INFECTION Flashcards
What is Pyrexia of unknown origin (PUO)?
Prolonged fever of > 38.3 on multiple occasions for at least 3 weeks
What are the causes of systemic inflammatory response (SIR)?
- Infection
- Malignancy
- Inflammatory conditions
- HIV
What are common symptoms associated with prolonged fever?
- Increased heart rate (HR)
- Increased respiratory rate (RR)
- Increased CRP
- Increased ESR
What basic investigations should be performed in cases of PUO?
- Blood cultures (3 sets)
- Urinalysis
- U/E, LFT
- Full blood count (FBC)
What is characteristic of Staphylococcus aureus?
Gram positive cocci in grape-like clusters
What conditions are commonly caused by Staphylococcus aureus?
- Soft tissue infections
- Recurrent abscesses
- Staphylococcal toxic shock syndrome
What is the mechanism of Staphylococcal toxic shock syndrome?
Activation of T cells by superantigens, primarily TSST-1
What is the first-line treatment for Group A streptococcal sore throat?
Phenoxymethylpenicillin
What are the symptoms of Group A streptococcal tonsillitis?
- Sore throat
- Headache
- Fever
What are the diagnostic tests for streptococcal infections?
- Streptococcal antigen test
- Culture
What are the key features of Staphylococcal toxic shock syndrome?
- Fever > 38.9
- Rash with diffuse macular erythroderma
- Desquamation 1-2 days after rash onset
What is the treatment protocol for sepsis?
- Administer IV antibiotics within 1 hour
- IV fluids
- Oxygen therapy
What is the CURB65 criteria used for?
Assessing the severity of pneumonia
What are the components of the CURB65 score?
- Confusion
- Urea nitrogen > 7mmol/L
- Respiratory rate > 30
- Blood pressure (systolic < 90 or diastolic < 60)
- Age 65 or older
What is the incubation period for influenza?
1-4 days
What are the symptoms of influenza?
- Fever
- Myalgia
- Headache
- Severe cough
What are neuraminidase inhibitors used for?
Treating influenza by inhibiting viral replication
What are the common symptoms of Hepatitis B?
- Constitutional symptoms
- Right upper quadrant pain
- Jaundice
- Nausea and anorexia
What laboratory markers indicate acute Hepatitis B infection?
- HBsAg (surface antigen)
- IgM antibodies
What are the key features of viral meningitis?
- Headache
- Neck stiffness
- Photophobia
- Fever
What is the most common cause of viral meningitis in the UK?
Enterovirus
What are the key symptoms of bacterial meningitis?
- Severe headache
- Rapid onset of fever
- Neck stiffness
- Focal neurological signs
What is the treatment for bacterial meningitis?
- IV ceftriaxone
- IV amoxicillin (in age extremes)
What is the significance of a low CD4 count in HIV patients?
Increased risk of opportunistic infections
What is the first-line treatment for tuberculosis?
Isoniazid, Rifampicin, Ethambutol, Pyrazinamide (4 for 2 months, then 2 for 4 months)
What are the side effects of Isoniazid?
Peripheral neuropathy
What are common symptoms of leprosy?
- Anaesthetic hypopigmented macules
- Thickened peripheral nerves
What is the primary causative agent of syphilis?
Treponema pallidum
What is a key feature of the secondary stage of syphilis?
Symmetrical maculopapular rash
What is the treatment for syphilis?
Penicillin
What is the healing time for the perianal area?
3-8 weeks
What are the symptoms of secondary syphilis?
- Symmetrical maculopapular rash (trunk, palms, soles, and face)
- Mucosal ulcers
- Lymphadenopathy
- Malaise
- Fever
- Hepatitis
- Glomerulonephritis
What percentage of untreated patients with syphilis will develop gummatous disease?
1 out of 3
What are the types of treponemal tests for syphilis?
- Treponema pallidum haemagglutination assay
- Treponemal enzyme immunoassay
What are non-treponemal tests for syphilis?
- Rapid plasma regain (RPR)
- Venereal disease reference laboratory (VDRL)
What is the first-line treatment for primary and secondary syphilis?
Single dose of intramuscular penicillin G (benzathine benzylpenicillin)
What is the treatment duration for tertiary and late syphilis?
2-3 weeks of IM penicillin G
What is the treatment for neurosyphilis?
IV penicillin G for 10-14 days
What is the first-line treatment for patients allergic to penicillin?
Doxycycline or tetracycline
What is rheumatic fever associated with?
Group A beta-haemolytic streptococcus infection (scarlet fever)
What is a major criterion for diagnosing rheumatic fever?
- Arthritis
- Pericarditis
- Valvulitis
- Sydenham’s chorea
What is the treatment for carditis in rheumatic fever?
Prednisolone
What is Lyme disease caused by?
Borrelia burgdorferi carried by ticks
What is the characteristic rash of early Lyme disease?
Erythema migrans (bull’s eye rash)
What are the early symptoms of Lyme disease?
- Flu-like symptoms
- Fever
- Chills
- Headache
- Fatigue
- Muscle and joint aches
What is the first-line treatment for Lyme disease?
Doxycycline
What are the two forms of rabies?
- Furious (70%)
- Paralytic (30%)
What is the incubation period for rabies?
1-3 months
What virus causes measles?
RNA paramyxovirus
What are Koplik spots?
Small areas of grey discolouration in the mouth associated with measles
What is the most common cause of viral infectious gastroenteritis?
Norovirus
What is the first-line treatment for cholera?
Rehydration with Na+/K+ with osmotic effect
What are the symptoms of typhoid fever?
- Rose coloured spots
- Fever
- Abdominal pain
- GI symptoms
- Bradycardia
What is the first-line treatment for uncomplicated malaria?
Oral doxycycline for 21 days or 28
What is the causative agent of schistosomiasis?
Freshwater snails
What is the first-line treatment for schistosomiasis?
Praziquantel
What type of bacteria causes C. difficile infections?
Clostridium difficile
What is the first-line treatment for a non-severe C. difficile infection?
Oral metronidazole
What is the most common cause of bacterial food poisoning in the UK?
Campylobacter jejuni
What is the characteristic stool appearance in cholera?
Rice-water stools
What is the treatment for severe or complicated malaria?
IV artesunate or IV quinine + doxycycline or clindamycin (oral)
What is the incubation period for malaria?
1 year, especially 3 months after traveling
What type of rash is associated with dengue fever?
Macular rash
What is a common complication of mumps?
Orchitis (epididymis-orchitis)
What is the most common cause of infantile gastroenteritis?
Rotavirus
What vaccine were children under 5 vaccinated against in 2013?
Norovirus
Norovirus is the most common cause of viral infectious gastroenteritis.
What is the most common cause of viral infectious gastroenteritis?
Norovirus
Norovirus outbreaks often occur in hospitals and care homes.
How is Norovirus transmitted?
Faecal-oral route or airborne transmission
Norovirus is highly contagious with a low infecting dose.
What are the common symptoms of Norovirus infection?
Non-bloody diarrhoea and vomiting
What type of testing is used for Norovirus?
Viral PCR / Antigen testing
What is Giardia lamblia?
A parasite
Giardia lamblia is associated with contaminated water supplies.
What test is used to diagnose parasitic infections?
Stool microscopy
What is Entamoeba histolytica?
A parasite
It is transmitted through foreign travel and poor hygiene.
What is Candida Albicans commonly associated with?
Oral thrush
Oral thrush presents as white spots on the roof of the mouth.
What are some risks associated with Candida Albicans infection?
Lymphoma, HIV, smoking, inhaled steroid use
What are the symptoms of oral candidiasis?
White or yellow plaques in mouth, mild burning, erythema, altered taste, furry tongue, dysphagia
What is Tinea?
A fungal infection
What is the treatment for ringworm (Tinea corporis)?
Topical antifungal cream (e.g., Terbinafine, Clotrimazole, Miconazole)
What is a common symptom of threadworm infection?
Perianal or vulval itching in a child
The itching is often worse at night.
What is the treatment for threadworm?
Oral mebendazole and hygiene measures for everyone in the house
What is the treatment for fungal nail infections?
Topical nail lacquer (Amorolifine) or oral terbinafine
How long should topical nail lacquer be applied for fingernails?
6 months
How long should topical nail lacquer be applied for toenails?
9-12 months
What should be monitored when treating fungal nail infections with oral terbinafine?
Liver function tests (LFT)
COMMMN CAUSESOF OTITIS MEDIA - BACTERIA
Whilst viral upper respiratory tract infections (URTIs) typically precede otitis media, most infections are secondary to bacteria. The most common is Streptococcus pneumoniae, followed by Haemophilus influenzae and Moraxella catarrhalis