Infectious Disease Flashcards
What is Toxoplasmosis?
Toxoplasmosis is a parasitic disease whose main reservoir is in cats.
Caused by the parasite Toxoplasmosis gondii protozoa that infects the body via GI tract, lung or broken skin.
It’s oocysts release trophozoites which migrate widely around the body including to the eye, brain and muscle
Toxoplasmosis Px?
Flu-like illness
Malaise, lymphadenopathy + myalgia
Can be asymptomatic
Most healthy individuals will clear the infection but it can cause complications of anaemia, seizure or chorioretinitis.
These mainly occur in neonates (born to mothers with acute infection) or immunocompromised patients.
What is the treatment for Toxoplasmosis?
None in normal people
Pyrimethamine and sulphadiazine in immunocompromised pts
What is Leptospirosis?
Leptospirosis is a disease caused by the spirochaete Leptospira interrogans (serogroup L. icterohaemorrhagiae), spread by contact with infected rat urine.
Commonly seen in sewage workers, farmers, etc or those working in abattoir.
Also common in the tropics, so may mention returning traveller.
What are the features of Leptospirosis?
Early phase is due to bacteraemia + lasts a week
- may be mild/subclinical
- flu-like symptoms
- subconjunctical suffusion (redness)/haemorrhage
Second immune phase may lead to more severe dx (Weil’s disease)
- AKI (in 50% of pts)
- Hepatitis: jaundice, hepatomegaly
- Aseptic meningitis
Leptospirosis management?
Mild: Doxycycline
Severe: IV Benzylpenicillin or Ceftriaxone.
What Abx do you use for animal bites?
Co-Amoxiclav
If penicillin-allergic then doxycycline + metronidazole is recommended
What Abx do you use for skin and ear conditions?
Flucloxacillin
What is Vancomycin used to treat?
Gram-positive infections, particularly methicillin-resistant Staphylococcus aureus (MRSA).
What organism is most commonly found in animal bite wounds?
Pasteurella multocida
What are the most common organisms found in human bite wounds?
Streptococci spp. Staphylococcus aureus Eikenella Fusobacterium Prevotella
What Abx do you give to a pt presenting with a human bite?
Co-Amoxiclav
What is the causative organism of Gonorrhoea?
Neisseria gonorrhoea (a Gram -ve diplpcoccus)
What is the incubation period of gonorrhoea?
2-5 days
What are the features of gonorrhoea?
- Males: urethral discharge, dysuria
- Females: cervicitis e.g. leading to vaginal discharge
- Rectal and pharyngeal infection is usually asymptomatic
Management of gonorrhoea?
A single dose of IM Ceftriaxone
(If the organism has a known sensitivity to ciprofloxacin then this should also be given)
If injection refused, give oral Cefixime + oral azithromycin.
What is the most common cause of septic arthritis in young adults?
Gonorrhoea
What is Disseminated gonococcal infection (DGI)?
Haematogenous spread of mucosal gonorrhoea (genital infection).
Px as triad of:
- Tenosynovitis
- Migratory poly arthritis
- Dermatitis
Later complications include septic arthritis, endocarditis and peri-hepatitis (Fitz-Hugh-Curtis syndrome)
What type of herpes simplex virus causes Genital herpes?
HSV 2
What type of herpes simplex virus causes cold sores?
HSV 1
What is the causative organism of Syphilis?
The spirochaete ‘Treponema pallidum’
What is the incubation period of the primary stage of Syphilis?
9-90 days
Px as a painless ulcer
What is Chancroid?
Chancroid is a tropical dx caused by Haemophilus ducreyi.
What is the Px of Chancroid?
Painful genital ulcers associated with unilateral, painful inguinalLN involvement.
Ulcers have sharply defined, ragged, undermined border.
What is the causative organism of Lymphogranuloma venereum (LGV)?
Chlamydia trachomiatis.
What are the stages of infection in Lymphogranuloma venereum (LGV)?
- small painless pustule which later forms an ulcer
- painful inguinal lymphadenopathy
- proctocolitis
What is the treatment for LGV?
Doxycycline
What is the treatment for Syphilis?
IM Benzathine penicillin is 1st line
Doxycycline is an alt.
What is a common complication of Syphilis treatment?
The Jarisch-Herxheimer reaction.
- Px as fever, rash + tachycardia after 1st dose.
- Unlike anaphylaxis, no wheeze or hypotension.
- Due to endotoxins following bacterial death
- Occurs a few hrs after treatment
- No Rx needed (if pyrexial, tie anti-pyretics)