Speciality: Infectious Diseases Flashcards
(38 cards)
1
Q
Patient - just returned from Africa, Erratic fever (41) w/ rigors and sweats, N&V, headache, diarrhoea, developing shock. Dark urine and reducing GCS. Anaemia.
A
Malaria
2
Q
Malaria Aetiology
A
- Protozoal infection.
- Female anopheles mosquito
- Plasmodium falciparum, vivax, ovale, malariae.
3
Q
Malaria pathology
A
- Female mosquito is infected and there is a growth cycle within the insects gut (temperature sensitive, denoting disease distribution)
- Innoculates human host
- Protazoa taken up by hepatocytes.
- Affects RBC’s
- Most effects relating to anaemia, cytokine release, organ damage and failure.
4
Q
Malaria Presentation
A
- Normal incubation period = 10-21 days.
- Fever (erratic and high)
- Rigors and sweats
- Malaise
- Headache
- N&V
- Diarrhoea
Vivax and ovale = more mild disease with emerging anaemia and self-limiting prognosis resolving in 2-6 weeks.
Falciparum = Can be severe w/ cerebral malaria, blackwater fever, DIC, ARDS and shock.
5
Q
Malaria Ix
A
1) Clinical - anyone unwell after travelling to endemic area.
2) Giemsa (thick and thin) blood film - 3x films before Dx.
3) Try to confirm Dx prior to Rx.
4) Rapid antigen testing is available in some places
6
Q
Malaria Rx
A
1) ABCDE
2) Uncomplicated = Chloroquinine (PV, PO, PM are sensitive) following Rx with chloroquine, a further 3 weeks of primaquine is required to prevent hepatic release of more protozoa.
3) Falciparum = Artemisinin based combo therapy.
4) Severe or complicated PF disease is a medical emergency. ITU. IV artesunate.
7
Q
Malaria prophylaxis
A
- Malarone, doxycyline, chloroquine
- Measures of insect avoidance
8
Q
Patient - Middle eastern, Middle aged just been commenced on immunosuppression therapy for RA (MTX), productive cough w/ heamoptysis, drenching night sweats, fevers, weight loss.
A
- TB
9
Q
TB Aetiology
A
- Mycobacterium TB, Bovis or africanum.
- Acid-fast bacilli
- RF’s = T2DM, HIV, STEROIDS, immunosuppression, alcohol, sex, homelessness, cramped housing.
10
Q
TB Pathology
A
- Associated with poor housing and ventilation and over-crowding due to being droplet spread.
- Often Primary infection is asymptomatic and causes only a mild illness.
- Alveolar macrophages eat the pathogen and release chemicals causing inflammation - necrosis and caseating granuloma.
- Often is reactivated when immunosuppressed etc.
11
Q
TB Presentation
A
- Pulmonary TB - Productive cough w/ haemoptysis, sweats, fever etc.
- Nodal TB - normally extrathoracic, firm and non-tender nodes.
- Miliary TB - multiple organ sites including CNS w/ microabscesses.
- GU TB - dysuria, frequency, loin pain, bladder and testicles.
- Bone TB - Vertebral collapse, potts vertebra.
- Skin TB - lupus vulgaris, jelly lesions on the face and neck.
12
Q
TB Ix
A
1) CXR - consolidation, effusion, calcification and hilar node lymphadenopathy.
2. Sputum MC&S
13
Q
TB Rx
A
1) HERZ ABx for 2 months followed by rifampicin + isoniazid for 4 months.
2) DOTS therapy.
14
Q
MRSA infection management
A
- Vancomycin or teicoplanin
- Linezolid
- Ciprofloxacin
15
Q
Sepsis 6
A
- Oxygen
- Blood cultures
- Abx
- Fluids
- Serum lactate - ABG/VBG
- Catheter
16
Q
Bacterial vaginosis
- Causes
- Presentation
- Ix
- Rx
A
- Overgrowth of vaginal flora
- Gardnerella vaginalis
- Fall in lactic acid producing lactobacilli resulting in raised pH. - Vaginal discharge; fishy
- Often asymptomatic. - Swab of discharge
- Clinical
- Whiff test - potassium hydroxide to the discharge = fishy. - Oral metronidazole 5-7days
17
Q
Cellulitis
- Causes
- Presentation
- Ix
- Rx
A
- Inflammation of skin and SC tissues.
- Strep pyogenes
- Staph aureus - Erythema
- Pain
- swelling
- Often on shins
- May be systemic upset. - Clinical
- Blood cultures
- Bloods for raised inflammation markers and WCC - Oral flucloxacillin or (clarithromycin)
- If severe admit for IV augementin, cefuroxime etc –> severe Sx, systemic upset, nec fasc.
18
Q
Gonorrhoea
- Causes
- Presentation
- Ix
- Rx
A
- STI
- Neisseria Gonorrhoeae
- Acute infection of the GU tract or the rectum and pharynx. - Incubation = 2-5 days
- Males - urethral discharge, dysuria
- Females - cervicitis, vaginal discharge - High vaginal swabs
- Mid stream urine. - IM ceftriaxone 1g
- Or IM ceftriaxone + oral azithromycin.
- Oral cefixime 400mg + oral azithromycin 2g.
19
Q
Legionella
- Causes
- Presentation
- Ix
- Rx
A
- Legionella pneumophilia.
- Colonises water tanks … AC units
- ‘Patient just returned home from spain …’ - Flu like Sx
- Dry cough
- bradycardia
- Confusion
- Lymphopenia
- Hyponatraemia
- Deranged LFT
- Pleural effusions. - CXR
- Urinary antigen testing. - Erythromycin/clarithromycin.
20
Q
Invasive diarrhoea (bloody diarrhoea and fever) management
A
- Often nil
- If severe clarithromycin.
21
Q
Kaposi Sarcoma
- Causes
- Presentation
- Ix
- Rx
A
- HHV-8
- HIV or severely immunosuppressed
- AIDS defining illness.
- Neoplasm of skin. - Skin lesions; nodular, popular or blotchy. May be red, purple, brown or black.
- See on or under mucus membranes
- Painless but can be inflamed or swollen. - Detection of latency associated nuclear antigen.
- Incurable.
- Rx underlying cause
- HAART will often reduce lesions.
- Radio/cryo/surgery.
- Systemic chemo is organ involvement.
22
Q
Hepatitis B
- Causes
- Presentation
- Ix
- Rx
A
- Double stranded DNA virus.
- spread via blood and bodily fluids.
- Vertical transmission. - Incubation = 6-20 weeks.
- Fever
- Jaundice
- LFT derangement
- Chronic hepatitis
- Liver failure
- HCC - Viral markers and viral load.
- HBsAG
- Anti-HBV IgM is diagnostic (acute phase)
- PCR of HBV DNA
- Test for HIV too. - Mainly asymptomatic
- Pegylated interferon alpha
- Tenofovir etc.
- treat Sx
23
Q
HBV immunisation
A
- children in the UK at 2,3 and 4mo.
- At risk groups.
- Vaccination contains HBsAg
- Good response = >100 Anti-HBs - booster at 5 years.
- Suboptimal response = 10-100 - one additional vaccine.
- Non-responder = <10 - test for current or past infection. Further vaccine course. May require HBIG.
24
Q
Viral haemorrhagic fever 1. Causes 2. Presentation 3, Ix 4. Rx
A
- Filoviridae virus
- Human to human transmission via blood. - Incubation = 2-21 days
- Patients are not infectious until they develop Sx.
- Sudden onset fever, fatigue, muscle pain, headache and sore throat.
- Vomiting, diarrhoea, rash, internal and external bleeding. - PHE
- PHE
25
Lyme disease
1. Causes
2. Presentation
3. Ix
4. Rx
1. Spirochete Borrelia Burgdorferi
- Spread via tics
2. Bulls-eye rash
- Systemic features of fever and arthralgia.
- Heart block and myocarditis
- Facial nerve palsy
- Meningitis
3. Clinically Dx if bulls-eye rash is seen
- ELISA of borrelia
4. Doxycycline if early disease.
- Ceftriaxone if disseminated disease.
26
Rifampicin
1. MOA
2. SE
1. CYP450 inducer
| 2. Can stain secretions such as sweat and urine red
27
Isoniazid
1. MOA
2. SE
1. CYP450 inhibitor
2. Drug induced lupus and peripheral neuropathy.
- Pyridoxine (vit B6) is given to prevent this
28
Streptomycin
1. MOA
2. SE
1. Aminoglycoside
| 2. Toxic to ears and kidneys
29
Ethambutol
1. MOA
2. SE
1. Prevents growth of TB
| 2. Eyesight problems; colour blindness and poor vision.
30
Genital warts
1. Causes
2. Presentation
3. Ix
4. Rx
1. HPV 6 & 11
- 16 & 18 predispose to Ca.
2. Small fleshy warts which may itch or bleed.
3. Clinical
- Swab and MC&S
4. Topical cryotherapy are first line depending on site.
- Imiquimod cream.
31
Syphilis organism
Treponema pallidum
32
Genital herpes
1. Causes
2. Presentation
3. Ix
4. Rx
1. Causes HSV2 (HSV1)
2. Primary infection - severe ulceration and pain
- Urinary retention
- Painful recurrent ulceration.
3. Clinical
- Swab and MC&S
4. Oral acyclovir
- Section if pregnant and herpes is present.
33
Post exposure prophylaxis
Hep A - vaccine or Human normal immunoglobin can be used.
Hep B - If the exposed person is a responder to the vaccine, booster should be given.
- Non-vaccinated HBIG + vaccine.
Hep C - monthly PCR, if seroconverting interferon + ribavirin.
HIV - Combo of oral antiretroviral (tenofovir etc) ASAP for 4 weeks, but can be started up to 72hrs post.
34
Infectious mononucleosis
1. Causes
2. Presentation
3. Ix
4. Rx
1. EBV
- others include, CMV and HHV-6.
2. Sore throat + pyrexia + lymphadenopathy.
- Other include; malaise, palatal petechiae, HSM, haemolytic anaemia.
- Maculopapular rash when taken amoxicillin.
- Resolves in 2-4 weeks.
3. Monospot test (heterophuil antibody test)
4. Rest + drinks + avoid alcohol
- Simple analgesia
35
Hepatitis E
- FO route
- Undercooked pork and shellfish
- 3-8 weeks incubation
- Carries significant mortality in pregnancy.
- Self-resolving.
36
MRSA
1. Causes
2. Presentation
3. Ix
4. Rx
1. Methicillin resistant SA
- screen all those waiting for elective admission (except, TOP, ophthalmic surgery)
- Nasal swab and lesion swab.
4. Suppression of MRSA w/ nasal mupirocin 2% in paraffin TDS 5 days + chlorhexidine wash for 5 days.
- ABx used = vancomycin, teicoplanin and linezolid.
37
Meningitis causes by age group
0-3mo
3mo-6yo
6-60yo
>60yo
- GBS, E.coli and listeria
- Neisseria meningitidis, S.pneumoniae, Haemophilus
- Meningococcus, S.pneumoniae
- S.pneumoniae, meningococcus and listeria
38
Pneumocystis Jiroveci Pneumonia
1. Causes
2. Presentation
3. Ix
4. Rx
1. Fungus - Pneumocystis jiroveci
- Aids defining illness
- CD4 count less than 200 should receive prophylaxis.
2. SOB
- Dry cough
- Desaturation of exertion
- Pneumothorax
- HSM
3. CXR - BL interstitial infiltrates.
- Sputum fails to show PCP
- BAL (silver stain)
4. Co-trimoxazole
- IV pentamidine in sever cases.
- Steroids if hypoxic.
