Infectious Disease Flashcards
Treatment of mild community acquired pneumonia
Amoxicillin
Treatment of mod community acquired pneumonia
Amoxicillin + clarithromycin
Treatment of severe community acquired pneumonia
Co amoxiclav + clarithromycin
Treatment of pneumocystis carinii
Co-trimoxazole
- trimethoprim + sulfamethoxazole
TB regimen
2 month s- RIPE
4 months - RI
R- rifampicin Isoniazid pyrazinamide ethambutol
Treatment of aspiration pneumonia
Amoxicillin + metronidazole
Treatment of meningitis in a GP clinic
IV or IM benzylpenicillin
Meningitis tx in hospital
Ceftriaxone
If >60 yrs - IV ceftroaxone + amoxicillin
Treatment of listeria meningitis
Ceftriazxoen + ampicillin + gentamicin
Meningitis prophylaxis for contacts
Cipro = preferred
Or
Rifampin
Treatment on uncomplicated lower UTI in a non pregnant person
Trimethoprim or nitrofurantoin
Vulvovaginal candidiasis treatment
Clotrimazole or fluconazole
Treatment of trichomoniasis vaginalis
Metronidazole
Treatment of bacterial vaginosis
Metronidazole
Treatment of cervicitis - chlamydial
Chlamydial - doxy 100mg BID fro 7 days
Other
Azithromycin 1g PO
+500mg PO OD for 2 days
Cervicitis tx - gonorrhoeal
Ceftriaxone 1g IM single dose
Or
Cipro 500mg PO - single dose
Symphilis treatment
Penicillin G
Treatment of genital herpes
Acyclovir
Salmonella/shigella/campylobacter
treatment
Erythromycin or azithromycin or clarithromycin
Or
Cipro
Pseudomembranous colitis
Treatment
Oral metronidazole - 1st line
Vancomycin if severe
Acute otitis media treatment
Amoxicillin
Treatment URTI
Pharyngitis/tonsillitis/laryngitis
Phenoxymethylpenicillin
Cellulitis / mastitis/ diabetic foot
treatment
Flucloxacillin - 1st line
If allergic - clarithromycin , (erythromycin if pregnant) or clindamycin
If MRSA - vancomycin
Septic arthritis / osteomyelitis
Treatment
Flucloxacillin + sodium fusidate
Scabies treatment
5% permethrin
Toxoplasmosis treatment
Pyrimethamine + sulfadiazine
Brucellosis
- mode of transmission
- incubation perio d
- organism
- areas
Bacteria brucellosis
5-30 day incubation period
Inhalation - main mode of transmission
( others : skin/mucous membrane , consumption - untreated mil/dairy , raw meat/liver)
Areas that have high exposure to animals
- Nigeria, s.America , Middle East, centra + south east Asia, Africa
Brucellosis
-symptoms
Can be asymptomatic
Fever, arthralgia, malaise, back pain , headache , confiscation , abdominal laundry
Lymphadenopathy, splenomegaly, hepatomegaly
Epididymis-or hit is , skin rash
Diagnosis of brucellosis - initial & gold standard
Treatment
Rose Bengal test or serum agglutination
gold - isolation of brucella soo from specimen
Tx - doxycycline + rifampin - 6 weeks
Important association of streptococcal pneumonia
Herpes labialis
Erythema multiforme seen in which pneumonia
Mycoplasma pneumonia
Pneumonia common in IV drug abusers and elderly
Staph aureus
Klebsiella commonly affects what part of lungs
Upper lobes - cavitation pneumonia
Pneumonia after flu think -
Staph aureus
Pneumonia after hx of exposure to water
Legionella
HIV isa risk factor for what types of pneumonia
Jirovecii/ Carinii - CD4 <200
Or
Streptococcal
Caseating granuloma in LNS
Sx of fever + cough
Diagnosis
TB lymphadenitis
Causes of non caseating granulomas
Sarcoidosis
Chronic disease
Linear tracks (burrows) + severe itching Dx? Organism Mechanism of itching Mode of transmission Treatment
Scabies Sarcoptes scabiei - parasite Permethrin 5%, NS line - malathion .5% MOT - skin-skin contact Itching - allergic reaction
Glandular fever/ infectious mono
Causative organism
Presentation
EBV aka human herpesvirus 4(HHV-4)
Sore throat , exudative tonsillar enlargement, fever, lymphadenopathy
+-Splenomegaly, palatial petechiae, jaundice
imp hint = receiving ampicillin/amoxicillin leads to pruritic maculopapular rash **
Infectious mono
Investigation
Dx
Treatment
FBC - raised ESR WBC , lymphocytosis - atypical lymphocytes >20%
Dx - heterophil antibody test - mono spot test - Paul funnel
Treatment - supportive
Risk factors for TB
Homeless
Drug abuser
Smoker
Low SE class
1st line investigation for TB
Sputum - AFB
If no sputum on cough. - bronchalveolar lavage
^ if refused by patient - gastric lavage
When and how is screening for contacts done in TB
Latent (NOT acute ) TB
Mantoux test - if they have not had BCG vaccine before
Interferon gamma test — if they’ve been vaccinated
Directly -observed therapy in TB
For underserved patients Homeless, imprisonments Drug/alcohol misuse Non adherent to throat Too ill to adhere to rtherapy
Known/suspected TB patients should be __
Isolated in negative pressure room
Chronic cough
Tender firm palpable LNS
Erythema nodosum
TB
When are gastroenteritis patients safe to return to work in the UK
48 hrs after last episode of vomiting/diarrhoea
Delayed complication of bacterial meningitis
Hearing loss
** arrange hearing test after treating meningitis!
Kaposi sarcoma
Features
Commonest sites
Cancer of connective tissue
Red/purple/brown/black nodules or papules that are usually non painful
Sites- mouth nose throat ( can also grow internally - lungs GIT)
RFs kaposi
Homosexual / bisexual
AIDS patient
Jewish/ Mediterranean
Chicken pox
- organism
- MOT
- infectivity
Varicella zoster
Mainly airborne but can also be transmitted via direct contact with vesicles (once dried and crusted - no transmission)
Infectivity - 4 days before rash , 5 days after rash
Chicken pox presentation
Fever
Itchy rash - macula s > papules> vesicles> dry crust
- starts on face - spreads to chest and back
When can a child w/ chicken pox return to school
After vesicles are dry and crusted = 5 days after onset of rash
Chickenpox management
<12 - reassure + supportive
If superimposed bacterial infection - discharging pustules, pinkish fluid secreted +_ high fever = oral antibiotics
When to give VZIG? (3)
- immunocompromised puts w/ exposure
- pregnant w/ exposure and no VZ antibodies
- newborns with pericardium exposure
When should oral acyclovir be given (2)
Immunocompromised patients who develop chicken pox
Pregnant woman who develops chickenpox
Lyme disease - Lymeborreliosis
Hx of camping/ walking in gardens/jungles
Erythema migrans
+- fever headache myalgia general aches & pains
Later on - facial paralysis, meningitis, AV heart block, myocarditis, arthritis
Annular rash with scaly edges, slow growing with associated
Most likely diagnostic investigation for meningitis
W/o rash
W/ rash
- for the exam
W/ -blood culture
W/o rash - LP - CSF analysis
Contraindications of LP
Raised ICP Bulging tense fontanelle Ongoing seizure GCS <9 or drop of >= 3 Unequal dilated unresponsive pupils Papilloedema
What should be done once there is clinical suspicion of meningitis
Notify local health protection team immediately
Septicaemia v meningitis
Septicaemia (n.meningitidis)
- arthralgia, muscle aches, cold periphery, pale/mottled skin
SOB, rash
Meningitis - photophobia , severe headache, neck stiffness
Malaria vs schistosomiasis
Schistosoma can’t have hepatomegaly and hematuria at the same time
Mansoni - affects intestines + liver - hepatomegaly
Hematobium - urinary bladder - hematuria, UB calcification, obstructive uropathy
Malaria can have both at the same time
Needle stick injury - management
1-rinse under running water, wash with soap
Request patients permission to investigate HIV HCV HBV
For pricked health care professional -
-if patient low risk ; test affected HCP for Hep B surface antibody
-pt high risk - start post exposure prophylaxis for affected HCP
-offer hep B booster if not received previously or can’t remember when last received
Return in 6 weeks to be tested for HIV HCV
Risk of transmission post needle prick
HIV
HBV
HCV
HIV - .3%
HBV - up tp 30%
HCV - 3%
Treatment of suspected meningitis with hypersensitivity to penicillin/cephalosporin
Chloramphenicol
Listeria meningitis - treatment
Ceftriaxone + ampicillin + gentamicin
Treatment of cryptococcal meningitis
Amphotericin B
What vaccines should not be given to HIV positive patients
BCG
Yellow fever vaccine
If CD4 <200 cells/ml - avoid MMR
<750 in children - avoid MMR
Tetanus prophylaxis
High risk wound - dirty contaminated / compound fracture
- not fully immunised - give immunoglobulin
- fully immunised - no need.
Low risk
- no need
Fully immunised/up2date (5 doses) - don’t vaccinate unless >10 years ago and wound is tetanus prone - give booster
Unknown/incomplete - complete course of tetanus vaccine
Course of tetanus vaccine
Adults -3 doses 1 month apart, 1st booster after 10yrs , 2nd booster after another 10yrs.
Children - 3 doses 1 month apart, 1st booster after 3 years, 2nd booster 10 years after 1st.
Tetanus prone wound
Animal bites - strays that dig in soil
Puncture injuries in contaminated area
Compound frx
Wound with foreign body
High risk tetanus prone wound
Wounds heavily contaminated with soil
Extensive wounds/burns
Vaccination unison tetanus
How do you manage
Clean - vaccine
Tetanus prone - vaccine + Ig
High risk - vaccine+ig
Mumps (paramyxovirus)
- MOT
- commonly affects
- causes the following
- symptoms
Saliva droplets - close contact
Affects salivary glands - mostly parotid
Causes - bilateral parotitis , orchitis
Symptoms - fever dry mouth , difficulty opening mouth
- orchitis = 4-5 days after parotitis but not always
Treatment of mumps
Reassurance
Supportive treatment - paracetamol, ibuprofen
When is HBsAg +ve ?
During acute + chronic infection
HBsAg +ve
HBeAg +ve
What does this mean?
Highly infectious - active viral replication
eAger to spread
What does Anti -HBe indicate?
Response to treatment
Anti-HBs +ve. =
Post vaccination
What antibodies are +ve at onset and remain +ve even after treatment
Anti-HBc
Indicates past or ongoing infection
First marker to be abnormal in Hep B
HBsAg - acute /chronic infection
High infectivity in Hep B indicated in
HBeAg
Recent vaccination in Hep B shown by
Anti -HBs
Past infection of Hep B indicated by
Anti-HBc
IgM anti-HBc indicates
Recent ACUTE infection
Single non painful genital ulcer
Dx?
Syphilis - chancre
Multiple painful genital ulcers +- dysuria and flu like symptoms
Dx?
Tx?
HSV genital herpes
Acyclovir
*ulcer start off as vesicles
Single painful ulcer on genitals
Dx?
Hemophilia Ducreyi - chancroid
- can be multiple but should start as single chancre
Multiple painless cauliflower growths
Dx?
HPV 6,11 genital warts
Haemophilus Ducreyi vs HSV genital herpes
HSV - vesicles > ulcers - painful (multiple)
HD - inflamed patches > ulcers (single or multiple)
Hx of travel to Far East Asia + fever, headache retro-orbital pain, rash , myalgia
Tender cervical lymphadenopathy
Dx?
Dengue fever
Tx of travel to India + flu like symptoms
Enlarged anterion LN s
Grey membranes on tonsils
Diphtheria
Hx of travel to South America + sever headache + patient in crouching position
Typhoid
High fever + watery diarrhoea + headache + myalgia
Later followed by bloody diarrhoea
Organism responsible?
Treatment
Campylobacter jejuni
1- macrolides - erythromycin, azithromycin, clarithromycin
2-cipro
Red eyes followed by yellow eyes afte hx o travel and water exposure
+ fever, rigours, malaise , arthralgia, myalgia
Dx?
Investigations
What is done to confirm the dx?
Leptospirosis
- blood & urine C&S
Confirm - serology
Organism detectable in blood first 7-10 day s
In uterine 7-30 days
Test for definitive diagnosis of malaria
Think + thick blood film for microscopy
Organism responsible for travellers diarrhoea
E.coli
Diarrhoea - 72 hrs (short period & self limited )
Watery diarrhoea + weight loss + abdominal pain Doul smelling flatulence, bloating Dx? 1st line investigation 1st line treatment
Giardiasis
- stool microscopy - ova parasite
- metronidazole + hygiene
HIV Post exposure prophylaxis
Anti retro viral meds ASAP after exposure to high risk
1-72 hrs after exposure
1st line - Truvada & Raltegravir - 28 days
F/u HIV testing - 8-12 weeks after exposure
All human bites - treat coamoxiclav PO 7 days if allergic - metro +doxy
When can you reassure the contact person of HIV
Antiretrovirals >= 6 months
And HIV viral load <200
Shingles in immunocompromised individual
Next step
Management
Obtain serology for varicella immunity
- if +ve (immune) - reassure
- if -ve (not immune) - give VZIG
Shingles treatment
Acyclovir
Ramsay hunt syndrome
Symptoms
Treatment
Herpes zoster Oticus
- facial nerve palsy - ipsitalateral, loss of taste ant 2/3
- otalgia - st symptom - tinnitus, vertigo, UHL
T - oral acyclovir r+ corticosteroids +amitriptyline
Herpes zoster ophthalmicus
Symptoms
treatment
In ophtlamic branch of trigeminal
Conjunctivitis keratitis painful vesicles around eye
Acyclovir
Annular rash w/ scaly edges on thigh + genera pains and aches
Likely Dx?
Appropriate investigation
1st line treatment
Lyme disease
- antibodies to Borrelia burgdorferi
1st line treatment - Doxycycline (if pregnancy - amoxicillin)
Cerebral toxoplasmosis
- symptoms
- causative organism
- reactivation
Raised ICP - headache eye pain seizures, focal neurological deficits, confusion
Visual hallucination, facial weakness
Org- toxoplasma Gondi (lives and reproduces in cat guts)
Reactivate din HIV (CD4<100)
Imaging for cerebral toxoplasmosis
Treatment
MRI w/ contrast brain - Ring enhancing lesions
Pyrimethamine + sulfadiazine
Anti malarial treatment
Latent phase/ dormant - primaquine (ovals/vivax)
Ovale/vivax ^ = ring form plasmodium w/ schuffners dots in RBCS / latent hypnozoites in liver
Non falciparum/ non hypnozoite malaria - chloroquine (targets active stage)
- if fails - quinine
Pregnant - mefloquine
Contraindication of primaquine
G6PD
Pregnancy, breastfeeding
Neutropenia sepsis (febrile neutropenia)
Neutrophils <= 0.5x10^9
Fever >= 38.5 or x2 seen above >38
Usually happens after chemo or within 1 year from BM transplant
Management of neutropenia sepsis
IV ABx - empirical - start immediate;lay
= IV Tazocin ( taco act am + piperacillin)
If still febrile after 48 h r- try meropenem +- vanco
If after 4-6 days still unwell - investigate a fungal infection - IV antifungal
Treatment of leptospirosis
Usually mild and self limited
Mild - oral doxy
Severe - ampicillin or benzyl penicillin
Doxycycline used to treat (3)
Leptospirosis
Lyme disease
Chlamydial cervicitis
CI in pregnancy - amoxicillin instead
Necrotising fasciitis
Risk factors
Symptoms
IM or SC drug injections / DM / immunosuppression
Initially resembles cellulitis with no response to flucloxacillin
- then bullseye > grey/black sin - septic shock
Very severe pain out of proportion to physical signs
Treatment of necrotising fasciitis
Urgent surgical debris event
IV antibiotics - clindamycin/ benzyl penicillin
Necrotising fasciitis vs erysipelas
Erysipelas - well demarcated
NF - diffuse and deep
Cerebral malaria vs meningitis
Anemia points more towards cerebral malaria
ABx prophylaxis in HIV
CD4 < 200 - cotrimoxazole (against P.J)
CD4 < 50 - azithromycin ( mycobacterium avium )
Red flags for sepsis (6)
SBP <9- HR >130 RR >= 25 UO < .5ml/kg/hr Lactate >= 2 mmol/l Recent chemo
Whipples disease
- organism
- common in
- features
Tropheryma Whippelii - Rare multisystem disease
HLA B 27 +ve & middle aged men
Malabsorption* - diarrhoea + weight loss Large joint arthralgia, lymphadenopathy Pleurisy, pericarditis Neuro - o.plegia, dementia , ataxia , seizures Hyperpigmentation + photosensitive
Whipples disease
Investigation
Treatment
Jejunal biopsy - stunted villi + macrophage deposition containing PAS (periodic acid -Schaffer) granules **** diagnostic
Guidelines vary : oral cotrimoxazole 1 year - lowest relapse rat e
- sometime preceded by IV penicillin
Whipples disease vs celiac disease
Jejunal biopsy -
WD = macrophages with PAS granules
CD - villus atrophy, crypt hyperplasia , lymphocytosis
Patient with known celiac disease - duodenal biopsy shows lymphomatous infiltrates
- Lymphoma
T cell lymphoma is a rare complication of celiac disease
Most common organism causing mastitis
S.aureus
Safe antidepressant in breastfeeding
Sertraline
- also SSRi of choice in hx of MI
HCV antibody indicates
If patient has ever been exposed to HCV
HCV RNA suggests
Current Hep C infection
Anti-TB drug avoided in pregnancy
Streptomycin
Side effects of isoniazid
INH = peripheral neuritis , hepatitis , SLE
- give vit B6
Side effects of rifampin
Red orange urine
P450 induction
Side effects of pyrazinamide
Raises uric acid - gout
Side effects of ethambutol
Eye problems
- red green discrimination
Optic neuritis and decreased visual acuity
Side effects of streptomycin
CI in pregnancy
Ototoxic
Travellers diarrhoea
Salmonella vs shigella
Both are main causes
Treatment
Cipro 1st for salmonella
Shigella - macrolides , cipro
Treatment of oral thrush
Oral fluconazole 50mg OD - 7 days or fluconazole oral suspension
If infection is mild and localised - miconazole gel 1st line
Most likely involved organ in infectious mono
Spleen
Investigation of HSV
1st line. - NAAT testing
Other - viral culture + DNA PCR
If negative or recurrent - anti HSV antibody
Investigation of syphilis
Penile ulcer present -
dark field microscopy in GU clinic
PCR in GP clinic
If penile/mouth ulcer both healed -
Serology for syphilis
Fibrin web in CSF
TB meningitis
Turbid or cloudy CSF on LP
Bacterial meningitis
Neisseria meningitidis vs strept meningitis
Turbid CSF ONLY - strept
Turbid CSF + rash - n.meningitis
Classification of osteomyelitis
Haematogenous
Non hematogenous
Haematogenous osteomyelitis
- cause
- common in
- what the most common form in adults
- RFs
Haematogenous - - bacteremia, usually monomicrobial Most common form in children Vertebral most common site in adults RFs - SCA, IV drug user, immuno suppression , infective endocarditis
Non - haemotogenous
- cause
- common in
RFs
From contiguous spread from adj soft tissue
Polymicrobial
RF - diabetic foot ulcers, pressure sores, DM , PAD
Most common organism causing osteomyelitis
Staph aureus
Except SCA - salmonella
Investigation of choice in osteomyelitis
MRI
90-100% sensitivity
Antibiotics that can cause pseudomembranous colitis
Clindamycin Amoxicillin Ampicillin Co-amoxiclav Cephalosporin Quinolones - cipro
Investigation of p.colitis
Treatment
CDT toxin in stool
Tx -
1 -oral metronidazole
2- oral vancomycin
- c.difficile can easily spread to others
Hep C work up
Initial test - HCV antibody
To confirm active infection - HCV RNA PCR
- if negative - repeat in 6 months
If hep C confirmed to pick antiviral regimen - HCV genotype test