Infectious disease Flashcards
what disease are sewage workers at risk of?
leptospirosis
what diseases are IVDU at risk of?
endocarditis
hep B/C, HIV
soft tissue infection
bugs most likely caught from restaurant
salmonella
campylobacter
unusual organism infections in HIv
TB PCP toxoplasma MAI [Mycobacterium avium complex] cryptococcus candidiasis
23 yr old female, 12 hr Hx of rapid onset severe headache, vomiting, neck stiffness, photophobia, fever,. Now drowsy, GCS 13/15, rash developing on abdo.
Likely diagnosis?
MENINGITIS WITH meningococcal septicemia
GP phones you in AMU about 23 yr old female, 12 hr Hx of rapid onset severe headache, vomiting, neck stiffness, photophobia, fever,. Now drowsy, GCS 13/15, rash developing on abdo.
Advice to GP?
give IM benzyl pneicillin
admit immediatelty
GP phones you in AMU about 23 yr old female, 12 hr Hx of rapid onset severe headache, vomiting, neck stiffness, photophobia, fever,. Now drowsy, GCS 13/15, rash developing on abdo.
Advice to GP if patient has penicillin allergy?
NO ben pen
admit
what is the triad of meningism?
headache, neck stiffness, photophobia
23 yr old female, 12 hr Hx of rapid onset severe headache, vomiting, neck stiffness, photophobia, fever,. Now drowsy, GCS 13/15, rash on abdo + limbs.
Temp 38.7, HR 98, BP 100/60.
Immediate Ix and Tx?
ABCDE!
cultures, ABG, CRP, FBC, clotting, U+E, UO [catheter]
cefotax/ceftriax
fluid resus [/inotropes/vasopressors]
O2 if sats require
[dex]
what rash would you expect to see in meningococcal septicaemia?
non-blanching petechial/purpuric rash
23 yr old female, 12 hr Hx of rapid onset severe headache, vomiting, neck stiffness, photophobia, fever,. Now drowsy, GCS 13/15, rash on abdo + limbs.
if the patient has been alert and orientated, with headache/fever/neck stiffness + NO RASH. what other Ix would you want to do?
LP
contraindications for LP
bleeding disorder
cardioresp compromise
local infection
^ICP [severe headache, reduced LOC, falling pulse, rising BP, vomiting, focal neurology, papilloedema
during or after an LP, what do you test the CSF for
pressure, appearance
glucose, protein, gram stain
2 organisms likely to cause meningitis in adults
neiss meningitidis
strep pneum
treatment of viral meningitis
self-limiting
what institution need to be informed of anyone diagnosed with a bacterial meningitis + what treatment might be advised for close contacts?
proper officer / consultant for communicable disease control [works for public health england]
ciprofloxacin [or rifampicin]
Ix in suspected malaria? What would you specifically do out of hours?
FBC [anaemia, thrombocytopenic] thick and thin films U+E, urine output [AKI] clotting [DIC] glucose [hypo] ABG [acidosis] urinalysis [haemoglobinuria] LFT, cultures
OOH: rapid diagnostic test
24 yr old, 1 day after returning from Kenya. Fever, headache, myalgia. Was “fully vaccinated” and took proguanil + chloroquine. Temp 39.5.
differentials
MALARIA typhoid dengue viral haemorrhagic fever diptheria yellow fever ebola etc!
24 yr old, 1 day after returning from Kenya. Fever, headache, myalgia. Was “fully vaccinated” and took proguanil + chloroquine. Temp 39.5.
Haematologist reports she has plasmodium falciparum with a parasitaemia of 3%.
What do you do now?
artesunate IV then artemether-lumefantrine PO
24 yr old, 1 day after returning from Kenya. Fever, headache, myalgia. Was “fully vaccinated” and took proguanil + chloroquine. Temp 39.5.
Haematologist reports she has plasmodium falciparum with a parasitaemia of 3%.
how would you monitor her response to treatment?
daily parasite count
what are the complications of severe malaria
pulm oedema/ARDS AKI impaired conscious/seizure shock hypoglycaemia anaemia spontaneous bleed/ DIC acidosis haemoglobinuria`
how many negative films do you need to exclude malaria?
3
what anti-malaria drugs can be used for prophylaxis?
chloroquine, proguanil, doxycycline, mefloquine, atorvaquone. e.g. malarone = atorvaquone-proguanil
AMU - 35 yr old male. Increasing SOB 10/7.
fevers, rigors, headache, myalgia 7/7.
Cough, dirty green sputum 7/7.
GP gave amoxi, no effect.
Pt returned from holiday in tenerife 10/7 ago.
HR 110, BP 110/80, RR 30, SpO2 92% OA, temp 38.5, signs of left lower lobe consolidation.
Diagnoiss~?
pneumonia
e.g. legionella
AMU - 35 yr old male. Increasing SOB 10/7.
fevers, rigors, headache, myalgia 7/7.
Cough, dirty green sputum 7/7.
GP gave amoxi, no effect.
Pt returned from holiday in tenerife 10/7 ago.
HR 110, BP 110/80, RR 30, SpO2 92% OA, temp 38.5, signs of left lower lobe consolidation.
Ix?
CXR FBC U+E LFT cultures sputum culture CRP atypical serology [legionella, mycoplasma, chlamydia]
name 5 markers of clinical severity ass. w/ increased risk of death in CAP
CURB-65
confusion urea >7 RR>30 BP <90/60 >65
commonest cause of CAP
strep pneum
main complicaitons of pneumonia
abscess
empyema
complications of legionaires
multiorgan failure needing ITU, e.g. AKI
ABx for legionellla pneumonia
IV clarith [+ rifampicin if ^severity]
whats the risk of using non-prokinetic antiemetics in D+V
toxic megacolon/ perf
50 yr old fishmonger, 3 day Hx of ^^^D+V, no blood or mucous.
Ate shellfish + turkey day before, no travel Hx.
differentials including likely palthogens
bacterial/ viral [norovirus] gastroenteritis
[IBD/IBS]
campylobacter, salmonella [mild can present without blood], noro
50 yr old fishmonger, 3 day Hx of ^^^D+V, no blood or mucous.
Ate shellfish + turkey day before, no travel Hx.
Investigations?
stool culture
blood culture
FBC
U+E
50 yr old fishmonger, 3 day Hx of ^^^D+V, no blood or mucous.
Ate shellfish + turkey at restaurant day before, no travel Hx.
Mx?
oral rehydration salts
encourage oral fluids, may need IV
[prokinetic antiemetics - metoclop, domperidone]
50 yr old fishmonger, 3 day Hx of ^^^D+V, no blood or mucous.
Ate shellfish + turkey at restaurant day before, no travel Hx.
public heath issues?
tell CCDC
stop work as fishmonger to prevent spread
CCDC will investigate restaurant
which bugs cause inflammation of the termninal large bowel, causing bloody mucous-y diarrhoea [dysentery], tenesmus.
shigella
salmonella
20 yr old plumber admitted with 3 day history of painful swelling of left leg and groin.
Generally unwell, fever, rigors.
Insulin-dependent DM.
Temp 38, pulse 108, BP 120/80.
Marked area of swelling and erythema over left shin spreading twards ankle + knee - warm/tender.
Also tender palpable lymph nodes in groin. No breaks in skin.
high WCC, CRP and BM.
Differntials?
cellulitis
DVT
charcot joint
20 yr old plumber admitted with 3 day history of painful swelling of left leg and groin.
Generally unwell, fever, rigors.
Insulin-dependent DM.
Temp 38, pulse 108, BP 120/80.
Marked area of swelling and erythema over left shin spreading twards ankle + knee - warm/tender.
Also tender palpable lymph nodes in groin. No breaks in skin.
high WCC, CRP and BM.
Investiagtions?
rule out DVT: doppler US
cultures
D-dimer would be high in either cellulitis or DVT due to inflamm
most likely pathogens for cellulitis
staph aureus
strep pyogenes [gram +ve group A beta haemolytic]
Mx of cellultitis
IV fluclox
20 yr old, 3 day history of painful swelling of left leg and groin. Unwell, fever, rigors.
Insulin-dependent DM.
Temp 38, pulse 108, BP 120/80.
Marked area of swelling and erythema over left shin spreading twards ankle + knee - warm/tender.
Also tender palpable lymph nodes in groin. No breaks in skin.
high WCC, CRP and BM.
You diagnose cellulitis. What other potentially dangerous condition should be considered?
necrotising fasciitis
what do you feel on examining leg in necrotising fasciitis
crepitus [gas in tissue]
clues + exam/Ix that a cellulitis is nec fasc?
disproportionate pain
systemically unwell
sweep test by plastic surgeon
bact in nec fasc
group A strep
or polymicrobial
Mx of nec fasc
debridement
+/- amputation
ABx - eg. clindamycin + benzylpenicillin
24 yr old HIV +ve man. 12 day Hx of ^SOB + non-productive cough. CD4 on diagnosis 3 yrs ago was 300, no ART since.
O/E: febrile. sat 87%, falling to 72% on exertion. Examination unremarkable.
CXR - bilateral fine peri-hilar infiltrates [bat wings].
What is the likely diagnosis?
PCP [Pneumocystis pneumonia]
what CD4 count is normal? and what count = AIDS?
what count do you need to have to get PCP?
> 500 is normal
<200 = AIDS
<200 to get PCP
Pt has PCP. List other important HIV associated lung conditions
strep pneumoniae still most common!
cryptococcus, TB, CMV, pseudomonas, lung KS
24 yr old HIV +ve man. 12 day Hx of ^SOB + non-productive cough. CD4 on diagnosis 3 yrs ago was 300, no ART since.
O/E: febrile. sats 87%, falling to 72% on exertion.
CXR - bilateral fine peri-hilar infiltrates [bat wings].
what Ix would you do to confirm a diagnosis of PCP?
bronchial lavage + PCR [cant get PCP from sputum]
re-do CD4
treatment for PCP?
co-trimoxazole [septrin]
+pred
in an HIV +ve patient with PCP and not on ART yet, do you give both ABx and ART together? or which would you start first?
TREAT INFECTIONS 1ST!
otherwise they get IRIS [Immune reconstitution inflammatory syndrome]
What prophylaxis is used to prevent infections in HIV patients?
pneumococcal, HepB + flu vaccines
co-trimoxazole [septrin] if CD4 <200 [AIDS] to prevent PCP + toxoplasma
azithromycin at CD4<50 for MAI
briefly describe a suitable ART regimen to start a patient on
3 drugs:
2 NRTIs [nucleoside reverse transcriptase]
and 1 from either protease inhibitors, integrase inhibitors, or NNRTI [non-nucleoside reverse transciptase]
describe the different incubation times for hepatitis viruses A-E
A + E short
B,C,D long [1-6/12]
given 2 patients, 1 a 30 yr old man born in ethiopia, the other a 30 yr old IVDU born in the UK, who is more likely to have Hep B and which Hep C?
hep B more likely transmitted vertically in an endemic area [or sex]
hep C more likely transmitted through injecting drugs [or anal sex]
18 yr old woman presents with fevers + jaundice. Moved to UK aged 4 from pakistan, husband moved to UK 3 months ago just prior to their marriage.
Temp 37.8, tender RUQ, deeply jaundiced, no rash or bowel upset.
most likely cause?
Hep B
if a 20 yr old contract hep B through sex, what chance do they have of clearing the virus vs chronic?
And in a child who contracted it from their mother vertically or in very early childhood?
age 20 - 95% clear the virus
baby - 95% go on to have chronic hep B
18 yr old woman presents with fevers + jaundice. Moved to UK aged 4 from pakistan, husband moved to UK 3 months ago just prior to their marriage.
Temp 37.8, tender RUQ, deeply jaundiced, no rash or bowel upset.
You think she has acute hep B, how do you treat?
no indication for treatment for acute infection
[unless rarely fulminant - requires transplant]
75 yr old man with know mixed mitral valve disease admitted for urinary retention secondary to BPH. Catheterised for 3 days, removed, then discharged.
2 weeks later: fever, sweats, malaise, ^SOB.
O/E: loud, harsh, systolic murmur and palpable thrill.
Diagnosis?
infective endocarditis from urosepsis
clinical features of endocarditis.
fever, rigors, malaise
murmur
roth spots, janeway lesions, splinter haemorrhages, oslers node, clubbing, hepatosplenomegaly, arthralgia
microscopic haematuria
emboli / abscess
who’s at risk of endocarditis?
IVDU heart murmur/ defect prosthetic valve Hx of rheum fever previous IE pacemaker/defib HCM
organisms for infective endocarditis
strep viridans
staph aureus [normal valve]
staph epidermidis [prosthetic valve]
Ix in suspected endocarditis
cultures X3
echo
FBC, ESR/CRP, rheumatoid factor, U+E, Mg, LFT.
urinalysis
CXR [cardiomeg, pulm oedema]
ECG [HB]
CT [emboli in brain/spleen etc]
how can you prevent endocarditis eg. in a pt with a catheter/ going for dental procedure who has a valve defect/ IDVU
amoxi prophylaxis
which side of the heart/ valves are affected in endocarditis usually? and which in IVDUs?
normally L sided/ mitral
IVDU right sided/ tricuspid
Abx of endocarditis of native vs prosthetic valve
4-6 weeks IV Abx based on micro consultation following cultures
e. g.
native: ampicillin, fluclox, gent
prosthetic: vanc + gent + rifampicin
duke criteria for endocarditis - give 2 major and 2 minor criteria
major:
cultures
+ve echo
minor: predisposed - IVDU/valve defect fever emboli/janeway lesion glomeneph/oslers
indications for surg in IE
HF VALVE OBSTRUCTION repeated emboli fungal persistent bacetraemia myocardial abscess unstable infected prosthetic valve
if strep bovis is cultured in an infective endocarditis patient, what ix should you do and why
colonoscopy
colon Ca is likely entry point
complications of infective endocarditis
stroke PE kidney infarct abscess HF
hep B, C and HIV. Which is most infectious in sexual transmission
B
what happens if you give amoxi in EBV
rash
transmission from needle stick, which is most likely - Hep B, C or HIV?
Hep B
in hepatitis serology, what does it mean if hepatitis antigens are present? [HBsAg/ HBeAg]
means the virus is there currently
If you’ve been immunised to hepB, will you have surface antibodies, or core antibodies, or both?
surface only, meaning youve made antibodies against the surface antigen and cleared it. Surface antigen not present as the virus is not present.
No core antibodies at the vaccine doesnt contain the core of the virus.
risk factors for developing fulminating hepatitis following viral hepatitis infection
imm.supp. drugs
pregnancy
HIV
IgG and IgM. Which infers acute and which chronic?
IgM is acute infection
IgG is past/previous infection
Mx of chronic hep B infection
tenofovir
clinical monitoring and Mx of hepC patient
liver US
HCC monitoring [alpha fetoprotein]
endoscopy screen for varices
direct acting antiviral drugs
what condition would you screen for in a TB infected patient?
hiv
how do you diagnose TB
sputum for acid fast bacilli/ microscopy/ culture
what do you do in a patient who you suspect has TB but culture and staining is negative?
not 100%, doesnt rule out TB. clinical/ radiological findings can be sufficient to treat
risk factors for TB
HIV
homelessness
from endemic area
standard TB Tx
isoniazid [6 months]
rifampicin [6 months]
ethambutol [1st 2 months- induction]
pyrazinamide [1st 2 months -induction]
SEs of TB drugs
N+V [give antiemetics]
pyrazinamide -arthralgia
isoniazid - peripheral neuropathy [pyridoxine]
liver toxicity [Is/Rif/Py]
ethambutol - optic neuritis
why viral load would keep going up in HIV despite ART?
wrong drug [mutation/resistance]
poor compliance
poor absorption [e.g. coeliac]
how is contact screening done in TB?
mantoux test [if +ve, CXR etc.]
pts with HIV at risk of what cancers
cervical [annual smear]
lymphoma
KS
KS is caused by what virus
human herpesvirus 8
what is meant by the “window period” in HIV
2-3 weeks after exposure, tests are false negative
[before host antibody response has been mounted]
what markers can be used to assess how advanced HIV disease is/ tx monitoring
CD4 count
viral load
you strongly suspect HIV in a patient, but HIV test is -ve. what do you do now?
re-test 12 weeks later [window period]
can do viral load/ talk to ID
infective cause of haematuria you should test for in patient recently arrived from africa
schistosomiasis
why can HIV pt get pancytopenia?
marrow suppression
SEs of cotrimoxazole
rash [stevens johnson/TEN]
marrow suppression
what advice do you give HIV positive new mum w/ regards feeding
exclusively bottle feeding
