Viruses

Question 1

Alphavirus Example

Answer 1

EEE, WEE, Venezuelan EE, RRV, Chikungunya

Question 2

Flavivirus Example

Answer 2

Dengue, Zika, JEV, MVE, West Nile, Yellow Fever, St Louis Encephalitis

Question 3

Bunyavirus Example

Answer 3

California encephalitis, La Crosse, Rift Valley Fever

Question 4

Rabies Transmission

Answer 4

Terrestrial mammals (99% dogs), Bats (Americas only), rare reports of tissue/organ transplant

Question 5

Rabies Virology

Answer 5

Bullet-shaped RNA wrapped in five proteins - matrix, envelope, nucleo, phospho and RNA polymerase

Question 6

Rabies Pathogenesis

Answer 6

Exposure -> centripetal retrograde axonal transport to brain along motor neurons, evades immune surveillance > CNS transynaptic spread, replication, inclusion (Negri) body formation, neurons intact but dysfunctional > centrifugal neuronal transport to salivary glands (viral excretion) carried to skin, heart, muscle tongue, but no viraemia

Question 7

Rabies Natural history

Answer 7

Once clinical signs evident, there is no treatment or survival

Question 8

Rabies Deaths per annum

Answer 8

60,000 (21,000 India)

Question 9

Rabies Furious rabies

Answer 9

80% cases - brain stem, cranial nerves, limbic system higher centres

Question 10

Rabies Paralytic rabies

Answer 10

20% cases - medulla, spinal cord, spinal nerves

Question 11

Rabies Prodromal symptom

Answer 11

Pruritus

Question 12

Rabies Clinical furious

Answer 12

Phases of arousal and lucid, CN II, VII, VIII, autonomic sitmulation, arrhythmia, priapism, survive <7d

Question 13

Rabies Hydrophobic spasm

Answer 13

Provoked by drinking > Inspiratory spasm, becomes more severe, can cause oesophageal tears and pneumothorax

Question 14

Rabies Clinical paralytic

Answer 14

Ascending paralysis (?GBS) loss of reflexes, bulbar sx, survive <30d

Question 15

Rabies Differential diagnosis

Answer 15

Post-vaccinal, paralytic polio, Flavivirus, Herpes B virus

Question 16

Rabies Clinical care

Answer 16

Palliative, barrier nursing (low evidence, but improves anxiety), vaccination of staff and household, inform public health authorities

Question 17

Rabies Diagnosis

Answer 17

Nuchal biopsy - immunofluorescence rabies Ag on innervation of hair follicle; saliva PCR (variably released); viral tissue culture; brain biopsy Negri bodies (inclusion in cytoplasm of Purkindje cells)

Question 18

Rabies Treatment

Answer 18

Only if American bat virus, early Ab response, ICU available - Milwaukee protocol discredited

Question 19

Rabies Pre-exposure vaccination

Answer 19

Endemic area, rabies lab worker, endemic animal handlers, travelers to dog rabies enzootic areas (esp children), HCW looking after rabies pt - at least 2 (WHO) ideally 3 (UK) vaccines

Question 20

Rabies Vaccine administration

Answer 20

IM deltoid (NOT gluteal), intradermal improves availability, accessibility and affordability in LMIC

Question 21

Rabies Post-exposure management

Answer 21

Cat 2+ Scrub with soap and water 15min, avoid suturing, give vaccine x2 (RIG and vax x4 if cat 3 AND unvaccinated)

Question 22

Rabies Category 1 exposure

Answer 22

Touching or feeding animals. Licks intact skin, includes drinking milk from rabid cow

Question 23

Rabies Category 2 exposure

Answer 23

Nibbling of uncovered skin, minor scratches or abrasions without bleeding, treat as cat 3 if bat exposure, bites on head/neck/face/hands/genitals (highly innervated) - stop Rx if animal well after 10d/proven negative

Question 24

Rabies Category 3 exposure

Answer 24

Single or multiple transdermal bites/scratches, contamination of mucous membranes or broken skin with saliva, exposures due to bats, includes raw meat of rabid animal - stop Rx if animal well after 10d/proven negative

Question 25

Rabies Immunosuppressed

Answer 25

PrEP x3, Ab response 2-4w later, PEP x5 and RIG for cat 2+

Question 26

Rabies Prevention

Answer 26

Mass dog vaccination (IM or oral), educate children, vigorous washing of all bites, vaccination

Question 27

Rabies PEP

Answer 27

RIG up to 1y after, but not if vax given >7d ago

Question 28

JEV Outcome

Answer 28

1/3 die 1/3-1/2 longterm disability

Question 29

JEV Epi

Answer 29

Asia/Pacific

Question 30

JEV Transmission

Answer 30

Arbovirus, Flavivirus

Question 31

JEV Amplifying host

Answer 31

Pigs, Water birds also involved, vaccination will not eradicate due to animal reservoir

Question 32

JEV Symptoms

Answer 32

> 99% asymptomatic, acute meningoencephalitis syndrome with seizures, Parkinsonism (basal ganglia predilection)

Question 33

JEV Diagnosis

Answer 33

Goldstandard seroneutralisation - paired, and not available outside large reference centres, ELISA available poor spec in serum, also perform on CSF

Question 34

JEV Vaccination

Answer 34

Ixiaro (UK), Imojev (Aus)

Question 35

HPV WHO 2030 Targets

Answer 35

90% fully vaccinated by 15y, 70% women screened by 35-45, 90% CaCx receive treatment and care

Question 36

HPV Genotype

Answer 36

CaCx 16/18, Anogenital warts 6/11

Question 37

HPV Epidemiology

Answer 37

Most infections will clear within 8m

Question 38

HPV Ab response

Answer 38

50% women develop no measurable Ab response following infection

Question 39

HPV HIV co-infection

Answer 39

Increase CaCx x6, Anal cancer x10, increased anogenital warts, HPV is RF for HIV acquisition, HIV decreases HPV clearance

Question 40

HPV CaCx diagnosis

Answer 40

Visual inspection (VIA) and HPV diagnostics have lower sens/spec in WLHIV compared with general population

Question 41

HPV WHO HPV screening

Answer 41

General HPV DNA from 30 every 5-10y; WLHIV HPV DNA from 25 every 3-5y

Question 42

HPV WHO Vaccine recommendation

Answer 42

2 doses from 9yo, option for 1-dose 9-20yo - aim before sexual debut