Infectious diseases Flashcards
Fever on alternating days, think
Fever on alternating days, think Malaria
CT head showing temporal lobe changes - think
CT head showing temporal lobe changes - think herpes simplex encephalitis
Herpes simplex encephalitis presentation
fever, headache, psychiatric symptoms, seizures, vomiting
focal features e.g. aphasia
peripheral lesions (e.g. cold sores) have no relation to the presence of HSV encephalitis
Atypical lymphocytes can indicate which infection?
Atypical lymphocytes - ?glandular fever
Campylobacter infection antibiotic of choice
Campylobacter infection is often self-limiting but if severe then treatment with clarithromycin may be indicated
Infective endocarditis in intravenous drug users most commonly affects which valve?
tricuspid valve
the most common cause of travellers’ diarrhoea
E.coli
C. difficile antigen positivity but C diffcile toxin negative. what does thi indicate?
C. difficile antigen positivity only shows exposure to the bacteria, rather than current infection
Shows C.difficile colonisation
What is used as prophylaxis for contacts of patients with meningococcal meningitis
Oral ciprofloxacin or rifampicin is used as prophylaxis for contacts of patients with meningococcal meningitis
commonest type of malaria
Falciparum malaria is the commonest type of malaria and most severe
falciparum malaria classic triad of symptoms
- flu-like illness
- classical triad of symptoms includes paroxysms of fever, chills, and sweating.
- These symptoms may occur every 48 hours corresponding to the erythrocytic cycle of the Plasmodium falciparum parasite.
- Fever is often high, intermittent, and may be accompanied by rigors.
- Initial manifestations can be non-specific and include malaise, headache, and myalgia, which might be mistaken for a viral syndrome.
falciparum malaria general features and severe features
falciparum malaria complications
- cerebral malaria: seizures, coma
- acute renal failure: blackwater fever, secondary to intravascular haemolysis, mechanism unknown
- acute respiratory distress syndrome (ARDS)
- hypoglycaemia
- disseminated intravascular coagulation (DIC)
management of falciparum malaria
Suspected bacterial meningitis: an LP should be done before IV antibiotics, unless:
- cannot be done within 1 hour
- signs of severe sepsis or a rapidly evolving rash
- significant bleeding risk
- signs of raised intracranial pressure
Giardiasis is caused by
It is spread by
Giardiasis is caused by the flagellate protozoan Giardia lamblia. It is spread by the faeco-oral route.
Giardiasis risk factors
foreign travel
swimming/drinking water from a river or lake
male-male sexual contact
Giardiasis features
- often asymptomatic
- non-bloody diarrhoea
- steatorrhoea
- bloating, abdominal pain
- lethargy
- flatulence
- weight loss
- malabsorption and lactose intolerance can occur
Giardiasis investigations and treatment
Investigations
* stool microscopy for trophozoite and cysts: sensitivity of around 65%
* stool antigen detection assay: greater sensitivity and faster turn-around time than conventional stool microscopy methods
* PCR assays are also being developed
Treatment is with metronidazole.
A patient who is awaiting an inguinal hernia repair is found to be positive for MRSA after screening at the pre-admission clinic. What treatment should he be offered, if any?
Nasal mupirocin + chlorhexidine for the skin.
What is the most appropriate investigation to test for Lyme disease?
blood test for serology
