Infectious Diseases Flashcards
Organinism? pneumonia, Green sputum + cold sore
Streptococcal
CAP organisms
Community acquired pneumonia (CAP) may be caused by the following infectious agents:
Streptococcus pneumoniae (accounts for around 80% of cases)
Haemophilus influenzae
Staphylococcus aureus: commonly after influenza infection
atypical pneumonias (e.g. Due to Mycoplasma pneumoniae)
viruses
Tetanus toxin MoA
Tetanus toxin (tetanospasmin) blocks the release of the inhibitory neurotransmitters GABA and glycine resulting in continuous motor neuron activity
ABx choice for meningococcal menigitis in penicillin allergy
Chloramphenicol is the antibiotic of choice for treating meningococcal infection in patients with a known penicillin allergy,
Katayama fever
Katayama fever, an acute manifestation of acute schistosomiasis.
The intermediate snail host of the parasitic flatworm which causes schistosomiasis is commonly found in the waters of Lake Malawi. Katayama fever typically presented with fever, urticarial rash, hepatosplenomegaly and bronchospasm.
acute schistosomiasis syndrome (Katayama fever)
fever
urticaria/angioedema
arthralgia/myalgia
cough
diarrhoea
eosinophilia
most common bacterial cause of pharyngitis (sore throat)
Streptococcus pyogenes. This organism, also known as Group A Streptococcus (GAS), is the most common bacterial cause of pharyngitis (sore throat) in children and young adults.
Which vaccinations is contraindicated in egg allergy
Yellow fever
(yellow like egg yolk)
Camylobacter ABx
Clarithromycin
4 viral heamorrhagic fevers
Yellow fever, Ebola, Lassa fever & Dengue
Yellow fever typical presentation
Yellow fever typically presents with flu like illness → brief remission→ followed by jaundice and haematemesis
Zoonotic inection - spread my mosquitos
classic description involves sudden onset of high fever, rigors, nausea & vomiting. Bradycardia may develop. A brief remission is followed by jaundice, haematemesis, oliguria
if severe jaundice, haematemesis may occur
Councilman bodies (inclusion bodies) may be seen in the hepatocytes
Fish tank granuloma organism
Mycobacterium marinum
The most common causes of viral meningitis in adults
enteroviruses e.g. coxsackie
Borrelia burgdorferi
Lyme disease
Burger with a lyme.
Bartonella henselae
Cat scratch fever
Bart has a cat.
A cat will try to scratch Barton’s Hens
Black Eschars in ID questions
think Anthrax or Rickettsia or Scrub typhus
Animal bites organism in cultures
Pasteurella multocida is a gram-negative coccobacillus which is the most likely organism to be isolated after a dog bite.
Send the animal out to pasture
Chancriod presentation
ChanCRIED in pain
Painful ulcer with ragged borders
SyphiLESS (painless)
LGV mix (starts with lymph so this is the painful bit)
ChanCRIED in pain
Syphilis ulcer presentation
Painless genital ulcer & painless IL
SyphiLESS (painless)
LGV mix (starts with lymph so this is the painful bit)
ChanCRIED in pain
LGV ulcer presentation
Painless ulcer painful IL
SyphiLESS (painless)
LGV mix (starts with lymph so this is the painful bit)
ChanCRIED in pain
Dapsone used for what?
Dapsone is an antimicrobial most commonly used in the treatment of leprosy and dermatitis herpetiformis. It has anti-inflammatory properties helpful in managing these conditions
all helminths rx = bendazoles
(excepts schisto + clonorchis = praziquantel
loa + wuchereria + toxocara canis = di-ethyl-carbamazine
river blindness + strongyloides = ivermectin)
all helminths rx = bendazoles
(excepts schisto + clonorchis = praziquantel
loa + wuchereria + toxocara canis = di-ethyl-carbamazine
river blindness + strongyloides = ivermectin)
TB meningitis CSF signs
can present with lymphocytic predominance, TB meningitis typically has a much higher protein level (>1 g/L), very low CSF glucose, and often has an opening pressure >25 cmCSF
In case of lynphocytosis of CSF, glucose must be checked. If higher than half of serum glucose, viral cause should be considered, otherwise TB Meningitis.
Normal CSF:serum glucose
> 0.6 is normal
Ratio less than this is bacterial or TB
South america + flulike illnes + periorbital oedema?
Chagas disease (American trypanosomiasis)
(siminal organism to african sleeping sickness)
Organism: Trypanosoma cruzi (Penelope cruz is from south america (not really shes from spain but for the purposes of remembering)
‘Americans drive Mercedes-BENZ’ (Benznidazole used in Chagas’ disease/American trypanosomiasis)
Cocci
makes catalase: Staphylococci
does not make catalase: Streptococci
Staphylococci
makes coagulase: S. aureus
does not make coagulase: S. epidermidis (novobiocin sensitive), S. saprophyticus (novobiocin resistant)
Cocci
makes catalase: Staphylococci
does not make catalase: Streptococci
Staphylococci
makes coagulase: S. aureus
does not make coagulase: S. epidermidis (novobiocin sensitive), S. saprophyticus (novobiocin resistant)
Abx for cholerra
Doxycycline
I think of Love in the Time of Cholera, and with love comes Chlamydia.. and with Chlamydia comes doxycycline
A grey dense pseudomembrane covering the tonsils is classically seen in
Diphtheria
anthrax Mx
Anthrax caused by Bacillis and treated by Cipro
MNEMONIC IS ABC
Leismanisis characeteristics
sandflies
Sudan
MASSIVE SPLENOMEGALY
ASHEN SKIN
presents with fever, weight loss, massive splenomegaly and pancytopenia. The additional clinical feature of ‘dark and ashen’ skin suggests visceral leishmaniasis as the cause
HIV: Mycobacterium avium complex management
Management
rifampicin + ethambutol + clarithromycin
MAC=REC ( both 3 letters)
Fite’s Faraco is a stain used to identify
mycobacterium leprae.
Ziehl-Neelsen stain (AKA Acid fast stain) reveals red cysts in the stool of infected individuals
Cryptosporidium (parasite)
Pruritic rash on the buttocks or soles + eosinophilia
Pruritic rash on the buttocks or soles ?Strongyloides stercoralis
Strongyloides stercoralis gains access to the body by penetrating the skin
This typically occurs via the soles of the feet but autoinfection in the perianal area may also occur.
Haemophilus ducreyi.
Chancroid : a tropical disease caused by Haemophilus ducreyi. It causes painful genital ulcers associated with unilateral, painful inguinal lymph node enlargement. The ulcers typically have a sharply defined, ragged, undermined border.
1st line option for immunocompromised patients requiring treatment for cerebral toxoplasmosis
Parasitic infection
Immunocompromised patients with toxoplasmosis are treated with pyrimethamine plus sulphadiazine
HIV, neuro symptoms, widespread demyelination + neuro Sx cause?
PML
Pogressive myltufocal leukoencephalopathy
due to infection of oligodendrocytes by JC virus (a polyoma DNA virus)
Lymphogranuloma venereum organism
Chamydia Trachomatis
Groove sign is separation inguinal nodes by the inguinal ligament and is characteristic of what disease?
Lymphgramuloma venerum
Rifamacin MoA?
Rifampicin inhibits RNA synthesis
Ri-fampicin Ri-bonucleic Acid (RNA)
RNA synthesis - Rifampicin
Anthrax treatment
Ciprofloxacin
Hepatitis A & E associated with which foods?
A - shellfsih
E - undercooked meat
E is assocaited with worse mortality in pregnant people if they contract it
How to diffeerentitate between two viral haemorrhagic fevers:yellow fever and Lassa fever?
Disease course
Yellow fever: jaundice and bipashic disease course
Lassa fever: NO JAUNDICE and one continuous disease course
Yellow - he first stage classically causes a non-specific illness which is often described as ‘flu-like’ with fever, malaise, nausea, myalgia and headache. This stage is due to the circulating virus in the bloodstream (viraemic stage). There is then a recovery stage when the viraemia clears. Most patients recover completely following this stage and do not progress to the third stage. Around 15% of patients progress after about 3-7 days after the onset of symptoms which presents with fever, nausea and vomiting, acute kidney injury, hepatitis with jaundice, and haemorrhage
Leishmaniasis subtypes (3) and how they present
Leismaniasis is a protozoa spread by sandflie bites in SOUTH AMERICA
- Cutaneous -> Leshmaniasis MEXICANA
- Mucocutaneous -> Leishmaniasis BRAZILIENSIS
- Visercral -> THIS ONE IS BAD
Leimanisasis DONOVANOSIS
Donovan is bad and grey
Paul Bunnell test used for what and what other name does it go by?
Used for infectious mononucleosis
AKA Heterophile antibodies
Paul Bunnell = Monospot = heterophile antibody test
In patients with infectious mononucleosis, empirical treatment with amoxicillin often leads to a morbilliform rash. A heterophile antibody test (Paul-Bunnell) has high specificity and moderate sensitivity for infectious mononucleosis.
Strongolodies treatment
Ivermectin - Ivan is a strongman
Al-bendazole is an al-ternative
Praziquant-lel - for shis (shistosomasis) and giggles
Remember:
Gram-positive cocci = staphylococci + streptococci (including enterococci)
Gram-negative cocci = Neisseria meningitidis + Neisseria gonorrhoeae, also Moraxella catarrhalis
Therefore, only a small list of Gram-positive rods (bacilli) need to be memorised to categorise all bacteria - mnemonic = ABCD L
Actinomyces
Bacillus anthracis (anthrax)
Clostridium
Diphtheria: Corynebacterium diphtheriae
Listeria monocytogenes
Remaining organisms are Gram-negative rods, e.g.:
Escherichia coli
Haemophilus influenzae
Pseudomonas aeruginosa
Salmonella sp.
Shigella sp.
Campylobacter jejuni
Live attenuated vaccines
Yellow fever, MMR, oral poliovirus
BCG
measles, mumps, rubella (MMR)
influenza (intranasal)
oral rotavirus
oral polio
yellow fever
oral typhoid
Vaccines contrindicated in ALL HIV patients
TB
Oral polio virus
CHolera
other live attenuated vaccines ar CI if CD4 count <200
Reminds me of Umbrella by Rihanna!
When CD4’s over two hundred
You can stand under my measles mumps rubella, yellow, varicella
ay ay ay§
second most common cause of UTIs in sexually active young women
Staphylococcus saprophyticus
gram-positive coccus that grows in clusters and is coagulase-negative.
Bacteria vaginosis organism
Bacterial vaginosis - overgrowth of predominately Gardnerella vaginalis
Your lady gadren smells fishy
Genital wart treatment
Genital wart treatment
Which antiboitic promotes acquision of MRSA
Ciprofloxacin
This is a FLUORQUINONLONE therfore could kill
american trypanosomiasis
Chagas - everything enlarges
African chagas - lymph nodes enalargement, CNS enalargement ( headache, meningo encephalitis
American chagas ( just like their life style ) - Cardiac enlargement ( cardiomyopathy) , GI enlargements ( megacolon , megaoesophagus)
Americans cruse (Cruzi) in Mercedes Benz (benznidazole)
conjugate vaccines
Conjugate vaccines are those that use a protein that attaches to the polysaccharide outer coat of the pathogen to make it more immunogenic. This is because polysaccharides alone are not very immunogenic, especially in infants and young children. By linking these polysaccharides to a protein, the immune system can recognise and respond more effectively to the pathogen.
e.g meningococcal
Diptheria characteristics
sore throat, bulky cervical lymph nodes, and a greyish-white membrane on the tonsils
Throat swab microscopy with methylene blue staining demonstrates a ‘Chinese letter pattern’ with metachromatic granules. -> Corynebacterium diphtheria
Tetnus protocol for woinds
Full course 5 vaccines, last within 10 years: No Ig or booster
Incompletely immunised + tetanus-prone wound: Tetanus Ig (give distant to vax site)
Incompletely immunised: immediate vaccine dose + further to complete schedule
Chiknguyna =
JOINT PAIN + fevers
ChikunGUNya
joint feels like you shot me with a GUN
If you shot with a GUN your bloods would be normal
shooting would be ABRUPT onset (abrupt fever onset)
no medical treatment for gun shots
he absence of a rash makes chikungunya more likely than dengue. and dnegue associated with thrrombocytopenia
HIV screening
P24 + antibody (immunoassay)
If patient is very recently infected -> test for HIV-1 NAAT (or) P24
If seroconversion symptoms / >10 days after exposure –> it means body has produced antibody –> prioritise immunoassay to test for antibody
Retro-orbital headache, fever, facial flushing, rash, thrombocytopenia in returning traveller → ?
dengue
viral haemorrhagic fever s
yellow fever, Lassa fever, Ebola, dengue
Botulinum toxin works by
inhibiting the release of acetylcholine at synapses of the nervous system, both peripherally and centrally
Typhoid fever
Typhoid fever, also known as typhoid, is a disease caused by Salmonella typhi bacteria. Symptoms may vary from mild to severe and usually begin 6 to 30 days after exposure, accompanied by weakness, abdominal pain, constipation, headaches, and mild vomiting. Some people develop a skin rash with rose coloured spots
tetracycline moa
Tetracyclines inhibit the 30S subunit of ribosomes
T = THIRTY S
Following a splenectomy patients are particularly at risk from
pneumococcus, Haemophilus, meningococcus and Capnocytophaga canimorsus* infections
Cavitating lung lesions on CXR with which pneumonia
Staph aureas
also associated with preceding viral UTI
Pneumonia + Alcoholic + Cavitation = Klebsiella
Pneumonia + Prior Flu = Staph Pneumonia
Pneumonia + Chicken Pox Rash = Varicella Pneumoniae
Pneumonia + Hemolytic Anemia = Mycoplasma
Pneumonia + Hyponatraemia + Travel History = Legionella
Pneumonia + Fleeting opacities = Cryptogenic Pneumonia
Penumonia + Fits/LOC = Aspiration Pneumonia
Pneumonia + HSV oral lesion = Strept Pneumonia.
Pneumonia + parrot = Chyledmia psitatssi
Pneumonia + farm animals = Q fever (coxillea brunte)
Pneumonia + HIV = think pcp but if straight forward case strep pneumonia is still most common
Pneumonia + Cystic fibrosis = consider pseudomonas/Burkohdera.
COPD + Pneumonia (or exacerbation) - Haemophilus Influenza
Buy AT 30:
- Aminoglycosides
- Tetracyclines
CELL at 50
- Clindamycin
- Erythromycin
- Linezolid
Nitazoxanide
broad-spectrum antiparasitic agent and can be used to treat immunocompromised patients with cryptosporidiosis
first-line antibiotic treatment for tetanus
metronisazole (give allongside immunoglobulin)
ABX FOR CAMYLOBACTER
CLARITHROMYCIN
Ribavirin
Ribavirin is an antiviral medication that works with other medications to treat hepatitis C.
Cat scratch disease - caused by
Cat scratch disease - caused by Bartonella henselae
Diloxanide furoate
Diloxanide furoate = ‘luminal agent’ (to eliminate intraluminal cysts) with metro in amoebiasis
most common cause of viral meningitis is
enetervirus e.g. coxsackie B
leptospirosis treatmnt
erythromycin/azithromycin is non severe
benpen if severe (neurological signs)
1st line treatment for severe p falcifurm infection
IV arestunate
Amantdadine MoA
Amantadine - inhibits uncoating (M2 protein) of virus in cell. Also releases dopamine from nerve endings
nitazoxanide
For patients with chronic refractory cryptosporidiosis, especially immunocompromised patients, nitazoxanide may be used - typically a 14-day course
Praziquantel
Praziquantel is used to treat schistosomiasis.
going for a waz PrWAZiquantal - shisto and bladders
Pneumonic for live vaccines: You Musn’t Prescribe BCG Incase They RIP
Yellow fever, MMR, Polio, BCG, Influenza, Typhoid, Rotavirus
anthrax treatment
CIprofloxacin
Rubeanic acid stain
Rubeanic acid = copper (Wilson’s)
Perl’s Prussian blue
= iron (Haemochromatosis)
Rose Bengal
= corneal damage
Congo red
= amyloidosis
Ziehl-Neelsen stain
= red cysts= Cryptosporidium infection
Warthin-Starry staining
= Bartonella henselae
Giemsa stain
= Toxoplasma gondii
Silver stain
= Pneumocystis carini
Granuloma inguinale organism
Klebsiella granulomatis. Granuloma inguinale, also known as Donovanosis, is a sexually transmitted infection caused by the bacterium Klebsiella granulomatis. It presents with painless genital ulcers and can progress to cause significant tissue destruction if left untreated.
Patients with hyposplenism should be vaccinated against
pneumococcal, Haemophilus type B and meningococcus type C
ABC - pneum A Haem B men C.
rhabditiform larvae are diagnostic of
strongyloidiasis
Strongyloides stercoralis exist as rhabditiform larvae in soil (non-infective first stage larvae) and as filariform larvae in humans (infective third stage larvae)
macrophages containing amastigotes.
Visceral leshimaniasis
(Tx with sodium stibogluconat)
