Parasites VI

Question 1

What is the TORCH complex?

Answer 1

classic organisms that can result in severe disease is transmitted mother to fetus
toxoplasma, treponema pallidum, rubella, cytomegalovirus, and herpes simplex 1 and 2.

Question 2

What are some features of toxoplasmosis?

Answer 2

obligate intracellular protozoa

two forms: motiale tachyzoites (rapidly dividing) or bradyzoites in tissue cysts (slowly dividing)

Question 3

What is the definitive host of toxoplasmosis?

Answer 3

cats

Question 4

What happens following toxoplasmosis oocyte ingestion?

Answer 4

formation of tissue cysts filled with bradyzoites

Question 5

What are the sings and symptoms of postnatal toxoplasmosis infection?

Answer 5

adults: typically asymptomatic, though can be a problem for the immunocompromised (brain abscesses, ecephalitis, disseminated disease)
ocular problems

Question 6

What are the signs and symptoms of congenital toxoplasmosis infection?

Answer 6

chorioretinitis, cerebral cacifications, and hydrocephalus (get all three)
other signs: paralysis of upgaze (setting sun sign), convulsions, retinal scars, rash, hepatosplenomegaly, low birthweight, hearing loss
spontaneous abortion

Question 7

How do you diagnose toxoplasmosis infection?

Answer 7

PCR analysis of amniotic fluid

post-birth: comparison of materal and fetal IgG reactivity or immunoabsorbant agglutination

Question 8

treponema pallidum: general features

Answer 8

spirochete
poorly staining
vertiacl transmission in untreated mothers nearly 100%

Question 9

signs/symptoms of postnatal tremonema pallidum infection

Answer 9

primary syphilis: chancre- painless
secondary- maculopapular rash on palms/soles
tertiary- CNS involvement, gummas, CV involvement

Question 10

signs and symptoms of congential treponema pallidum infection?

Answer 10

fetal/perinatal death common
cuvred tibia, saddle nose deformities, hutchinson teeth (notched incisors), mulberry molars, olympia brow, painful jts
juvenile paresis, sensorineural deafness
potental for blindness, rash, condyloma lata (wart like lesions)
snuffling, hemolytic anemia

Question 11

How do you diagnose treponema pallidum infection?

Answer 11

VDRL and RPR- false positives, but become negative when infection clears
or, TPHA (agglutination assay), FTA-ABS, and TPPA- more specific but remain positive with treatment

Question 12

Rubella: general features

Answer 12

enveloped ssRNA
togavirus
very low incidence due to immunization
transmitted by respiratory droplets

Question 13

rubella signs and symptoms of postnatal infection

Answer 13

non-specific- low grade fever, lymapdenopathy, headache, fatigue, coalescing rash on the face/neck that migrates downward

Question 14

What are the signs and symptoms of congenital rubella?

Answer 14

almost all organ systems can be affected. triad: congenital heard disease, cataracts, and deafness. blueberry muffin rash

Question 15

rubella diagnosis

Answer 15

IgM assay or PCR on kid

monitor mom for seroconversion if she is exposed

Question 16

cytomegalovirus general features

Answer 16

enveloped dsDNA, herpes family

high prevalence: direct contact transmission

Question 17

signs and symptoms of congenital CMV infection

Answer 17

;greatest risk if mom has primary infection during pregnancy
can cause microcephaly, intercranial cacifications, chorioretinitis, and sensorineural hearing loss.
some get inclusion disease- jaundice, hepatomegaly, coagulopathy, prematurity, growth restriction

Question 18

how do you diagnose CMV infection?

Answer 18

viral culture or PCR

Question 19

HSV 1 and 2: general features

Answer 19

enveloped dsDNA virus

common

Question 20

What are the signs and symptoms of HSV postnatal infection/

Answer 20

painful vesicular rash. most severe with primary infection. also cause dysuria, headache, and fever

Question 21

Signs and symptoms of neonatal HSV infection

Answer 21

usually transmitted during vaginal birth process (transplacental transmission very rare and usually leads to spontaneous abortion, premature deliver, intrauterine growth restriction)
can begin as vescicular lesions and progress to encephalitis and or disseminated disease. mortality of disseminated disease 90% if untreated

Question 22

How do you diagnose HSV?

Answer 22

viral culture is gold standard
PCRalso used
start acyclovir based on clinical suspicion because disease is serious- 90% mortality to baby if untreated.