Infectious Diseases Flashcards
Post-exposure prophylaxis for Hep C?
none
> do monthly PCR - if seroconversion then IFN +/- ribavarin
what test remains positive after treatment in syphilis?
TPHA - treponemal specific antibody tests
most common isolated organism following dog / animal bite?
Pasteurella multocida
mx of animal bite?
cleanse wound + Co-amoxiclav
most common causes of viral meningitis?
enteroviruses e.g. coxsackie B, echovirus
Ix of Aspergilloma?
CXR: rounded opacity, may seen Crescent sign
High titres Aspergillus precipitins
features of Leptospirosis?
early phase: fever, flu-like symptoms
- subconjunctival suffusion (redness)/haemorrhage
- bilateral calf myalgia
second immune phase may lead to more severe disease (Weil’s disease):
- AKI (seen in 50%)
- hepatitis: jaundice, hepatomegaly
- aseptic meningitis
Ix of leptospirosis?
serology: antibodies to leptospirosis develop after ~7d,
PCR, culture (takes several weeks)
Mx of leptospirosis?
high dose benzylpenicillin or doxycycline
Features of Q fever?
fever, malaise, PUO.
- transaminitis
- atypical pneumonia
- culture-negative endocarditis
- exposure to farm animals
organism implicated in Q fever?
coxiella burnetii, a rickettsia
- source; typically an abattoir, cattle/sheep, infected dust
mx of Q fever?
doxycycline
IV dexamethasone should be given to reduce the risk of neurological sequelae, but BNF advise to withhold if:
septic shock, meningococcal septicaemia, immunocompromised, meningitis following surgery
Mx of meningitis if patient has immediate hypersensitivity reaction to penicillin or to cephalosporins?
chloramphenicol
1st line mx of gonorrhoea?
Single dose IM ceftriaxone 1g
- if ceftriaxone refused: oral cefixime 400mg + oral azithromycin 2g single doses
Key features of disseminated gonococcal infection?
tenosynovitis, migratory polyarthritis, dermatitis
Features include diarrhoea, abdominal pain, papulovesicular lesions where the skin has been penetrated by infective larvae e.g. soles of feet and buttocks,
larva currens: pruritic, linear, urticarial rash, if the larvae migrate to the lungs a pneumonitis similar to Loeffler’s syndrome may be triggered
Strongyloides stercoralis
Mx of strongyloides stercoralis?
Ivermectin (1st line) and -bendazoles (2nd line- albendazole)
perianal itching, particularly at night; girls may have vulval symptoms
entorebius vermicularis (pinworm)
diagnosis of enterobius vermicularis (pinworm) infection?
apply stick plastic tape to perianal area and send to lab for microscopy to see eggs
mx of enterobius vermicularis (pinworm)?
-bendazoles
Larvae penetrate skin of feet; gastrointestinal infection → anaemia
Thin-shelled ova
Ancylostoma duodenale, necator americanus (hookworms)
Mx: -bendazoles
Transmission by deer fly and mango fly
Causes red itchy swellings below the skin called ‘Calabar swellings’, may be observed when crossing conjunctivae
Loa Loa
Mx of Loa Loa infection?
diethylcarbamazine
Typically develops after eating raw pork
Features include fever, periorbital oedema and myositis (larvae encyst in muscle)
trichinella spiralis
mx: -bendazoles
Causes ‘river blindness’. Spread by female blackflies
Features include blindness, hyperpigmented skin and possible allergic reaction to microfilaria
Onchocerca volvulus
mx: ivermectin
rIVERblindness = IVERmectin
Transmission by female mosquito
Causes blockage of lymphatics → elephantiasis
Wucheria Bancrofti
- mx: diethylcarbamazine
Mx of wucheria Bancrofti?
diethylcarbamazine
Eggs are visible in faeces
May cause intestinal obstruction and occasional migrate to lung (Loffler’s syndrome)
ascaris lumbricoides (giant roundworm)
mx: -bendazoles
Transmission through ingestion of eggs in dog faeces. Definite host is dog, which ingests hydatid cysts from sheep, who act as an intermediate host. Often seen in farmers.
Features include liver cysts and anaphylaxis if cyst ruptures (e.g. during surgical removal)
Echinococcus granulosus (tapeworm)
mx: -bendazoles
Often transmitted after eating undercooked pork. Causes cysticercosis and neurocysticercosis, mass lesions in the brain ‘swiss cheese appearance’
Taenia solum (tapeworm)
mx: -bendazoles
mx of tapeworms?
-bendazoles
Hosted by snails, which release cercariae that penetrate skin.
Causes ‘swimmer’s itch’ - frequency, haematuria. Risk factor for squamous cell bladder cancer
Schistosoma haematobium
mx: praziquantel
mx of schistosomiasis?
praziquantel
features of strongyloidiasis?
- GI symptoms: bloating, discomfort, diarrhoea, larvae passed in stool
- larva currens: urticarial band that typically starts in the peri-anal area. (rash rapidly migrates) -> this is the larvae in the skin
Features of toxoplasmosis?
- accounts for 50% of cerebral lesions in patients with HIV
- constitutional symptoms, headache, confusion, drowsiness
- CT: usually single/ multiple ring enhancing lesion +/- mass effect
- in immunocompetent patients: symptomatic, or presents similar to infectious mono (Fever, LNpathy, malaise)
Mx of toxoplasmosis?
sulfadiazine and pyrimethamine
Features of primary CNS lymphoma?
- 30% of cerebral lesions in HIV
- assoc w EBV
- CT; single/ multiple homogenous enhancing lesions
tx of Primary CNS lymphoma?
steroids (may significantly reduce tumour size), chemotherapy (e.g. methotrexate) +/- whole brain irradiation. surgery may be considered
Ix to differentiate between toxoplasmosis and Primary CNS lymphoma?
Thallium SPECT
Toxoplasmosis: Thallium spect NEGATIVE
Lymphoma; thallium SPECT POSITIVE
Features of cryptococcal CNS infection in HIV?
meningitis, headache, fever, malaise, N+v, seizures, focal neurological deficit
- CSF: high opening pressure, India ink test positive
- CT: meningeal enhancement, cerebral oedema
Features of botulism
patient usually fully conscious with no sensory disturbance flaccid paralysis diplopia ataxia bulbar palsy
Mx of botulism?
botulism antitoxin and supportive care
mx of giardiasis?
metronidazole
Ix of suspected meningococcal septicaemia?
blood cultures - might be negative if taken after abx
blood PCR- sensitivity of over 90%
lumbar puncture is usually contraindicated
full blood count and clotting to assess for disseminated intravascular coagulation
pathophysiology of tetanus?
- clostridium tetani releases tetanospasmin exotoxin
- tetanospasmin prevents release of GABA
features of tetanus?
prodrome fever, lethargy, headache
trismus (lockjaw)
risus sardonicus (spasm of facial muscle - appears to be grinning)
opisthotonus (arched back, hyperextended neck)
spasms (e.g. dysphagia)
Mx of tetanus?
supportive: ventilatory support, muscle relaxants e.g. diazepam
IM human tetanus Ig for high risk wounds
metronidazole as antibiotic of choice
features of Cat scratch disease?
fever, history of a cat scratch, regional lymphadenopathy
headache, malaise
- Bartonella henselae (gram -ve rod)
1st line ix for suspected ascending cholangitis?
USS abdomen
most common organisms in ascending cholangitis?
- E coli most common
followed by klebsiella, enterococcus, streptococcus
Reynolds pentad of ascending cholangitis?
Charcot’s triad: fever, RUQ pain, jaundice
+ confusion and hypotension
Tx of ascending cholangitis?
ERCP- usually after 72h of abx
Percutaneous transhepatic cholangiogram and biliary drain
features of congenital toxoplasmosis?
- neurological damage to unborn child: cerebral calcification, hydrocephalus, chorioretinitis
- ophthalmic damage: retinopathy, cataracts.
mx of toxoplasmosis in immunocompetent patients?
no treatment required unless patient has a severe infection or is immunosuppressed
Ix of choice to diagnose acute Hep C infection?
HCV RNA
`complications of chronic hep c?
- rheumatological problems: arthralgia, arthritis
- eye problems: Sjogren’s syndrome
- cirrhosis (5-20% of those with chronic disease)
- hepatocellular cancer
- cryoglobulinaemia: typically type II (mixed monoclonal and polyclonal)
- porphyria cutanea tarda (PCT)
- membranoproliferative glomerulonephritis
Mx of chronic HCV infection?
treatment depends on viral genotype- this should be tested prior to treatment
- combination of protease inhibitors (e.g. daclatasvir + sofosbuvir or sofosbuvir + simeprevir) +/- ribavarin
mx of listeria meningitis?
IV amoxicillin + gentamicin
Mx of listeriosis in pregnancy?
amoxicillin
complications of malaria?
cerebral malaria: seizures, coma
- acute renal failure: secondary to intravascular haemolysis
- ARDS
- hypoglycaemia
- DIC
Mx of severe falciparum malaria?
- if parasite count >2%, IV artesunate
- if Parasite count >10%, + exchange transfusion
Most common organism found in central line infections
Staphylococcus epidermidis
vaccines which should not be given to immunocompromised?
live attenuated
- BCG
- Yellow fever
- Oral polio
- Intranasal influenza
- Varicella
- Measles, mumps and rubella (MMR)
- oral rotavirus/ typhoid
1st line mx of UTI in pregnant woman in first trimester?
nitrofurantoin
mx of acute pyelonephritis?
broad spec cephalosporin or quinolone for 10-14 days
Viral meningitis: but LP shows particularly low glucose?
- normally CSF glucose in viral meningitis should be 60-80% plasma glucose
- mumps assoc low glucose
- also herpes encephalitis
Features of leprosy?
- patches of hypopigmented skin typically affecting the buttocks, face, and extensor surfaces of limbs
- sensory loss
Mx of multibacillary (>6 lesions) leprosy?
triple therapy: rifampicin, dapsone, clofazimine
- for 12 months
mx of shigella diarrhoea?
usually self limiting and does not require antibiotic treatment
- safety net - if severe disease, immunocompromised, bloody diarrhoea -> give ciprofloxacin
Ix of Lyme disease?
- clinical diagnosis if erythema migrans present -> indication to start abx
- ELISA antibodies to Borrelia burgdoferi is 1st line
- if negative but high suspicion, repeat ELISA 4-6 wks after first
- if equivocal: immunoblot test for Lyme disease
Mx of disseminated Lyme disease?
Ceftriaxone
Mx of Lyme disease?
doxycycline
amoxicillin in pregnancy
most common cause of non-falciparum malaria
Plasmodium vivax
1st line mx for Plasmodium vivax and Plasmodium ovale?
Chloroquine or Artemisin-based combination therapy (e.g. Artemether-lumefantrine)
What should be given to patients with ovale or vivax malaria following acute treatment to prevent relapse?
primaquine
- to destroy liver hypnozoites and prevent relapse
Features of yellow fever?
sudden onset high fever, rigors, N+V, bradycardia. Jaundice, haematemesis, oliguria.
- councilman bodies (inclusion bodies) may be seen in the hepatocytes
Pathophysiology of Dengue fever?
- can progress to viral haemorrhagic fever
- transmitted by Aedes mosquito
- form of DIC can develop
- low Platelets, raised transaminase levels
mx of dengue fever?
entirely symptomatic
Ix of legionella pneumonia?
Urinary antigen
causative agent of hairy leukoplakia?
EBV
Causative agent of primary CNS lymphoma?
EBV
Diagnosis of Infectious mononucleosis?
Monospot test (heterophil antibody test) in 2nd week of illness + FBC
Mx of infectious mono?
Supportive
post-exposure prophylaxis for Hep B?
- known responder to vaccine: booster dose
- non responder/ in the process of vaccination: Hep B IG + vaccine
features of Chancroid?
- haemophilus ducreyi
- PAINFUL genital ulcers
- unilateral, painful inguinal LN enlargement
- ulcers typically have a sharply defined, ragged, undermined border
Features of Lymphogranuloma venereum?
- chlamydia trachomatis
- stage 1: small painless pustule -> ulcer
- stage 2: painful inguinal Lymphadenopathy
- stage 3: proctocolitis
treatment of lymphogranuloma venereum?
doxycycline
Secondary features of Syphilis?
- occurs 6-10 weeks after primary infection
systemic symptoms: fevers, lymphadenopathy
rash on trunk, palms and soles
buccal ‘snail track’ ulcers (30%)
condylomata lata (painless, warty lesions on the genitalia )
Tertiary features of Syphilis?
- gummas (granulomatous lesions of the skin and bones)
- ascending aortic aneurysms
- general paralysis of the insane
- tabes dorsalis
- Argyll-Robertson pupil
features of congenital syphilis?
- blunted upper incisor teeth (Hutchinson’s teeth), “mulberry” molars
- rhagades (linear scars at the angle of the mouth),
- keratitis
- saber shins
- saddle nose
- deafness
Mx of HSV gingovostomatitis?
oral acyclovir, chlorhedixine mouthwash
Mx of HSV cold sores?
topical acyclovir
Mx of genital herpes?
oral aciclovir
rash, headache + single/ multiple eschars + history of recent foreign travel?
rickettsial infections
Features of listeria monocytogenes infection?
diarrhoea, flu-like illness
pneumonia , meningoencephalitis
ataxia and seizures
Ix of suspected listeria infection?
blood cultures
Complications of listeria infection in pregnancy?
miscarriage, premature labour, stillbirth and chorioamnionitis
Mx of preventing tetanus if vaccination hx incomplete or unknown? OR full course of tetanus vaccines, with last dose >10 years ago
reinforcing dose of vaccine, regardless of wound severity
- high risk wounds: + Tetanus Ig
Mx of preventing tetanus if full course of tetanus vaccines, with last dose <10 yr ago?
Nothing regardless of wound severity
most commonly affected site of necrotising fasciitis?
perineum (Fournier’s gangrene)
Management of necrotising fasciitis?
urgent surgical debridement + IV abx
Classification of necrotising fasciitis?
type 1: most common. mixed anaerobes and aerobes. often post surgery in diabetics
type 2: streptococcus pyogenes
which type of malaria is associated with nephrotic syndrome?
plasmodium malariae
Most frequent and severe manifestation of Chagas disease?
cardiomyopathy
Features of Sleeping sickness aka African trypanosomiasis?
- trypanosome chancre- painless subcut nodule at site of infection
- intermittent fever
- enlargement of posterior cervical LNs
- later: CNS involvement e.g. somnolence, headaches, mood changes, meningoencephalitis
Types of African trypanosomiasis/ Sleeping Sickness?
Trypanosoma rhodisiense: East Africa, acute course (Rapid)
Trypanosoma gambiense: West Africa, gradual course
Mx of African trypanosomiasis/ Sleeping Sickness?
early disease: IV pentamidine/ Suramin
later disease/ CNS involvement: IV melarsoprol
Features of Chagas disease (aka American trypanosomiasis)?
95% are asymptomatic in the acute phase, sometimes will see a chagoma (erythematous nodule at site of infection) and periorbital oedema.
- parasites in HEART: myocarditis, dilated cardiomyopathy (w apical atrophy) and arrhythmias
- and GI TRACT: megaoesophagus and megacolon -> dysphagia/ constipation
Mx of Chagas disease?
acute: benznidazole/ nifurtimox
chronic: treat the complications e.g. heart failure
Features of Rabies
prodrome: headache, fever, agitation
hydrophobia: water-provoking muscle spasms
hypersalivation
Negri bodies: cytoplasmic inclusion bodies found in infected neurons
Mx of preventing rabies Following an animal bite in at-risk countries?
- wash wound
- if already immunised: 2 further doses of vaccine
- not immunised: Full course vaccination + Human Rabies IG
Most common opportunistic infection in AIDS?
pneumocystis carinii pneumonia
Complications of pneumocystis carinii pneumonia?
common: pneumothorax Rare: - hepatosplenomegaly - lymphadenopathy - choroid lesions
Mx of pneumocystis carinii pneumonia?
- Co-trimoxazole
- Severe: IV pentamidine
- aerosolised pentamidine is an alternative, but less effective
- Steroids if hypoxic!!
Ix of chronic Hepatitis C?
anti-HCV antibody test
Management of Cysticercosis (type of tape worm)?
Niclosamide
Mx of Hydatid disease?
albendazole
Features of Hydatid disease?
- caused by dog tapeworm Echinococcus granulosus
- Dogs ingesting hydatid cysts from sheep liver
- often seen in farmers
- can cause liver cysts
Mx of meningeal tuberculosis?
RIPE + steroids for 12 months
Side effects of ethambutol?
optic neuritis: check visual acuity before and during treatment
Side effects of pyrazinamide?
hyperuricaemia causing gout
arthralgia, myalgia
hepatitis
Side effects of isoniazid?
peripheral neuropathy: prevent with pyridoxine (Vitamin B6)
hepatitis, agranulocytosis
liver enzyme inhibitor
Side effects of rifampicin?
potent liver enzyme inducer
hepatitis, orange secretions
flu-like symptoms
MOA of Aciclovir/ Ganciclovir?
DNA polymerase inhibitor
- Guanosine analogue, phosphorylated by thymidine kinase, which in turn inhibits the viral DNA polymerase
MOA of Ribavarin (used in Chronic hep C, RSV)?
- Inhibits IMP (inosine monophosphate) dehydrogenase, interferes with the capping of viral mRNA
- guanosine analogue
MOA of Amantadine (e.g. influenza/ parkinsons disease)?
inhibits uncoating (M2 protein) of virus in cell - also releases dopamine from nerve endings
MOA of Oseltamivir (used in influenza)?
Inhibits neuraminidase
MOA of Foscarnet (used in CMV/ HSV if not responding to aciclovir)?
Pyrophosphate analogue which inhibits viral DNA polymerase
MOA of IFN-alpha (used in Hep B/C, hairy cell leukaemia)?
human glycoproteins which inhibit synthesis of mRNA
Class of medications:
Zidovudine, Didanosine, lamivudine, stavudine, zalcitabine
NRTI
- nucleoside analogue reverse transcriptase inhibitors
Class of medications:
Indinavir, nelfinavir, ritonavir, saquinavir?
Protease inhibitors
Class of medications:
e.g. nevirapine, efavirenz?
NNRTI
- non-nucleoside analogue reverse transcriptase inhibitors
Ix of choice for diagnosing chlamydia?
NAATs
- nucleic acid amplification tests
- urine (1st line for men), vulvovaginal (1st line for women)/ cervical swab
1st line Management of chlamydia?
7 day course of Doxycycline
- doxycycline CI: azithromycin
Mx of chlamydia in pregnancy?
azithromycin, erythromycin or amoxicillin
what does strep pyogenes (Group A beta haemolytic streptococcus) cause
Erysipelas, impetigo, cellulitis, type 2 Nec fasc, pharyngitis/tonsillitis, rheumatic fever, post strep glomerulonephritis, scarlet fever
`mx of cutaneous anthrax?
Ciprofloxacin
Main organism in BV?
gardnerella vaginalis
- gram + coccobacilli
Acute manifestation of Schistosomiasis?
- swimmers' itch acute schistosomiasis syndrome (Katayama fever): -- fever -- urticaria/angioedema -- arthralgia/myalgia -- cough -- diarrhoea -- eosinophilia
Features of chronic Schistosoma haematobium infection?
- egg clusters (pseudopapillomas) deposited in bladder, causing inflammation
- Xray shows calcification of egg clusters
- obstructive uropathy/ kidney damage
- risk factor for squamous cell bladder ca
- frequency, haematuria, bladder calcification
Bladder calcification on X-ray?
Schistosoma haematobium
Mx of schistosome haematobium?
single oral dose of praziquantel
Features of schistosome mansoni/ japonicum infection?
- > chronic GI symptoms: intermittent, bloody diarrhoea
- > progressive hepatomegaly and splenomegaly due to portal vein congestion
- > liver cirrhosis, variceal disease, cor pulmonate
most common cause of infective diarrhoea in HIV patients?
cryptosporidium
Ix of Cryptosporidium diarrhoea?
Modified Ziehl-Neelsen stain of stool: characteristic red cysts of Cryptosporidium
Mx of Cryptosporidium diarrhoea in HIV?
supportive
Mx of mycobacterium avian intracellulare diarrhoea in HIV?
Rifampicin, ethambutol and clarithromycin
Mx of Staphylococcal toxic shock syndrome
removal of infection focus (e.g. retained tampon)
IV fluids
IV antibiotics
Pneumonia related to cold sores?
strep pneumoniae
Organism implicated in Rocky Mountain spotted fever?
Rickettsia ricketsii
Features of Rocky Mountain spotted fever?
headache, fever, rash - initially maculopapular before becoming vasculitic
- tick-borne
Features of Brucellosis
- exposure to unpasteurised cheese
- hyperhidrosis with “wet hay” smell
- fluctuating temperatures
- transient arthralgia/ myalgia
- hepatosplenomegaly
- sacroiliitis: spinal tenderness may be seen
- complications: osteomyelitis, infective endocarditis, meningoencephalitis, orchitis
- leukopenia often seen
Best test for diagnosis of Brucellosis?
Brucella serology
Mx of Brucellosis?
doxycycline and streptomycin
Prophylaxis of Mycobacterium avium intracellulare in HIV patients with CD4<100 cells/mm3
clarithromycin/ azithromycin
MOA of Macrolides e.g. clarithromycin/ erythromycin and Clindamycin and Chloramphenicol?
Binds to 50S subunit, inhibiting translocation of tRNA
exception: Chloramphenicol - binds to 50S subunit, inhibits peptide transferase
MOA of aminoglycosides e.g. gentamicin and tetracyclines e.g. doxycycline?
Binds to 30S subunit
What are some gram negative cocci?
Neisseria meningitidis + Neisseria gonorrhoea, Moraxella catarrhalis
What are some Gram positive rods?
ABCD L A. - Actinomyces B - Bacillus anthracis (anthrax) C- Clostridium D- Diphtheria: Corynebacterium diphtheriae L- Listeria monocytogenes
For a patient undergoing an elective splenectomy, when to give the pneumococcal vaccine?
2 week before surgery
features of measles?
prodrome: irritable, conjunctivitis, fever
Koplik spots (before rash): white spots (‘grain of salt’) on buccal mucosa
rash: starts behind ears then to whole body, discrete maculopapular rash becoming blotchy & confluent
diarrhoea occurs in around 10% of patients
Ix of measles?
IgM antibodies to measles
Most common complication of measles?
otitis media
most common cause of death from measles?
pneumonia
Mx of Lassa fever?
ribavarin
How is Lassa fever transmitted?
contact with rat faeces
characteristic CT findings of numerous small focal calcification throughout both hemispheres, with no enhancement
Neurocysticercosis
Most common cause of cutaneous larva migrans?
Ancylostoma braziliense
Most common cause of visceral larva migrans?
Toxocara canis
- Eye granulomas, liver/ lung involvement
Features of Orf?
- sheep/ goat farmers
- hands and arms: initially small raised, red-blue papules
- later may increase in size to 2-3cm -> flat topped and haemorrhagic
Features of Lyme disease?
Early:
- erythema migrans
- systemic symptoms: malaise, fever, arthralgia
Later features:
- CVS: heart block, myocarditis
- neurological: cranial nerve palsies, meningitis
- polyarthritis
Raltegravir, elvitegravir, dolutegravir
- MOA?
- gravir
- INTEGRASE inhibitors
indinavir, nelfinavir, ritonavir, saquinavir
- MOA?
-navir
PROTEASE inhibitors
Which protease inhibitor is a potent inhibitor of the p450 system?
ritonavir
Maraviroc, enfuvirtide?
MOA
Entry inhibitors
- maraviroc (binds to CCR5, preventing an interaction with gp41),
- enfuvirtide (binds to gp41, also known as a ‘fusion inhibitor’)
Screening for latent TB?
Mantoux test
Features of Chikungunya?
- abrupt onset high fever
- severe joint pain +/- joint swelling
- myalgia, headache, fever
Mx: symptomatic
Mx of paucibacillary leprosy (5 or less lesions)?
rifampicin and dapsone for 6 months
Features of Diphtheria?
- recent visitors to Eastern Europe/Russia/Asia
- sore throat with a ‘diphtheric membrane’ - grey, pseudomembrane on the posterior pharyngeal wall
- bulky cervical lymphadenopathy -> ‘bull neck’ appearance
- neuritis e.g. cranial nerves
- heart block
Ix of Diphtheria?
culture of throat swab: use tellurite agar or Loeffler’s media
Mx of Diphtheria?
IM penicillin, diphtheria antitoxin
C botulinum vs C tetani
C botulinum:
- prevents ACh release -> flaccid paralysis
C tetani:
- prevents release of glycine from Renshaw cells in the spinal cord -> spastic paralysis
Features of visceral leishmaniasis (kala-azar)?
- fever, sweats, rigors
- massive splenomegaly. hepatomegaly
- poor appetite*, weight loss
- grey skin - ‘kala-azar’ means black sickness
- pancytopaenia secondary to hypersplenism
Gold standard for diagnosis of visceral leishmaniasis?
bone marrow/ splenic aspirate
Features of Staphylococcal toxic shock syndrome?
- fever: temperature > 38.9ºC
- hypotension: systolic blood pressure < 90 mmHg
- diffuse erythematous rash
- desquamation of rash, especially of the palms and soles
- involvement of three or more organ systems: e.g. gastrointestinal (diarrhoea and vomiting), mucous membrane erythema, renal failure, hepatitis, thrombocytopenia, CNS involvement (e.g. confusion)
organism implicated in granuloma inguinale?
Klebsiella granulomatis
Painful vs painless genital ulcers
Painful:
- Chancroid
- HSV
Painless:
- Syphilis
- Lymphogranuloma venereum (Chlamydia trachomatis)
- Donovanosis: klebsiella granulomatis
Should live vaccines be given together?
can be given concomitantly on same day.
If not, should be given >/=4 wks apart.
Which vaccines are conjugate vaccines?
- linked to proteins to make them more immunogenic
- pneumococcus
- haemophilus
- meningococcus
gram positive, catalase and coagulase positive cocci
Staph aureus
gram positive, catalase +ve, coagulase NEG cocci?
Staph epidermidis, Staph saprophyticus
Gram positive, catalase NEG, non haemolytic cocci?
Enterococcus
Gram positive, catalase NEG, ALPHA haemolytic cocci?
Strep pneumoniae, Strep viridian’s
Gram positive, catalase neg, beta haemolytic cocci?
e.g. Strep pyogenes, Strep agalactiae
Mx of pelvic inflammatory disease?
oral ofloxacin + oral metronidazole
OR
IM ceftriaxone + oral doxycycline + oral metronidazole
Rabbit/ beaver bite. erythematous papulo-ulcerative lesion at the site of the bite with reactive and ulcerating regional lymphadenopathy
Tularaemia
- F. tularensis
- tx: doxycycline
Common organisms in human bite?
Streptococci spp. Staphylococcus aureus Eikenella Fusobacterium Prevotella
What parasitaemia count suggests a severe infection in Plasmodium knowlesi?
> 1%
- due to fastest erythrocytic cycle -> capable of producing very high parasite counts in a short space of time.
Causes of false positive VDRL/RPR anti-cardiolipin test?
pregnancy SLE, anti-phospholipid syndrome TB leprosy malaria HIV
what vaccines are CI in HIV patients regardless of CD4 count?
Cholera CVD103-HgR
Intranasal Influenza
BCG
Oral polio
Vaccinations one should get post splenectomy?
Haemophilus influenza (Hib) Meningitis A + C
- annual influenza
- pneumococcal vaccine every 5 years
- Pen V prophylaxis
Mx of Shigella?
if severe/ immunocompromised/ bloody diarrhoea: Ciprofloxacin
Mx of cellulitis in pregnancy?
clarithromycin/ erythromycin
Mx of cellulitis if allergic to penicillin?
clarithromycin/ doxycycline
Mx of severe cellulitis?
co-amoxiclav, cefuroxime, clindamycin, ceftriaxone
Diagnosis of mycoplasma pneumoniae?
Mycoplasma serology
Features of japanese encephalitis?
headache, fever, seizures, confusion.
- Parkinsonism features indicate basal ganglia involvement
- may have flaccid paralysis
mx: supportive
Diagnosis of Japanese encephalitis?
serology/ PCR
- flavivirus transmitted by culex mosquitoes
Mx of non-gonococcal urethritis?
Oral azithromycin/ doxycycline
Features of Zika virus?
fever, rash arthralgia/arthritis conjunctivitis myalgia headache retro-orbital pain pruritus
Strongest risk factor for melioidosis/ whitmore’s disease?
Diabetes mellitus
- other RF: agriculture work, immunocompromised, chronic liver/renal/ lung disease
Mx of Melioidosis/ Whitmore’s disease?
IV ceftazidime, imipenem/ meropenem for 10-14 days
followed by eradication therapy: oral TMP/SMX (+ doxycycline) for 3-6mo
Organism implicated in Melioidosis/ Whitmore’s disease?
Burkholderia pseudomallei
mx of cholera?
oral rehydration therapy,
doxycycline/ ciprofloxacin
Leishmania donovani
Visceral leishmaniasis
Leishmania braziliensis
Mucocutaneous leishmaniasis
Leishmania tropica or Leishmania mexicana
Cutaneous leishmaniasis
complications of lemierre’s syndrome- infectious thrombophlebitis of the IJV?
septic pulmonary emboli
mx of close contacts of pneumococcal meningitis?
no action needed
features of mucocutaneous leishmaniasis?
ulceration of skin + mucosae of nose, pharynx
IX of entamoeba histolytica/ amoebic colitis?
stool microscopy: trophozoites if examined within 15 min/ kept warm “hot stool”
- stool PCR: now gold standard, not as sensitive but does not need to be examined within 15 mins
mx of entamoeba histolytic/ amoebic colitis?
metronidazole followed by luminal amoebicide (e.g. diloxanide furoate)
severe hepatitis in pregnant woman?
hep E
- pregnant women are at particular risk from hep E
Rifampicin MOA?
inhibits RNA synthesis
Amphotericin B MOA?
Binds with ergosterol (component of fungal cell membranes), forming pores -> lysis of cell wall + subsequent fungal cell death
Terbinafine MOA?
inhibits the fungal enzyme squalene epoxidase, causing cellular death
- used to treat ringworm, pityriasis versicoloured, fungal nail infections
SE of trimethoprim?
myelosuppression
- transient rise in Creatinine: as trimethoprim competitively inhibits the tubular secretion of creatinine
Post-exposure prophylaxis of HIV?
Triple therapy: Tenofovir + emtricitabine + raltegravir,
continued for at least 28 days.
features of cutaneous leishmaniasis?
- presents with a nodule 1-2 months after infected sandfly bite, which gradually ulcerates, often w thick fibrous crust over the surface
Most common side effect of ribavarin?
haemolytic anaemia
- also teratogenic, must prevent pregnancy
Mx of visceral leishmaniasis?
sodium stibogluconate IV or pentamidine
1-3 beta D glucan levels in PCP?
BDG is a polysaccharide in the walls of Pneumocystis jirovecii cysts
- will be elevated in PCP
Malaria prophylaxis in patient with epilepsy? best option
Malarone (proguanil and atovaquone)
- chloroquine resistance is present in some places + not recommended in seizures
- mefloquine can cause seizures
Which HIV medication might lead to renal stones?
indinavir
Which HIV medication induces P450 system?
nevirapine
Haemorrhagic fever with renal syndrome - endemic in Korea and other Asian countries?
Hantavirus
Features of typhus?
fever, headache
- black eschar at site of original inoculation
- rash e.g. maculpapular or vasculitis
- complications: deranged clotting, renal failure, DIC
mx: doxycycline
Mx of typhus/ rickettsial diseases?
doxycycline
ix of syphilitic ulcer?
swab ulcer and send for PCR
Features of granuloma inguinale/ donovanosis?
- klebsiella granulomatis
- painless, spreading ulcer with friable edges
- can become infected/ locally destructive
- may lead to SCC
- rarely heal without treatment
1st line mx of epididymo-orchitis in >35?
ofloxacin
- Gram negative enteric bacteria is most common
empirical first line mx of osteomyelitis?
flucloxacillin
Which human antigen is involved in the entry of Plasmodium vivax into the human red cell?
Duffy glycoprotein
- if not expressed, resistant to infection by Plasmodium vivax
golden crusted lesions on face
impetigo
- staph aureus
- tx: topical fusidic acid
Zanamivir in asthmatics?
may trigger bronchospasm
What vaccines can’t be used in those with egg allergy?
yellow fever, live attenuated influenza
best option for malaria prophylaxis in pregnancy?
mefloquine
- RF: tooth extractions, fractures of the jaw, periodontal abscesses
- acute, usually odontogenic, abscess of floor of the mouth
- can spread to involve head and neck
- sulphur granules on microscopy
cervicofacial actinomycosis
tx: amoxicillin
Hand foot mouth disease - organism?
coxsackie virus group A, type 16
causes of tinea pedis/ athletes foot?
Trichophyton: multiple small microconidia
Microsporum: single microconidia/ multiseptate macroconidia
Epidermophyton: does not produce conidia
- soil/ thorn causing cut
- begins as reddish/ non tender maculopapular lesion
- over next few wks, similar nodules form along proximal lymphatic channels
- break down to form a row of ulcers
Cutaneous sporotrichosis
- caused by sporothrix schenckii
- diagnosis through culture of biopsy samples on Sabouraud dextrose agar
- Tx: itraconazole. if severe/ immunocompromised: IV amphotericin B
Tx of Cutaneous sporotrichosis?
itraconazole.
if severe/ immunocompromised: IV amphotericin B
- South East asia (e.g. Thailand)
- worker in a paddy field with regular contact with wet soil
- fever, cough, pleuritic chest pain, bone pain, cellulitis
- cutaneous abscesses
Melioidosis
- Burkholderia pseudomallei
- tx: IV Ceftazidime for at least 10 days
What HIV medication may cause hypertriglyceridaemia?
protease inhibitors e.g. ritonavir, lopinavir
Infectious mono severe tonsillar swelling -> possible respiratory obstruction … mx?
ENT rv + IV hydrocortisone
What are the HACEK organisms of culture negative infective endocarditis?
Haemophilus spp Aggregatibacter spp Cardiobacterium homonis Eikenella corrodens Kingella spp
increasing PR interval in infective endocarditis?
suggests aortic root abscess
- need surgical referral
Mx of chronic Hep C?
Daclatasvir (stops hep C viral replication) + sofosbuvir +/- ribavarin
What type of bacteria is clostridium botulinum?
gram positive anaerobic bacillus
Cryptosporidiosis in immunocompromised: management?
Rifaximin or nitazoxanide
Options for antibiotic prophylaxis to prevent travellers’ diarrhoea? (In immunocompromised population)
ciprofloxacin, norfloxacin or rifaximin
Hep B: management?
1st line: pegylated IFN alpha
2nd: tenofovir/ entecavir/ telbivudine
Legionella pneumonia: management?
erythromycin/clarithromycin
OR
Levofloxacin if infection severe
What viral haemorrhagic fever is associated with caves/ bats?
Marburg virus
What is paragonimiasis?
- common tropical infection (presents similarly to TB)
- productive cough w brown / red sputum
- constitutional symptoms
- eosinophilia.
Paragonimiasis: management?
praziquantel
most common cause of epilepsy worldwide?
neurocysticercosis
neurocysticercosis: treatment?
praziquantel / albendazole and prednisolone.
neurocysticercosis: diagnosis?
Diagnosis is made with MRI or CT imaging.
Calcified cysts in skeletal muscle may be found incidentally on x-ray.
HHV 5 = ?
CMV
CMV infections in post transplant patient: management if there is ganciclovir resistance?
foscarnet or cidofovir
spinal epidural abscess: most common causative organism?
staph aureus
what organisms are group D Streptococci? (gram positive cocci)
Enterococcus
e.g. enterococcus faecalis (common gut commensal and cause of intra-abdominal infections
Infuenza: 1st line management in severely immunocompromised individuals?
zanamivir
necrotising fasciitis in chickenpox: most likely organism?
invasive group A streptococcus
what is Yaws infection?
- chronic infection that affects mainly skin, bone and cartilage
- occurs mainly in low socio-economic communities in tropical areas of Africa, Asia and Latin America
- caused by Treponema pertenue (a subspecies of Treponema pallidum)
- yaws is a non-venereal infection
primary yaws infection features?
a single skin lesion develops at the point of entry of the bacterium after 2-4 weeks. This nodule can break down into an exudative ulcer.
secondary yaws infection features?
multiple lesions appear all over the body, more commonly over the face, trunk, genitalia and buttocks.
-> eventually widespread bone, joint and soft tissue destruction can occur.
Management of brucellosis?
6 weeks of oral doxycycline with 3 weeks of either intramuscular streptomycin or intravenous gentamicin
Or
6 weeks of PO rifampicin and doxycycline
antibiotic options for carbapenemase producing enterobacteriaceae (CPE)?
polymyxins e.g. colistin
tigecycline
fosfomycin
aminoglycosides e.g. gentamicin
councilman bodies in hepatocytes?
Yellow fever
TB: management in cases of confirmed isoniazid resistance?
rifampicin and ethambutol are continued for further 4 months after RIPE for 2 months
difference in where to find the different sleeping sickness bugs?
Trypanosoma gambiense in West Africa e.g. Nigeria
and
Trypanosoma rhodesiense in East Africa
Mx of tick borne encephalitis?
Supportive
Diagnosis of tick borne encephalitis?
CSF/serum serology for TBE-specific antibody
Mx of multi drug resistant TB?
18-24 months of at least 5 drugs
Features of amoebic dysentery (entamoeba histolytica)?
profuse, bloody diarrhoea
- possible long incubation period
stool microscopy may show trophozoites if examined within 15 minutes or kept warm (‘hot stool’)
Treatment of typhoid fever?
Cefotaxime/ ceftriaxone
Or ciprofloxacin
What does Nocardia infection typically cause?
- pneumonia in immunocompromised patients
- may cause brain abscesses
Nocardia (gram positive rod)
What does actinomycoses israelii infection normally cause?
- chronic, progressive granulomatous disease
- oral/facial abscesses with sulphur granules in sinus tracts
- Possible abdominal mass (ie RIF)
> commensals become pathogenic when mucosal barrier breached.
What does actinomycoses israelii infection normally cause?
- chronic, progressive granulomatous disease
- oral/facial abscesses with sulphur granules in sinus tracts
- Possible abdominal mass (ie RIF)
> commensals become pathogenic when mucosal barrier breached.
Risk factor for Abdominopelvic actinomycosis
Previous appendicitis
Management of actinomycosis infection?
- Long-term antibiotic therapy usually with penicillin
- Surgical resection indicated for extensive necrotic tissue, non-healing sinus tracts, abscesses or where biopsy is needed to exclude malignancy.
Who should get prophylaxis for close contacts of bacterial meningitis?
Close contacts for up to 7 days prior
High loa loa microfilaraemia is associated with encephalopathy following treatment with which drugs?
Ivermectin or DEC
- CI if loa loa microfilaraemia exceeds 2500 mf/ml.
most serious and frequent complications of Typhoid fever?
bowel perforation and haemorrhage
> caused by bacterial destruction of the Peyer’s patches in the small intestine and classically occurs late in the 2nd week of illness or early in the third week.
What vaccinations can you not give AT ALL in HIV?
- Cholera CVD103-HgR
- Influenza-intranasal
- Poliomyelitis-oral (OPV)
- BCG
What vaccinations can you give in HIV ONLY if CD4 count >200?
Measles, Mumps, Rubella (MMR)
Varicella
Yellow Fever
What medication is unlikely to be effective in dual tropism HIV virus?
Maraviroc
- blocks HIV binding to CCR5 receptor
- not useful if the virus is ‘CXCR4 tropic’ or ‘dual tropic’
What zoonotic vector transmits the Marburg virus (and causes a viral haemorrhagic fever)?
Bats and caves
What anti HIV medication should be avoided if HLA B*5701 allele positive?
Abacavir
most serious and frequent complications of Typhoid fever?
GI perforation and haemorrhage
- caused by bacterial destruction of the Peyer’s patches in the small intestine and classically occurs late in the 2nd week of illness or early in the 3rd week
tick borne malaria-like illness:
fevers, chills, riggers, haemolytic anaemia + haemoglobinuria
Babesiosis
- intra-erythrocytic protozoan Babesia > destroy RBCs
- frequent in endemic parts of USA e.g Long Island, New York, Nantucket, Massachusetts
- if no spleen: infection will be more severe
diagnosis of babesiosis?
often clinical
management of immunocompetent individual with mild-mod babesia infection?
oral azithromycin + atovaquone
management of severe babesia infection?
IV azithromycin + PO atovaquone (usually 7-10d)
or
IV clindamycin + oral quinine
if pt immunocompromised: may need up to 6/52 of tx
management of severe babesia infection if high grade parasitaemia (>10%), severe haemolysis (Hb<10) or organ (liver, renal, lung) impairment?
exchange transfusion
risk of transmission of hep c from mother to child?
6%
are there any methods recommended to reduce risk of vertical transmission of hep c from mother > child?
no evidence based advice
best method of confirming Strongyloides stercoralis eradication following treatment
Repeat serological testing
- post-treatment to pre-treatment titre ratio of < 0.6 = good indicator of treatment success.
mx of CNS cryptococcal infection?
IV amphotericin B + flucytosine