Infectious Diseases Flashcards
(78 cards)
1
Q
Causative organism in Q fever?
A
Coxiella Burnetii
2
Q
Acute Q Fever symptoms
A
Fever Extreme fatigue Chills, rigors, myalgia, headache Bone pain Petechial rash in persistent infection May have Abdominal pain
3
Q
Q Fever - occupational risk factors for vaccination
A
Contact with domestic ruminants farmers, hobby farmers and shooters abattoir workers, including visitors and tradesmen meat inspectors shearers wool sorters veterinarians and animal handlers animal transporters people who handle linen soiled by animal products.
4
Q
Complications of Q Fever
A
Chronic Q fever Hepatitis/osteomyelitis Post Q fever fatigue syndrome - psychologist review and gentle exercises Infective endocarditis
5
Q
What do you need to know about Vaccination in Q Fever?
A
Needs - skin test, blood test, history of previous exposures - if you give the vaccine to someone who has had Q fever it can be reactogenic Not for people under 15 years Not for egg allergy sufferers
6
Q
How is Q fever transmitted?
A
Handling of infected tissues Dust (aerosolised particles) from infected feces/animal matter
7
Q
Diagnostic test in Q fever?
A
Q Fever PCR Serology - becomes positive later
8
Q
Where does Q fever occur?
A
Mainly Nthn NSW and southern QLD
9
Q
Acute Mx of Q fever
A
Oral Doxycycline 100mg twice daily for two weeks
10
Q
Clinical presentation of Scabies?
A
Intense itch - worse at night Spares head and neck (Except in infants) Burrows and papules - in web spaces of fingers and toes Breasts, genitals, wrists are often affected Secondary bacterial infections - surrounding erythema, yellow crust, pus
11
Q
Management of Scabies
A
Premethrin 5% top to toe for 8 hours Repeat in seven days Treat all household contacts Environnmental cleaning of home Hot laundering of fomites
12
Q
How would you treat secondary bacterial infection in scabies?
A
Bacterial infection: Cephalexin 12.5mg/kg every six hours for five days
13
Q
What are the symptoms of acute prostatis?
A
Symptoms of UTI - urinary frequency, acute dysuria, urgency Systemic features - fever - 38 deg or higher, chills, sweats Obstructive urinary symptoms - weak stream, hesitancy, dribbling, urinary retention Symptoms of prostatic involvement - Pelvic/perineal pressure, prostatic tenderness on gentle digital rectal examination
14
Q
Complications of acute prostatis?
A
Prostatic Abcess Urinary retention Chronic prostatis Sepsis
15
Q
Treatment of acute prostatis?
A
Oral trimethoprim 300mg once daily for two weeks
16
Q
What are the clinical features of acute cystitis in adults?
A
Acute dysuria,urinary frequency, urinary urgency, occasional supra pubic tenderness
17
Q
Who should you investigate with acute cystitis?
A
pregnant women men aged-care facility residents patients who have recently taken antibiotics patients with recurrent infection patients with risk factors for multidrug-resistant bacteria FOr these groups - Mid stream urine sample for microscopy, culture and sensitivities.
18
Q
What is considered significant bacteriuria?
A
he established definition of significant bacteriuria is 10 to the 8 or more colony forming units (CFU)/L from a midstream urine sample. Lower bacterial counts (10 to the 5 CFU/L or more) may be indicative of UTI in: women with symptoms of a UTI patients with a UTI caused by organisms other than Escherichia coli and Proteus species men patients already taking antimicrobial therapy.
19
Q
What does The growth of mixed bacterial types on urine culture or the presence of large numbers of squamous epithelial cells on microscopy represent?
A
contamination with normal genital tract flora.
20
Q
When is urological evaluation required in acute cystitis?
A
recurrent UTIs or an inadequate response to appropriate antibiotics
21
Q
Should you perform post treatment urine culture in acute cystitis?
A
Not for non pregnant asymptomatic people Post treatment urine culture - in pregnant women and men with prostatis
22
Q
Most common cause of acute uncomplicated cystitis?
A
- Ecoli - 95% 2. Staph. Saprophiticus in 5%
23
Q
WHen do complicated UTI’s occur - which organisms?
A
Occur in anatomical or funcitonal abnormalities. Eg neurogenic bladder, nephrolithiaisis Ecoli is most common - but also Klebsiella, Proteus, Pseudomonas
24
Q
When would you refer urology for pyelonephritis?
A
- Men 2. WOmen after 2 episodes of pyleo 3. All ppl with pyelo caused by a proteus species
25
What about non antibiotic therapy in cystitis/UTI?
Analgesia to patients with symptoms - PCM/NSAID Safety and efficacy of urinary alkalinising agents has not been established - Also a) they decrease the effect of nitrofurantoin b) shouldn't be used with quinolones as they can cause crystalluria Cranberry products, Ascorbic acid, methenamine hippurate are not effective for UTI
26
Non pregnant women with acute cystitis - managment?
Oral trimethoprim 300mg once daily for three days OR nitrofurantoin 100mg 6 hourly for five days (this is dose for preg) If can't use either Cephalexin 500mg BD for five days If resistant - check susceptibilities on urine Try Amoxicillin + clavulanate - 500 + 125 bd for seven days
27
What are the clinical features of pyelonephritis in adults?
flank pain nausea and vomiting fever (38 degrees or higher) costovertebral angle tenderness
28
Whats your approach for a patient with pyelonephritis?
1. Obtain a MSU before commencement of antibiotic therapy 2. Consider imaging of urinary tract eg ultrasound to exclude urinary obstruction, kidney stone disease, obstruction, esp. if patient is febrile after 72 hrs of treatment 3. All men with pyelo, women on second episode and anyone with proteus pyelo need urological evaluation 4. Initial IV therapy is required if nability to tolerate oral therapy fever (38°C or higher) systemic symptoms (eg tachycardia, nausea, vomiting) sepsis or septic shock. If they dont have the above - oral therapy is ok
29
Oral therapy for non severe pyelo while awaiting results of investigations?
amoxicillin+clavulanate 875+125 mg orally, 12-hourly for 14 days. If clinical response is rapid, stop therapy after 10 days. If they have a penicillin hypersensitivity use: ciprofloxacin 500 mg orally, 12-hourly for 7 days.
30
When is hospital admission and IV therapy required in acute pyelonephritis?
Inability to tolerate oral therapy fever (38°C or higher) systemic symptoms (eg tachycardia, nausea, vomiting) sepsis or septic shock.
31
What's your approach to asymptomatic bacteriuria in pregnancy?
Untreated bacteriuria in pregnancy is associated with a 20 to 30% increased risk of developing pyelonephritis in later pregnancy. This is likely due to physiological changes to the urinary tract during pregnancy. Untreated bacteriuria may be associated with preterm birth and low birth weight. Antibiotic treatment of asymptomatic bacteriuria reduces the risk of symptomatic urinary tract infection (UTI) during pregnancy. Screen for asymptomatic bacteriuria during pregnancy by obtaining a urine sample for culture and susceptibility testing at 12 to 16 weeks gestation (or at the first antenatal visit, if this occurs later). Confirm asymptomatic bacteriuria with a second urine culture.
32
What can untreated bacteriuria in pregnancy lead to?
20-30% increased risk of developing pyelonephritis Untreated bacteriuria may be associated with preterm birth and low birth weight.
33
What if strep agalactiae (GBS) is detetected in urine during pregnancy?
If Streptococcus agalactiae (group B streptococcus [GBS]) is detected in urine at any stage of pregnancy, intrapartum prophylaxis for GBS is usually indicated
34
What if a pregnany woman presents with recurrent UTI's or recurrent bacteriuria?
Following the resolution of a urinary tract infection (UTI), recurrent bacteriuria occurs in up to one-third of pregnant women. Perform repeat urine culture at antenatal visits to monitor for recurrent bacteriuria. Choose treatment for recurrent bacteriuria based on the results of culture and susceptibility testing Treat acute episodes as appropriate.
35
When would you give antibiotic prophylaxis for recurrent utis in preg?
For women with recurrent bacteriuria OR women with bacteriuria with risk factors like immune compromise, diabetes, neurogenic bladder USE: Cephalexin 250mg nocte for remainder of preg OR nitrofurantoin 50mg nocte orally for remainder of preg
36
How would you treat acute cystitis during pregnancy?
nitrofurantoin 100 mg orally, 6-hourly for 5 days [Note 1] [Note 2] OR cefalexin 500 mg orally, 12-hourly for 5 days. (use cephalexin close to delivery - after 37 weeks or earlier if early delivery is planned as nitrofurantoin can cause haemolytic anaemia and neonatal jaundice) REPEAT A MSU 1-2 weeks post treatment to assess for recurrent UTI or bacteriuria.
37
Time course of most acute diarrhoea? Chronic diarrhoea?
less than 2 weeks
viral
doesnt need abx (exception is CMV)
Chronic/subacute - 4-6 weeks
38
Patient presents acutely with abdominal pain, rectal bleeding and worsening diarrhoea. Hx of AF - Dx?
Ischaemic colitis
39
Diarrhoea history questions ?
**FLUID INTAKE AND OUTPUT**
* vomiting, urine output, urine colour
* stool characteristics - onset, frequency, type, volume, blood?
**PAST MEDICAL HX AND VACCINATION STATUS**
- ?Sources of infections - travel, questionable food consumed, sick contacts, animal exposures, recent occupational history/exposures
* *MEDICATIONS**
abx - clostridium?
PPI? - increased risk of infectious diarrhoea
immunosupressants? - Increased risk of CMV, and parasites
Absorption of some meds could be reduced - COCP
Some meds more likely to cause ADR in presence of dehydration - NSAIDS, ACEI, ARBS, Diuretics, Dig, warf, metfor, lith
**COMORBIDITIES**
immunocompromise, GIT issues?
**PREGNANCY**
Listeriosis risk increases 20 fold
**EPIDEMIOLOGICAL EVIDENCE**
Similar recent presentations, food history, sick contacts, travel
40
Diarrhoea Examination findings?
General inspection - appearance
- Weight, Hydration status (conscious state, mucous membranes, tissue turgor, cap refill, BP)
Vital Signs
GIT signs:
masses, distension, tenderness, peritonism, bowel sounds?
DRE - blood? mucous?
41
Complications of Diarrhoea?
Dehydration and electrolyte imbalance
Acute Kidney Injury
Sepsis
**Specific complications of bacterial enteritis** are: reactive arthritis, pericarditis, myocarditis and HUS
42
Indications for stool culture?
Profuse watery diarrhoea with signs of dehydration (Severity)
Frequent small volume stools with blood or mucous
Bloody diarrhoea
TEMP 38Degrees
SEVERE abdo pain
Recent antibiotic use or hospitalisation
Age over 70 or Immunocompromise
Comorbidities that could be exacerbated by hypovolaemia
Symptoms persisting OVER one week
Public health concerns: HCW, food handlers, teachers, childcareworkers - at beginning of a epidemic
43
What would you advise a patient about collecting a stool culture?
Collect in a sterile container
Refrigerate to prevent overgrowth of non pathogenic organisms
Process as soon as possible - within 1-2 days of collection
44
Are Stool cultures prone to false negatives?
Pathogens are usually excreted constantly throughout illness so a negative culture is usally not false
45
Investigations for severe, chronic diarrhoea?
1. stool culture for microscopy, culture and sensitivity
2. Faecal multiplex PCR - result in 24 hrs
3. If dehydrated -UEC
46
Management of Acute diarrhoea?
1. Maintain hydration and treat dehydration.
-
2. Dietary advice
Maintain fluid intake. Eat if hungry.
Fatty foods or foods high in simple sugars can increase osmotic load
Can be a transient lactase deficiency post diarrhoea.
3. Antidiarrhoea agent - eg Loperamide - avoid in elderly and children - can lead to toxic megacolon. Also avoid in bloody diarrhoea unless on concurrent abx.
Can help with severe symptoms
4. Hygiene precautions
Regular Hand washing
5. Return to work advice
48 hours after stools have returned to normal can return to work
47
Common causes of acute viral gastroenteritis?
1. Rotavirus - common in winter months - associated with vomiting and fever in children.
2. Norovirus - Prominent vomiting, cramping abdominal pain, later diarrheoa, Virus is common in institutional setting
3. Enteric adenovirus
4. Astrovirus
48
Route of transmission for most viral gastroenteritis? Mangement
Faecal oral
However infection with norovirus and calici viruses can occur after ingestion of contaminated water.
Supportive - Hydrate, rest, hygiene
49
Incubation periods of common bacterial pathogens implicated in bacterial diarrhoea
**Salmonella is quick - 6 - 72 hours**
Shigella - 1-7 days
Campylobacter 1-10 days
Shiga Toxin producing Ecoli (Ecoli 0157) - 2-10 days
Yersinia - 4-7 days (_NB: Arthralgia in 50% of adults)_
Entamoeba histolytica - days to weeks
50
Red flags to consider Bacterial cause of Gastro?
Blood
Severe systemic symptoms
Recent travel
Recent antibiotics
Management is still mainly supportive.
Indications for Abx use - **reduce** duration/severity of symptoms/extra GIT complications or spread of bacteria
51
What is the best test for giardia?
Antigen testing of stool
52
Clinical features of giardia lamblia? Amoebiasis
Bubbly, green, foul smelling diarrhoea in giardia (usually no blood)
Blood, mucous, fever in amoebiasis (Antigen testing in stool is best test)
53
How do you treat a parasitic diarrhoea?
Metronidazole
- giardia - 2g daily for three days
entamoeba histolytica - 800mg 8hourly for one week
54
Complications of a parasitic diarrhoea?
Can get lactase deficiency
or post infectious IBS
which can give loose stools for weeks - months
- Refer to gastroenterologist for confirmation
- Refer to dietician
55
Advice to avoid travellers diarrhoea?
The ABCD of avoiding diarrhoea
## Footnote
**A**void anything that may be contaminated with faecal material. Water and food are the biggest culprits
**B**ottled water is the safest option. Check seals and method of purification
**C**lean and Cover: Wash hands thoroughly using an alcohol based cleanser. Cover your feet
**D**isease: if you are immunocompromised, you are at risk of a wider range of disease. Take extra caution and tell your physician this when you get unwell so they can look for different pathogens
56
When must Hep A vax be given prior to exposure/travel?
The hepatitis A and typhoid combined vaccine (brand name: Vivaxim) is administered via the intramuscular route and can be administered to patients aged aged 16 years or older. It must be given at least 14 days before risk of exposure.
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58
If giving Varicella vaccine to an adult - what is the regime? What is the regime fro post exposure vaccination?
Varicella vaccination is recommended for those who are non-immune (from 12 months of age). Adolescents and adults aged 14 years and older need **two doses - at least 4 weeks** apart. Varicella tends to be a more severe illness in adults compared with children.
For post-exposure vaccination, people should receive varicella vaccine within 5 days after exposure, and preferably within 3 days.
If varicella vaccine is not contraindicated, it can be offered to non-immune age-eligible children and adults who have had a significant exposure to varicella or herpes zoster and want protection against primary infection with varicella
59
What are the symptoms and signs of Diptheria
In UNVACCINATED
URTI symptoms initially
Then **Bull neck** (huge cervical lymphadenitis) and an **adherent pseudomembrane** in the pharynx (Thick coating in the back of throat - leads to problems swallowing and acute respiratory obstruction).
Dip Toxin - can cause myocarditis, cranial neuropathies, peripheral neuritis, renal damage.
Cutaneous - Skin Ulcers
60
What is investigation and managment of Diptheria?
**Throat and Nasopharyngeal cultures - swab - MCS**
**Treat with antibiotics (penicillin/erythromycin**) and **Diptheria anti-toxin in severe cases**
Careful **airway managment** (Due to risk of resp. obstruction)
**Close contact**s - cultured and considered for prophylactic abx
**Vaccinate** patients after recovery and vaccinate close contacts who are not fully immune.
61
What is Diptheria?
Infection by toxigenic strain of corynebacterium diptheriae
Aerosol spread (or contact with skin lesions)
Grows on mucous membranes
Incubation period is one week. Then contagious for four weeks after usually.
62
Clinical features of scarlet fever?
Starts as fever and sore throat
Then red, papular rash starts in the skin folds - groin, axillae - then spreads to trunk
then spreads to extremities
Scarlet tongue and circumoral Pallor
It later desquamates
In the folds like antecubital fossa - can get linear petechial lines - pastias lines.
63
Investigation and managment of Scarlet fever?
Throat swab culture or RAPID STREPTOCOCCAL ANTIGEN TEST taken from posterior pharynx
Check Anti-streptolysin O and Anti dexoyribonuclease B titres
MANAGEMENT
Penicillin for 10 days. (May need IM shot initially)
soft foods and cool liquids (soothing)
Oral antihistamine and topical emmolient for itch
Highly contagious - isolate patient for 24 hrs (Esp from young kids)
Don't share towels/beds/utencils
64
Epidemiology of pertussis?
Caused by BACTERIUM - bordetella pertussis
Infants under 6 months most at risk - severe pneumonia, encephalopathy, Apnoeas - usually infected by older family members
CAN occur in immunised kids - but illness is usually less severe
iNfectious period - just before onset of cough UNTIL 21 days after onset of cough.
65
History questions - pertussis?
1. Cough?
2. Coryza?
3. Pattern/Chronicity of cough - eg cough and coryza for one week (Cattarharal phase) followed by paroxysms/spells of coughing (paroxysmal phase)
4. Vomiting after coughing?
5. Whoop after couging?
6. Infants - apnoea/cyanosis with coughing?
7. Close contacts with cough?
8. Close contacts with pertussis?
9. Often well between coughing spasms
66
Examination in pertussis?
Often no signs
Children often well between spasms
Fever is uncommon
67
Investigations in pertussis?
Usually not needed - clinical diagnosis - may be helpful for infection control
Can do **Nasopharyngeal aspirate/Swab for PCR**
test will usually be neg after 21 days or 5-6 days after abx commenced.
serology is not necessary - takes two weeks to come back
68
When would you give Antibiotis in acute pertussis infeciton?
IF earlier than 2 weeks since onset of cough/ (**Cough for less than 2 weeks)**
**Complications -** cyanosis/apnoea/pneumonia
Admitted to hospital
Diagnosed in cattarharal phase (Early)
69
Antibiotic treatment for pertussis? Adult? Child?
Adult - Azithromycin 500mg orally DAY1, then 250mg daily for next four days.
Child over 6 months - 10mg/kg azithromycin up to 500mg on day one, then 5mg/kg up to 250mg orally daily for next four days.
70
Who should get antibiotic prophylaxis for pertussis?
FIRST - have they had close contact with an infectious person **within 21 days from the onset of their cough (infectious period) and before they had 5 days of antibioitics?**
SECOND: Is it a child **under 6months** - then GIVE
THIRD - ADULTS: **Preg mum in LAST month of preg**
**Healthcare worker in maternity unit or newborn nursery**
**childcare worker with close contact with infants less than 6 months**
**They have a household member less thn 6 months**
71
What's the antibiotic prophylaxis regimen for pertussis?
Adult - Azithromycin 500mg orally DAY1, then 250mg daily for next four days.
Child over 6 months - 10mg/kg azithromycin up to 500mg on day one, then 5mg/kg up to 250mg orally daily for next four days.
72
Vaccination in contacts of pertussis case?
Close contacts who are not fully up to date with immunisations should receive dTPA as soon as poss
Consider dTPA vax for adults who've not had a pertussis containing vaccine for last **ten years**
73
School exclusion for pertussis?
_Unimmunised (less than 3 doses)_ and _close childcare contacts less than 7 years of age_ - exclude from school for **14 days** from last exposure (or until they have had *5 days of oral abx)*
74
Admission criteria for pertussis? Public health issues?
Less than 6 months
OR complications (Apnoea, encephalopathy, cyanosis, pneumonia)
Antibiotic prophylaxis for at risk contacts
School exclusion for at risk contacts
**NOTIFICATION to health department of all suspected or proven cases**
75
Head lice - diagnosis?
Pediculus humanus var. Capitus
eggs noticed in hair
itching of scalp or nape of the neck
excoriations and papules on occiput and nape of neck
active infestation - observing a moving louse
76
Head lice management?
1. Wet combing (wet hair and apply conditioner liberally which stuns the lice. Then use a fine tooth comb to brush out the hair in 3 to 4 sections. Wipe conditioner off comb and place on paper towel and look for lice and eggs.
2. Repeat at intervals
3. If not improving then **MALDISON 0.5% topically - leave for 8 hours - then repeat in seven days.**
4. Wet comb the day after application
5. Inform school
6. Hot laundering of pillow cases and hair brush
7. Check contacts and household members - treat if head lice are found.
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78
What's your approach to Latent TB testing?
