Travel Medicine

Question 1

Big three issues for travel medicine

Answer 1

1) Vaccine use in travel
2) Management of traveler’s diarrhea
3) Prevention of malaria

Question 2

When to schedule pretravel clinic visit

Answer 2

Pretravel advice should be sought 4–6 weeks before departure to best prepare the traveler and ensure that appropriate vaccinations can be provided

Question 3

Key counseling points for travel medicine visit

Answer 3

All travelers should be advised on vaccine-preventable illnesses/required immunizations, avoidance of insects, malaria chemoprophylaxis if visiting an area of risk, prevention and self-treatment of TD, and responsible behaviors (e.g., wearing seatbelts, helmets on motorcycles).

Question 4

Altitude sickness prevention and management

Answer 4

Altitude sickness should also be discussed if high-altitude destinations are planned or patients have a history of altitude sickness. a. Prophylaxis with acetazolamide is usually effective and can hasten recovery if symptoms develop. b. Dexamethasone may also be used, but is more commonly considered as an adjunct in descent.

Question 5

Percentage of malaria and typhoid in the US from visiting friends and relatives

Answer 5

About 50% of malaria imported into the United States in 1999–2003 occurred in VFR travelers. c. Around 75% of imported typhoid cases also occurred in this population.

Question 6

Most serious infection in returning travelers

Answer 6

Malaria, specifically Plasmodium falciparum malaria, is the most serious infection in returning travelers and remains the most common cause of death.

Question 7

Early fever in returning travelers

Answer 7

If fever develops beyond 21 days, dengue, rickettsial infections, Zika virus, and viral hemorrhagic fevers are less likely.

Question 8

Malaria incubation period

Answer 8

Incubation period is often 1–4 weeks but can be longer, depending on the patient’s immune status, dos- ing of chemoprophylaxis, and infecting Plasmodium strain. Febrile patients presenting before 7 days are unlikely to be infected unless exposed to infected mosquitoes before travel.

Question 9

Rabies incubation period

Answer 9

20-60 days (can be months to years)

Question 10

Incubation period: anthrax

Answer 10

Cutaneous: 1 day; Pulmonary: 1-7 days

Question 11

Incubation period: plague

Answer 11

Bubonic plague: 2-6 days

Pneumonic plague: 1-3 days

Question 12

DEET cutoffs by age

Answer 12

For travelers with children and/or infants (older than 2 months) DEET is considered safe, but the concentration should not exceed 30%. c. DEET should not be used in infants younger than 2 months. 4. An alternative to DEET is picaridin,

Question 13

Purposes of thick and thin smears for malaria

Answer 13

Thick smears screen large amounts of blood for the presence of parasites.

health department. 5. Thin smears are used to determine the infecting Plasmodium spp. with significant implications for pharmacotherapy.

Question 14

Most important diagnosis for returning traveler

Answer 14

Any traveler presenting with fever and a history of travel to a malaria-endemic area in the past 3 months should be considered to have malaria until ruled out.

Question 15

Malaria chemoprophylaxis regimens starting 1-3 weeks before travel

Answer 15

Chloroquine & mefloquine; continue 4 weeks after return

Question 16

Malaria ppx regimes, start 1-2 days before travel

Answer 16

Atovaquone/proguanil - continue 1 week after
Primaquine - continue 1 week after
Doxycycline - continue 4 week after

Question 17

Treatment of uncomplicated malaria

Answer 17

Artemether/lumefantrine x3 days
Atovaquone/proguanil x 3 days
Hydroxychloroquine x48 hours
Chloroquine x48 hours
mefloquine x2 doses
Quinine + (doxycycline or tetracycline or clindamycin) x7 days

Question 18

Incubation periods for travelers diarrhea

Answer 18

Incubation period is typically up to 3 days, but can be within hours for bacterial and viral pathogens versus some protozoal pathogens, which may take 1–2 weeks and is less likely to present early in travel.

Question 19

Average duration of untreated travelers diarrhea

Answer 19

Average duration of untreated diarrhea is 4–5 days, but is pathogen-dependent. Comparatively, proto- zoal pathogens may cause diarrhea for weeks to months if left untreated.

Question 20

Etiology of travelers diarrhea

Answer 20

Disease etiology is predominantly secondary to bacterial enteropathogens (up to 85%); however, viruses and protozoa/parasites should also be considered causative pathogen

Question 21

Role of prophylaxis in travelers diarrhea

Answer 21

Antimicrobial prophylaxis is not currently endorsed by the IDSA guidelines and should only be used in travelers for whom development of diarrhea would be more likely to lead to complications.

considered for antimicrobial prophylaxis: a. Patients who should avoid dehydration b. History of stroke/transient ischemic attack c. Insulin-dependent diabetes mellitus d. Chronic renal failure e. Patients with possibility of complex diarrheal episodes i. Inflammatory bowel disease ii. AIDS iii. Patients with ileostomies/colostomies

Question 22

Travelers diarrhea prophylaxis medications and duration

Answer 22

Ppx regimens:
Bismuth 2 tabs q6h
Cipro qd-bid
Rifaximin qd-bid ac

If indicated, prophylactic antimicrobials should be taken for the duration of the trip, but limited to no longer than 3 weeks.

Question 23

Activity of antimicrobials vs TD pathogens

Answer 23

Fluoroquinolones are effective against most bacterial pathogens except for C. jejuni.

Rifaximin is not considered active against mucosally invasive pathogens such as Shigella, Salmonella, or Campylobacter.

Azithromycin is a useful alternative where Campylobacter spp. are more common

Question 24

Zika virus sexual transmission

Answer 24

Sexual transmission from infected travelers to non-traveler partners has occurred within 20 days of first sexual contact in all transmissions studied to date.

In males, the CDC recommends the use of condoms and/or abstaining from sexual activity for at least 6 months after exposure or travel to an area of risk because of documented viral persistence in semen.

In females, the CDC recommends 8 weeks of consistent condom use or abstinence after exposure or travel to an area of risk.

Question 25

Zika virus natural history

Answer 25

Clinical presentation a. Clinical illness usually mild b. Around 20% of infections are symptomatic c. Incubation period is about 6 day

Question 26

Ebola virus natural history

Answer 26

Clinical presentation a. Incubation period is 2–21 days, with a mean of about 7 days

Most patients infected do not have hemorrhagic manifestations of disease

Question 27

Chikungunya natural history

Answer 27

Clinical presentation a. Most infected people are symptomatic. Less than 15% experience asymptomatic seroconversion. b. Incubation period 3–7 days (range 1–12 days) c. Primary clinical symptoms include fever and polyarthralgia (usually bilateral).

Chikungunya Virus 1. Overview a. Single-stranded RNA virus b. Transmitted by A. aegypti and A. albopictus, which also transmit Zika and dengue viruse

Question 28

Symptoms: chikungunya vs dengue

Answer 28

C: more arthralgias
D: more lab abnormalities (neutropenia, thrombocytopenia)

Question 29

Dengue natural history

Answer 29

Typical incubation period is 3–14 days (mean 7 days) with symptoms following three phases: i. Initial febrile phase – Characterized by high temperature with headache, myalgias, vomiting, and joint pain

Critical phase (a) Typically occurs around the time of defervescence (b) Some patients experience a systemic vascular leak syndrome that manifests as hemocon- centration, hypoproteinemia, pleural effusions, and ascites. (c) Clinicians should be aware of this phase because patients can rapidly deteriorate to den- gue shock syndrome.

Question 30

West Nile Virus natural history

Answer 30

Clinical presentation a. Incubation is 2–14 days; may be longer in immunocompromised patients b. Most infected travelers are asymptomatic. c. Around 25% of infected patients develop abrupt febrile illness called West Nile fever.

Less than 1% of patients will develop meningitis or encephalitis after infection, which represents severe disease. h. Symptoms are consistent with a typical meningitis clinical picture, including: i. Abrupt fever and headache ii. Signs of meningeal irritation iii. Photophobia

mortality associated with severe disease (neuroinvasive disease) is about 10% and approaches 20% in those older than 70