Infectious Diseases Flashcards
TB Meningitis Tx
Rifampicin, Isoniazid, Pyrazinamide, Ethambutol for 2 months
R + I for 10 more months
+/- dexamethasone
+/- fludrocortisone
side effects of ethambutol
optic neuritis
AVOID if renal impairment (CrCl 10-50ml/min)
side effects of pyrazinamide
hepatitis
arthralgia
contraindicated in gout, porphyria
side effects of rifampicin
orange secretions
enzyme (CYP450) induction
hepatitis
if renal impairment-> reduce rifampicin dose by 50%
side effects of isoniazid
hepatitis
peripheral sensory neuropathy
(can give Vit B6 - pyridoxine alongside)
tx for latent TB
Rifampicin + Isoniazid for 3 months
or
Isoniazid alone for 6 months
hypopigmented, insensate plaques
trophic ulcers
thickened nerves
keratitis

mycobacterium leprae
pauci vs multibacillary leprosy
- what is the difference?
Pauci: 2-5 spots
Multi: >5 spots
tx of lepromatous leprosy
(mycobacterium leprae)
tx for 2 years
rifampicin monthly
clofazamine + dapsone daily
tuberculoid vs lepromatous leprosy
- who develops lepromatous leprosy?
failure of Th1 cell activation
tx of tuberculoid leprosy?
6 month tx
rifampicin monthly
clofazamine daily
mycobacterium avium intracellulare (MAI)
- who is affected?
usually HIV patients / any immunosuppressed
CD4 <100
symptoms of MAI (mycobacterium avium intracellulare) complicating HIV infection
widely disseminated disease: lungs/ GIT
fever, night sweats, weight loss
diarrhoea
hepatomegaly
in immunocompromised host,
begins as a painless dermal papule or subcutaneous edematous nodule, which, over a period of weeks to months, breaks down to form an extensive necrotic ulcer with undermined edges
Buruli Ulcer
mycobacterium ulcerans

buruli ulcer
which organism?
mycobacterium ulcerans
fish tank granuloma
what organism?
mycobacterium marinum
oral neuraminidase inhibitor
against Influenza A and B
Oseltamivir
inhaled neuraminidase inhibitor
against Influenza A and B
Zanamivir
how does HIV seroconversion present?
transient illness 2-6 wks after exposure
fever, malaise, myalgia, pharyngitis, macpap rash
sore throat, lymphadenopathy
Dx of HIV?
HIV PCR
p24 antigen tests: usually +ve wk1 - wk3/4
screening ELISA- for serum anti-HIV Abs
confirmatory Western Blot: HIV Abs (95% by 4-6 wks)
Monitoring of HIV
using?
CD4 count
Viral Load (HIV RNA)
FBC, U+Es, LFTs, lipids, glucose
Ix of suspected HIV?
HIV diagnostic tests
Drug resistance studies
Mantoux test
Serology: CMV, toxo, HBV, HCV, syphilis
CD4<50 - prophylaxis against MAI?
azithromycin
HIV CD4 <100: prophylaxis against toxoplasmosis?
co-trimoxazole
HIV + CD4 <200: prophylaxis against PCP
co-trimoxazole
Diagnosing TB in HIV pts
problems?
higher false -ve skin tests
higher false -ve sputum cultures
presentation of PCP?
dry cough
exertional dyspnoea
fever
desaturation on exercise
CXR signs of PCP?
bilateral perihilar interstitial shadowing
may be normal
CMV in HIV patients causes?
CMV retinitis
+ pneumonitis, colitis, hepatitis
Tx for CMV retinitis in HIV pt
Ganciclovir
signs of CMV retinitis
decreased visual acuity
eye pain
photophobia
pizza sign on fundoscopy
CT/MRI head findings of toxoplasmosis
ring shaped contrast enhancing lesions
tx of toxoplasmosis in HIV pts
pyrimethamine
+
sulfadiazine
+
folate
presentation of toxoplasmosis in HIV Pts
posterior uveitis
encephalitis
focal neurology
tx for oral candidiasis?
nystatin suspension
tx of oesophageal candidiasis
PO itraconazole
presentation of oesophageal candidiasis?
dysphagia
retrosternal pain
Ix for suspected cryptococcal meningitis?
India Ink CSF stain
Raised CSF pressure
CrAg in blood and CSF
What virus causes progressive multifocal leukoencephalopathy?
JC virus
Tx of cryptococcal meningitis
Amphotericin B + Flucytosine for 2 wks
then
Fluclonazole for 6 months/ until CD4 count >200
Ix of suspected PML?
JC viral PCR
HIV patient
with
Weakness, paralysis, visual loss, cognitive decline.
you suspect a demyelinating inflammation of brain white matter
Progressive multifocal leukoencephalopathy
caused by JC virus
Mx of PML in HIV pt
HAART
benign recurrent aseptic meningitis?
mollaret’s meningitis
mostly HSV-2
Ix of herpes encephalitis
CSF findings: high lymphocytes
CSF PCR
MRI head
herpes infection
painful red finger
herpetic whitlow
mx: topical aciclovir
genital herpes
-> urinary retention + sacral sensory loss
Elsberg Syndrome
HSV-2 Sacral radiculiltis
Complications of chicken pox
pneumonitis
encephalitis
hepatitis
haemorrhage
increased risk in immunocompromised/ pregnancy
complications of shingles
post-herpetic neuralgia
(severe dermatomal pain)
Ramsay Hunt Syndrome
(Facial palsy, vesicles in ear, decreased taste/ hearing)
starry sky appearance
t(8;14)
c-myc
jaw or abdo mass
Burkitt’s lymphoma
what cells does EBV infect?
B lymphocytes
HIV pt
painless shaggy white plaque along lateral tongue border
oral hairy leukoplakia
EBV
tx of oral hairy leukoplakia
Aciclovir
lymphoma following solid organ transplant?
B cell proliferation
post-transplant lymphoproliferative disorder
Tx of post transplant lymphoproliferative disorder
Rituximab
mx of neisseria gonorrhoea?
ceftriaxone 500 mg IM + azithromycin 1 g oral
features of disseminated gonococcal infection?
tenosynovitis
migratory polyarthritis
dermatitis (lesions can be maculopapular or vesicular)
Later complications include septic arthritis, endocarditis and perihepatitis (Fitz-Hugh-Curtis syndrome)
pathophysiology of tetanus?
clostridium tetani produces exotoxin
- > prevents the release of inhibitory transmitters GABA and glycine
- > generalise muscle overactivity
presentation of tetanus?
prodrome: fever, malaise, headache
trismus
risus sardonicus (spasm of facial muscles that appears grinning)
opisthotonus (hyperextension of neck/ spine)
spasms may -> resp arrest
autonomic dysfunction: arrhythmias, fluctuating BP
Mx of tetanus?
Mx in ITU: may need intubation
Human tetanus Ig
Metronidazole, benpen
Prevention of tetanus?
active immunisation w tetanus toxoid
clean minor wounds
- uncertain hx / <3 doses: give vaccin
3 or more doses: only vaccinate if > 10 yrs since last dose
Heavily contaminated wounds
- uncertain hx/ < 3 doses: vaccine + Tetanus Ig
3 or more doses: vaccinate if 5 or more years since last dose
Actinomycosis features?
Subcut infections: esp. on jaw
Forms sinuses which discharge pus containing sulphur granules.

tx of actinomycosis?
Ampicillin for 30d, then Pen V for 100d
Swelling of eyelid (Romana’s sign)
fever, swollen lymph nodes, headaches, or local swelling at the site of the bite
enlargment of heart ventricles -> heart failure
enlargement of oesophagus/ colon
Chagas Disease
transmitted by kissing bugs (Reduviids)
diagnosis of african trypanosomiasis (sleeping sickness)?
thick and thin films -> flagellated protozoa
serology
Tender subcut nodule @ site of infection
Haemolymphatic Stage (1st stage):
- rash, fever, rigors, headaches
- itchiness
- joint pains
- LNs and HSM
- Posterior cervical nodes (Winterbottom’s sign)
Miningoencephalitic Stage (2nd stage)
- Wks – Mos after original infection
- Convulsions, agitation confusion
- Apathy, depression, hypersomnolence, coma
Sleeping sickness
African trypanosomiasis
transmitted by Tsetse fly
T. gambiense: more common, gradual onset
T. rhodesiense: rapid, more severe
skin ulcer @ bite -> depigmented scar
bitten by sandflies

Cutaneous Leishmaniasis
(L. major, L. tropica)
Bitten by sandflies
Widespread nodules which fail to ulcerate?

Diffuse cutaneous Leishmaniasis
bitten by sand flies
skin and mucosal ulcers with damage primarily of the nose and mouth

Mucocutaneous leishmaniasis (L braziliensis)
bitten by sandflies
Dry, warty hyperpigmented skin lesions (dark face and hands)
- Prolonged fever
- Massive splenomegaly, LNs, abdo pain

visceral leishmaniasis (Kala Azar)
L donovani
leishman-donovan bodies

lymphatic filariasis
- Wuchereria bancrofti
- elephantiasis
what carrier is responsible for transmitting dengue fever?
Aedes mosquito
(RNA virus)
features of dengue fever?
Flushes: face, neck, chest
Central macpap rash
Headache, arthralgia
Hepatosplenomegaly
Jaundice
Haemorrhage: petechial, GI, gums or nose, GU
NB. can exclude if fever starts >2wks after leaving endemic area.
mx of uncomplicated falciparum ovale, vivax, malariae?
chloroquine then primaquine
mx of uncomplicated falciparum malaria?
artemeter-lumefantrine (Riamet)
Quinine + doxy
mx of severe falciparum malaria?
need ITU mx
IV Quinine (Antimalarials)
Prophylaxis against malaria in pt w no resistance?
proguanil + chloroquine
prophylaxis against Malaria in pts with resistance?
mefloquine or Malarone (atovaquone + proguanil)
Which antimalarial causes haemolysis if G6PD deficiency?
primaquine
Diagnosis of malaria?
serial thick and thin blood films
parasitaemia level
Ix in malaria after diagnosis?
FBC: anaemia, thrombocytopenia
Clotting: DIC
Glucose
ABG: lactic acidosis
U+E: renal failure
Urinalysis: haemoglobinuria
features of falciparum malaria?
90% present within 1 month.
v acute illness
flu like prodrome: headache, myalgia, malaise
Rigors
fever every 3-4 days
signs in malaria?
anaemia
jaundice
hepatosplenomegaly
no rash, no LNs
which type of malaria species causes fever every 72 h?
(Quartan fever)
Plasmodium malariae
which type of malaria species causes tertian rhythm fever (every 48h)?
Plasmodium falciparum
Plasmodium vivax
& ovale
which species of malaria have a chronic liver stage?
vivax and ovale
pathophysiology of Malaria?
Plasmodium sporozoites injected by females Anopheles mosquito.
Sporozoites migrate to liver, infect hepatocytes and multiply asymptomatically (incubation period) → merozoites
Merozoites released from liver and infect RBCs
Multiply in RBCs
Haemolysis
RBC sequestration → splenomegaly
Cytokine release

Features of Primary Syphilis?
indurated, painless ulcer = Chancre
Regional LNs
Heals in 1-3wks
features of secondary syphilis?
6wks -6mo wks after chancre
Systemic bacteraemia → fever, malaise
Skin rash: Symmetrical, non-itchy, mac pap / pustular
Rash on Palms, soles, face, trunk
Buccal snail-track ulcers
Warty lesions: condylomata lata
features of tertiary syphilis?
2-20yrs latency
- Gummatous syphilis
Gummas: Granulomas in skin, mucosa, bones, joints
- Neurosyphilis
Tabes Dorsalis
Argyll Robertson pupil
dementia
- cardiovascular syphilis
Aortic aneurysm
Aortic regurg
features of Syphilitic aortitis?
Aortic aneurysm
Aortic regurg
features of Neurosyphilis?
Paralytic dementia
Meningovascular: CN palsies, stroke
Tabes dorsalis
- Degeneration of sensory neurones, esp. legs
- Ataxia and +ve Romberg’s
- Areflexia
- Plantars ↑↑
- Charcot’s joints
Argyll-Robertson pupil
accommodates, doesn’t react
Diagnosis of Syphilis?
Cardiolipin antibody
E.g. VDRL, RPR
Not treponeme specific
False +ve: pregnancy, pneumonia, SLE, malaria, TB
+ve in 1O and 2O syphilis (wanes in late disease)
Reflects disease activity: -ve after Rx
Treponeme-specific Ab
+ve in 1O and 2O syphilis
Remains +ve despite Rx
THPA and FTA
Treponemes
Seen by dark ground microscopy of chancre fluid
Seen in lesions of 2O syphilis
May not be seen in late syphilis
What marker is used to monitor disease activity in syphilis?
RPR
What test would remain +ve even after tx of syphilis?
THPA and FTA:
treponene-specific Ab
Mx of syphilis?
IM Benzathine Penicillin 2-3 doses
or Doxycycline for 28 days
What reaction is common after receiving tx for syphilis?
Jarisch-Herxheimer Reaction
Fever, ↑HR, vasodilatation hrs after first Rx
? sudden release of endotoxin
Rx: steroids
features of Jarisch-Herxheimer reaction?
Fever, ↑HR, vasodilatation hrs after first Rx
? sudden release of endotoxin
Rx: steroids
Mx of travellers diarrhoea?
E coli
Cipro
Commonest bacterial diarrhoea
Bloody diarrhoea, fever
assoc w Guillain-Barre + Reactive arthritis
Campylobacter jejuni
- unpasteurized milk, animal faeces
2-5d incubation
Mx of Campylobacter jejuni GI infection?
Dx by stool MCS
erythromycin
or
Ciprofloxacin
Commonest cause of diarrhoea/ vomiting in adults
50% of all gastroenteritis worldwide
Fever, diarrhoea, projectile vomiting
Norovirus
12-48h incubation time
Commonest cause of diarrhoea in children
Secretory diarrhoea and vomiting
Rotavirus
Profuse diarrhoea, abdo pain, vomiting
assoc w Raw/undercooked seafood
Japan
Vibrio parahaemolyticus
tx: Doxycycline
100-200mg/d PO
Rice-water stools
Shock, acidosis, renal failure
Vibrio cholera
Faecal-oral spread
Dirty water
hrs-5d incubation
diagnosis by stool MCS
Mx of vibrio cholera?
dx by stool MCS
Rehydrate
- Cooked rice powder solution
- Hartmann’s w K+ supplements
Cipro
Zn supplement
Watery diarrhoea + cramps
assoc w gas gangrene
Clostridium perfringens
- assoc w reheated meat
Mx of clostridium perfringens?
Diagnosis by stool MCS
Benpen + metro
Afebrile
Descending symmetric flaccid paralysis
No sensory signs
Autonomic: dry mouth, fixed dilated pupils
recently eaten canned/ vacuum packed food
Kids = honey
students = beans
Clostridium botulinum
dx: Toxin in blood samples
Mx of clostridium botulinum?
Antitoxin
Benpen + metro
Bloody diarrhoea, abdo pain, fever - foul smelling
Pseudomembranous colitis
Toxic megacolon
GI perforation
C difficile
assoc w antibiotic use
cephalopsporins, ciprofloxacin, clindamycin
Faecal oral spread
Environment: spores
Mx of C difficile?
Stop causative Abx
1st: Metronidazole 400mg TDS PO for 10d
2nd: Vanc 125mg QDS PO
Colectomy may be needed
Watery diarrhoea, cramps, flu-like
Pneumonia
Meningoencephalitis
Miscarriage
assoc w refrigerated food, soft cheeses, pates
Listeria monocytogenes
Mx of listeria monocytogenes?
diagnosis by blood culture
Ampicillin
Diarrhoea, vomiting, fever, abdo pain
Poultry, eggs, meat
Salmonella enteritidis
features of gonorrhoea?
Men: - Purulent urethral discharge, dysuria, prostatitis
Women: - Usually asympto, dysuria, discharge
diagnosis of Gonorrhoea?
Urine NAATs
Culture is gold standard
- Intracellular Gm- diplococci
- Transport in Stuart’s Medium
Mx of gonorrhoea?
Cefixime PO
Ceftriaxone IM
+
azithromycin
complications of gonorrhoea?
Prostatitis
Epididymitis
Salpingitis / PID
Reactive Arthritis
Ophthalmia neonatorum
Features of chlamydia?
v common iin <25 yr group
Asympto in 50% men and 80% women
Men: - Urethritis
Women: - Cervicitis, urethritis, salpingitis
diagnosis of chlamydia?
1st line NAATs (Nucleic Acid Amplification Test)
- Urine
Culture
- Endocervical swab
- Discharge
mx of chlamydia?
Azithromycin 1g PO once
or
Doxycycline PO 100mg BD for 7 days
complications of chlamydia?
Prostatitis
Epididymitis
Salpingitis / PID
increased incidence of ectopic pregnancies
Reactive Arthritis
Opthalmia neonatorum
perihepatitis (Fitz-Hugh-Curtis syndrome)
features of Lymphogranuloma venereum
primary stage?
caused by the invasive serovars L1, L2, L2a or L3 of Chlamydia trachomatis
primarily an infection of lymphatics and lymph nodes.
common in MSM
tropical STI
- painless genital ulcer, heals fast
- balanitis, proctitis, cervicitis
features of lymphogranuloma venereum?
Inguinal syndrome
caused by the invasive serovars L1, L2, L2a or L3 of Chlamydia trachomatis
primarily an infection of lymphatics and lymph nodes.
common in MSM
tropical STI
- Painful inguinal buboes
- Fever, malaise → genital elephantiasis

features of lymphogranuloma venereum?
anorectal syndrome
caused by the invasive serovars L1, L2, L2a or L3 of Chlamydia trachomatis
primarily an infection of lymphatics and lymph nodes.
common in MSM
tropical STI
- Proctocolitis → Rectal strictures → Abscesses and fistulae
diagnosis of lymphogranuloma venereum?
Chlamydia serovars L1, L2, L3
NAATs
Mx of lymphogranuloma venereum?
Azithromycin / doxycycline
Complications of lymphogranuloma venereum?
Genital elephantiasis
Rectal strictures
features of HPV 6/11
often asymptomatic
genital warts
Mx of genital warts
multiple, non-keratinised warts: topical podophyllum
solitary, keratinised warts: Cryotherapy
Features of HSV?
Flu-like prodrome
Inguinal LNs
Painful grouped vesicles → ulcers
Dysuria may -> urinary retention
diagnosis of HSV
PCR
Serology
mx of HSV
Analgesia
Aciclovir
cold sores: topical aciclovir
Complications of HSV?
Meningitis
Elsberg Syndrome: sacral radiculomyelitis → retention + saddle paraesthesia
sacral radiculomyelitis → retention + saddle paraesthesia
HSV?
Elsberg syndrome
features of Chancroid?
Papule → Painful soft genital ulcer
- base covered in yellow/grey
Progressing to inguinal buboes
Haemophilus ducreyi
mainly Africa
Diagnosis of Chancroid?
Haemophilus ducreyi
- Culture
- PCR
Mx of Chancroid?
Azithromycin
Features of Donovanosis?
aka Granuloma inguinale
- Klebsiella granulomatis
Painless, beefy-red ulcer
Subcutaneous inguinal granulomas = Pseudobuboes
Possible elephantiasis
Diagnosis of Donovanosis?
Donovan bodies
- Giemsa stain
Mx of Donavonosis?
Erythromycin
secretory vs inflammatory diarrhoea?
Secretory Diarrhoea
Bacteria only found in lumen: don’t activate innate immunity
No / low fever
No faecal leukocytes
Caused by bacterial toxins: Cholera, E. coli (except EIEC), S. aureus
Toxin → ↑cAMP→ open CFTR channel → Cl loss followed by HCO3, Na and H2O loss → secretory diarrhoea
Inflammatory Diarrhoea
Bacteria invade lamina propria: activate innate immunity
Fever
PMN in stool
Campylobacter, shigella, non-typhoidal salmonella, EIEC
malaise, headache, cough, constipation
high fever w relative bradycardia
Rose spots: patchy red macules
Epistaxis, splenomegaly
Diarrhoea after 1st wk
Salmonella typhi/paratyphi
(typhoid fever)
incubates 3-21d
main features of typhoid fever?
constipation
high fever w relative bradycardia
Rose spots: patchy red macules
splenomegaly
diagnosis of typhoid fever?
Leukopenia
Blood culture: salmonella typhi/ paratyphi
Urine or stool culture
mx of typhoid fever?
Cefotaxime or cipro
abdo pain, fever, diarrhoea
Mesenteric adenitis
Reactive arthritis, pharyngitis, pericarditis
Erythema Nodosum
Yersinia enterocolitica
dx: by serology
mx: cipro
Bloating, explosive diarrhoea, offensive gas
Malabsorption → steatorrhoea and wt. loss
symptoms for 1-4wk
assoc w MSM, Hikers, Travellers
Giardia lamblia
diagnosis of giardia?
Direct fluorescent Ab assay
Stool microscopy: Pear-shaped trophozoites w 2 nuclei
Duodenal fluid analysis on swallowed string
mx of giardia?
Tinidazole
Who should be screened for MRSA?
all patients awaiting elective admissions
(exceptions include day patients having terminations of pregnancy and ophthalmic surgery. Patients admitted to mental health trusts are also excluded)
all emergency admissions screened
How should a patient be screened for MRSA?
nasal swab and skin lesions or wounds
the swab should be wiped around the inside rim of a patient’s nose for 5 seconds
the microbiology form must be labelled ‘MRSA screen’
Suppression of MRSA from a carrier once identified?
nose: mupirocin 2% in white soft paraffin, tds for 5 days
skin: chlorhexidine gluconate, od for 5 days.
Apply all over but particularly to the axilla, groin and perineum
what antibiotics are commonly used in the treatment of MRSA infections?
vancomycin
teicoplanin
linezolid
recommended abx for Hospital-acquired pneumonia?
Within 5 days of admission: co-amoxiclav or cefuroxime
More than 5 days after admission: piperacillin with tazobactam
OR a broad-spectrum cephalosporin (e.g. ceftazidime) OR a quinolone (e.g. ciprofloxacin)
recommended abx for Exacerbations of chronic bronchitis?
Amoxicillin or tetracycline or clarithromycin
recommend abx for UTI?
Trimethoprim or nitrofurantoin.
Alternative: amoxicillin or cephalosporin
Recommended abx for acute prostatis?
Quinolone (e.g. cipro) or trimethoprim
recommended abx for Acute pyelonephritis?
Broad-spectrum cephalosporin or quinolone (e.g. cipro)
recommended abx for Animal or human bite?
Co-amoxiclav
(doxycycline + metronidazole if penicillin-allergic)
recommended abx for Mastitis during breast-feeding?
Flucloxacillin
recommended abx for Erysipelas?
Flucloxacillin (erythromycin if penicillin-allergic)
recommended abx for Cellulitis?
Flucloxacillin
(clarithromycin or clindomycin if penicillin-allergic)
recommended abx for Impetigo?
Topical fusidic acid
oral flucloxacillin or erythromycin if widespread
recommended abx for Throat infections?
Phenoxymethylpenicillin
(erythromycin alone if penicillin-allergic)
recommended abx for Sinusitis?
Amoxicillin or doxycycline or erythromycin
recommended abx for Otitis media?
Amoxicillin (erythromycin if penicillin-allergic)
recommended abx for Otitis externa*?
Flucloxacillin (erythromycin if penicillin-allergic)
recommended abx for Periapical or periodontal abscess?>
Amoxicillin
recommended abx for Gingivitis: acute necrotising ulcerative?
Metronidazole
recommended abx for Pelvic inflammatory disease?
Oral ofloxacin + oral metronidazole
or IM ceftriaxone + oral doxycycline + oral metronidazole
recommended abx for Chlamydia?
Doxycycline or azithromycin
recommended abx for Gonorrhoea?
IM ceftriaxone + oral azithromycin
recommended abx for Syphilis?
Benzathine benzylpenicillin or doxycycline or erythromycin
recommended abx for Bacterial vaginosis?
Oral or topical metronidazole or topical clindamycin
recommended abx for Shigellosis/ Salmonella (non-typhoid)?
Ciprofloxacin
painful vs painless Genital ulcers?
painful: herpes, chancroid
painless: syphilis, lymphogranuloma venereum (may have painful inguinal lymphadenopathy)
dysentery, wind, tenesmus
weight loss if chronic
liver abscess
- RUQ pain, swinging fever, sweats
- mass in R lobe
flask shaped ulcer on histo
Entamoeba histolytica
assoc w MSM, travelling
1-4 wks incubation
features of Entamoeba histolytica?
dysentery, wind, tenesmus
weight loss if chronic
liver abscess
- RUQ pain, swinging fever, sweats
- mass in R lobe
flask shaped ulcer on histo
assoc w MSM, travellers
Diagnosis of entamoeba histolytica?
Stool micro:
- motile trophozoite w 4 nuclei
Stool Ag
Mx of Entamoeba histolytica?
Metronidazole
- Tindazole if severe or abscess
Migrating urticarial rash on trunk and legs
Pneumonitis, enteritis
Malabsorption → chronic diarrhoea
Strongyloides stercoralis
Endemic in sub-tropics
Hyperinfestation in AIDS
mx: Ivermectin
what is enteric fever?
Abdo pain, fever, mononuclear cells in stool
e.g Typhoidal salmonella, Yersinia enterocolitica, Brucella
features of Rabies?
animal bites
Prodrome: headache, malaise, itch, odd behaviour
Furious Rabies: Hydrophobia, Muscle spasms
hypersalivation
Dumb Rabies: flaccid limb paralysis
Diagnosis of Rabies?
“bullet shaped” RNA virus
Negri bodies
Mx of rabies?
immunised:
diploid vaccine
Unimmunised:
vaccine + rabies Ig
features of Toxoplasmosis?
cats are definitive hosts
mostly asympto
reactivated in immunodeficiency
- > encephalitis: confusion, seizures, focal
- > SOL/ raised ICP
- > Posterior uveitis
Diagnosis of Toxoplasmosis?
CT/ MRI head: ring-shaped contrast enhancing CNS lesions
Serology
Mx of toxoplasmosis?
Pyrimethamine + sulfadiazine
Septrin (co-trimoxazole) Prophylaxis in HIV
features of cat scratch disease?
bartonella henselae
hx of cat scratch
tender regional LNs
Mx of cat scratch disease?
Azithromycin
Diagnosis: +ve cat scratch skin Ag test
Features of Anthrax?
Cutaneous
- ulcer w Black centre
- rim of oedema
Inhalational:
- massive Lymphadenopathy
- mediastinal haemorrhage
- resp failure
GI
- severe bloody diarrhoea
Mx of anthrax?
Cipro + clindamycin
features of Lyme Disease?
Borrelia burgdorferi
Ixodes tick bite
walkers, hikers
Early localised: erythema migrans (target lesions)
Early disseminated: mirgatory arthritis, malaise, LN, hepatitis
Late persistent:
Arthritis, focal Neuro (Bells Palsy), heart block, myocarditis
Lymphocytoma: blue/ red ear lobe
Mx of Lyme Disease?
Rash: Doxycycline
Complications: IV benpen
Undulant Fever (PUO): peak PM, normal AM
sweats, malaise, anorexia
arthritis, spinal tenderness
LN, HSM
Rash, jaundice
assoc w unpasteurised milk/ cheeses
Brucellosis
Diagnosed by pancytopenia,
Positive Rose Bengal Test: anti-O-polysaccharide Ag
Mx of Brucellosis?
Doxy + Rifampicin + Gent
High fever, headache, myalgia / myositis
Cough, chest pain ± haemoptysis
± hepatitis w jaundice
± meningitis
assoc w infected rat urine, swimming, canoeing
Leptospirosis
mx: doxycycline
presentation of Hepatitis A?
prodromal phase:
fever, malaise, arthralgia, nausea, anorexia
distaste for cigarettes
Icteric phase:
jaundice, HSM, lymphadenopathy, cholestasis
Ix of hepatitis A?
↑↑ALT, ↑AST (AST:ALT <2)
IgM+ ~25d after exposure = recent infection
IgG+ for life
Mx of Hepatitis A?
Supportive
Avoid alcohol
IFN-a for fulminant hepatitis
prevention: passive Ig -> <3 mo protection
can give active vaccine
Ix of Hep B?
HBsAg +ve = current infection
+ve >6mo = chronic disease
HBeAg +ve = high infectivity
Anti-HBc IgM = recent infection
Anti-HBc IgG = past infection
Anti-HBs Ab = cleared infection or vaccinated
HBV PCR: monitoring response to Rx
complications of Hep B?
Fulminant hepatic failure
Chronic hepatitis (5-10%) -> cirrhosis in 5%
HCC
glomerulonephritis
polyarteritis nodosa
cryoglobulinaemia
Ix of Hep C?
Anti-HCV Abs
HCV-PCR
Liver biopsy if PCR +ve to assess liver damage and need for tx
HCV genotype
Mx of Hepatitis C?
Indications
- Chronic haepatitis
- ↑ ALT
- Fibrosis
treatment depends on viral genotype - test prior to tx
combination of protease inhibitors (e.g. daclatasvir + sofosbuvir or sofosbuvir + simeprevir) +/- ribavarin
↓ efficacy if:
- Genotype 1, 4, 5 or 6
- ↑ VL
- Older
- Black
- Male
what diseases are assoc w EBV?
Infectious mononucleosis
Burkitt’s lymphoma
Post Transplant Lymphoproliferative Disorder
Oral hairy leukoplakia
Primary brain lymphoma
Nasopharyngeal Ca
Jaw or abdo mass
Endemic: Africa, malaria
Sporadic: non-African, impaired immunity
Immunodeficiency: HIV or post-Tx
Burkitt’s lymphoma
Diagnosis of Burkitt’s lymphoma?
Starry-sky appearance
CD10, BCL6
t(8;14)
complications of infectious mono?
splenic rupture
CN lesion (e.g. 7)
ataxia GBS
pancytopenia with megaloblastic marrow
meningoencephalitis
chronic fatigue
Diagnosis of Infectious mono?
Lymphocytosis
Atypical Lymphocytes
+ve heterophile abs: Monospot, Paul Bunnell
NICE guidelines suggest FBC and Monospot in the 2nd week of the illness to confirm a diagnosis of glandular fever.
Blood: serology, PCR
features of infectious mono?
Saliva or droplet spread
Fever, malaise, sore throat, cervical LNs +++
Splenomegaly, hepatitis (→ hepatomegaly and jaundice)
features of CMV reactivation?
immunocomprised
HIV: retinitis > colitis > CNS disease
Transplant: penumonitis > colitis > hepatitis > retinitis
Diagnosis of CMV?
Blood; PCR, serology
Owl’s Eye intranuclear inclusions
Atypical Lymphocytes
Mx of PCP?
co-trimoxazole
IV pentamidine in severe cases
steroids if hypoxic (if pO2<9.3 kPa then steroids reduce risk of resp failure by 50% and death by 1/3)
choice of antibiotic for UTI in breastfeeding mother?
Trimethoprim
most common infective cause of diarrhoea in HIV patients?
Cryptosporidium
Presentation is very variable, ranging from mild to severe diarrhoea
A modified Ziehl-Neelsen stain (acid-fast stain) of the stool may reveal the characteristic red cysts of Cryptosporidium.
Treatment is difficult, with the mainstay of management being supportive therapy*
what organism may cause diarrhoea in HIV pts w CD4 count <50?
Mycobacterium avium intracellulare
ypical features include fever, sweats, abdominal pain and diarrhoea.
may be hepatomegaly and deranged LFTs.
Diagnosis is made by blood cultures and bone marrow examination
Management is with rifabutin, ethambutol and clarithromycin
what organism is most common in bronchiolitis?
Respiratory syncytial virus
what organism is most responsible in croup?
parainfluenza virus
what organism is most responsible for pneumonia following influenza?
staph aureus
Atypical pneumonia
Classically spread by air-conditioning systems, causes dry cough.
Lymphopenia, deranged liver function tests and hyponNa may be seen
Legionella pneumophilia
post-exposure prophylaxis for Hep A?
Human Normal Immunoglobulin (HNIG) or hep A vaccine
Post-exposure prophylaxis for Hep B?
HBsAg positive source: hepatitis B immune globulin (HBIG) and accelerated course of the vaccine
unknown source: HBIG and accelerated course of the HBV vaccine
Post-exposure prophylaxis for Hep C?
monthly PCR - if seroconversion then interferon +/- ribavirin
Post-exposure prophylaxis of HIV?
combination of oral antiretrovirals (e.g. Tenofovir, emtricitabine, lopinavir and ritonavir) asap (i.e. Within 1-2 hours, but may be started up to 72 hours following exposure) for 4 weeks
serological testing at 12 weeks following completion of PEP
diagnosis of legionella pneumophilia?
urinary antigen
tx: w erythromycin
mx of infectious mono?
supportive
rest during the early stages, drink plenty of fluid, avoid alcohol
simple analgesia for any aches or pains
avoid playing contact sports for 8 weeks after having glandular fever to reduce the risk of splenic rupture
main test to check for latent TB?
Mantoux test
IGRA:
when Mantoux test is positive or equivocal
people where a tuberculin test may be falsely negative:
miliary TB
sarcoidosis
HIV
lymphoma
very young age (e.g. < 6 months)
HIV+ve
associated with the Epstein-Barr virus
CT: single or multiple homogenous enhancing lesions
Primary CNS lymphoma
treatment generally involves steroids (may significantly reduce tumour size), chemotherapy (e.g. methotrexate) + with or without whole brain irradiation. Surgical may be considered for lower grade tumours
Toxoplasmosis vs primary CNS lymphoma?
Toxoplasmosis
Multiple lesions
Ring or nodular enhancement
Thallium SPECT negative
Lymphoma
Single lesion
Solid (homogenous) enhancement
Thallium SPECT positive
most common fungal infection of CNS?
Cryptococcus
headache, fever, malaise, nausea/vomiting, seizures, focal neurological deficit
Ix of cryptococcus?
CSF: high opening pressure, India ink test positive
CT: meningeal enhancement, cerebral oedema
widespread demyelination
due to infection of oligodendrocytes by JC virus (a polyoma DNA virus)
symptoms, subacute onset : behavioural changes, speech, motor, visual impairment
MRI is better - high-signal demyelinating white matter lesions are seen
Progressive multifocal leukoencephalopathy (PML)
Pneumonia in an alcoholic?
Klebsiella pneumoniae
mx of anti-HbS <10 mIU/ml after undergoing primary immunisation against hep B?
Non-responder.
Test for current or past infection.
Give further vaccine course (i.e. 3 doses again) with testing following.
If still fails to respond then HBIG would be required for protection if exposed to the virus
mx of anti-HbS 10-100 mIU/ml after undergoing primary immunisation against hep B?
Suboptimal response
- one additional vaccine dose should be given.
If immunocompetent no further testing is required
mx of anti-HbS >100 mIU/ml after undergoing primary immunisation against hep B?
Indicates adequate response, no further testing required.
Should still receive booster at 5 years
recommended abx prophylaxis for close contacts of pt w meningococcal meningitis?
oral ciprofloxacin (preferred) or rifampicin or may be used
abx for mengingitis caused by listeria?
IV amoxicillin + gentamicin
Mx of rabies immunised person who just got an animal bite?
the wound should be washed
if an individual is already immunised then 2 further doses of vaccine should be given
if not previously immunised then human rabies immunoglobulin (HRIG) should be given along with a full course of vaccination. If possible, the dose should be administered locally around the wound

Kaposi’s sarcoma
caused by HHV-8
presents as purple papules or plaques on the skin or mucosa
may later ulcerate
respiratory involvement may cause massive haemoptysis and pleural effusion
Mx of kaposis sarcoma?
radiotherapy + resection
what virus causes progressive multifocal leukoencephalopathy?
JC virus
what type of medications should be stopped during a c diff infection?
medications which are anti motility or anti-peristaltic (e.g. opioids)
For a patient undergoing an elective splenectomy, when is the optimal time to give the pneumococcal vaccine?
at least 2 weeks before surgery
mx of bacterial vaginosis?
metronidazole
Treatment should be offered to all pregnant woman who are symptomatic. Symptomatic BV in pregnancy is associated with late miscarriage and preterm delivery.
what organism is mainly implicated in bacterial vaginosis?
Gardnerella vaginalis
This leads to a consequent fall in lactic acid producing aerobic lactobacilli resulting in a raised vaginal pH.
What are Ansels criteria for diagnosis of BV?
3 of the following 4 points should be present:
thin, white homogenous discharge
clue cells on microscopy: stippled vaginal epithelial cells
vaginal pH > 4.5
positive whiff test (addition of potassium hydroxide results in fishy odour)
Malignancies associated with EBV infection
Burkitt’s lymphoma*
Hodgkin’s lymphoma
nasopharyngeal carcinoma
HIV-associated central nervous system lymphomas
which pneumonia commonly causes reactivation of the herpes simplex virus resulting in ‘cold sores’?
Streptococcus pneumoniae
diagnosis of mycoplasma pneumoniae?
diagnosis is generally by Mycoplasma serology
positive cold agglutination test
PEP for Hep C?
monthly PCR - if seroconversion then interferon +/- ribavirin
PEP for HIV?
a combination of oral antiretrovirals (e.g. Tenofovir, emtricitabine, lopinavir and ritonavir) as soon as possible (i.e. Within 1-2 hours, but may be started up to 72 hours following exposure) for 4 weeks
serological testing at 12 weeks following completion of post-exposure prophylaxis
most common causes of meningitis in 0-3 mo old?
Group B Streptococcus (most common cause in neonates)
E. coli
Listeria monocytogenes
Causes of meningitis is immunosuppressed?
Listeria monocytogenes
classic description involves sudden onset of high fever, rigors, nausea & vomiting. Bradycardia may develop. A brief remission is followed by jaundice, haematemesis, oliguria
Councilman bodies (inclusion bodies) may be seen in the hepatocytes
Yellow fever
Type of viral haemorrhagic fever (also dengue fever, Lassa fever, Ebola).
live attenuated vaccines?
BCG
measles, mumps, rubella (MMR)
influenza (intranasal)
oral rotavirus
oral polio
yellow fever
oral typhoid
Toxoid (inactivated toxin) vaccines?
tetanus
diphtheria
pertussis
Inactivated preparations
vaccines?
rabies
hepatitis A
influenza (intramuscular)