Infectious diseases Flashcards
Measles
RNA paromyxovirus
Rash from behind ears
Koplik spot
Warthin finkeldy giant multinucleate cells
pneumonia, otitis media, keratitis, encephaitis
subacute sclerosing panencephalitis
at risk if vit A defic - blindness
Mumps
RNA paromyxovirus
parotid, orchitis, pancreatitis, asceptic meningitis
acute transient viruses
measles
mumps
polio - 1% symptomatic
west nile virus
viral haemorrhagic fever
alpha latent viruses
Infect epithelial cells, latent in neurons
HSV1, HSV2, VZV
Beta latent viruses
lymphotropic, invade variety cell types
CMV, HHV6 (roseala infantum), HHV7
Gamma latent viruses
EBV, HHV8 (kaposi assoc)
latent in lymphoid cells
CMV cells
owls eye
large cells, large inculsion bodies surrounded by halo
pleomorphic
EBV
atypical cytotoxic T cells
mono
reed sternberg like cells
assoc B cell neoplasm and burkitts
HPV
DNA virus
infects squamous epithelial
6&11 low risk
16&18 high
proteins E6+7 supress p53
Staph aureus virulence factors
surface protein aderence host cells
enzymes e.g. lipase S degrades lipids
toxins - alph beta, superantigens(TSS)
proteins causing AB resistance
Beta haemolytic trep
group A - pyogenes - pharyngitis, scarlet fever, erysipelas, impetigo, rheumatic fever, toxic shock, neck fasc, GN
group B - agalacticae - female genital tract, chorioamnionitis, neonatal sepsis
Alpha haemolytic strep
pneumoniae - CAP, meningitis
viridans - mutans group caries and endocarditis
Strep virulence factors
GBS + pneum - encapsulated
Pneum - pneumolyin destroys cell membranes
pyogenes - m protein inhibits complement and destroys cell membranes, exotoxin causing fever and rash (scarlet)
Encapsulated bacteria
Group B Streptococcus (agalacticae), Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Escherichia coli, Salmonella species, Klebsiella, and Pseudomonas aeruginosa.
Yes some killer bacteria have pretty nice capsules
Diphtheria
gram +ve rod
grey exudate over pharynx or skin
membrane off -> bleeding risk asphyxiation
upper airway infections –> heart and nerves
AB toxin
Listeriosis
INTRACELLULAR gram +ve rod facultative anaerobe
food bourne
still birth and neonatal sepsis
NK cells early, T cells late
gram +ve intracellular bacilli in CSF
Intracellular bacteia
Legionella, Listeria, and Mycobacterium.
Obligate - mycoplasma, rickettsia
Anthrax
gram +ve spore forming rod, facultative anaerobe
cutaneous - fine
resp - death
GI - 40% mort
AB toxin
Neisseria
gram -ve aerobic diplococci ENCAPSULATED
meningitides - lots of serotypes, 10% mort
gonorrhoea - 2nd most common STI, neonatal conjunctivitis
invade non ciliated epithelia CD46
has OPA protein
Pertussis
gram -ve aerobic coccobacillus
dx PCR
invades ciliated epithelial cells
AB toxin
+ toxin paralyses cilia
Pseudomonas
opportunistic gram-ve aerobic rod
sever in CF, burns, neutropenic
AB toxin
phospholipase C lyses RBCs and surfactant
Elastase degrades ECM
necrotising inflamation
Infections caused by pseudomonas
HAP
keratitis (contact lenses)
swimmers otitis externa
hot tub folliculitis
necrotic lesions in burns
endocarditis IVDU
osteomyelitis IVDU
catheter associated UTI
Mantoux test false
-ve - overwhelming viral infection, other viral, sarcoid, malnutritino, immunosupression
+ve - vaccination, atypical mycobacterium
TB interleukins
dendritic -> IL12 -> Th1 -> TNFy