Infectious Diseases Flashcards
Acute epiglottitis is serious infection caused by….
Haemophilus influenzaetype B.
rapid onset
high temperature, generally unwell
stridor
drooling of saliva
‘tripod’ position: the patient finds it easier to breathe if they are leaning forward and extending their neck in a seated position
Features of
Acute epiglottitis
Management of acute epiglottitis
endotracheal intubation may be necessary to protect the airway
oxygen
intravenous antibiotics
Cellulitis is most commonly caused by infection with………..1…….or less commonly………2……..
- Streptococcus pyogenes
- Staphylcoccus aureus
Indications for iv antibiotics in cellulitis
- immunocompromized.
- Has significant lymphoedema.
- Has facial cellulitis (unless very mild) or periorbital cellulitis.
- very young (under 1 year of age) or frail.
- severe or rapidly deteriorating cellulitis
- Eron Class III or Class IV cellulitis.
Management of cellulitis
- oral flucloxacillinas first-line treatment for mild/moderate cellulitis
oral clarithromycin,erythromycin (in pregnancy)or doxycycline is recommended in patients allergic to penicillin
- oral/IV co-amoxiclav, oral/IV clindamycin, IV cefuroxime or IV ceftriaxone
Necrotising fasciitis can be classified according to the causative organism:
Type 1 : mixed anaerobes and aerobes(often occurs post-surgery in diabetics). This is the most common type
Type 2: caused byStreptococcus pyogenes
Risk factors of Necrotising fasciitis
- skin factors: recent trauma, burns or soft tissue infections
- DM : most common & with SGLT2 inhibitors
- Iv drug use
- immunosuppression
Management of Necrotising fasciitis
urgent surgical referral debridement
intravenous antibiotics
causes painless black eschar(cutaneous ‘malignant pustule’, but no pus)
typically painless and non-tender
may cause marked oedema
GI bleeding
Features of….?
Anthrax
Anthrax is caused by
Bacillus anthracis, a Gram positive rod
Management of Anthrax
ciprofloxacin
antibiotics are commonly used in the treatment of MRSA infections:
vancomycin
teicoplanin
linezolid
Leptospirosis is caused by
the spirochaeteLeptospira interrogans(serogroupL. icterohaemorrhagiae)
Leptospirosis classically being spread by contact with….?
infected rat urine
6 Features of leptospirosis
- Fever
- Flu like symptoms
- subconjunctival
- AKI
- hepatitis: jaundice, hepatomegaly
- aseptic meningitis
Managment of leptospirosis
high-dose benzylpenicillin or doxycycline
Meningism by doxycycline
Investigations of leptospirosis
serology: antibodies to Leptospira develop after about 7 days
PCR
culture
Brucellosis has an incubation period …….
2 - 6 weeks
Four major species cause brucellosis in humans:
B. melitensis(sheep),
B. abortus(cattle),
B. canis( dogs )
B. suis(pigs).
Features of brucellosis
- hepatosplenomegaly
- sacroiliitis: spinal tenderness may be seen
- osteomyelitis,
- infective endocarditis,
- meningoencephalitis,
- orchitis
- leukopenia often seen
Treatment of brucellosis
doxycycline and streptomycin
False negative tuberculin tests may be caused by:(5)
- miliary TB
- sarcoidosis
- HIV
- lymphoma
- very young age (e.g. < 6 months)
The treatment forlatent tuberculosis
3 months of isoniazid (with pyridoxine) and rifampicin OR 6 months of isoniazid (with pyridoxine)
Side effects of rifampicin
hepatitis, orange secretions
flu-like symptoms
Side effects of isoniazid
peripheral neuropathy: prevent with pyridoxine (Vitamin B6)
hepatitis, agranulocytosis
Side effects of pyrazinamide
hyperuricaemia causing gout
arthralgia, myalgia
hepatitis
Side effects of ethambutol
optic neuritis: check visual acuity before and during treatment
Lyme disease is caused by ……..& spread by…..
the spirochaete Borrelia burgdorferi and is spread by ticks.
Early features of Lyme disease
- erythema migrans
- systemic features
headache
lethargy
fever
arthralgia
Later features of Lyme disease
- cardiovascular
- Heart block
- Peri/ myocarditis - Neurological
- facial nerve palsy
- radicular pain
- meningitis
Lyme disease can be diagnosed clinically if ……….. is present
erythema migrans
Management of Lyme disease
Management of suspected/confirmed Lyme disease
- doxycycline if early disease.
Amoxicillin is an alternative if doxycycline is contraindicated (e.g. pregnancy) - ceftriaxone if disseminated disease
3 Causes of meningitis in > 60 years
- Streptococcus pneumoniae
- Neisseria meningitidis
- Listeria monocytogenes
2 Causes of meningitis in 6 years - 60 years
- Neisseria meningitidis
- Streptococcus pneumoniae
3 Causes of meningitis in 3 months - 6 years
- Neisseria meningitidis
- Streptococcus pneumoniae
- Haemophilus influenzae
3 Causes of meningitis in 0 - 3 months
Group BStreptococcus(most common cause in neonates)
E. coli
Listeria monocytogenes
Causes of meningitis in Immunosuppressed
Listeria monocytogenes
warning signs of meningitis
rapidly progressive rash
poor peripheral perfusion
RR < 8 or > 30
HR < 40 or >100
GCS < 12
PH < 7.3
WBC < 4
Lactate > 4
poor response to fluid resuscitation
Initial empirical therapy of meningitis, aged > 50 years
IV cefotaxime (or ceftriaxone) + amoxicillin (or ampicillin)
Initial empirical therapy of meningitis, aged 3 months - 50 years
IV cefotaxime (or ceftriaxone)
Initial empirical therapy of meningitis, aged < 3 months
IV cefotaxime + amoxicillin (or ampicillin)
Treatment of Meningococcal meningitis
IV benzylpenicillin or cefotaxime (or ceftriaxone)
Treatment of Pneumococcal meningitisor Meningitis caused byHaemophilus influenzae
IV cefotaxime (or ceftriaxone)
Treatment of Meningitis caused by Listeria
IV amoxicillin (or ampicillin) + gentamicin
Mycobacterium marinum typically presents in patients who have had an exposure to, or frequently work with ..?.
fish
Treatment of Mycobacterium marinum
tetracyclines, fluoroquinolones, sulfonamides and macrolides.
3 Risk factors of Viral meningitis
- patients at the extremes of age (< 5 years and the elderly)
- immunocompromised, e.g. patients with renal failure, with diabetes
- Iv drug users
Listeria monocytogenesis a Gram………… which has the unusual ability to multiply at ……. temperatures.
Listeria monocytogenesis a Gram-positive bacillus which has the unusual ability to multiply at low temperatures.
4 Risk factors of listeria
- elderly
- neonates
- immunosuppression
especially glucocorticoids
- pregnancy
Management of Listeria monocytogenes
Listeria meningitis should be treated with IV amoxicillin/ampicillin and gentamicin
Clostridium botulinum is Gram………..
gram positive anaerobic bacillus
Clostridium botulinum produces botulinum toxin, a neurotoxin which irreversibly blocks
the release of acetylcholine
4 Features of Botulism
flaccid paralysis
diplopia
ataxia
bulbar palsy
Treatment of botulism
botulism antitoxin and supportive care
Treatment of UTI in non pregnant women
trimethoprim or nitrofurantoin for 3 days
Treatment of UTI in pregnancy
first-line: nitrofurantoin(should be avoided near term)
second-line:amoxicillin or cefalexin
trimethoprim is teratogenicin the first trimester and should be avoided during pregnancy
Swimmer’s ear is caused by …….
And severe in …..
- Pseudomonas aeruginosa.
- Diabetic patients
Diphtheria is caused by the Gram ……
positive bacterium Corynebacterium diphtheriae
sore throat with a ‘diphtheric membrane’ - grey, pseudomembrane on the posterior pharyngeal wall
bulky cervical lymphadenopathy
may result in a ‘bull neck’ appearanace
neuritis e.g. cranial nerves
heart block
Features of…?
Diphtheria
Management of Diphtheria
IM penicillin
diphtheria antitoxin
incubation period of dengue fever
2 - 14 days
Dengue fever is caused by
Aedes mosquitos
high fever, rigors
nausea & vomiting.
Bradycardia .
A brief remission is followed by jaundice, haematemesis, oliguria
Features of …..?
dengue fever
treatment of Lassa fever
ribavirin
Lassa fever is contracted by contact with the excreta of
infected African rats (Mastomys rodent) or by person-to-person spread.
Tetanospasmin prevents the release of
GABA
Management of Tetanus
- supportive therapy including ventilatory support and muscle relaxants
- intramuscular human tetanus immunoglobulin for high-risk wounds
- metronidazole
Post-splenectomy changes
- Platelets will rise first
- Blood film will change over following weeks, Howell-Jolly bodies will appear
- Other blood film changes include target cells and Pappenheimer bodies
- Increased risk of post-splenectomy sepsis
Post-splenectomy sepsis Typically occurs with ……. organisms
encapsulated
Scarlet fever is a reaction to erythrogenic toxins produced by
Group A haemolytic streptococci (usuallyStreptococcus pyogenes).
Scarlet fever is spread via
the respiratory route by inhaling or ingesting respiratory droplets or by direct contact with nose and throat discharges, (especially during sneezing and coughing).
Pentad of Scarlet fever
- Fever
- Pharyngitis
- Cervical lymphadenopathy
- strawberry’ tongue
- sandpaper Rash
Diagnosis of scarlet fever
throat swab is normally taken but antibiotic treatment should be commenced immediately, rather than waiting for the results
Management of Scarlet fever
- oral penicillin V for 10 days
- patients who have apenicillin allergy should be given azithromycin
When can children with Scarlet fever return to school ?
24 hours after commencing antibiotics
6 Complications of Scarlet fever
- otitis media
- Rheumatic fever
- Acute GN
- Meningitidis
- Bacteraemia
- Necrotizing fasciitis
Which viral hepatitis is DNA hepadnavirus?
HBV
incubation period of HAV
incubation period: 2-4 weeks
incubation period of HEV
incubation period: 3-8 weeks
Superinfection of HDV is associated with high risk of
fulminant hepatitis,
chronic hepatitis status
cirrhosis.
incubation period of HBV
incubation period is 6-20 weeks.
Anti-HBs level (mIU/ml) Indicates adequate response if level
> 100
Anti-HBs level (mIU/ml) Indicates suboptimal response if level
10 - 100
Anti-HBs level (mIU/ml) Indicates no response if level
< 10
A better response to pegylated interferon-alpha is predicted by
- Female
- Age < 50 years old
- Non Asian
- Low HBV DNA levels
- Negative HIV
- High degree of information on liver biopsy
telbivudine is
a synthetic thymidine nucleoside analogue)
incubation period of HCV
incubation period: 6-9 weeks
Breastfeeding & HCV
not contraindicated
Treatment of chronic hepatitis C
combination of protease inhibitors
- sofosbuvir + daclatasvir
- sofosbuvir + simeprevir
with or without ribavirin are used
ribavirin - 3 side-effects:
haemolytic anaemia,
cough.
Women should not become pregnant within 6 months of stopping ribavirin as it is teratogenic
interferon alpha - 5 side-effects
flu-like symptoms,
depression,
fatigue,
leukopenia,
thrombocytopenia
Treatment of H1N1 influenza
- Oseltamivir (Tamiflu) oral medication*
- Zanamivir (Relenza) inhaled medication*
side-effects of Tamiflu
nausea, vomiting, diarrhoea and headaches
Side effects of Zanamivir (Relenza)
may induce bronchospasm in asthmatics
The Salmonella group are Gram …
are aerobic, Gram-negative rods
typhoid is transmitted via
faecal-oral route (also in contaminated food and water)
rose spots on abdomen is more common in ….?
paratyphoid
Complications of Typhoid and paratyphoid
- Osteomyelitis
- GI bleeding/ perforation
- Meningitis
- Cholecystitis
- chronic carriage (1%, more likely if adult females)
Giardiasis is caused by
the flagellate protozoanGiardia lamblia.
Giardiasis is spread by
the faeco-oral route
Treatment of Giardiasis
metronidazole
In Amoebic dysentery, stool microscopy may show trophozoites if …..
examined within 15 minutes or kept warm (known as a ‘hot stool’)
Treatment of Amoebic dysentery
- oral metronidazole
- luminal agent’ (to eliminate intraluminal cysts) is recommended usually as well e.g. diloxanide furoate