Infectious diseases Flashcards
What are the Eron classifications
criteria were used to guide how cellulitis is managed.
class 1 no signs of systemic toxicity
class 2 pt systematically well or unwell but has co-morbidity which may complicate or delay the resolution of infection
class 3 acute morbidity that may interfere with the treatment of cellulitis or limb-threatening infection due to vascular compromise
class 4 sepsis or life-threatening infection such as necrotizing fasciitis
MGT of cellulitis
Mild to moderate –> Flucloxacillin (1st line)
Severe –> co-amoxiclav/ cefuroxime/ clindamycin/ ceftriaxone
Bacterial vaginosis
+ causative organism
+ Amsel’s criteria
+ MGT
overgrowth of anaerobic organisms such as Gardnerella vaginalis
Amsel’s criteria for diagnosis of BV - 3 out of 4
- 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)
MGT
- 5-7 days of metronidazole
- topical metronidazole or topical clindamycin as alterntives
Bacterial vaginosis vs Trichomonas
both have
- offensive vaginal discharge
- high ph >4.5
- treatment with metronidazole
BV
- white discharge
- clue cells under microscope
- fishy smell
Trichomonas
- Frothy, yellow-green discharge
- vulvovaginitis
- strawberry cervix
- wet mount shows motile trophozoties
Metronidazole adverse effects
- Reaction with alcohol -> because of a disulfiram-like reaction
- increases the anticoagulant effect of warfarin
STI ulcers: causes
Genital herpes- painful
Syphilis- painless
Chancroid- Painful ulcers caused by Haemophilus ducreyi
Lymphogranuloma venereum (chlamydia)- painless
Behcet’s disease- painful
other causes
Carcinoma
Granuloma inguinale
Influenza vaccine
- timing
- how is children’s vaccine given
- contraindications
given btwn sep and early november
Three things about child vaccine
- given intranasally
- first dose at 2-3 yrs then annually
- it is a live vaccine (inactivated given IM)
contraindications
immuno-compromise/ less than 2 years/ febrile or wheeze illness/ egg allergy/ pregnancy or breastfeeding/ aspirin due to risk of reye’s syndrome
SE of live vaccine given intranasally
headache/ anorexia/ blocked nose or rhinorrhea
SE of inactivated vaccine given intramusculary
Fever and malaise
takes 10-14 days before antibody levels are protective
Listeria
- feature
- diagnosis
- management
- complications in pregnant women
Features
diarrhea, flu-like illness, pneumonia, meningoencephalitis, ataxia, and seizures
Dx only blood cultures
MGT
- amoxicillin/ampicillin (cephalosporins usually inadequate)
- Listeria meningitis should be treated with IV amoxicillin/ampicillin and gentamicin
Pregnant women are most vulnerable (20 times)
complications
- miscarriage
- premature labour
- stillbirth
- chorioamnionitis
UTI in pregnancy
first line nitrofurantoin (should be avoided near term)
second-line: amoxicillin or cefalexin
trimethoprim is teratogenic in the first trimester and should be avoided during pregnancy
Herpes simplex virus
HSV1 - oral lesions
HSV2 - genital sores
but there is an overlap
features
- primary infection- gingivostomatitis
- cold sores
- painful genital ulcers
MGT
aciclovir
MGT of lower UTI
non-pregnant women
pregnant women
men
catheterized patients
non-pregnant women
-> trimethoprim or nitrofurantoin for 3 days
pregnant women treat for 7 days (send urine culture before and after abx therapy)
–> avoid trimethoprim during pregnancy
–> avoid nitrofurantoin near term but is the first line
–> amoxicillin or cefalexin second line
men
–> trimethoprim or nitrofurantoin for 7 days
catheterised patients
–> send cultures
–> treat for 7 days only if symptomatic
When do you need to send for culture
send a urine culture if:
aged > 65 years
visible or non-visible haematuria
pregnant
men
notifiable dx in the UK
Acute encephalitis
Acute infectious hepatitis
Acute meningitis
Acute poliomyelitis
Anthrax
Botulism
Brucellosis
Cholera
COVID-19
Diphtheria
Enteric fever (typhoid or paratyphoid fever)
Food poisoning
Haemolytic uraemic syndrome (HUS)
Infectious bloody diarrhoea
Invasive group A streptococcal disease
Legionnaires Disease
Leprosy
Malaria
Measles
Meningococcal septicaemia
Mumps
Plague
Rabies
Rubella
Severe Acute Respiratory Syndrome (SARS)
Scarlet fever
Smallpox
Tetanus
Tuberculosis
Typhus
Viral haemorrhagic fever (VHF)
Whooping cough
Yellow fever
MSRA
Methicillin-resistant Staphylococcus aureus
MGT - for carrier
MGT - for infection
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
MRSA infections:
vancomycin
teicoplanin
linezolid
MSRA
Methicillin-resistant Staphylococcus aureus
MGT - for carrier
MGT - for infection
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
MRSA infections:
vancomycin
teicoplanin
linezolid
Lyme disease
causative organism
spirochaete Borrelia burgdorferi and is spread by ticks.
Features of lyme disease
Early and late
Early features (within 30 days)
erythema migrans
- ‘bulls-eye’ rash at the site of the tick bite
- develops 1-4 weeks after the initial bite but may present sooner
- usually painless, more than 5 cm in diameter and slowly increases in size
- present in around 80% of patients.
systemic features
headache
lethargy
fever
arthralgia
Later features (after 30 days)
cardiovascular: heart block, peri/myocarditis
neurological: facial nerve palsy, radicular pain, meningitis
Diagnosis of Lyme disease
clinically rash (erythema migrans) is present
or serologically
enzyme-linked immunosorbent assay (ELISA) antibodies to Borrelia burgdorferi are the first-line test
–> next test is immunobolt
MGT of confirmed lyme disease (clinically with rash only or serologically)
doxycycline if early disease. Amoxicillin is an alternative if doxycycline is contraindicated (e.g. pregnancy)
ceftriaxone if disseminated disease
Jarisch-Herxheimer reaction is sometimes seen after initiating therapy: fever, rash, tachycardia after the first dose of antibiotic (more commonly seen in syphilis, another spirochaetal disease)
MGT of confirmed lyme disease (clinically with rash only or serologically)
doxycycline if early disease. Amoxicillin is an alternative if doxycycline is contraindicated (e.g. pregnancy)
ceftriaxone if disseminated disease
Jarisch-Herxheimer reaction is sometimes seen after initiating therapy: fever, rash, tachycardia after the first dose of antibiotic (more commonly seen in syphilis, another spirochaetal disease)
Treatment of
- invasive diarrhea (causing bloody diarrhea and fever)
- non-invasive diarrhea
- traveler’s diarrhea
invasive diarrhea –> ciprofloxacin
non-invasive –> most resolve on their own, if needed use metronidazole
traveller diarrhea –> metronidazole
Causative organisms for typhoid and paratyphoid (Enteric fever)
Salmonella typhi and Salmonella paratyphi (types A, B & C)
features of enteric fever (typhoid/ paratyphoid caused by salmonella group)
headache, fever, arthralgia
initially systemic upset as above
relative bradycardia
abdominal pain, distension
constipation
rose spots: present on the trunk in 40% of patients, and are more common in paratyphoid
complications of typhoid
osteomyelitis (especially in sickle cell disease where Salmonella is one of the most common pathogens)
GI bleed/perforation
meningitis
cholecystitis
chronic carriage (1%, more likely if adult females)
Investigating herpes simplex
nucleic acid amplification tests (NAAT) is the investigation of choice in genital herpes and are now considered superior to viral culture
HSV serology may be useful in certain situations such as recurrent genital ulceration of unknown cause
Tetanus management of wounds
classify wound first (clean/ tetanus prone/high-risk tetanus prone)
Patient has had a full course of tetanus vaccines, with the last dose < 10 years ago
no vaccine nor tetanus immunoglobulin is required, regardless of the wound severity
Patient has had a full course of tetanus vaccines, with the last dose > 10 years ago
if tetanus prone wound: reinforcing dose of vaccine
high-risk wounds (e.g. compound fractures, delayed surgical intervention, significant degree of devitalised tissue): reinforcing dose of vaccine + tetanus immunoglobulin
If vaccination history is incomplete or unknown
reinforcing dose of vaccine, regardless of the wound severity
for tetanus-prone and high-risk wounds: reinforcing dose of vaccine + tetanus immunoglobulin
Gonorrhoea (Neisseria gonorrhoeae)
- features
- complications
- MGT
gonorrhea is a gram -ve diplococcus
in females (cervicitis –> vaginal discharge)
in males - urethral discharge
reinfection is common
complications
- urethral strictures
- epididymitis
- salpingitis
- infertility
- Disseminated gonococcal infection (DGI)
MGT
-The first-line treatment is a single dose of IM ceftriaxone 1g
- if ceftriaxone is refused (e.g. needle-phobic) then oral cefixime 400mg (single dose) + oral azithromycin 2g (single dose) should be used
Disseminated gonococcal infection
Initially there may be a classic triad of symptoms:
- tenosynovitis,
- migratory polyarthritis and
- dermatitis.
Later complications include septic arthritis, endocarditis and perihepatitis (Fitz-Hugh-Curtis syndrome)
MGT of Kaposi sarcoma
radiotherapy and resection
what is chancroid?
Tropical disease caused by Haemophilus ducreyi
It causes painful genital ulcers associated with unilateral, painful inguinal lymph node enlargement.
The ulcers typically have a sharply defined, ragged, undermined border.
Live attenuated vaccine
- may pose a risk for immunocompromised patients
BCG
measles, mumps, rubella (MMR)
influenza (intranasal)
oral rotavirus
oral polio
yellow fever
oral typhoid
Malaria prophylaxis
Atovaquone+ proguanil (SE GI upset)
Cholorquine (SE headache)
* contraindicated in epilepsy
Doxycycline (SE photosensitivity +oesophagitis)
*contraindicated in pregnancy
Mefloquine (SE neuropsychiatric disturbance)
* contraindicated in epilepsy
Proguanil
Proguanil + chloroquine
Malaria prophylaxis
Atovaquone+ proguanil (SE GI upset)
Cholorquine (SE headache)
* contraindicated in epilepsy
Doxycycline (SE photosensitivity +oesophagitis)
*contraindicated in pregnancy
Mefloquine (SE neuropsychiatric disturbance)
* contraindicated in epilepsy
Proguanil
Proguanil + chloroquine
malaria prophylaxis in pregnancy
chloroquine can be taken
proguanil: folate supplementation (5mg od) should be given
Malarone (atovaquone + proguanil): the BNF advises to avoid these drugs unless essential. If taken then folate supplementation should be given
mefloquine: caution advised
doxycycline is contraindicated
MGT of animal and human bites
(bites are usually polymicrobial)
Animal bite
cleanse wound
Puncture wounds should not be sutured closed unless cosmesis is at risk
current BNF recommendation is co-amoxiclav
if penicillin-allergic then doxycycline + metronidazole is recommended
Human Bites
co-amoxiclav
consider risk of HIV and hepatitis
Rifampicin - adverse effects
potent CYP450 liver enzyme inducer
hepatitis
orange secretions
flu-like symptoms
MGT of toxoplasmosis (toxoplasma gonaii is an obligate intracellualr protozoan)
in immunocompetent pts
- most are asymptomatic
- no treatment needed
in immunosuppresed pts
pyrimethamine plus sulphadiazine for at least 6 weeks
Antibiotic guidance (respiratory)
- Exacerbation of chronic bronchitis
- Uncomplicated CAP
- Pneumonia with atypcial pathogen
- HAP
- Exacerbation of chronic bronchitis (Amoxicillin/ tetracycline/ clarithromycin)
- Uncomplicated CAP (Amoxicillin if pen allergic - doxycycline or clarithromycin) if staph infection suspected in influenza then add fluclox
- Pneumonia with an atypical pathogen (clarithromycin)
- HAP (within five days - co-amoxiclav or cefuroxime/ more than five days tazocin/ceftazidime/ciprofloxacin)
Antibiotics guidance (urinary tract)
- lower UTI
- Acute pyelonephritis
- Acute prostatitis
- lower UTI (Trimethoprim or nitrofurantoin. Alternative: amoxicillin or cephalosporin)
- Acute pyelonephritis (Broad-spectrum cephalosporin or quinolone)
- Acute prostatitis (Quinolone or trimethoprim)
Antibiotics guidance (urinary tract)
- lower UTI
- Acute pyelonephritis
- Acute prostatitis
- lower UTI (Trimethoprim or nitrofurantoin. Alternative: amoxicillin or cephalosporin)
- Acute pyelonephritis (Broad-spectrum cephalosporin or quinolone)
- Acute prostatitis (Quinolone= ciprofloxacin or trimethoprim)
Antibiotics guidance (skin)
- Impetigo
- Cellulitis
- Cellulitis near the eye or the nose
- Erysipelas
- Aminal or human bite
- Mastitis during breastfeeding
- Impetigo (Topical hydrogen peroxide, oral flucloxacillin or erythromycin if widespread)
- Cellulitis (Flucloxacillin or alternatives clarithromycin, erythromycin or doxycycline)
- Cellulitis near the eye or the nose (Co-amoxiclav (clarithromycin, + metronidazole if penicillin-allergic)
- Erysipelas (Flucloxacillin* (clarithromycin, erythromycin or doxycycline if penicillin-allergic)
- Aminal or human bite- co-amoxiclav (doxycycline + metronidazole if penicillin-allergic)
- Mastitis during breastfeeding- Flucloxacillin
Antibiotics guidance (ENT)
- Throat infection
- Sinusitis
- Otitis media
- Otitis externa
- Periapical or periodontal abscess
- Gingivitis
- Throat infection (phenoxymethylpenicillin or erythromycin if allergic)
- Sinusitis (phenoxymethylpenicillin)
- Otitis media- Amoxicillin
- Otitis externa- Flucloxacillin
- Periapical or periodontal abscess- Amoxicillin
- Gingivitis - metronidazole
abx for GI infections
- Clostridioides difficile
- Salmonella (non-typhoid)
- Shigellosis
- Campylobacter
- Clostridioides difficile (first vancomycin / other episodes fidaxomicin)
- Salmonella (non-typhoid)- cipro
- Shigellosis- cipro
- Campylobacter jejuni (commonest GI infective cause)- clarithroymicn is first line / cipro is an alternative
Treatment of gonorreha
first-line treatment is a single dose of IM ceftriaxone 1g (i.e. no longer add azithromycin).
If sensitivities are known (and the organism is sensitive to ciprofloxacin) then a single dose of oral ciprofloxacin 500mg should be given
if ceftriaxone is refused (e.g. needle-phobic) then oral cefixime 400mg (single dose) + oral azithromycin 2g (single dose) should be used
CAP organism common in alcoholics
Characteristic features of pneumococcal pneumonia
rapid onset
high fever
pleuritic chest pain
herpes labialis (cold sores)