transmission of organisms


Question Answer
Flagellated protozoa -- Replicates Extracellularly -> Sporozoite oocysts ingested (released from Cat/Mice/Birds) -> tachyzoites disseminate to tissues -> bradyzoites infect tissues and form cystsToxoplasma gondii
Enveloped + ssRNA virus -- Replicates in cytoplasm -> directly translated by host ribosomesRubella virus
Enveloped dsDNA virus -- Replicates in nucleusHCMV
Gram-negative spirilla -- Replicates extracellularlyTreponema pallidum
Enveloped ssRNA (retrovirus) -- Replicates in the nucleusHIV
Gram-positive bacilli -- Motile and Beta-hemolytic -- Replicates intracellularListeria monocytogens
Enveloped partial dsDNA virus -- 90% of infants are infected by carrier mothers -- Dx by Liver function test and anti-viral-AbHep B
Enveloped dsDNA virus -- Child will present with skin lesion/scars; limb hypoplasia; chorioretinitis -- Dx with PCR for DNAVaricella-zoster virus
Acid fast non-motile bacilli -- Chronic nasal discharge and Characteristic NODULAR LESIONS ON EARLOBES -- Dx with acid-fast staining of skin biopsyMycobacterium leprae
Naked ssDNA virus -- Presents as hydrops fetalis (fluid accumulation in 2 body areas), Hepatitis, Severe anemia, inflammation of heart, cardiac failure -- Dx with PCR for DNAParvovirus B19
Enveloped dsDNA virus -- Replicates in nucleus -- Clinical features: Asymptomatically shedding during birth via herpetic lesions -> if Positive for this organims, get C-sectionHSV

clinical features and congenital anomalies


Question Answer
Clinical features: Mother usually asymptomatic but may have flu-like illness and lymphadenopathy (usually at site of transmission) -- Congenital Abnormalities: No signs at birth but appears within few years, Initially see Chorioretinits (90%), microcephaly, hepatosplenomegaly, jaundice -- Eventually see hydrocephaly, mental deficiency, vision lossToxoplasma
Clinical features: fever, headaches, rash (on face first THEN trunk), Pink eye, Arthralgia -- Congenital Abnormalities: See within <3 months -> Mental deficiency, hearing loss, balance/motor dysfunction, cataracts, !!!PDA!!! (see mixing of blood and Increased BP)Rubella virus
Clinical features: Flu-like illness with fever, pharyngitis, Purpura, cervical lymphadenopathy -- Congenital Abnormalities: 40% of fetus will be exposed to virus, See mental deficiency, microcephaly, chorioretinitis, jaundice, hepatosplenomegalyHCMV
Clinical features: Chancre if primary; Rash/fever/transmission to fetus if Secondary -- If asymptomatic -> do routine screening with anti-cardiolipin -- Congenital Abnormalities: See around >4 months gestation, See Rhinitis (IMMEDIATELY), Saddle-shaped nose; skin rash (blistered lesions); Mucosal lesions (patches); hepatosplenomegaly; lymphadenopathyTreponema pallidum
Clinical features: mother is (+) for this virus (Low CD4 count; rupture membranes) -- Congenital Abnormalities: Baby will have recurrent bacterial infections or unusual infections, Oral candidiasis, Herpesvirus infections, Growth failure (w/o cause), developmental delay, oral ulcers, cardiomyopathy, hepatosplenomegalyHIV
Clinical features: Some are asymptomatic but can be flu like illness -- Congenital Abnormalities: Induce premature birth, Causes septicemia (chills, high fever, rapid pulse), Pneumonia, abscesses/granulomas in multiple organsListeria monocytogens
Clinical features: Asymptomatically shedding during birth via herpetic lesions -> if Positive for this virus, get C-section -- Congenital Abnormalities: 25% have skin rashes/lesions, 25% are disseminated infections with hepatic/pulmonary/neruo, 30-40% are CNS infections -> ENCEPHALITIS (!!high mortality!!)HSV

transmission and lab testing


Question Answer
Transmitted by ingestion of cysts in undercooked meats/contaminated water -- Replicates in mucosa -> disseminates and cysts in neural/muscle tissue -- One of the TORCH bugs that cross placenta to infect fetus (30-50% infection rate from infected mother)Toxoplasma
Toxoplasma Lab testingELISA to detect anti-toxoplasma IgM/IgG -- IgM + = recent infection (tachyzoites); IgG + = infected for at least 6 months (bradyzoites) -- If seropositive for toxoplasmosis -> check amnio/fetal blood via PCR and ELISA
Transmitted via INHALATION of contaminated respiratory droplets, Replication in URT (nasopharynx) epithelial cells and cervical lymph nodes, Viremia spreads via lymph to skin/organs (CNS) -- One of the TORCH bugs that cross placenta (70% infection rate if mother infected during first trimester)Rubella virus
Rubella virus Lab testingPCR to detect in mother/baby via nasopharyngeal swab or CSF/blood, ELISA Detection in baby for rubella specific IgM (via baby) or IgG (Declining IgG are maternal infection Abs declining; if no decline then baby is infected)
Transmitted via Direct contact of body fluids (LEADING CAUSE of viral birth defects) -- Replication in epithelial cells at exposure site -> Viremia to local nerves (can be latent infection) -- One of the TORCH bugs that cross placenta (50% of mothers will shed virus while only 1% is fetal acquisition)HCMV
HCMV Lab testingPCR detection, ELISA IgM detection in fetal blood (+ means infected), Microscopy -> stain for inclusion body
Transmitted via direct contact with active lesions -- Replication at site of inoculation -> Viremia via blood -- Transplacental infection in 70-100% untreated mothers (vs 1% in treated)Treponema pallidum
Treponema pallidum Lab testingMicroscopy to look for spirochetes, Western blot detection of anti-treponema IgM from fetus (newborn infection), VDRL/RPR detection of non-treponemal antibodies or FTA-ABS/TP-MHA testing on mother, If mother is treated near birth -> check baby via long bone radiography and Lumbar Puncture to check CSF
Transmitted via Direct contact -- Transmitted to baby in utero, perinatal, or milk (MOST TRANSMISSIONS OCCUR DUIRNG VAGINAL DILVER OR BREAST FEEDING)HIV
C-sections are encouraged in mothers (+) for this virus -- 25% transplacental acquisition if untreated -- Replication: infects cell by binding to CCR5/CXCR4 -> fusion and uncoating -> reverse transcription and integration into host DNA -> replication produces more viral RNA (provirus) -> packaged and buds off -- Viremia via CD4+ and CCR5+ immune cells (then CXCR 4) through lymphatics, organs, bones, and CNS (latency)HIV
HIV Lab testingELISA screening for anti-HIV Ab of mother, If mother is seropositive -> PCR infant blood (most sensitive in 2 weeks-2 months), Also ELISA/western blot for Ab but mother's IgG from breast milk may give false-positive (but can be confirmation after ~1 year)
Transmitted via Ingestion of contaminated food (processed meats, milk, cheese, veggies) -- Replication at site of inoculation (enterocytes, M-cells, phagocytes, hepatocytes, etc) -> bacteremia to liver/spleen via MacrophagesListeria monocytogens
Listeria monocytogens Lab testingCulture -> grows well on PALCAM agar @1-45 C and high salt (refrigeration/preservation doesn’t hinder growth); CATALASE POSITIVE; BETA-HOMLYSIS
Transmitted via direct contact -- Replication in epithelial cells and can lie latent in local nerves -- TORCH bug that can be transmitted to newborn with contact of secretions during birthHSV
HSV Lab testingculture or PCR