Infectología

Question 1

Syphilis is caused by

Answer 1

the spirochete Treponema pallidum

Question 2

genital ulcers caused by syphilis are a major cofactor for bidirectional transmission of

Answer 2

human immunodeficiency virus

Question 3

T pallidum subspecies are

Answer 3

pallidum, pertenue and endemicum cause venereal syphilis, yaws, and endemic syphilis, respectively

Question 4

Treponema carateum causes

Answer 4

pinta

Question 5

T pallidum must acquire essentially all nutrients from its obligate human host and generates

Answer 5

ATP primarily by glycolisis

Question 6

T pallidum cannot be cultivated in vitro, diagnosis depends on

Answer 6

direct demonstration of treponemes in clinical samples or reactivity in serologic tests, or both

Question 7

Are useful for detecting treponemes in exudative lesions, principally chancres

Answer 7

Darkfield microscopy and Polymerase Chain Reaction

Question 8

Serodiagnosis of syphilis involves 2 types of serologic tests

Answer 8

Nontreponemal and treponemal. the former detects antibodies against lipoidal antiagents (primarily cardiolipin) whereas the latter detects antibodies against T pallidum proteins

Question 9

Therapy of T pallidum

Answer 9

Penicillin G is the preferred therapy for all stages. 2.4 Million units of IM Benzathine Penicillin

Question 10

Alternative for nonpregnant, penicillin -allergic patients for therapy of T pallidum

Answer 10

Doxycycline

Question 11

Penicillin allergic pregnant females should be

Answer 11

desensitized

Question 12

Incubation period

Answer 12

Lating up to 90 days and an average of 3 weeks

Question 13

primary stage is characterized by

Answer 13

An ulcer, the chancre, at the site of inoculation, often associated with regional lymphadenopathy

Question 14

diseminated stage (Secondary syphilis) characterized by

Answer 14

skin rash, mucocutaneous lesions and lymphadenopathy capable of involving any organ system

Question 15

one third of untreated patients, a recrudescent, tertiary stage involving

Answer 15

the ascending aorta (cardiovascular syphilis) or the CNS (neurosyphilis) or causing necrotizing granulomatous lesions (gumma) in almost every organ

Question 16

T pallidum is considered the most virulent because it is only subspecies capable of regularly breaching both

Answer 16

The blood brain and maternal fetal barriers

Question 17

measures of T pallidum

Answer 17

.2 um in diameter, has tapering ends, and ranges in length from 6 to 20 um

Question 18

high resolution time-lapse microscopy has confirmed earlier reports that, like Lyme disease, T pallidum has

Answer 18

Flat wave morphology

Question 19

grampositive or negative

Answer 19

Gramnegative

Question 20

The syphilis spirochete lacks erroneous from a phylogenetic stand point, lacks the fenes for synthesis of

Answer 20

lypopolysaccharide (LPS)

the hallmark glycolipid of gramnegative organisms, and does not take up Gram stain

Question 21

In gram - bacteria, the peptidoglycan resides directly beneath the outer membrane in T pallodum, the murein layer is found

Answer 21

Midway in the periplasmic space, beneath the flagellar filaments

Question 22

The highest incidence of syphilis in the US is evidence from

Answer 22

poor, underserved minority communities in southern states from Maryland to Florida to eastern Texas

Question 23

untreated pregnant women will experience adverse outcomes in their pregnancies. Including:

Answer 23

early fetal loss (20-28 w of gestation) and stillbirth (>28 weeks gestation), neonatal death, low birth weight infants and infants with clinical evidence of infection

Question 24

individuals with venereal syphilis are most infectious during

Answer 24

the primary and secondary stages when moist, mucocutaneous lesions are present

Question 25

Micrographs showing that spirochetes are abundant within the

Answer 25

epidermis and superficial layers of the dermis in secondary syphilitic lesions

Question 26

the agents of yaws, pinta and endemic syphilis are transmitted by

Answer 26

nonsexual contact with open lesions, usually during childhood

Question 27

In primary syphilis, progression of the vasculopathic changes to frank endarteritis obliterans causes

Answer 27

Tissue necrosis, ultimately giving rise to a genital ulcer, the chancre

Question 28

In secondary syphilis skin lesions, include

Answer 28

a wide variety of histologic patterns, including granuloma during later phases

Question 29

The gumma of terciary syphilis histologically is composed of a dense infiltrate of

Answer 29

lymphocytes, plasma cells, epithelioid cells and multinucleated giant cells surrounding a caseous necrotic core; fibroblasts and fibrosis also may present

Question 30

Endarteritis and perivascular inflammation help to distinguish syphilitic gummas from those caused by

Answer 30

Tuberculosis

Question 31

obliterative endarteritis involving the

Answer 31

vasa vasorum, the nutrient vessles of the aortic adventitia, is the key pathologic lesion in cv syphilis. The ascending aorta and arch are most frequently affected

Question 32

In general, there is diffuse thickening and lymphocytic infiltration of the meninges with 2 kinds of arteritis

Answer 32

Heubner endarteritis, affecting large and medium sized arteries, crescentic collagenous thickening of the intima
Nissl Alzheimer endarteritis of small vessels, proliferation of endothelial and adventitial cells

Question 33

In paresis, diffuse meningovascular inflammatory changes are associated with striking, progressive

Answer 33

loss of cerebral cortical neurons, resulting in gross cerebral atrophy (greatest in the frontal and temporal lobes), and proliferation of astrocytes and glial cells

Question 34

Microglial cells are hypertrophied and elongated and often contain abundant

Answer 34

Iron

Question 35

Tabes dorsalis is characterized by

Answer 35

demyelination of dorsal root ganglia with secondary wallerian degeneration of the posterior columns of the spinal cord

Question 36

syphilis commences clinically when spirochetes replicating at the site of inoculation induce local inflammatory response sufficient to generate a

Answer 36

macule, which over the course of 1 to 2 weeks becomes papular and then ulcerates, producing the defining lesion of primary syphilis

Question 37

what is the lesion of the primary syphilis

Answer 37

the chancre

smooth, clean and without exudate; the borders are raised and have a cartilaginous consistency

Question 38

principal difference between the genital ulcers caused by Haemophilus ducreyi (chancoid) and herpes simplex virus, compared with the chancre of T pallidum

Answer 38

the chancre of T pallidum is painless and non tender on examination. Spirochetal infiltration of cutaneous sensory nerves may explain this phenomenon

Question 39

Chancres in the anal area may be exquisitely

Answer 39

painful and mistaken for anal fissures

Question 40

primary syphilis must be differentiated principally from

Answer 40

herpes simplex virus infections, chancroid and traumatic suprainfected genital lesions