Microbiology Flashcards
1
Q
reportable condition
A
every case of disease must be reported at the state level
2
Q
notifiable condition
A
data must be forwarded to the CDC→morbidity and mortality weekly report and annual report
3
Q
SARS 2003
A
- new highly contagious pneumonia
- started in China
- animal (civet) coronavirus
- 8,000 cases, 800 deaths
4
Q
Swine Flu 2009
A
- H1N1 virus
- started in Mexico
- triple recombination between human and animal influenza virus
- not nearly as bad as 1918 or 1968 pandemics
- 250,000 deaths
5
Q
MERS 2013-2014
A
- started in Saudi Arabia
- coronavirus endemic to camels, appeared in humans in 2011
- 100 deaths
6
Q
Ebola 2014-2015
A
- sudden resurgence of mutated bat virus
- hemorrhagic fever
- 27,000 cases, 11,000 deaths
7
Q
general trends of infectious disease
A
- continuing reductions of vaccine-preventable infections
- gradual increase in pertussis, legionella, and syphilis
- occasional outbreaks of previously known conditions and occasional emergence of previously unknown microorganism
8
Q
N. gonorrhoeae
A
- gram- diplococci (kidney bean shaped); facultative aerobe; oxidase+; catalase+
- women usually asymptomatic
- neonates must be protected by prophylatic eye ointement (prevents opthalmia and blindness)
- virulence factors: IgA proteases, pili, LOS, porins, Opa
- testing: NAAT preferred but culture may be required for sensitivity testing
- use thayer-martin if normal flora, use chocolate if normally sterile
- treatment: ceftriaxone
9
Q
C. trachomatis
A
- small obligate intracellular bacterium
- elementary bodies (tiny infectious rugged cells) “unpack” into reticulate bodies after infection, form inclusions and replicate
- 18 serovars
- testing: NAAT preferred but cuture works well (does not gram stain though)
- test for coincidence chlamydia in all STD patients
- treatment: doxycycline (erythromycin for pregnant/ pediatric/ allergic patients)
10
Q
what are the 18 serovars of c. trachomatis?
A
- A, B, Ba, C: blinding trachoma (leading cause of preventable blindness in Africa)
- L1-L3: lymphogranuloma venereum ( small, painless ulcer→swollen painful lymph nodes)
- D-K: genital tract infection (MC bacterial STD in US; men often asymptomatic; possibility for verticle transmission)
- pneumonia
11
Q
pediculosis
A
- head lice: school kids, itchy behind ears
- body lice: homeless, itchy at night
-
pubic lice (crabs): promiscuous individuals, itchy groin
- perform full STD panel as well
- visual diagnosis
- treatment: nit combing and hot laundering
12
Q
spirochetes
A
- spiral shaped with axial filament→corkscrew motion
- too small to see by microscopy, can’t be cultured, and poorly visible on gram stain (gram- envelope) so use darkfield
13
Q
T. pallidum
A
- extremely infectious obligate pathogen (not intracellular)
- invade lymphatics and blood stream immediately and virulence is based on immune evasion→low inflammation and humans rise mostly-usely antibodies (reagin)
- labs: serology for reagin (VDRL, RPR) is best test for disease-in-progress, confirm exposure with tests for treponeme-specific antibodies
- treatment: single injection of penicillin G
- potential for Jarisch-Herxheimer reaction
14
Q
what are the stages of syphilis?
A
- primary: 3-6 weeks→ painless chancre at site of infection
- secondary: 4-10 weeks→body-wide rashes, condylomata lata, patchy alopecia
- latent: organism remains although secondary symptoms resolve
-
tertiary: 3-10 years later→ gummas, neurosyphilis (meningitis, tabes dorsalis, general paresis)
- check for argyll-robertson pupil
- cardiac involvement
- congenital syphilis: kills 50% fetus/newborn, survivors are infected→ bone deformities, interstitial keratitis
15
Q
Yaws and Pinta
A
- both are treponema infections (like syphilis) but are transmitted through direct contact
- both will give +VDRL and +RPR
- yaws: primarily a dermatologic manifestation
- pinta: hypo and hyperpigmented skin plaques
