Infectious Disease Flashcards
Antibiotic for animal bites
Co-amox
Doxy and metronidazole if pen allergic
Antibiotic for human bites
Co-amox
Antibiotic for exacerbations of chronic bronchitis
Amox, tetracycline, or clarithromycin
Antibiotic for uncomplicated CAP
Amox
Doxy or clarithro in pen allergic, add fluclox if staph suspected e.g. in influenza
Antibiotic for ?atypical pneumonia
Clarithromycin
Antibiotic for HAP
If within 5 days of admission - co-amox or cefuroxime
If more than 5 days after admission - taz or broad spectrum ceph, e.g. ceftazidime, or quinolone e.g. cipro
Antibiotic UTI
Trimethoprim or nitro
Alternative: amox or cephalosporin
Antibiotic acute pyelonephritis
Broad spectrum cephalosporin or quinolone
Antibiotic acute prostatitis
Quinolone or trimethoprim
Antibiotic impetigo
Topical hydrogen peroxide
Oral fluclox or erythromycin if widespread
Antibiotic cellulitis
Fluclox
Clarithromycin, erythromycin, or doxycycline if pen allergic
Antibiotic cellulitis near the eyes or nose
Co-amox
Clarithromycin and metronidazole if pen allergic
Antibiotic erysipelas
Fluclox
Clarithromycin, erythromycin, or doxy if pen allergic
Antibiotics mastitis
Fluclox
Antibiotics throat infections
Phenoxymethylpenicillin
Erythromycin if pen allergic
Antibiotic sinusitis
Phenoxymethylpenicillin
Antibiotic otitis media
Amoxicillin
Erythromycin if pen allergic
Antibiotics otitis externa
Fluclox
Erythromycin if pen allergic
Antibiotics periapical or periodontal abscess
Amox
Antibiotics acute necrotising ulcerative gingivitis
Metronidazole
Antibiotics gonorrhoea
IM ceftriaxone
Antibiotics Chlamydia
Doxycycline or azithromycin
Antibiotics pelvic inflammatory disease
Oral ofloxacin and oral metronidazole
or
IM ceftriaxone and oral doxy and oral metronidazole
Antibiotics syphilis
Benzathine benzylpenicillin
or
Doxycycline and erythromycin
Antibiotics bacterial vaginosis
Oral or topical metronidazole
or
Topical clindamycinA
Antibiotics C. diff
First episode: oral vancomycin
Second/subsequent episode: oral fidaxomicin
Antibiotics campylobacter enteritis
Clarithromycin
Antibiotics salmonella (non-typhoid)
Ciprofloxacin
Antibiotics shigellosis
Ciprofloxacin
Adverse effects aminoglycosides
- Nephrotoxicity
- Ototoxicity
Adverse effects tetracyclines
- Discolouration of teeth
- Photosensitivity
Adverse effects chloramphenicol
Aplasia anaemia
Adverse effects clindamycin
C. Diff
Adverse effects macrolides
Nausea (esp erythromycin)
P450 inhibitor
Prolonged QT
Adverse effects azoles
P450 inhibition
Liver toxicity
Adverse effects amphotericin B
Nephrotoxicity
Flu like symptoms
Hypokalaemia
Hypomagnasaemia
Adverse effects griseofulvin
Induces P450 system
Teratogenic
Adverse effects flucytosine
Vomiting
Adverse effects caspofungin
Flushing
Contraindications BCG vaccine
- Previous BCG vaccine
- Past history TB
- HIV
- Pregnancy
- Positive tuberculin test
- Over 35 (no evidence it works)
Most common bacterial cause of infectious intestinal disease in UK
Campylobacter
Features of campylobacter
Prodrome of headache and malaise
Often bloody diarrhoea
Abdo pain
Most common protozoal cause of diarrhoea in UK
Cryptosporidiosis
Features of cryptosporidial diarrhoea
- More common in immunocompromised and young children
- Watery diarrhoea
- Abdominal cramps
- Fever
Complication of cryptosporidial diarrhoea in immunocompromised
Entire GI tract may be affected resulting in sclerosing cholangitis and pancreatitis
Management of cryptosporidial diarrhoea -
- Supportive if immunocompetent
- Nitazoxanide or rifaximin for immunocompromised
Features of diptheria
Diptheric membrane on tonsils - grey, pseudomembrane on posterior pharyngeal wall
Bulky cervical lymphadenopathy
Neuritis, e.g. cranial nerve
Heart blocka
Management of diptheria
IM penicillin
Diptheria antitoxin
Features of enteric fever (typhoid/paratyphoid)
- Systemic features - fever, headache, arthralgia
- Relative bradycardia
- Abdominal pain and distention
- Constipation
- Rose spots (more common in paratyphoid)
Complications of enteric fever
Osteomyelitis
GI bleed/perforation
Meningitis
Cholecystitis
Chronic carriage
Most common cause of travellers diarrhoea
E coli
Most common causes of acute food poisioning
- Staphylococcus aureus
- Bacillus cereus
- Clostridium perfringens
Features of E coli gastroenteritis
Watery stools
Abdominal cramps and nauseaF
Features of giardiasis gastroenteritis
Prolonged, non-bloody diarrhoea
Foul smelling burps
Bloating
Steatorrhoea
Malabsorption and lactose intolerance
Features of cholera gastroenteritis
Profuse, watery diarrhoea
Severe dehydration resulting in weight loss
Not common in travellers
Features of shigella gastroenteritis
Bloody diarrhoea
Vomiting and abdominal pain
Features of S aureus gastroenteritis
Severe vomiting
Short incubation period
Features of campylobacter gastroenteritis
Flu-like prodrome usually followed by crampy abdominal pain, fever, and diarrhoea which may be bloody
Can mimic appendicitis
Features of bacillus cereus gastroenteritis
Vomiting within 6 hours
Diarrhoeal illness occurring after 6 hours
Features of amoebiasis gastroenteritis
Gradual onset bloody diarrhoea, abdominal pain, and tenderness which may last several weeks
Which pathogens causing gastroenteritis have incubation period of 1-6 hours
Staph aureus
Bacillus cereus
Which pathogens causing gastroenteritis have incubation period 12-48 hours
Salmonella
E coli
Which pathogens causing gastroenteritis have incubation period 48-72 hours
Shigella
Campylobacter
Which pathogens causing gastroenteritis have incubation period >7 days
Giardiasis
Amoebiasis
Virus causing genital herpes
HSV-1 and HSV-2 (more so HSV-2)
Management of HSV in pregnancy
Elective section at term if primary attack of herpes after 28 weeks
Recurrent herpes in pregnancy treated with suppressive therapy, risk of transmission to baby is low
Virus causing genital warts
HPV 6 and 11
Virus causing cervical cancer
HPV 16, 18, 33
First line treatment for genital wards
Topical podophyllum if multiple, non-keratinised warts
Cryotherapy if solitary keratinised warts
Second line treatment for genital warts
Imiquimod
Treatment for giardiasis
Metronidazole
Features of hepatitis A
Flu like prodrome
Abdominal pain, typically RUQ
Tender hepatomegaly
Jaundice
Deranged LFTs
Features of acute hepatitis B
Fever
Jaundice
Raised LFTs
Complications of hepatitis B
- Chronic hepatitis (5-10%)
- Fulminant liver failure (1%)
- Hepatocellular carcinoma
- Glomerulonephritis
- Polyarteritis nodosa
- Cryoglobulinaemia
Risk factors for non-response to hep B vaccine
- Age over 40
- Obesity
- Smoking
- Alcohol excess
- Immunosuppression
Criteria for testing anti-HBs to assess response to hep B vaccine
- Risk of occupational exposure
- CKD
What anti-HBs level indicates adequate response
> 100
What anti-HBs level indicates suboptimal response
10-100
Management of suboptimal response to hep B vaccine
One additional vaccine dose given. If immunocompetent, no further testing required
What anti-HBs level indicates non-responder
<10
Management of non-responder to hep B vaccine
Test for current or past infection
Give further vaccine course (3 doses again) and then testing
Management of non-responder to hep B vaccine after repeat course
HBIG for protection if exposed to virus
Management of hepatitis B infection
Pegylated interferon-alpha
Breastfeeding and hep C
Not contraindicated
Features of acute hep C infection
- Transient rise in serum aminotransferases/jaundice
- Fatigue
- Arthralgia
Only about 30% get these symptoms
Complications of chronic hep C
- Rheumatological probelms
- Sjorgens syndrome
- Cirrhosis
- Hepatocellular cancer
- Cryoglobulinaemia
- Porphyria cutanea tarda
- Membranoproliferative glomerulonephritis
Rheum problems in chronic hep C
Arthralgia
Arthritis
Management of chrnoic hep C
Combination of protease inhibitors e.g. sofosbuvir + daclatasvir or simeprevir, with or without ribavirin
SEs of ribavirin
Haemolytic anaemia
Cough
Teratogenic (no pregnancy for 6 months after stopping)
SEs of interferon alpha
Flu like symptoms
Depression
Fatigue
Leukopenia
Thrombocytopenia
Cause of Kaposi’s sarcoma
HHV-8 (in HIV patient)
Features of Kaposi’s sarcoma
Purple papules or plaques on skin or mucosa, e.g. GI, resp tract
Skin lesions may later ulcerate
Resp involvement → haemoptysis and pleural effusion
HIV treatment
At least 3 drugs - typically 2 nucleoside reverse transcriptase inhibitors (NRTI) and either protease inhibitor (PI) or non-nucleoside reverse transcriptase inhibitor (NNRTI)
Examples of NRTI
Zidovudine
Tenofovir
Didanosine
General SEs NRTIs
Peripheral neuropathy
SE tenofovir
Renal impairment
Osteoporosis
SEs zidovudine
Anaemia
Myopathy
Black nails
SEs didanosine
Pancreatitis
Examples of NNRTI
Nevirapine
EfavirenzS
SEs NNRTI
P450 enzyme interaction
Rashes
Examples protease inhibitors
Indinavir
Nelfinavir
Ritonavir
SEs protease inhibitors
Diabetes
Hyperlipidaemia
Buffalo hump
Central obesity
P450 enzyme inhibition
SEs indinavir
Renal stones
Asymptomatic hyperbilirubinaemia
SEs ritonavir
Potent inhibitor of P450
CXR findings PCP pneumonia
Bilateral interstitial pulmonary infiltrates
May be normal
Features of PCP pneumonia
Dyspnoea
Dry cough
Fever
Exercise induced desat
Very few chest signs
Management PCP pneumonia
Co-trimoxazole
IV pentamidine in severe cases
Steroids if hypoxic
Cause of infectious mononucleosis
EBV aka HHV-4
Features of infectious mononucleosis
- Sore throat
- Lymphadenopathy (anterior and posterior triangles)
- Pyrexia
- Palatal petechiae
- Splenomegaly (50%)
- Hepatitis, transient rise in ALT
- Lymphocytosis
- Haemolytic anaemia
Infectious mononucleosis + amoxicillin =
Maculopapular, pruritic rash
Diagnosis of infectious mononucleosis
Heterophil antibody test (monospot test)
Mode of administration of child flu vaccine
Intranasal
Nasal flu vaccine live or inactivated
Live
Contraindications nasal flu vaccine
Immunocompromised
Aged <2
Current febrile illness or blocked nose/rhinorrhoea
Current wheeze or history of severe asthma
Egg allergy
Pregnancy/breastfeeding
If child taking aspirin (risk of Reye’s syndrome)
Adult flu vaccine live or inactivated?
Inactivated
Contraindications adult flu vaccine
Hypersensitivity to egg protein
Features of Legionnaire’s disease
Flu like symptoms inclduing fever
Dry cough
Relative bradycardia
Confusion
Lymphopenia
Hyponatraemia
Deranged liver function test
Pleural effusion
Diagnosis of Legionnaire’s disease
Urinary antigen
CXR findings Legionnaire’s disease
Mid to lower zone predominance of patchy consolidation
Pleural effusions in 30%
Management of Legionnaires disease
Erythromycin/clarithromycin
Features leptospirosis
Early phase (lasts around a week):
- Mild or subclinical
- Fever
- Flu like symptoms
- Subconjunctival redness/haemorrhage
Second immune phaes (Weil’s disease)
- AKI
- Hepatitis - jaundice and hepatomegaly
- Aseptic meningitis
Management leptospirosis
Mild-to-moderate - doxycycline or azithromycin
Severe disease - IV benzylpencillin
How is leptospirosis spread
Rat urine
Diagnosis of Lyme disease
Clinical diagnosis of erythema migrans present
ELISA antibodies to Borrelia burgdorferi if doubt. If neg and still suspected, repeat ELISA in 4-6 weeks. If still negative and symptomatic for 12 weeks, immunoblot test
Management of Lyme disease
Doxycycline if early disease, amox if contraindicated
Ceftriaxone if disseminated disease
Features of plasmodium vivax
Found in central America and Indian subcontinent
Fever, headache, splenomegaly
Cyclical fever every 48 hours
Features of plasmodium ovale
Typically from Africa
Cyclical fever every 48 hours
Fever, headache, splenomeglay
Features of plasmodium malariae
Fever, headache, splenomegaly
Nephrotic syndrome
Treatment for non-falciparum malaria
In chloroquine sensitive areas, either artemisinin based combo therapy (ACT) or chloroquine
In resistant areas, ACT
Patients with ovale or vivax - primaquine following acute treatment to prevent relapse
Options for malaria prophylaxis
Malarone (atovaquone and proguanil)
Chloroquine
Doxycycline
Lariam (meflouquine)
Paludrine (proguanil)
SEs malarone
GI upset
When to take malarone prophylaxis
1-2 days before
7 days after
SEs chloroquine
Headache
Contraindications chloroquine
Epilepsy
When to take chloroquine
1 week before
4 weeks after
Taken weekly
SEs doxycyline (malaria prophylaxis)
Photosensitivity
Oesophagitis
When to take doxycycline malaria prophylaxis
1-2 days before
4 weeks after
SEs mefloquine
Dizziness
Neuropsychiatric disturbance
CIs mefloquine
Epilepsy
When to take mefloquine malaria prophylaxis
2-3 weeks before
4 weeks after
When to take proguanil malaria prophylaxis
1 week before
4 weeks after
Considerations pregnancy and malaria
Avoid travelling to regions where malaria endemic, diagnosis difficult as parasites may not be detected due to placental sequesteration
Malaria prophylaxis in pregnancy
Chloroquine ok
Proguanil - needs folate supplements
Malarone - avoid, if essential then folate
Avoid mefloquine
Doxy contraindicated
Malaria prophylaxis for children
Avoid travel
DEET spray - repels 100% mosquitos if used correctly, can be used from 2 months
Doxycyline if over 12
CSF findings in bacterial meningitis
- Cloudy
- Low glucose (<1/2 plasma)
- High protein (>1g/L)
- 10-5,000 white cells
CSF findings viral meningitis
- Clear/cloudy
- 60-80% plasma glucose
- Normal/raised protein
- 15-1000 white cells
CSF findings tuberculous meningitis
- Slightly cloudy, fibrin web
- Low glucose (<1/2 plasma)
- High protein (>1g/L)
- 30-300 white cells
CSF findings fungal meningitis
- Cloudy
- Low glucose
- High protein
- 20-200 white cells
Empirical antibiotics bacterial meningitis <3 months
IV cefotaxime and amox
Empirical antibiotics bacterial meningitis 3 months - 50 years
IV cefotaxime or ceftriaxone
Empirical antibiotics bacterial meningitis
IV cefotaxime (or ceftriaxone) and amoxicillin (or ampicillin)
Antibiotics meningococcal meningitis
IV benzylpenicillin or cefotaxime (or ceftriaxone)
Antibiotics pneumococcal meningitis
IV cefotaxime (or ceftriaxone)
Antibiotics haemophilus influenzae meningitis
IV cefotaxime (or ceftriaxone)
Antibiotics listeria meningitis
IV amoxicillin (or ampicillin) and gentamicin
Antibiotics meningitis contact prophylaxis
Ciprofloxacin or rifampicin
Antibiotics MRSA
Vancomycin
Teicoplanin
Linezolid
Treatment mumps
Rest
Paracetamol
Notifiable
Complications mumps
Orchitis
Hearing loss
Meningoencephalitis
Pancreatitis
Features of mycoplasma pneumonia
Prolonged and gradual onset
Flu like symptoms preceding dry cough
Bilateral consolidation on XR
Complications mycoplasma pneumonia
- Cold agglutins → haemolytic anaemia, thrombocytopenia
- Erythema multiforme, erythema nodosum
- Meningoencephalitis, Guillain-Barre syndrome
- Bullous myringitis
- Pericarditis/myocarditis
- Hepatitis, pancreatitis
- Acute glomerulonephritis
Treatment mycoplasma pneumonia
Doxycycline or macrolife (erythromycin/clarithromycin)
Presentation of parvovirus B19
Erythema infectiosum aka slapped cheek syndrome
Pancytopenia in immunosuppressed
Aplastic criss in sickle cell
Hydrops fetalis if pregnant
Features of erythema infectiosum
Mild feverish illness
Bright red cheeks appear as child feels better
Can be triggered by warmth for months afterwards
Most common cause of CAP
Streptococcus pnuemoniae
CAP after flu
Staph aureus
Pneumonia in alcoholics
Klebsiella
PEP hep A
Human normal immunoglobulin (HNIG) or hep A vaccine
PEP hep B positive source
If known responder to vaccine, booster dose given
If non-responder (<10), hep B immune globulin and booster vaccine
PEP hep B unknown source
If known responder to vaccine, consider booster
If non-responder, HBIG and vaccine
If in process of being vaccinated, accelerated course
PEP hep C
Monthly PCR - if seroconversion, inferon +/- ribavirin
PEP HIV
Combination of oral anti-retrovirals ASAP (ideally within 1-2 hours, up to 72 hours) for 4 weekse
Serological testing 12 weeks following completion of PEP
PEP varicella zoster
VZIG in IgG neg preg women/immunocompromised
Rabies treatment (animal bite in at risk countries)
Wash wound
If immunised, 2 further doses of vaccine
If unimmunised, human rabies immunoglobulin (HRIG) given with full course of vaccination - if possible, administer locally around wound
Most common cause of bronchiectasis exacerbations
H influenzae
Rubella features
Prodrome - low grade fever
Maculopapular rash, initially on face → body
Suboccipital and postauricular lymphadenopathy
Complications rubella
Arthritis
Thrombocytopenia
Encephalitis
Myocarditis
Features of chancroid
Painful genital ulceration
Unilateral painful inguinal lymph node enlargement
Sharply defined, ragged, undermined border
Cause of lymphogranuloma venereum
Chlamydia trachomatis
Features of lymphogranuloma venereum
Stage 1 - small painless pustule which later forms ulcer
Stage 2 - painful inguinal lymphadenopathy
Stage 3 - proctocolitis
Treatment for lymphogranuloma venereum
Doxycycline
Features primary syphilis
Chancre (painless ulcer at site of sexual contact)
Local non-tender lymphadenopathy
Often not seen in women (may be on cervix)
Features secondary syphilis
Systemic features - fevers, lymphadenopathy
Rash on trunk, palms, soles
Buccal ‘snail track’ ulcers
Condylomata lata (painless, warty lesions on genitalia)
Features tertiary syphilis
Gummas (granulomatous lesions of skin and bones)
Ascending aortic aneurysms
General paralysis of the insane
Tabes dorsalis
Argyll-Robertson pupil
Features of congenital syphilis
- Blunted upper incisor teeth
- Rhagades (linear scars at angle of mouth)
- Keratitis
- Saber shins
- Saddle nose
- Deafness
Treatment syphilis
IM benzathine penicillin, doxy if contraindicated
What can occur after antibiotic treatment for syphilis
Jarisch-Herxheimer reaction - fever, rash, tachycardia after first dose of antibiotic. No wheeze or hypotension.
Routine tetanus vaccine given at…
2, 3, 4 months
3-5 years
13-18 years
What is classified as tetanus prone wound
Puncture type injuries in contaminated environment, e.g. gardening injuries
Wounds containing foreign bodies
Compound fractures
Wounds or burns with systemic sepsis
Certain animal bites and scratches
What is classified as high risk tetanus prone wounds
Heavy contamination with material likely to contain tetanus spores, e.g. soil, manure
Wounds or burns with extensive devitalised tissue
Wounds or burns requiring surgical intervention
Management of tetanus prone wounds
If full course vaccines with last dose <10 years ago, no action
If full course vaccines with last dose >10 years ago, reinforcing dose of vaccine
If vaccination history incomplete or unknown, reinforcing dose of vaccine and tetanus immunoglobulin
Management of high-risk tetanus prone wound
If full course vaccines with last dose <10 years ago, no action
If full course vaccines with last dose >10 years ago, or vaccine history unknown/incomplete reinforcing dose of vaccine and tetanus immunoglobulin
Examples of tetracyclines
Doxycycline
Tetracycline
Adverse effects tetracyclines
Discolouration of teeth (should not be used <12 years of age)
Photosensitivity
Angioedema
Black hairy tongue
Tetracyclines in pregnancy/breastfeeding
Do not use due to risk of teeth discolouration
Toxoplasmosis in immunosuppressed/HIV can cause…
Cerebral toxoplasmosis
Chorioretinitis
Features of cerebral toxoplasmosis
Constitutional symptoms
Headache
Confusion
Drowsiness
CT features cerebral toxoplasmosis
Usually single or multiple ring enhacing lesions, mass effect may be seen
Management cerebral toxoplasmosis
Pyrimethamine plus sulphadiazine for at least 6 weeks
Features of congenital toxoplasmosis
Neuro damage
- Cerebral calcification
- Hydrocephalus
- Chorioretinitis
Opthalmic damage
- Retinopathy
- Cataracts
Features of trichomonas vaginalis
Vaginal discharge - offensive, yellow/green, frothy
Vulvovaginitis
Strawberry cervix
pH >4.5
Usually asymptomatic in men, can cause urethritis
Investigation findings trichomonas vaginalis
Microscopy of wet mount shows motile trophozoites
Management trichomonas vaginalis
Oral metronidazole 5-7 days (or one off dose 2g metronidazole)
Diagnosis of latent TB
Positive tuberculin skin test or interferon gamma release assay, with normal CXR to exclude active TB
Treatment latent TB
3 months of isonazid + pyridoxine and rifampicin (if under 35 and hepatotoxicity a concern)
6 months of isonidazid with pyridoxine (if interactions with rifamycins a concern, e.g. HIV, transplant)
Treatment active TB
2 months - rifampicin, isoniazid, pyrizinamide, ethambutol
Then next 4 months - rifampicin, isoniazid
Treatment meningeal TB
Prolonged treatment (at least 12 months) wtih steroids
Live attenuated vaccines
BCG
MMR
Intranasal flu
Oral rotavirus
Oral polio
Yellow fever
Oral typhoid
Inactivated vaccines
Rabies
Hepatitis A
IM flu
Toxoid vaccines
Tetanus
Diptheria
Pertussis
Subunit/conjugate vaccine
Pneumococcus
Haemophilus
Meningococcus
Hep B
HPV