Infectious Diseases ILOs Flashcards
Define sepsis
Life-threatening organ dysfunction as a result of dysregulated host response to infection
Outline SIRs criteria in which 2 or more are needed to diagnose sepsis
- HR >90 BPM
- Temp. >38 or <36
- RR > 20 per minute
- WCC >12 or <4
Outline sepsis 6
Take: blood culture, urine output, serum lactate
Give: IV AVX, IV Fluid, O2
Outline the Q-SOFA scoring system for sepsis in which a score of 2 or more indicates poorer outcomes
- Systolic BP<100
- Altered mental status
- RR >22
Give 2 common causes of viral gastroenteritis
Rotavirus
Norovirus
How is norovirus transmitted and treated?
Person to person, water and food-borne
Tx: fluid, antispasmodic, analgesia, antipyretic
What population does rotavirus mainly affect and how is it transmitted?
Under 2s
Faeco-oral route
Where does salmonella come from and what is it’s incubation period?
Pork, poultry and dairy
12-72hr incubation
Give 2 symptoms of campylobacter and what ABX can be used in persistent disease
Diarrhoea
Blood in stool
Macrolides/Quinolones
What type of E coli infection is associated with infants and returning travellers?
Enterotoxigenic E coli
What is the incubation time of Staph Aureus in terms of food poisoning and give 1 symptoms
30 mins-6 hours
Profuse D&V
Give 2 common causative agents in the common cold
Rhinovirus and Coronavirus
Give 2 viruses which cause pharyngitis
Adenovirus and Rhinovirus
What is croup and what virus commonly causes it?
Inspiratory stridor leading to increased RR in 6 month-3 y/o mainly
Parainfluenza virus 1-4
What is bronchiolitis and who is mainly affected?
Caused by paramyxovirus, most infected by 2 y/o
Which type of influenza virus is mainly in humans with 2 circulating types?
Influenza B
Give 2 treatments for influenza
Ribiviren
Neuraminidase inhibitor
Give 3 common causative bacteria in CAP
- Strep. Pneumoniae (most common cause)
- Haemophilus influenzae
- Moraxella catharralis
Give 4 signs and symptoms of pneumonia
- Productive cough
- Pleuritic chest pain
- Bibasilar crepitations
- Dull to percussion
What antibiotics are used to treat non-severe and severe CAP?
NS: oral amoxicillin, doxycycline or clarithromycin
S: IV Clarithromycin + Amoxicillin
Outline the CURB65 severity score for CAP
Confusion Urea>7 RR>/=30 SBP<90 or DPB<60 Age>65
(3 or more is severe)
When does HAP occur and give 2 causative bacteria
Acquired after at least 48 hours of admission to hospital
Strep. pneumoniae
Pseudomonas
Give 1 ABX for non-severe and severe HAP
NS: oral co-amoxiclav
S: IV Levofloxacin
Give 3 features of MRSA infection
Erythematous skin lesions or pustules
Infection unresponsive to penicillins
Fever
What is the difference between community associated and healthcare associated MRSA in terms of treatment?
Community: Oral ABX
Healthcare: IV ABX
Give 3 investigations for MRSA
- FBC
- Cultures (urine, tissue, sputum)
- CXR
Give 2 antibiotics which are effective against MRSA
Vancomycin
Clindamycin
Give 3 risks for MRSA
Age >50
Native American
IVDU
Define Clostridium Difficile and give the 4C ABX which cause it
Infection of colon characterised by formation of pseudomembranes o Clindamycin o Cephalosporins o Co-amoxiclav o Ciprofloxacin
Outline the pathophysiology of C diff
Disruption of bowel flora by ingestion of heat-resistant spores occurring on days 4-9 of ABX therapy
Give 3 symptoms of C diff infection
- Diarrhoea
- Abdominal pain
- Fever
Give 2 investigations and 2 ABX used in C diff
- Faecal occult blood +
- Stool immunoassay for toxins A and B +
Vancomycin + Metranidazole
Define meningitis and give two bacteria which commonly cause it
Inflammation of meninges +/- cerebrum caused by bacteria or virus. All pt. treated empirically for bacterial
- Pneumococcal (common in alcohol users)
- Listeria (pregnancy)
Give 5 symptoms of meningitis
- Headache
- Neck stiffness
- Fever
- Confusion
- Rash (purpuric+/-petechiae)
What should be done for patients with suspected meningitis before CT and why?
Antibiotics pre-CT to cover bacteria as bacterial meningitis is so deadly
As well as antibiotics, what should be given to patients with pneumococcal meningitis?
Corticosteriods
What additional measure must be considered when a pt. is diagnosed with bacterial meningitis
Chemoprophylaxis for close contacts
Give 3 features seen on LP in bacterial meningitis
- Neutrophils
- Raised protein
- Reduced glucose
What is the tx for viral meningitis?
Aciclovir in immunocompromsied
Otherwise no Tx
What is cryptococcal meningitis and how is it treated?
Occurs in immunodeficiency usually HIV
Tx: ABX, anti fungal, shunt in raised ICP
Define tuberculosis and give 4 symptoms
Infectious disease caused by mycobacterium tuberculosis
- Cough
- Haemoptysis
- Fever
- Night sweats
Give 2 pathological features of TB which may be seen on CXR
Granuloma
Ghon complexes
Give 3 investigations for TB
- Positive AFB smear
- Solid or liquid culture
- CXR
What is the treatment for active TB?
- 6 month rifampicin
- 6 month Isoniazid
- 2 month Ethambutol
- 2 month pyrazinamide
Define HIV and which type is the most common worldwide
A retrovirus that destroys CD4 T cells and is the aetiological agent of acquired immunodeficiency syndrome (AIDS)
HIV 1
Give 3 routes of transmission of HIV
- Anal or vaginal sex
- IV drug use
- Mother to child transmission e.g. birth and breastmilk
Outline the pathology of HIV
- HIV infects helper T cells, CD4+ cells depleted
- Abnormal B cell activation = inappropriate immunoglobulins
- CD4+ level <200 = OPPORTUNISTIC INFECTIONS
How is HIV diagnosed?
4th generation testing: p24 antigen and HIV antibody (4 weeks after exposure)
What is the current Tx of HIV?
HAART (triple therapy in one tablet)
What is seroconversion?
Primary HIV, an acute illness 1-2 months after contracting the virus.
Fever, rash…
What does Herpes simplex 1 cause compared to HSV 2?
HSV1: herpies labiallis + genital herpes
HSV2: genital herpes
Give 2 risks of herpes simplex virus
- HIV
- Immunosuppressive medications
Outline the pathophysiology of herpes simplex
Acquired at mucosal surfaces or broken skin and enters latent stage allowing immune system evasion and lifelong infection
Give 2 management options for herpes simplex
- Symptomatic relief
- Aciclovir to clear symptoms
Give 2 features of an immunocompromised host
Asplenic
Organ transplant
What level defines neutropenia?
<0.5 x 109/L or <1.0 x 109/L and falling
How does neutropenia occur in cancer patients?
Chemo/irradiation = less proliferation of haemopoietic progenitor cells and depleted marrow = neutropenia
What is chronic granulomatous disease?
Inherited disorder where gene coding NADPH oxidase is defective = intracellular killing of pathogens can’t happen
= Recurrent infection
How does infection usually occur in pt. with neutropenia
If no site is located for infection probably due to translocation across a compromised mucous membrane
What are the components of a sexual health screen?
Chlamydia
Gonorrhoea (NAAT test)
HIV
Syphilis
Give 2 symptoms and one Tx of gonorrhoea
Dysuria, urethral discharge
Ceftriaxone
Give 2 symptoms and one Tx of chlamydia
Asymptomatic + intermenstrual bleeding
Doxycycline
What type of bacteria is syphilis and how many phases of disease exist?
Gram positive spirochete
3 stages
Give one Tx for syphilis
Benzathine penicillin
What causes trichomonas vaginalis and what population is mainly affected?
Protozoon
Black females
Give 3 causes of staph aureus bacteraemia
Catheter
Line
Prosthetic
How is staph aureus bacteraemia treated?
Uncomplicated: 2 weeks IV ABX
Complicated: 4-6 weeks IV ABX
Define malaria and how it occurs
Parasitic infection caused by protozoa of genus Plasmodium
Bite from female Anopheles mosquito
Give 4 symptoms of malaria
- Myalgia
- Diarrhoea
- Jaundice
- Renal impairment
Give 3 ways to investigate malaria
- Antigen testing
- Blood film (parasite in erythrocytes)
- PCR
Give 2 Tx for malaria
Quinine and doxycycline
Give 3 possible disease causes of fever in returned traveller
Typhoid fever
Dengue fever
Viral haemorrhagic fever
Define infectious mononucleosis
aka glandular fever, clinical syndrome caused by EBV in most cases
Give 4 symptoms of infectious mononucleosis
- Fever
- Pharyngitis
- Lymphadenopathy
- Splenomegaly
Give 2 tests and 2 management options for infectious mononucleosis
FBC (lymphocytosis)
EBV specific antibodies
Supportive
Corticosteroids
Define fever of unknown origin and give 3 possible causes
Temp >38.3 on several separate occasions
- TB
- Intra-abdominal/pelvic abscesses
- Malaria
Give 3 tests in the investigation of fever on unknown origin
Blood culture
Urine culture
Skin test and CXR for TB
Define Tetanus
Life threatening neurological syndrome characterised by tonic muscle spasms and hyperreflexia, caused by exotoxic Clostridium tetani
Define dysentery
Infection of intestine causing bloody/mucus diarrhoea
Define cholera
Secretory diarrhoeal illness caused by Vibrio Cholerae causing watery diarrhoea and dehydraton
Define Leprosy
Chronic infectious disease caused by acid-fast bacteria, characterised by skin lesions and peripheral nerve involvement
Define Rabies
Acute viral encephalomyelitis caused by rabies virus transmitted by animal bites causing hydrophobia and aerophobia
Define toxoplasmosis
Caused by a protozoan parasite with cats being the definitive host, usually asymptomatic but can cause encephalopathy
Define Lyme disease
Caused by a spirochete transmitted by ticks, characterised by erythema migrans rash, facial palsy + encephalopathy
Define measles
Highly infectious measles virus, characterised by maculopapular rash, cough, conjunctivitis, fever…
Define mumps
Acute systemic infection caused by RNA paramyxovirus causing parotid swelling, orchitis + aseptic meningitis
