Diseases

Question 1

Duration of yellow fever vaccine
Exemptions
Precautions

Answer 1

Lifelong

Exemptions: age

Question 2

Yellow fever:

1. Genus
2. Incubation period
3. Infectious period

Answer 2

1. Flavivirus
2. 3-6 days
3. Just before fever for 3-5 days

Question 3

Measles

1. Incubation period
2. Reproductive rate
3. Infectious period
4. Timing of rash

Answer 3

1. 7 - 18 days (usually 10 days)
2. 15-18
3. 1 day prior to prodromal illness to 4 days after rash appearance
4. rash appears day 3-4 and lasts 4-7 days

Question 4

Listeria

1. Incubation period
2. Period of communicability
3. Risk factors
4. Source
5. Diagnosis

Answer 4

1. 3-70 days (median 3 weeks)
2. 7-10 days (mother to baby)
3. Pregnant women/fetuses, newborns, immunosuppression
4. contaminated food particularly cheese, ready-to-eat meals and salads, deli meats, pate
5. Usually blood cultures or another sterile site (e.g. CSF)

Question 5

Define a community outbreak of IMD

Answer 5

3 or more confirmed or probable cases of IMD with no direct epidemiologic link within a defined area within 3 months with a primary attack rate of 10 per 100 000

Question 6

What changes in epidemiology of meningococcal disease are suggestive of an outbreak? (3)

Answer 6

• increased rate of disease (or increase in number in small populations)
• clustering of cases in an age group or a shift in the age distribution of cases
• phenotyphic or genetic similarity among cases

Question 7

Define an organisation-based outbreak of IMD

Answer 7

2 or more probable or confirmed cases within 4 weeks among an organisation e.g. high school but no close contact with each other

Question 8

What are the national case definitions for measles:

1. Confirmed case
2. Probable case

Answer 8

1. Confirmed case = lab definitive evidence, or
   clinical and epi evidence
2. Probable case = lab suggestive evidence and clinical evidence.
   clinical evidence = generalised maculopapular rash for 3 or more days + fever>38 at time of rash onset + [cough or coryza or conjunctivitis or koplik spots]
   **epi evidence = contact with an infectious/suspected case
   **lab-suggestive evidence: IgM detected by a non-reference lab (except if recently had measles vaccine)

Question 9

Measles lab tests:
<3 weeks
>3 weeks

Answer 9

3 weeks: nasopharyngeal swab and urine for NAT and culture. Blood for serology and WGS
>3 weeks: serology

Question 10

Measles

1. what are the r/f for severe disease?
2. what are the potential complications?
3. what is the case fatality?

Answer 10

1. R/F: young children, malnutrition, vitamin A deficiency
2. haemorrhagic rash, protein-losing enteropathy, otitis media(6%), severe skin infections, pneumonia (9%)
   - exacerbation of vitamin A deficiency -> blindness
   Subacute sclerosing panencephalitis (1/100 000) several years after infection
3. Case fatality 3-5% in developing countries

Question 11

What is the incubation period of hepatitis A?

Answer 11

15-50 days (commonly 28-30)

Question 12

What is the infectious period of hepatitis A?

Answer 12

from a few days prior to illness to a few days after jaundice

Question 13

Case definition for hepatitis A

1. Confirmed case
2. Probable case

Answer 13

1. Confirmed = Lab-definitive evidence (IgM or NAT)

2. Probable = Clinical and epi evidence

Question 14

1. For hepatitis A contacts who should you consider post-exposure prophylaxis (vaccine or Ig)>
2. which groups should receive NHIG?

Answer 14

1. -household or sexual contacts
   - if case in childcare centre -> contacts
   - if case in food handler -> contacts who ate food prepared or other food handlers
   Use NHIG for
   -

Question 15

What is the incubation period of IMD?

Answer 15

1-7 days (up to 10)

Question 16

What are the case definitions for IMD?

confirmed and probable

Answer 16

Confirmed case = lab definitive evidence (isolation of N. meningitidis from a sterile site, or NAT)
OR lab-suggestive (gram neg diplococci or IgM) and clinical evidence (clinically compatible illness)
Probable case = clinical evidence

Question 17

What are the main considerations during an outbreak of IMD?

Answer 17

• Establish a team, lab-communication and comms
• Confirm the diagnosis and serotype
• Active surveillance: age-specific or region-specific rates
• Information provision early: public (media releases, press conference), HCW, prepare for increase in calls
• Manage contacts: clearance ABx
• Consider vaccination depending on strain and size of organisation or community

Question 18

Who are the at-risk contacts and other groups for meningococcal disease?

Answer 18

contacts:
-household or other intimate
-childcare/school/uni
-HCW
- lab workers
Other: 
-Immunosuppressed
-ATSI
-crowding/smoke exposure

Question 19

What is the incubation period for Legionella?

Answer 19

Legionnaires disease: 2-10 days (usually 5-6)

Pontiac fever: 5-72 hous (usually 1-2 days)

Question 20

What are the diagnostic tests for Legionella?

Answer 20

LP antigen in urine (in Tas just LP1)
4-fold rise in titre of LP of 3-6 weeks
Culture

Question 21

When do you start investigating a cluster of Legionnaire’s disease?

Answer 21

2 or more cases with a common exposure (within 100m) over a 3 month period

Question 22

What are the most likely potential sources of a legionella outbreak?

Answer 22

Aerosolised water (e.g. veg section of supermarket)

• car washes
• cooling towers (e.g. shopping centres, clubs)
• spas
• fountains
• warm water systems

Question 23

What is the incubation period for zika virus?

What is the typical duration of illness for Zika virus?

Answer 23

3-12 days

duration: 4-7 days

Question 24

What is the incubation period for pertussis?

Answer 24

4-21 days (usually 7-10)

Question 25

What is the incubation period for varicella zoster (chickenpox) virus?

Answer 25

10-21 days (usually 14-16)

Question 26

What is the SAFE strategy for trachoma?

Answer 26

Surgery Antibiotics Facial cleanliness Environmental health

Question 27

What is considered endemic trachoma?

Answer 27

Prevalence of active trachoma >5% in ATSI children aged 5-9 years or prevalence of trichiasis of >0.1%in the adult ATSI population

Question 28

What are the case definitions for Zika virus?

Answer 28

Confirmed and probable notifiable as flavivirus infection (unspecified) Confirmed: lab definitive evidence (NAT, virus isolation, IgG seroconversion or fourfold rise in titre, IgM in CSF) and clinical evidence Probable: lab suggestive evidence and epi evidence (travel to zika country within 2 weeks or sexual exposure to a confirmed/probable case) Clinical evidence: acute illness within 2 weeks of exposure and 2 or more of fever, headache, myalgia, arthralgia, rash, non-purulent conjunctivitis

Question 29

What are the current diseases of concern under the Biosecurity Act 2015?

Answer 29

``` SARS MERS Viral haemorrhagic fever Human influenza with pandemic potential Plague Smallpox Yellow fever (in northern Australia) ```

Question 30

What is meningococcal disease and how many serogroups are there? - which are the most common?

Answer 30

Neisseria meningitidis, gram negative bacteria 16 serogroups known ABCWY are the most common globally

Question 31

What is the case fatality for pertussis in babies < 6 months?

Answer 31

0.5-0.8%

Question 32

Measles post-exposure prophylaxis <72 hours >72 hours

Answer 32

<72 if not immune (born after 1966 and no record of 2xMMR or serology): MMR vaccine - NHIG if: immunocompromised, babies<8 months, pregnancy >72 hours: NHIG if <18 months, pregnant, immunocompromised. Also HCW and close contacts if NO previous vaccines.

Question 33

What are the recommendations for isolation of susceptible contacts of a case of measles? 1. childcare attendees or primary schools 2. adult in regular workplace or tertiary education

Answer 33

1. isolate for 14 days after initial case developed rash - 3 days only if given MMR - 6 days if given NHIG 2. don't isolate, just educate

Question 34

Who are the priority contacts to follow up for a case of pertussis?

Answer 34

Children <5 years, particularly babies<6 months People in contact with babies <6 months (e..g childcare workers) Pregnant women in T3

Question 35

What are the current antibiotic options for treatment of pertussis?

Answer 35

azithromycin, clarithromycin, erythromycin, Bactrim

Question 36

Definition of a contact of pertussis - close contact - general contact - high risk

Answer 36

during infectious period: close contact: stayed overnight or lived in house together general contact: face-to-face exposure (within 1 metre) for atleast 1 hour high-risk: babies<6 months or people who may transmit pertussis to them (including maternity wards, nurseries)

Question 37

Who should receive antibiotic prophylaxis against pertussis?

Answer 37

If within 14 days of contact with an infectious case and <6 months of age or close contact of baby <6 months of age ie. all household contacts of a baby <6 months and all childcare contacts (other kids in room and staff of a baby <6 months, pregnant women in T3, maternity or nursery staff)