Infection 2 Flashcards
What is aseptic meningitis?
Clinical and lab evidence of meningeal inflammation but negative routine bacterial cultures. May be secondary to : enteroviruses (most common), mcyobacteria, funci, spirochetes.
Autoimmune = sarcoidosis, behcets, SLE
Malignancy e.g. lymphoma, leukaemia, metastatic carcinoma
medication = NSAIDS, trimethroprim, azathioprine
Causative bacteria for meningitis?
Strep pneumoniae, Neisseria meningtidis, Haemophilus influenzae B, viral, fungal, arasites
Cause of encephalitis?
Infectious and non-infectious causes. Viruses mainly (herpes)
Meningitis symptoms, investigations and management?
Photpphobia, neck stiffness, headache and fever.
Ix: LP for CSF
Mx: Ceftriaxone and vancomycin for antimcrobial
Encephalitis symptoms and investigations?
Altered state of consciousness, seizures, personality hange, cranial nerve palsies, speech problems and motor and sensory deficit
Ix: Blood cultures, neuroimaging (MRI), CSF analysis
Causes of meningitis and RFs in neonates?
Group B strep (extnded labour and infection in prior pregnancy)
E.COli (late neonatal infection)
Also Listeria monocytogenes
Causes of meningitis in kids and teenagers?
Gram -ve diplococci -> Neisseria meningitides
Unvaccinated -> Haemophilus influenzae
Causes of meningitis in adults and elderly?
Gram +ve cocci -> Strep pneumoniae
Elderly, cheese, unpasteurized milk, alcoholics -> Listeria monocytogenes
Signs of meningitis?
Brudzinskis sign = Neck stiffness causes knees and hips to flex when neck brought forward from supine
Kernigs SIgn = severe stiffness of hamstrings mean legs cannot be straightened when hips at 90 degrees
Signs of meningitis infection?
Fever, tachycardia, hypotension
Altered mental state
Skin rash - petechiae -> meningococcal septicaemia
When to avoid LP?
Neurological signs suggesting raised ICP
Superficial infection over LP site
Coagulopathy
Bacterial CSF infection?
Turbid appearance, very high neutrophils, Very high protein, very low glucose and positive gram stain
Viral CSF infection?
Clear/cloudy appearance, high WCC of lymphocytes, increased protein and normal glucose
TB or fungal CSF infection?
Clear/fibrin web appearance, High WCC - lymphocytes, increased protein and decreased glucose
What is management of non-blanching rash or meningococcal septicaemia?
Admit and single dose IV benzypenicillin
Causes of encephalitis?
Viral : herpes viruses
Bacterial: neisseria meningitides, TB, syphilis, listeria
Fungal: crytococcus, candida
Parasitic: toxoplasma gondii, malaria
Para-infectious: acute diseeminsated encephalomyelitis, acute haemorrhagic leukoencephalitis
Prion disease e.g. mad cow
Autoimmune: encephalomyelitis
Causative organisms of infective endocarditis and associated RFs?
1) streptococci -> abnormal valves e.g. congenita e.g, DiGeorgel, post-rheumatic, calcification, degeneration
Strep Bovis with GI malignancy
Strep viridans from dental
2) Staphylococci -> prosthetic heart valves and IV drug use
3) Enterococci
4) Other organisms (HACEK) - negative blood culture
Other RFs: tubrulent flow e.g. PDA or VSD and recent dental work
WHat are the HACEK organisms for IE?
Hameophilus, actinobacillus, cariobacterium, eikenella, kingella.
Also Coxiella, histoplasma
IE Symptoms and signs?
Fever with sweats/chills/rigors.
Malaise, arthralgia, myalgia, confusion
Sings: pyrexia, tachycardia, anaemic signs,
Clubbing, New murmur (frequency M>A>T>P)
Splenomegaly, vasclitic lesions
What are the IE vasculitis lesions?
Petechiae e.g. retina = roths spots, pharyngel and conjunctival lesiosn, janeway lesions,
Osleers nodes and splinter haemorrhages
IE mneumonic?
FROM JANE with Heart
Fever, Roth spots, Oslers nodes, Murmur, Janeway lesions, ANaemia, Nail bed haemorrhages, Emboli
Buzzwords for IE?
Prosthetic valves, dental procedures, new onset murmur, vegetation on echo, right heart and indwelling catheter
IE investigations?
Bloods : FBC (high neutrophils, normocytic anaemia), ESR and CRO, U&Es, rheumatoid factor positive
3 blood cultres, 1 hour aprt, in 24 hours
Urgent ECHO, DUKES classifcaiton and borad spectrum abx till sensitivity
IE complications?
CHF, valve incompetence, aneurysm formation, systemic embolization, renal failure and glomerulonephritis
IE management?
4-6 weeks Abx
Native valves: penicillin sensitive strep viridans = benzypenicillin + gentamicin. S.aureus = flucloxacillin
Prosthetic: staph = fluclocaclloin/vancomycin + rifampicin + gentamicin
If resistant or penicillin allergic replace with vancomycin
Viral gastroenteritis causes?
ROTAVIRUS, adenovirus, astrovirus and calcivirus
Bacterial gastroenteritis causes?
CAMPYLOBACTER jejuni, E.COLI (O157), SALMONELLA< shigella, Vibrio cholera, listeria, yersernia enterocolitica
Protozoal gastroeneteritis causes?
Entamoeba histolytica, cryptosporidium parvum, giradia lamblia
Toxin producing things for gastroenteritis?
From Staphylococcus aureus, Clostridium botulinum, Clostridium perfringens,
Bacillus cereus, mushrooms, heavy metals, seafood.
Common contaminated food?
Improperly cooked meat (S. aureus, C. perfringens),
old rice (B. cereus, S. aureus), eggs and poultry (Salmonella), milk and cheeses (Listeria,
Campylobacter), canned food (botulism).
Dysentery (bloody) causes?
CHESS Campylobacter/clostridium Haemorrhagic ECOLI Entamoeba histolytica Shigella Salmonella
Diarrhoea C.Difficile indicators?
Abx use, antiperistaltic drugs
Staph aureus indicators diarrhoea?
Food, 1-6 hours eating, short lived
Cholera diarrhoea indicators?
Rice water diarrhoea, poor sanitation, shock
E.COli diarrhoea indicators?
Leafy vegetables
Bacillus cereus diarrhoea indicators?
reheated rice
Can cause cerebral abscess
Salmonella diarrhoea indicator?
EGGS, poultry may present with constipation and multplies in peyers patches of intestine
Campylobacter dysentery clue?
Uncooked poultry
Haemorrhagic ECOLI dysentery clue?
leafy vegetables.
Bloody diarrhoea followed by haemolytic uraemic synrdrome
Entamoeba histolytica dysentery clues?
poor sanitation, tropical places and MSM
Shigella dysentery clues?
person to person, poor sanitation and MSM
Salmonella dysentery clues?
Eggs
GE symptoms?
Sudden onsent nausea, vomiting, anorexia, diarrhoea (+/_- blood), abdo pain, fever and malaise
GE Ix?
Examination: mucous membranes, skin turgor, cap refill for dehydration
HR/BP for shock
Temp
Bloods: FBC,CRP/ESR U&Es
Stool MC&S: bacterial pathogens, ova cysts, parasites
GE management?
No systemic signs -> supportive (bed rest, fluids and electrolytes with oral rehydration solution)
Systemic signs(>39, visible blood, dehydrarion>2weeks) -> admit and oral fluids, Abx if organism identified. Need direct faecal smear then culture
Key features of hepatitis?
Aetiology = vral A-E, alcoholic and autoimmune
Fever, jaundice and raised ALT and AST
WHich Viral hepatitis have stronger links to HCC?
B and C
Viral hepatitis investigations?
Blood : FBC, LFTs, U&E CLotting: Prolonged PT USS for other causes Viral serology and PCR Liver biopsy (useful for cirrhosis diagnosis)
Key Hep A &E Features?
Faceo-oral
Hep A: Acute - travel history (water)
Asymptomatic
Hep E: Enteric, Epidemics (water), Expectant mothers E - immunocompromised
Management: supportive and avoid alcohol
Hep B features?
Acute infection -> nausea, anorexia, RUQ pain and jaundice
Chronic = 10%
Tranmission: Baby-making -> unprotected sex, MSM
Blood
Birthing
Acute : symptom supportive
Chronic: peginterferon alpha or tenofovir
Hep C Features?
Chronic
HCC Rf
Management: Curative antiretrovirals
Sofosbuvir (NS5B inhibitor)
Ledipasvir (NS5A inhibitor)
Grazoprevir (NS3/4 protease)
UTI definition?
Presence of >100,000 of colony-forming units per milimetre of urine. May be cystitis, pyelonephritis or prostatis
UTI signs and symptoms?
Cystitis: frequency, urgency, dysuria, Haematuria Foulsmelling +/- cloudy Suprapubic or loin pain
Pyelonephritis:
Rigors, pyrexia, nause + vomiting
Acute confusional stae -> elderly
Aetiology of UTI?
E>COLI!!! (gram -ve)
Proteus mirabilis
Klebsiella
Enterococci
UTI investigations?
Assess RF,
Distick urinalysis: positive nitrates +/- leukocytes
Urine MC&S
ABso USS to exclude ut obstruction or renal stones
Management of UTI?
Trimethroprim or nitrofurantoin
Malaria definition and aetiology?
Plasmodium protozoa
Usually incubates 1-2 weeks
Anopholes mosquito tranmission
Spp, FACIParum, Vivx/ovale, malaria
Malaria signs and symptoms?
Symptoms: HEADACHE. weakness, myalgia, arthralgia, anorexia, FEVER severe cold and rigors then sweating paroxysms
Signs: pyrexia, anaemia, splenomegaly
Malaria investigations?
Giemsa-stained thock and thin blood smears
Thick - parasite present
thin - species detection
FBC, Clotting, U&E, blood glucose, urinalysis
What are yersinia, leptosiria and coxiella features?
Yersinia causes plaques
Leptosiria due to water with animal urine
Coxiellla burnetti cauese Q fever, from cattle, sheep and goats
