Infection Flashcards
distinctive feature of PCP pneumonia
exercised induced oxygen desaturation
treatment for severe PCP pneumonia
IV pentamidine
what investigation is done to demonstrate the presence of Pneumocystitis jirovecii
bronchoalveolar lavage (BAL) and silver staining
which infections are associated with a vaginal pH >4.5
trichomonas vaginalis
bacterial vaginosis
which infection has yellow/green vaginal discharge
trichomanos vaginalis
treatment for trichomonas vaginalis
oral metronidazole for 5-7 days
microscopy finding in trichomonas vaginalis
microscopy of a wet mount shows motile trophozoites
which infection is characterised by a strawberry cervix
trichomonas vaginalis
What is Weil’s syndrome in leptospirosis infection?
The immune phase that occurs 5-7 days later when antibodies against the organism start to develop.
During the immune phase, patients may present with multisystem involvement such as renal failure, hepatic dysfunction, pulmonary haemorrhage and myocarditis with arrhythmias
When do antibodies test positive in Leptospirosis infection
after day 7
vector of leptospirosis
infected rat urine
main investigation for leptospirosis
serology for AB
management of leptospirosis
high-dose benzylpenicillin or doxycycline
what type of microbe is leptospira interrograns
spirochaete
when should prophylactic treatment for PCP pneumonia begin?
when CD4 count is below 200
How is MRSA from a carrier suppressed [2]
nose: mupirocin 2% in white soft paraffin, tds for 5 days
skin: chlorhexidine gluconate, od for 5 days
3 Abx used in MRSA treatment
vancomycin
teicoplanin
linezolid
What is the most effective single step to reduce the incidence of MRSA?
hand hygiene
what does the combined HIV test test for?
Ab against HIV and the p24 antigen
when must PEP be started after UPSI with an HIV carrier
within 72 hours
when should asymptomatic patients with HIV be tested?
4 weeks from exposure
what is the gold standard for diagnosing HIV
combined test
prophylaxis for contacts of patients with meningococcal meningitis [2]
how many doses?
oral ciprofloxacin or rifampicin now
single dose to all contacts in the 7 days to onset of symptoms, regardless of vaccination status
Abx for bacterial meningitis for patients aged 3 months to 50 years
IV cefotaxime or ceftriaxone
Abx for bacterial meningitis for patients aged >50
cefotaxime (or ceftriaxone) + amoxicillin (or ampicillin)
to cover for Listeria
indicated for delayed LP in meningitis investigation [4]
1) signs of severe sepsis or a rapidly evolving rash
2) severe respiratory/cardiac compromise
3) significant bleeding risk
4) signs of raised intracranial pressure:
- focal neurological signs
- papilloedema
- continuous or uncontrolled seizures
- GCS ≤ 12
Abx for meningococcal meningitis
Intravenous benzylpenicillin or cefotaxime (or ceftriaxone)
Pneumonia with lymphopenia, hyponatraemia & deranged LFTs
Legionella
Pneumonia associated with erythema multiforme (target)
mycoplasma
Pneumonia associated with red currant jelly sputum
Klebsiella
Pneumonia associated with rusty coloured sputum
Strep pneumo
diagnostic test for Legionella
urinary antigen
treatment for legionella
erythromycin/clarithromycin
which infection is a risk factor for hepatocellular carcinoma
Hep B
How are cirrhosis patients monitored for HCC
six-monthly intervals consisting of abdominal ultrasound and measuring AFP levels.
Main treatment for Hep B
pegylated interferon-alpha
vector for yellow fever
mosquitoes
features of yellow fever
mild flu-like illness lasting less than one week
sudden onset of high fever
rigors
nausea & vomiting
Bradycardia
A brief remission is followed by jaundice, haematemesis, oliguria
Councilman bodies (inclusion bodies) may be seen in the hepatocytes
alongside abx, what medication improves outcomes in bacterial meningitis patients? why is it used?
IV dexamethasone
by reducing neurological sequelae
contradictions to using dexamethasone in treatment of bacterial meningitis [4]
septic shock
meningococcal septicaemia.
immunocompromised
meningitis following surgery
treatment of UTI for symptomatic pregnant women
duration
first-line: nitrofurantoin (should be avoided near term)
second-line: amoxicillin or cefalexin
7 days
GI infection that presents as prolonged, non-bloody diarrhoea, bloating, flatulence, steatorrhoea
giardiasis
GI infection that presents as severe vomiting and short incubation period
staph aureus
GI infection that presents as gradual onset bloody diarrhoea, abdominal pain and tenderness which may last for several weeks
amoebiasis
Abx used for UTI that is contraindicated in pregnancy
trimethoprim
treating a symptomatic UTI in catheterised patient
7 day Abx with catheter change if its been there for more than 7 days
when should the repeat combined HIV test be done
in 12 weeks times but start ART right away
definition of pyrexia of unknown origin
Defined as a prolonged fever of > 3 weeks which resists diagnosis after a week in hospital
neoplastic causes of PUO [4]
lymphoma
hypernephroma
preleukaemia
atrial myxoma
which patients need a urine culture sent before ABx are started for UTI [4]
- men
- pregnant women
- non -pregnant women over 65
- visible or non-visible haematuria
how is bacteriuria treated in catheterised patients
no treatment if asymptomatic
treatment of post splenectomy sepsis
Penicillin V 500mg BD or amoxicillin 250mg BD
treatment of neutropenic sepsis
tazocin (piperacillin + tazobactam)
Suspected bacterial meningitis: an LP should be done before IV antibiotics, unless [4]
cannot be done within 1 hour
signs of severe sepsis or a rapidly evolving rash
significant bleeding risk
signs of raised intracranial pressure
treatment of legionella
clarithromycin
treatment of latent TB [2 ways]
3 months of isoniazid (with pyridoxine) and rifampicin
or
6 months of isoniazid (with pyridoxine)
investigations for mycoplasma pneumonia
name of test
diagnosis is generally by Mycoplasma serology
positive cold agglutination test → peripheral blood smear may show red blood cell agglutination
treatment for mycoplasma pneumonia
doxycycline or macrolide
causative agent of Kaposi sarcoma
HHV-8
management of wound: Patient has had a full course of tetanus vaccines, with the last dose < 10 years ago
no vaccine nor tetanus immunoglobulin is required, regardless of the wound severity
management of wound: Patient has had a full course of tetanus vaccines, with the last dose > 10 years ago
if tetanus prone wound: reinforcing dose of vaccine
high-risk wounds (e.g. compound fractures, delayed surgical intervention, significant degree of devitalised tissue): reinforcing dose of vaccine + tetanus immunoglobulin
management of wound: If vaccination history is incomplete or unknown
reinforcing dose of vaccine, regardless of the wound severity
for tetanus prone and high-risk wounds: reinforcing dose of vaccine + tetanus immunoglobulin
main complication of mumps
orchitis
treatment of Lyme’s disease with doxycycline allergy
amoxicillin
treatment of chlamydia
doxycycline
if pregnant: azithromycin, erythromycin or amoxicillin
what does an aspergillioma usually grow secondary to
previous TB infection
characteristic Chest X-ray sign of aspergillioma
The air crescent sign on chest x-ray is a characteristic finding of aspergilloma where a crescent of air that surrounds a radiopaque mass present in a lung cavity is visible.
how many drugs does ART consist of and which drugs make it up?
Antiretroviral therapy (ART) involves a combination of at least three drugs
typically two nucleoside reverse transcriptase inhibitors (NRTI) and either a protease inhibitor (PI) or a non-nucleoside reverse transcriptase inhibitor (NNRTI).
This combination both decreases viral replication but also reduces the risk of viral resistance emerging
management of syphillis
benzathine penicillin is the first-line management
alt: doxycycline
what should be monitored after syphilis treatment
nontreponemal (rapid plasma reagin [RPR] or Venereal Disease Research Laboratory [VDRL]) titres should be monitored after treatment to assess the response
treatment of HSV gingivostomatitis
gingivostomatitis: oral aciclovir, chlorhexidine mouthwash
treatment of multiple, non-keratinised genital warts
topical podophyllum
treatment of solitary, keratinised warts
cryotherapy
which pneumonia does previous influenza predispose you to
Staphylococcus aureus
treatment of syphilis
benzylpencilllin
early phase features of leptospirosis [4]
may be mild or subclinical
fever
flu-like symptoms
subconjunctival suffusion (redness)/haemorrhage
Features if typhoid [5]
fever
abdominal pain
constipation
‘rose’ spots
bradycardia
which viral hepatitis is associated with thrombocytopenia
Hep E
which viral hepatitis is associated with undercooked pork
Hep E
which viral hepatitis is associated with shellfish
Hep A
cause of Lymphogranuloma venereum (LGV)
Chlamydia trachomatis
three stages of Lymphogranuloma venereum
stage 1: small painless pustule which later forms an ulcer
stage 2: painful inguinal lymphadenopathy
stage 3: proctocolitis
treatment of Lymphogranuloma venereum
doxycycline
investigation of choice for herpes
NAAT
3 signs of Jarish-Herxheimer reaction
fever
tachycardia
rash
post abx, treat with paracetamol
treatment of malaria: in areas which are known to be chloroquine-sensitive then WHO recommend [2]
artemisinin combination therapy (ACT)
or
chloroquine
treatment of malaria: in areas which are known to be chloroquine-resistant use
Artemisinin combination therapy
patients with ovale or vivax malaria should be given ___________ following acute treatment with chloroquine to destroy liver hypnozoites and prevent relapse
patients with ovale or vivax malaria should be given primaquine following acute treatment with chloroquine to destroy liver hypnozoites and prevent relapse
investigation for Lyme’s disease
can start Abx upon clinical diagnosis
ELISA (serology)
treatment of bacterial vaginosis
oral metronidazole 7 days
how many tetanus vaccinations are given to provide life long immunity
5
treatment of syphilis in pregnancy
IM benzathine penicillin
what is seen on microscopy in BV
clue cells
treatment of oral cold sore
topical aciclovir
treatment of genital herpes
oral aciclovir
complications of mycoplasma:
- neuro [2]
- cardio [2]
- gastro [2]
- renal [1]
- neuro: GBS and immune mediated disease
- cardio: myocarditis/pericarditis
- gastro: hepatitis, pancreatitis
- renal: acute glomerulonephritis
what should be used in management of meningitis if the patient has anaphylactic allergies to penicillins and cephalosporins
IV chloramphenicol
gram stain and shape of neisseria gonorrhoea
gram -ve diplococci
cause of non-gonococcal urethritis
Mycoplasma genitalium
how do symptoms of primary herpes infection compare to eventual recurrent episodes
primary infection is most severe
what can be used to treat gonorrhoea if the patient refuses IM ceftriaxone injections [2]
oral cefixime + oral azithromycin
first line treatment of Lyme’ s disease
doxycycline
how does Yellow fever present [3]
classic description involves sudden onset of high fever, rigors, nausea & vomiting. Bradycardia may develop.
A brief remission is followed by jaundice, haematemesis, oliguria
histological feature in hepatocytes in Yellow Fever
Councilman bodies (inclusion bodies) may be seen in the hepatocytes
Disseminated gonococcal infection triad
tenosynovitis, migratory polyarthritis, dermatitis
post exposure prophylaxis for HBsAg positive source
known responder to the HBV vaccine then a booster dose should be given
non-responder (anti-HBs < 10mIU/ml 1-2 months post-immunisation) they need to have hepatitis B immune globulin (HBIG) and a booster vaccine
triad of infectious mononucleosis
sore throat, pyrexia and lymphadenopathy
other:
malaise, anorexia, headache
palatal petechiae
splenomegaly - occurs in around 50% of patients and may rarely predispose to splenic rupture
hepatitis, transient rise in ALT
lymphocytosis: presence of 50% lymphocytes with at least 10% atypical lymphocytes
haemolytic anaemia secondary to cold agglutins (IgM)
a maculopapular, pruritic rash develops in around 99% of patients who take ampicillin/amoxicillin whilst they have infectious mononucleosis
management of infectious mononucleosis
rest during the early stages, drink plenty of fluid, avoid alcohol
simple analgesia for any aches or pains
consensus guidance in the UK is to avoid playing contact sports for 4 weeks after having glandular fever to reduce the risk of splenic rupture
adverse effects of metronidazole
disulfiram-like reaction with alcohol
increases the anticoagulant effect of warfarin
CMV retinitis
common in HIV patients with a low CD4 count (< 50)
presents with visual impairment e.g. ‘blurred vision’. Fundoscopy shows retinal haemorrhages and necrosis, often called ‘pizza’ retina
IV ganciclovir is the treatment of choice
causes of HIV diarrhoea
Cryptosporidium + other protozoa (most common)
Cytomegalovirus
Mycobacterium avium intracellulare
Giardia
Post-exposure prophylaxis for HIV: duration of treatment
4 weeks of ART followed by a HIV tests at 12 weeks
which TB investigation allows to assess drug sensitivities in TB
sputum culture
what is Group A strep
Strep pyogenes
what is Group B strep
Strep agalactiae
treatment for amoebiasis
metronidazole
features of Dengue fever
Retro-orbital headache, fever, facial flushing, maculopapular rash, thrombocytopenia in returning traveller, bone pain,
features of Legionella
flu-like symptoms including fever (present in > 95% of patients)
dry cough
relative bradycardia
confusion
lymphopaenia
hyponatraemia
deranged liver function tests
pleural effusion: seen in around 30% of patients
Cause of false negative Mantoux tests include
TB
AIDS
Long-term steroid use
Lymphoma
Sarcoidosis
Extremes of age
Fever
Hypoalbuminaemia
Anaemia
causative agent of chancroid
Haemophilus ducreyi.
how does chancroid present
painful genital ulcers associated with unilateral, painful inguinal lymph node enlargement. The ulcers typically have a sharply defined, ragged, undermined border.
not to be confused with chancre in syphilis which are painless
live vaccines
MR V-BOY
MMR
Varciella
BCG
Oral polio
Yellow Fever
what must be done before giving the BCG
tuberculin skin test
Ebola presentation
what is the incubation period
First symptoms are the sudden onset of fever fatigue, muscle pain, headache and sore throat. This is followed by vomiting, diarrhoea, rash, symptoms of impaired kidney and liver function, and in some cases, both internal and external bleeding.
The incubation period is 2 to 21 days, and patients are not infectious until they develop symptoms.
do human bites require HIV PEP
no
EBV associated malignancies
Burkitt’s lymphoma
Hodgkin’s lymphoma
nasopharyngeal carcinoma
treatment of disseminated Lyme disease
ceftriaxone
Amsel’s criteria for diagnosis if BV
3 of 4
thin, white homogenous discharge
clue cells on microscopy: stippled vaginal epithelial cells
vaginal pH > 4.5
positive whiff test (addition of potassium hydroxide results in fishy odour)
which condition has rose spots
salmonella typhi
which condition has an increased risk of GI perforation
salmonella typhi
most common cause of osteomyelitis in those with SCD
salmonella
