Infectious Disease

Question 1

Rifampicin
INH
Ethambutol
Pyrazinamide
Kanamycin

Answer 1

Hepatitis, Thrombocytopenia
Hepatitis, Peripheral Neuropathy
Optic Neuritis
Hepatitis, Gout
Hearing loss

Question 2

Moxyfloxacin
Bedaquiline
Terizidone
Clofazimine
Linezolid

Answer 2

• Tenosynovitis (including Achilles rupture), Peripheral Neuropathy
• QT prolongation, leading to cardiac arrhythmia
• Cross-resistance between bedaquiline and clofazimine
• photosensitivity, brownish skin discoloration, ichthyosis, QT prolongation, neurologic
  -Bone marrow suppression, neuropathy, GI symptoms, and/or retinitis
  Risk of serotonin syndrome - should not be administered with SSRIs and TCAs. Or diet high in tyramine-containing foods (such as cheese, red wine)

Question 3

Malaria (signs)

Answer 3

Jaundice
Splenomegaly
Anemia
Pulmonary edema
Deep breathing due to metabolic acidosis
Neurological signs

Question 4

Malaria (symptoms)

Answer 4

Headache
Paroxysm of fever, shaking chills, and sweats (every 48 or 72 hours, depending on species)
Fatigue and malaise
Arthralgia and myalgia
Cough
Less common:
Anorexia
Nausea and vomiting
Diarrhea
Jaundice

Question 5

Severe Malaria

Answer 5

Renal impairment (Creat > 265 / Urea > 20)
Cerebral Malaria
Metabolic acidosis
Pulmonary oedema / ARDS
Shock (systolic BP < 80)
Severe anemia (Hb < 7)
Hypoglycaemia
High parasite count (>5%)

Question 6

Cerebral Malaria

Answer 6

Confusion
Depressed level of consciousness
Convulsions
Any focal neurology
Infected RBC becomes “sticky” and cause obstruction of the microcirculation in the brain

Question 7

Options to diagnose of Malaria

Answer 7

Thin and thick smears = Still gold standard
Rapid diagnostic testing (RDT) = Bedside test, Fast
PCR= Sensitive and can identify species, butexpensive

Question 8

Further test for Malaria

Answer 8

FBC = low platelets, Hb, WCC for co-infection,
Blood Culture = exclude co-infection
U&E = exclude renal impairment (severe Malaria)
CXR = exclude resp. causes
Glucose (confusion pt) = Diff reason for conf.. vs cerebral malaria
Blood gas = exclude metabolic acidosis (severe malaria)

Question 9

Malaria Treatment

Answer 9

Artemisinins: Severe malaria – IVI artesunate
Quinine: Gold standard!
Vivax and Ovale

Question 10

HIV (Sero-conversion)

Answer 10

2-4 weeks after initial exposure
Transient drop in CD4 with assoc. opportunistic infections
Symptoms:
Constitutional symptoms: Fever, Myalgias and Fatigue
Lymphadenopathy
Pharyngitis
Headache and photophobia due to aseptic meningitis
Typical rash - nonpruritic, erythematous, and maculopapular on the face and trunk
Other possible skin features - desquamation of the palms and soles, generalized urticaria, vesiculopustular rash, erythema multiforme, or alopecia
Oral and genital mucocutaneous ulceration
Diarrhea

Question 11

HIV(Clinical effects)

Answer 11

Low CD4 with immune suppression = Opportunistic Inf.
Malignancy = loss of immune surveillance
High CD4 = Neuro (GBS), HIV assoc. arthritis, Psoriasis & seborrheic dermatitis
Direct infection by HIV = HIVAN, HIV associated encephalopathy, Hematological abnormalities

Question 12

Opportunistic infection

Answer 12

Tuberculosis
Cryptococcus
Toxoplasmosis
Pneumocystis
Chronic diarrhoea

Question 13

HIV & TB

Answer 13

TB more challenging in HIV co-infected pt
More smear-negative case, Atypical presentation
Management (Latent TB) = Isoniazide Preventative Therapy
Drug interaction
IRIS

Question 14

Diagnostic tests for TB in HIV pt

Answer 14

Sputum Culture = sensitivity 80% (relative to clinical reference standard), Response to therapy (1-6 Weeks)
Smear microscopy = Sens. (30-40%) cannot distinguish Non-TB from TB mycobacteria. Response to therapy
X-pert MTB/RIF = Rapid turnaround time, Detect Resistance (Rifampicin), Not to monitor response to therapy.
TB LAM Ag (urine) = High speci…, Best performance ( CD4 c <50). Poor sensi… (CD4 c >100)

Question 15

Symptoms screening of all new pts

Answer 15

Prophylactic screening for TB and CCM
TB screening: Cough, weight-loss, fever, night sweats, TB contact. If postive = Sputum Xpert, Urine LAM (CD4 <200), CXR
CCM screening: new headache

Question 16

Cryptococcus Neoformans (Signs & Symptoms)

Answer 16

Indolently over 1-2/52
Symptoms: Fever, malaise, headache, photophobia and vomiting.
Signs: Neck stiffness, confusion, cranial neuropathies, raised intra-cranial pressure, coma and death
Disseminated disease: cough, dyspnea and skin rash.

Question 17

Cryptococcus Neoformans (Management)

Answer 17

Cryptococcal prophylaxis
CD4 < 200 – do serum CrAg
If positive = do LP (confirm meningism pre-emptive treatment) 1 out of 3 serum positive pts has no symptoms despite positive LP (Raised Protein & lymphocytes eg Viral Meningitis), CLAT sensitive, Indian ink specific, sensi…(60%), culture = Response to therapy

Question 18

Toxoplasmosis Gondii

Answer 18

contaminated food or cats
infections, most asymptomatic, but maybe flu-like illness – toxoplasmosis become dormant in host – life long.
HIV-pt = Cerebral disease: Headache, confusion, convulsion, depressed LOC and neurological signs depending on where the lesions are. Retinal disease

Question 19

Pneumocystis jirovecii

Answer 19

Cause fever, cough and dyspnea
Can be severe – leading to respiratory failure
CXR typically show “ground glass” opacifications
Dx: Can not be cultured, PCR of respiratory fluids’
Microscopy with special staining, Raised Beta-D-glucan levels but not specific to PJP eg Candida, other yeast.
Clinical Dx:
-Severe dyspnea
-Low CD4
-Ground glass on CXR

Question 20

Cause Pneumonia in immune compromised pts

Answer 20

HIV positive
Hematological malignancies on chemotherapy
Rheumatological conditions on immune suppressions

Question 21

Chronic diarrhoea in the immune compromised

Answer 21

Long list of organisms
Both those involved in immune competent
Some specific to low CD4
Features:
- Fever and severe immunosuppression – CMV, Mycobacterium avium complex (MAC)
- Fever, weight loss and hepatosplenomegaly - MAC, histoplasmosis, or lymphoma
- Abdominal tenderness - abdominal abscess, colitis, or biliary tract or pancreatic disease
- Perirectal tenderness – Gonorrhea, Chlamydia or lymphogranuloma venereum
-Overt blood – CMV, Herpes simplex virus (HSV) proctitis, or neoplasia

Question 22

Malignancy

Answer 22

Immunosuppression (loss of natural killer), coinfection with other oncogenic viruses (HHV-8, EBV, HPV)
AIDS-defining Cancers:
Kaposi’s sarcoma [KS]
Cervical cancer
Non-Hodgkin lymphoma [NHL] including systemic NHL, CNS lymphoma, primary effusion lymphoma
Non-AIDS-defining:
melanoma and cancers of the oral cavity, liver, female breast, prostate, and thyroid
HAART preventing severe immunosuppression for prolonged decreases in the incidence

Question 23

HIVAN

Answer 23

Typical patient:
Advanced Immune Suppression
Fair rapidly progressive renal impairment
Nephrotic range proteinuria (without the other features of nephrotic syndrome)
Typical features on biopsy = seldom biopsied Large kidneys on Ultrasound
Exclude (other renal causes):
-Pre-renal causes
-Drug related
-Usual causes like GN

Question 24

HIV associated encephalopathy

Answer 24

Occur with lower CD4
Subacute onset of 3 typical components:
Cognitive deficits = substantial memory deficits, impaired executive functioning, poor attention and concentration, mental slowing, and apathy
Behavioral and mood changes = apathy, lack of motivation, irritable mood, sleeplessness, restlessness, and anxiety
Motor signs = slowness of movement and gait, difficulty with smooth limb movement, dysdiadochokinesia, hyperreflexia
Differential Diagnosis:
opportunistic infections, primary CNS lymphoma, nutritional deficits, other causes of delirium
Therefore pt needs CT/MRI, potentially LP

Question 25

HIV associated haematological abnormalities

Answer 25

Anemia of Chronic disease
Idiopathic Thrombocytopenia (ITP)
Pancytopenias = Due to infiltration of bone marrow by opportunistic organisms, HIV direct destruction of bone marrow
Pure red cell aplasia: severe anemia, Low reticulocyte production index since issue in bone marrow, Rare, but has been associated with 3TC and FTC, Bone marrow examination to confirm the condition, Parvo B19 PCR to exclude this more common cause for PRCA

Question 26

Diagnosis of HIV (confirm)

Answer 26

Rapid test + ELISA
Rapid test + viral load
ELISA + viral load

Question 27

Prophylaxis against Opportunistic infections

Answer 27

1 Cotrimoxaole prophylaxis (CD4 >200, 800/160, 1 double strength tablet/ 2 single)
2 Cryptococcal antigen screening and pre-emptive treatment
3 TB preventative therapy