Travel Medicine

Question 1

What are the “big 3” DDx for fever in the returned travellor with no localising symptoms? What is the incubation period for each?

Answer 1

Dengue: 4-5 days
Malaria: 1-4 weeks (usually 2 weeks)
Typhoid: 7-28 days (usually 3 weeks)

Question 2

Which species of plasmodia causes almost all deaths and cases of severe malaria?

Answer 2

P. falciparum

Question 3

What causes typhoid?

Answer 3

Salmonella enteritica serotype typhi, paratyphi

Question 4

typhoid

Answer 4

1st week: rising (“stepwise”) fever, bacteraemia
2nd week: abdo pain, rash (“rose spots”: faint salmon-coloured macules on trunk and abdo)
2rd week: hepatosplenomegaly, intestinal bleeding and perforation (related to ileocaecal lymphatic hyperplasia of peyer’s patches, may occur with secondary bacteraemia and peritonitis

Question 5

typhoid

Answer 5

Constipation more common than diarrhoea

Called enteric fever because it replicates in the gut

Question 6

typhoid

Answer 6

Often emperic due to low sensitivity and specificity of available Ix

Question 7

Typhoid treatment

Answer 7

Ciprofloxacin: 10 days ?PO (treatment of choice but growing problem of resistance)
Ceftriaxone: 7-14 days IV (requires hospital stay)

Question 8

List 5 features which suggest a serious infection

Answer 8

Rigors
Acute onset (presents to hospital within hours and deteriorates quickly)
Profound effect on the patient
Severe headache
N+V in absence of diarrhoea

Question 9

What travel vaccines should be considered with travel to a tropical area?

Answer 9

Hepatitis A
Typhoid (+ yellow fever if endemic area)
Malaria prophylaxis (depending on area)

Question 10

24 year old female planning on travelling as a tourist to Kenya, Tanzania Ethiopia, South Africa for 2/12
Born in Australia
Thinks she is up to date with her childhood vaccinations but has brought no documentation with her
What issues need to be discussed?

Answer 10

General advice: consider route of transmission of different infections to discuss appropriate behavioural advice (advice regarding safe food and drink, insect avoidance, respiratory exposures, environmental and animal exposures, blood-borne infection, sexual encounters), consider non-infectious risks (e.g. trauma)
Vaccination: update routine, travel-related considerations
Medications: e.g. malaria prophylaxis, self-Rx for travellers’ diarrhoea

Question 11

What pre-travel advice should be given regarding food?

Answer 11

“Boil it, cook it, peel it or forget it”
All raw food is high risk: avoid salads, uncooked veg, unpasteurized milk and cheese
Eat food that has been cooked and is still hot, or fruit that can be peeled
Undercooked and raw meat, fish and shellfish are high risk
Avoid food from street vendors

Question 12

What pre-travel advice should be given regarding water?

Answer 12

If chlorinated tap water is unavailable or sanitation is poor, only the following are safe to drink: beverages (eg. tea, coffee) made with boiled water, canned or bottled beverages, beer and wine
Avoid ice and avoid brushing teeth with tap water

Question 13

How can travellers minimise exposure to prevent vector-borne infections?

Answer 13

Sleep in screened and/or air conditioned room
Avoid outside activities esp between dusk and dawn
Cover arms and legs
Use insect repellents (tropical-strength DEET)
Permethrin impregnated clothing/mosquito nets
Use an insecticide aerosol in the room

Question 14

How else (besides minimising exposure) might a traveller protect against vector-borne infection?

Answer 14

Malaria prophylaxis

Question 15

Give 2 examples of infections commonly seen in travellers which can be acquired through respiratory exposures

Answer 15

Influenza

Meningococcus

Question 16

Give 2 examples of infections commonly seen in travellers which can be acquired through environmental and animal exposures

Answer 16

Rabies
Tetanus
Altitude

Question 17

Give 2 examples of infections commonly seen in travellers which are blood-borne

Answer 17

HBV
HCV
HIV

Question 18

Traveller who has returned home after a 2/12 trip in India comes to see you complaining of diarrhoea
Said they had a bad episode of diarrhoea in the 1st week of their trip which were resolved, they were then okay for most of their trip but since the last 2 days of their trip the diarrhoea has returned
Have now been home for 2 weeks
Ix and Mx?

Answer 18

Stool MCS

If negative, consider empiric therapy

Question 19

How is travellers’ diarrhoea usually define?

Answer 19

3 or more loose stools/day

Question 20

What is the “attack rate” of travellers’ diarrhoea?

Answer 20

20-50% in developing countries

Question 21

Describe the typical natural Hx of travellers’ diarrhoea

Answer 21

Usually begins abruptly, generally self-limited

Most cases resolve in 1-2 days even without treatment (10% last >1 week, longer than that is relatively uncommon)

Question 22

In what % of cases of travellers’ diarrhoea is there no identifiable cause?

Answer 22

20-50%

Question 23

What are the common causative organisms in acute travellers’ diarrhoea?

Answer 23

ETEC (40-70%)
Viral
Cholera
Shigella
Salmonella
Campylobacter
Entamoeba histolytica

Question 24

Which of the common causes of acute travellers’ diarrhoea produce watery diarrhoea vs blood diarrhoea?

Answer 24

Watery: ETEC, viral, cholera
Bloody: Shigella, Salmonella, Campylobacter, Entamoeba histolytica

Question 25

How long does travellers' diarrhoea need to last for it to be classified as chronic?

Answer 25

Usually >2 weeks

Question 26

What are the common causes of chronic travellers' diarrhoea?

Answer 26

Parasites (e.g. Giardia)

Question 27

How should travellers' diarrhoea be managed during travel?

Answer 27

Often resolves without treatment Don't give prophylaxis but give therapy for empiric self-treatment of acute TD Sometimes also give empiric Rx for persistent diarrhoea directed against Giardia

Question 28

What agents can be used for empiric self treatment of travellers' diarrhoea?

Answer 28

Quinolone (e.g. ciprofloxacin; note increasing resistance, esp of Campylobacter in Thailand, India, Nepal) Azithromycin (alternative) For persistent diarrhoea (directed against Giardia): tinidazole

Question 29

List 3 food/water borne infections for which there is a pre-travel vaccine available

Answer 29

Hepatitis A Typhoid Cholera

Question 30

List 2 vector-borne infections for which there is a pre-travel vaccine available

Answer 30

Yellow fever | Japanese encephalitis

Question 31

List 3 respiratory borne infections for which there is a pre-travel vaccine available

Answer 31

Meningococcal Influenza (TB)

Question 32

List 1 blood/body fluid borne infection for which there is a pre-travel vaccine available

Answer 32

HBV

Question 33

List 3 environmental/animal borne infections for which there is a pre-travel vaccine available

Answer 33

Rabies | Tetanus

Question 34

What routine vaccines are important to update pre-travel?

Answer 34

MMR Polio Others

Question 35

What regions is hepatitis A endemic in?

Answer 35

SE Asia Africa South America

Question 36

What % of HAV infections are asymptomatic in children

Answer 36

70%

Question 37

What demographic has an increased risk of mortality from HAV?

Answer 37

>50 years

Question 38

What is the usual schedule for HAV vaccination?

Answer 38

2 doses at least 6/12 apart If long delay since 1st dose, no need to restart full course No booster recommended

Question 39

In what forms is the HAV vaccine available?

Answer 39

HAV only | In combination with HBV or typhoid

Question 40

Who does the NHMRC recommend the HAV vaccine for?

Answer 40

Recommended for all travellers to, and all expatriates living in, moderately to highly endemic areas (includes all developing countries; "investment" for young, elderly at risk of complications)

Question 41

Who should be screened for pre-existing natural immunity when considering HAV vaccination? What should you do if unsure?

Answer 41

Born

Question 42

Is there a vaccine for HEV?

Answer 42

No

Question 43

What is the major complication with HEV?

Answer 43

Associated with up to 20% maternal mortality if acquired in the 3rd trimester of pregnancy

Question 44

What circumstances confer the greatest risk for travellers of acquiring enteric fever?

Answer 44

Travel SE Asia (6-30x risk; also high risk of multi-drug resistance) Travellers visiting friends or relatives

Question 45

What type of vaccine are Typherix and Typhim Vi?

Answer 45

Injectable polysaccharide

Question 46

How many years of protection are afforded by the injectable typhoid vaccine?

Answer 46

3

Question 47

What forms of typhoid vaccine are available?

Answer 47

Injectable (polysaccharide) | Oral (live attenuated)

Question 48

How many years of protection are afforded by the oral typhoid vaccine?

Answer 48

4 doses provide 5 year protection

Question 49

Who does the NHMRC recommend be vaccinated against typhoid? When should vaccination be completed?

Answer 49

All travellers ≥2 years of age going to endemic regions | Vaccinated should be completed at least 2 weeks before travel

Question 50

Who is at increased risk of typhoid and therefore strongly recommended to be vaccinated?

Answer 50

Individuals travelling to endemic regions to visit friends and family

Question 51

What is Dukoral?

Answer 51

Oral cholera vaccine

Question 52

What is the cholera vaccine composed of?

Answer 52

Killed V. cholerae O1 organisms and non-toxic B subunit of cholera toxin

Question 53

How is the cholera vaccine administered?

Answer 53

Oral vaccine, 2 doses given 1-6 weeks apart

Question 54

What is the efficacy of the cholera vaccine?

Answer 54

60-80%

Question 55

Are tourist travellers at risk of cholera?

Answer 55

Rarely

Question 56

What other disease may the cholera vaccine protect against? When should it be used for this purpose?

Answer 56

Travellers' diarrhoea (provides approx 50% reduction in ETEC; overall reduces TD by about 10-20% but only provides 3 months protection) NB Not licensed for TD in Aus, consider off-label use if underlying GI disease, immunosuppression

Question 57

What is the difference between the flu seasons in the Southern and Northern Hemisphere, and the tropics?

Answer 57

Southern: April-Sep Northern: Nov-March Tropics: throughout the year

Question 58

Where are the "at-risk" areas for meningococcus, for whic vaccination is recommended?

Answer 58

Sub-Saharan Africa (esp dry season Dec-June) | Saudi Arabia for pilgrims during Hajj

Question 59

What vaccines are available for meningococcus? Which serogroup is covered by each? How long is the protection afforded by each?

Answer 59

Conjugate vaccine: serogroup C (used in childhood) Polysaccharide (Mencevax/Menomune): serogroups A,C,Y,W135 (cover for 3 years; less immunogenic) Conjugate quadrivalent vaccine (Menveo/Menactra): serogroups A,Y,W135 (cover for ?5 years)

Question 60

Which meningococcal vaccine is typically administered to travellers?

Answer 60

Quadrivalent (most travellers also require protection for serogroups A,Y,W135)

Question 61

What is yellow fever? How is it spread? What does it cause?

Answer 61

Acute viral disease Spread by mosquitoes Causes hepatitis and encephalitis

Question 62

For which populations is the yellow fever vaccine indicated?

Answer 62

All travellers to endemic countries

Question 63

When should the yellow fever vaccine be given?

Answer 63

≥10 days before entry into risk area

Question 64

How long does the yellow fever vaccine offer protection for?

Answer 64

10 years

Question 65

List 4 CIs to yellow fever vaccine

Answer 65

Severe egg allergy Immunodeficiency Pregnancy Infants

Question 66

High prevalence areas for HBV

Answer 66

``` Africa SE Asia Middle East Pacific Islands Amazon River basin Parts of Caribbean ```

Question 67

What is the name of the HBV vaccine?

Answer 67

Engerix | H-B-VAX II

Question 68

When are the 3 doses of the HBV vaccine given routinely?

Answer 68

0, 1 and 6 months

Question 69

Describe the accelerated schedule for the HBV vaccine

Answer 69

Days 0, 7, 21 and then again at 12 months

Question 70

Is there a need to routinely check HBV Abs?

Answer 70

No

Question 71

What factors may result in poorer seroconversion following HBV vaccination?

Answer 71

CKD | Immunosuppression

Question 72

When should HBV be considered as a travel vaccine?

Answer 72

Consider if travelling to intermediate or high prevalence areas (risk is generally low) Adventure travellers, Peace Corps volunteers, missionaries and military personnel may have increased risk (i.e. people travelling to endemic areas either long-term or for frequent short terms is the advice of the NHMRC)

Question 73

When should pre-exposure prophylaxis be considered for rabies?

Answer 73

Occupational risk | Travel to rural areas/high endemic countries for >3-6/12

Question 74

How is pre-exposure prophylaxis for rabies administered?

Answer 74

3 doses 1mL IM days 0, 7, 28

Question 75

Describe the principles of post-exposure treatment (PET) for rabies

Answer 75

Give any time after exposure (but best within 48 hours): 1) Wound care, may need tetanus toxoid/Abx 2) 4 doses of vaccine (5 in some high risk situations) on days 0, 3, 7, 14 (28), administered into deltoid or thigh (if previously vaccinated, only 2 booster doses are required on days 0 and 3) 3) human rabies immunoglobulin (HRIG): 20IU/kg into wound, given within 8 days of starting HDCV

Question 76

24 year old female returns from 2/12 trip to Africa Has been home for 3/7 and presents with a fever Additional info?

Answer 76

Incubation period Precise travel itinerary Type of exposures

Question 77

How does knowledge of the incubation period of a returned travellers' illness aid diagnosis?

Answer 77

>3 weeks: excludes many arboviruses (e.g. dengue) and viral haemorrhagic fevers Shortest incubation for malaria is 7-10 days (can be years)

Question 78

How does knowledge of precise travel itinerary of a returned travellers' illness aid diagnosis?

Answer 78

Yellow fever is endemic in Africa and Latin America but NOT Asia Japanese encephalitis confined to Asia Lassa fever restricted to West Africa

Question 79

What kinds of infectious disease does swimming in fresh water in Africa predispose to?

Answer 79

Schistosomiasis

Question 80

What are the 4 most common syndromes seen in the unwell returned traveller?

Answer 80

Travellers' diarrhoea Respiratory tract infections Skin problems (infections, rash, bites) Febrile illnesses

Question 81

What life-threatening illnesses must be considered in the unwell returned traveller?

Answer 81

Falciparum malaria Bacterial sepsis (including enteric fever) Viral haemorrhagic fevers (including dengue)

Question 82

What is the typical incubation period for illness seen in returned travellers? What are the exceptions?

Answer 82

Most

Question 83

What is the typical incubation period for enteric fever?

Answer 83

7-21 days

Question 84

What are the clinical symptoms of enteric fever?

Answer 84

Non-specific febrile illness +/- diarrhoea or constipation, sometimes a rash

Question 85

In what areas is enteric fever common?

Answer 85

``` SE Asia India Africa Middle East South America ```

Question 86

What is one serious complication of enteric fever?

Answer 86

Bowel perforation

Question 87

How is enteric fever diagnosed?

Answer 87

FBE: normal WCC with "left shift" LFT: commonly abnormal (mixed pattern) Blood culture: Gram negative bacilli, stool culture

Question 88

How is enteric fever treated?

Answer 88

Abx (ceftriaxoe or quinolone if sensitive, or azithromycin)

Question 89

What is the fatality rate of enteric fever without treatment?

Answer 89

10-20%

Question 90

How many cases of malaria are seen in Australia annually?

Answer 90

~700 cases per year