Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
20 Cards in this Set
- Front
- Back
|
Obstetric-perinatal Infections
|
• pregnant women are more susceptible to
some infections and to reactivation of existing infections due to changes in immunity and hormones. • diseases include candidiasis (Candida albicans), influenza, and urinary tract infections (various bacteria including E. coli). |
|
|
Neisseria gonorrhoeae (p. 311-
316) |
• GNC in pairs; positive oxidase test is also
diagnostic • Causes the STI gonorrhea • Can cause purulent conjunctivitis in neonates born to women with infected birth canal – Prevented by 1% silver nitrate, 1% tetracycline, or 0.5% erythromycin creams at birth – Penicillin is used to treat adults but penicillinresistance is increasing |
|
|
Escherichia coli (p. 326-330)
|
• Along with group B strep causes most
CNS infections in children < 1 YO • Most strains that cause meningitis have virulence factor of capsule type K1 – Can be isolated from GIT of both pregnant women and newborns |
|
|
Listeria monocytogenes (p.273-277)
|
• Short, GPR, often described as coccobacilli; sometimes
will stain as gram-negative • Motile at 25 oC, non-motile at 37 oC • Hemolysis () on sheep blood agar • Widely found in environment; survives well in cold • Can come from vegetables or in unpasteurized milk or contact with infected animals and their feces • Can be normal gut flora in humans and passed transplacentally • Unknown virulence factors, but survives inside macrophages |
|
|
Listeria monocytogenes 2
|
• Can lead to abortion, premature delivery or neonatal
pneumonia • Can also cause infections in pregnant women (minor flulike disease) |
|
|
Clostridium botulinum (p. 409-411)
|
• GPR, spore-formers, anaerobic, commonly
found in soil and water • Causes infant botulism (< 100 cases/yr) – Seen as flaccid paralysis (floppy baby syndrome) – Treated with antibacterial drugs and resp support • Bacteria produce neurotoxin from infants’ GIT – C. botulinum is out-competed by normal gut flora in adults, but neonates lack normal flora • Associated with the consumption of spores in honey |
|
|
Listeria monocytogenes 3
|
• Diagnosed by isolation from blood, CSF
• Treatment with ampicillin or penicillin often in combination with gentamicin • Difficult to prevent exposure since it’s so widespread; pregnant women advised not to eat unpasteurized dairy products (milk, cheese, etc.) |
|
|
Other Bacterial Infections (Treponema pallidum)
|
• Treponema pallidum: causes syphilis
– Can be acquired during passage through infected birth canal – Can be prevented by C section |
|
|
Early onset neonatal disease (Listeria monocytogenes)
|
acquired transplacentally
in utero – Abscesses and granulomas form at multiple sites – High mortality rate unless treated quickly |
|
|
Rubella (p. 645-648)
|
• Family: togaviridae (ssRNA, + sense; envolope)
• Exits cell by budding without lysing cells • Identification: isolated in cell culture; Ab test • Infection can cause congenital malformations and mental retardation – can also cause cataracts in newborns – evidenced by low birth weight but severe problems may not be seen until later in childhood (especially mental retardation and deafness) • Virus can be isolated from the infant’s throat or urine; can infect others after birth |
|
|
Late onset neonatal disease (Listeria monocytogenes)
|
usually occurs 2-3 weeks after birth
– Infants can be infected shortly after birth by other babies or by hospital staff – Appears as meningitis or meningoencephalitis with septicemia – Sometimes confused with other causes of neonatal CNS infections |
|
|
Cytomegalovirus (CMV) (p. 558-562)
|
• Family: herpesviridae (dsDNA; envelope); virus attaches
and enters by fusion • Virtually all infections in immunocompetent people are subclinical (no symptoms), however 40% of fetuses are infected if mothers have active infection during pregnancy |
|
|
Other Viruses Causing Disease
|
• HIV: can be transmitted transplacentally
by infected mothers – Much lower incidence if pregnant women are treated • Coxsackie B virus: can cause rare myocardial or pericardial infections in newborns; can also cause meningitis • Hepatitis B: can be passed vertically |
|
|
Toxoplasma gondii (p. 867-869)
|
• Sporozoan (non-motile protozoan); forms cysts;
• Found in cats: oocytes shed in feces after cat eats infected birds – Gets on human hands and into blood stream through ingestion – Can cross placenta and infect fetus in utero • About 35% of healthy adults are seropositive for T. gondii • In infants, can see convulsions, microcephaly (small head/brain), chorioretinitis, mental retardation, defective vision – Signs and symptoms may not show up for several years after birth • Ab test in cord blood to identify • Treatment: spyromycin or pyrimethamine |
|
|
Group B Streptococci (p.247-250)
|
• Streptococcus agalactiae; GPC in chains,
usually -hemolytic on SBA but some strains are non-hemolytic • Diagnosed with culture, antigen tests, and PCR test • Generally treated with penicillin and an aminoglycoside • Pregnant women are advised to be screened and treated if positive • Vaccine testing underway |
|
|
Early-onset disease (Group B Streptococci)
|
within 7 days of birth,
neonates can get meningitis, pneumonia, sepsis – May have lasting consequences (blindness, deafness, retardation) |
|
|
Late-onset disease (Group B Streptococci)
|
after one week, bacteremia
and meningitis |
|
|
In pregnant women (Group B Streptococci)
|
UTI with possible
dissemination – Leads to increased risk of premature delivery – Premature infants more susceptible to group B strep |
|
|
Rubella 2
|
• Transmission: respiratory droplets
• No lesion at site of entry but viremia enables spread to eye and other sites • No treatment but live, attenuated vaccine (MMR: mumps, measles, rubella) • Uncommon currently due to enforcement of immunization |
|
|
CMV 2
|
• Can cause retinitis, mental retardation, hearing defects,
anemia • Generally persists for long times in body, often in latent form in neurons, monocytes, T and B cells, body secretions; can reactivate • Identification: Ab’s in cord blood • Newborns most often infected; more common in poor and in infants in day care • Vaccines are being developed |
