ID 1

Question 1

How is Hepatitis B transmitted?

Answer 1

Vertical - mother to child

Horizontal

• Sexual : much more infectious than HIV or HCV
• Blood transfusion, dialysis or operations
• Needles or sharps
• Household - razors/toothbrush

Question 2

What is the HBsAg?

Answer 2

HBV surface antigen - found in serum during ACUTE or CHRONIC infection

• appears in serum 1-10 weeks after exposure, before onset of symptoms or raised ALT
• if recover, undetectable after 4-6 months (if more than 6 months = chronic infection)

Question 3

What is HBeAg?

Answer 3

HBV Envelope Antigen - marker of viral replication and high infectivity

only released when virus is replicating

Appears in later phase of disease in both acute and chronic as evidence of immune response

Question 4

What is HBsAb?

Answer 4

HBV surface antibody

indicates immunity to hepatitis B either following immunisation or infection

Question 5

What is HBcAb?

Answer 5

HBV core antibody

found in most people exposed to HBV

tested as total IgG and IgM

NOT found in people following immunisation, only after infection

Question 6

While HBsAg be present following immunisation?

Answer 6

Yes until body clears it and is replaced with HBsAb

Question 7

Using serology how would you test someone for Hepatitis B?

Answer 7

Screen : HBcAb, HBsAg

HBcAb - will indicate if there’s been a previous infection , can be used to differentiate between acute, chronic or past infection, IgG (acute), IgM (chronic)

HBsAg - will indicate ACTIVE infection

if positive :

HBeAg - check how infective, what viral replication is like
HBV viral load - direct count of copies of virus

Question 8

What does a positive HBsAb result indicate?

Answer 8

immune response to HBsAg = either vaccination or post-infection

Question 9

How would you investigate suspected Hep b?

Answer 9

LFTs
Coagulation profile
HBsAg
HBsAb
HBcAb (IgM + IgG)
HBeAg
HBV DNA

AFP
Fibro scan
USS liver

Question 10

Treatment of HBV?

Answer 10

Acute : supportive care

Chronic : tenofovir & PEGylated interferon alfa SC once weekly for 48 weeks

HBV vaccine - contacts

Question 11

Presentation of Hep C?

Answer 11

Asymp
Hepatic illness - malaise, nausea, RUQ pain and subsequent jaundice (more likely to clear virus than asymp)
Chronic HCV - aymp, non-specific (malaise, fatigue or intermitten, fleeting RUQ)

Question 12

Extra-hepatic manifestations of Hep C?

Answer 12

Essential mixed cryoglobulinaemia, membronoproliferative glomerulonephritis, autoimmune thyroid

Lichen planus
Sjogren’s
B-cell lymphoma
interstitial lung disease

Question 13

How would you diagnose Hep C?

Answer 13

Serology (enzyme immunoassay) - followed by confirmatory testing by means of an immunoblot assay

If positive for HCV antibody - test for HCV RNA by PCR

Question 14

What are the most common genotypes of HCV seen in the UK?

Answer 14

Genotype 1 - 40-50%
Genotype 2 - 40-50%
Genotype 4, 5 and 6 - 5%

Question 15

How likely is a HCV patient to progress to end-stage liver disease? What are RFs?

Answer 15

1/3 at 25 years

1/3 will develop them beyond 25 years

1/3 will never progress to ESLD

RFs - co-existing liver pathology
HIV
African americans

Question 16

Once infected, what are some routine tests HCV patients will go through?

Answer 16

patients with advanced fibrosis or cirrhosis undergo screening for HCC in the form of 6 monthly AFP and liver USS

If there is evidence of portal hypertension - screening for gastric or oesophageal varices with OGD

Question 17

How would you treat a HCV patient?

Answer 17

Fibroscan - check liver transient elastography

direct -acting antiviral drugs (DAAs) - many combinations

Sofosbuvir + Velpatasvir
- G1-6 rarely given with ribavirin

If not succesfull with dual combinations

Sofosbuvir + Velpatasvir + Voxilaprevir - contra-indicated in patients with decompensated cirrhosis - SVR12 acheievd in 99% of patients

Question 18

What is cure defined as in HCV?

Answer 18

Undetectable HCV RNA in blood 12 weeks after end of treatment = sustained virological response = SVR12

Question 19

On suspicion of HIV, what symptoms would you be wary of?

Answer 19

IVDU, homo/hetero unprotected sex, needle pric injury

fevers and night sweats - exclude TB and malaria

weight loss - malnutrition, TB, HIV wasting

rashes and post-inflamm scars - shingles, seborrhoiec dermatitis, popular eruptions, fungal skin and nail infections

oral ulcers, angular cheilitis oral thrush

diarrhoea >1 month

depression and anxiety

recent hosp admissions - TB, bact, pneumocystis jirovecii, fungal infections

generalised lymphadenopathy

Kaposi’s sarcoma - pink or violaceous patch on the skin (AIDS-defining condition)

Chornic herpes infection of genitals or anus >1 months - AIDS-defining illness

Chronic vaginal candidiasis

multidermatomal shingles - AIDS-defining illness

Question 20

What can be used to establish how advanced a patient’s disease is in HIV? Why?

Answer 20

CD4 - T-helper lymphocytes, carry CD4 on their surface. Part of innate immune response to infection and are DIRECTLY attacked by HIV virus

Viral load - actual quantity of virus per ml of patient’s serum. Stable on treatment patient = cannot transmit HIV through unprotected sex

Question 21

What is normal CD4 count? What infections can be seen at lower levels?

Answer 21

Normal range : 450-1600

<200 - pneumocystis jirovecii pneumonia (PCP)
- toxoplasmosis

<50 - mycobacterium avium intracellulare and CMV

Question 22

What is AIDS? How is it diagnosed?

Answer 22

Acquired Immune Deficiency Syndrom

CD4 < 200 or by AIDS-defining illness

PCP
CMV
TB
sentinel tumours - Kaposi’s sarcoma or lymphoma

Question 23

What is HAART?

Answer 23

highly active anti-retroviral therapy

3 different anti-retrovirals, which act on virus in different ways and reduce emergence of resistance - must be taken REGULARLY

Question 24

What are some examples of HAART drugs? Side-effects?

Answer 24

NRTI (nucleoside reverse transcriptase inhibitors) - prevents elongation of DNA chain from viral RNA - Lamivudine, Abacavir, Zidovudine (haemolytic anaemia)

NNRTI (Non-nucleoside reverse transcriptase) - act near the active site of reverse transcriptase, to block viral replication - Efavirenz, Nevirapine (rash, liver tox, drug interactions, sleep disturbance)

PI (protease inhibitors) - blocks cleavage of active proteins from polyprotein formed by viral transcription - atazanavir (GI disturbance, diarrhoea, pancreatitis, abnormal lipid profiles, peripheral neuropathy)

Fusion inhibitors (injection only)

Integrase inhibitors - raltegravir, elvitegravir

entry inhibitors

boosting agents

Question 25

What are the most common combinations of HAARt drugs?

Answer 25

NRTI backbone (2NRTIs) w/ integrase inhibitor, an NNRTI or a PI

Question 26

What can be given as post-exposure prophylaxis?

Answer 26

4 week course Truvuda (tenofovir and emtricitabine) and Raltegravir *same as PrEP - pre-exposure prophylaxis

Question 27

What are some barriers towards HIV medication compliance?

Answer 27

``` Side-effects Social support available Psychological issues about having HIV Taking tablets fitting tablet into lifestyle ``` Stigma with friends and family

Question 28

What is prophylaxis against opportunistic infections for patients who have <200 CD4 count?

Answer 28

Co-trimoxazole - PCP and toxoplasma (rash or bone marrow suppression) Nebulised pentamidine - PCP but not Toxo (teratogenic, that's why adminitsred in a negative-pressure room) Azithromycin - mycobacterium avium intracellulare Ganciclovir - CMV

Question 29

When is prophylaxis against opportunistic infections withdrawn?

Answer 29

Once patients have recovered their immune function on HAART - CD4 > 200 for at least 3 months

Question 30

When is the transmission most likely between mother and child?

Answer 30

during delivery breast feeding

Question 31

What can be done as prophylaxis for HIV positive pregnanct mother?

Answer 31

Anti-retoviral medication commenced from end of 1st trimester Viral load measure every 2 weeks from 30 weeks gestation - undetectable = vaginal delivery can be considred Caesarean otherwise

Question 32

What is given to baby of HIV positive mother postnatally?

Answer 32

AZT monotherapy for 4 weeks exclusive formula bottle feeding

Question 33

What can cause Viral Haemorrhagic fever?

Answer 33

Filovirus - Ebola, Maburg virus | Flavivirus - Yellow fever, Zika, JE, tick-borne encephalitis

Question 34

How does viral haemorrhagic fever present?

Answer 34

Incubations 2-21 days Fever, Headache, myalgia, anorexia, nausea, facial flushing, conunctivitis, vomiting, flu-like symptoms Maculopapular/petechial rash, hepatic involvement if (MArburg/Ebola)

Question 35

When would you suspect viral heamorrhagic fever?

Answer 35

Febrile illness Returning from foreign travel Exposure to bats, rodents, insects

Question 36

How would you investigate and manage VHF?

Answer 36

FBC, LFT, Coag, D-Dimer (DIC) Notify PHE and local communicable disease consultant Prevent transmission Barrier Nursing Antivirals - ribavirin

Question 37

How would Giardia present? Organism responsible? Spread?

Answer 37

Asym Lethargy, Bloating, Abdo pain, Non-bloody diarrhoea, lactose intolerance Giardia Lamblia - faeco-oral

Question 38

How would you investigate and treat Giardia?

Answer 38

Stool microscopy - for trophozoite and cysts are classically negative Duodenal fluid aspirate or 'string-tests' Treat with metronidazole

Question 39

What is typhoid? Organisms? Presentation?

Answer 39

Salmonella group - (salmonella typhi and salmonella paratyphi) Enteric fevers - headache, fever, arthralgia Abdo pain, CONSTIPATION, rose spots (on trunk, more common in paratyphoid)

Question 40

How do you treat typhoid? Complications

Answer 40

Ceftriaxone + Azithromycin ``` osteomyelitis GI bleed/perf Meningitis chelocystitis chronic carriage ```

Question 41

What organisms responsible for Malaria? Spread? Protective conditions?

Answer 41

``` Plasmodium Falciparum (severe malaria) other 3 normally cause benign malaria Vivax Ovale Malariae ``` Spread by female anopheles mosquito Sickle-cell trait, G6PD deficiency, HLA-B53 and absence of duffy antigens = protective

Question 42

How does Malaria Falciparum present? Complications?

Answer 42

Temp >39, malaise, myalgia, headache and vomiting Severe anaemia Hepatosplenomegaly Jaundice ``` COMPS : Hypoglycaemia Cerebral malaria Reduced consciousness AKI DIC Haemolytic Anemia - black pee ```

Question 43

How would you investigate Malaria?

Answer 43

Giemsa stained -Blood Film - 3 samples are sent over 3 consecutive days (48 hr cycle - can have days which are negative) Rapid diagnostic testing FBC, clotting, U&Es, LFTs PCR Arbovirus - rule out dengue, chikugunya, zika *if higher than >2% erythrocytes paratises = SEVERE DISEASE

Question 44

Treatment of Malaria?

Answer 44

Riamet (artemether and lumefantrine) Malarone (proguanil and atovaquone) Quinine Sulphate Doxycycline IF SEVERE = IV Artenusate, Quinine

Question 45

Depending on geography, which medication would you most effective in Malaria?

Answer 45

Quinine - Africa (hypoglycaemia) Artenusate - Asia

Question 46

What is Malaria prophylaxis?

Answer 46

DEET spray Mosquito Nets and barriers Malorone - daily 2 days before and one week after trip (EXPENSIVE) Mefloquine - once weekly for 2 weeks, during and 4 weeks after Doxycycline - daily 2 days before, during and 4 weeks after. (sun rash, sunburn, diarrhoea, thrush)