Travel Medicine

PEBC

pre travel consultation

• see travel specialist at least 6 weeks before travel

• clinicians review patients medical and immunization history

• trip specific health concerns based on pt medical hx and area of travel

prevention strategies

• high altitude illness

• insect protection

• sun safety

• water and food safety

• thrombosis prevention

• jet lag

• vaccinations

high altitude illness

• travelling to high elevations = these areas have lower partial pressure and can lead to hypoxia (inadequate oxygen supply at the tissue level)

• ask pts if travelling to regions higher than 2000 meters above sea level

• leads to Acute Mountain Sickness (AMS)

High altitude mountain sickness (AMS)

• symptoms (w/in 48 hr of new altitude):

  • CNS = HA, lightheadedness

  • GI = Anorexia/ loss of appetite

  • MSK = weakness, fatigue

• can progress to more serious forms:

  • High altitude cerebral edema (HACE) = end stage of AMS

  • High altitude pulmonary edema (HAPE) = not necessarily a progression form! it can occur on its own

• prevention:

  • Ascend slowly and avoid direct transport to altitudes >3000 meters

  • spend 1-2 nights at 2500-3000m to acclimatize

  • >2500-3000m, sleeping altitude should not be increased by more than 300-500m/night (rest 2 nights at the same altitude every 2-3 days)

  • avoid alcohol/sedatives/hypnotics

  • high carb diet decreases AMS sx by 30%

  • avoid overexertion

treatment of AMS

• Acetazolamide 250mg Q12H - initiated soon after AMS sx and continue until sx cleared (to a max of 4 days)

  • s/e = Diarrhea, upset stomach, or throwing up, Change in taste, Decreased appetite, Blurred eyesight, Feeling dizzy, sleepy, tired, or weak, Headache, Flushing, Feeling nervous and excitable

  • take with food to decrease stomach upset

• rest and acclimatization at 1 altitude

• dexamethasone 4mg q6H until 24hr after symptoms resolve or descent (limited to 48-72 hrs)

• simple analgesics = ibuprofen or acetaminophen for HA

  • HA = cardinal smx of AMS

prophylaxis for rapid ascents

<24hr and >3000m or prior Hx of AMS/HAPE/HACE

• Acetazolamide 125mg Q12H beginning day before ascent until 48hr after highest altitude reached or descent initiated

  • s/e = Diarrhea, upset stomach, or throwing up, Change in taste, Decreased appetite, Blurred eyesight, Feeling dizzy, sleepy, tired, or weak, Headache, Flushing, Feeling nervous and excitable

  • take with food to decrease stomach upset

• Dexamethasone 4mg Q12H

high altitude cerebral edema (HACE)

• uncommon

• is an end stage of AMS and normally occurs within 3 days

• most often associated with HAPE

• Symptoms = same as AMS (HA, lightheadednes, Anorexia/ loss of appetite, weakness, fatigue) and with what seems like alcohol intoxication (neurological sx):

  • Ataxia = degenerative disease of NS —> death can occur w/in 24 hrs of development is person fails to descend

  • changes in mental status

  • severe headache

high altitude pulmonary edema (HAPE)

• not really a progression of AMS! Symptoms can occur on its own

• Sx:

  • Respiratory = dyspnea, cough, congestion

  • Pulmonary sounds = crackles, wheezing

  • CV = tachycardia, chest tightness, cyanosis

• can be MORE RAPIDLY FATAL THAN HACE!

insect protection

• consult public health agency of Canada (PHAC) to evaluate risk of insect-borne illness that are endemic to area

methods of prevention:

• Avoidance - 2 types of insects

  • Aedes = mosquitos active during daytime = dengue fever, zika

  • Anopheles = mosquitos active during night = malaria

• Physical Barriers

  • use screens around beds and room (permetherin-treated recommended)

  • screens (<1.5mm) over windows

  • wear shoes, socks and full clothing during Peak hours

• Chemical Barriers

  • DEET = 30% TID for ADULTS >12y

  • DEET = 10% TID for children 2-12 yr

  • DEET = 10% daily for Children 6months - 2yrs

  • Icaridin = 20% BID for children >6 months

  • Mosquito net <6 months

malaria

• caused by protozoan parasite: Plasmodium genus —> transmitted by mosquitos

• 5 different species:

  • P. falciparum - more serious

  • P. malariae

  • P. Ovale

  • P. vivax —> use Primaquine

  • P. knowlesi

• clinical presentation:

  • flu-like sx = fever, chills, sweating, HA, myalgia

  • GI sx = Nausea/ vomiting

  • severe sx of P. falciparum = Jaundice, abnormal bleeding, convulsions (leading to shock, kidney failure, even death)

• Risk = endemic to specific regions —> check CDC

• prophylaxis:

  • patient factors:

    • Pt Hx of malaria prevention

    • area of travel

    • other risk factors = Pregnancy, extremes of age and immunocompromised

  • medication efficacy:

    • no medication is 100% effective

    • need to use medications + insect protection measures

  • resistance patterns:

    • always check local resistance patterns and patients medications

atovaquone proguanil (malarone)

• adults = 250/100mg daily

• children >5kg = 62.5/25mg —> dosed by weight

• take with fatty food (or milk)

• directions:

  • 1-2 days BEFORE TRAVEL

  • DAILY while in risk area and

  • continue for 7 DAYS after leaving malaria risk area

• well tolerated (mild abdominal pain, HA, N/V, insomnia)

• Pros:

  • good for last minute travellers (b/c only need to take 1-2 days before)

  • good for short trips (only need to take 7 days after travel)

  • pediatric formulations available

• Cons:

  • More expensive than others

  • AVOID IN PREGNANCY/ BREASTFEEDING, Children <5kg

  • AVOID IN RENAL IMPAIRMENT (CrCl<30 ml/min)

primaquine

• use in P. vivax endemic areas, PART (presumptive anti-relapse tx) or alternative agent in chloroquine resistant areas

• 30 mg tab daily

  • begin 1-2 days BEFORE travel and

  • continue 7 days after end of trip

• s/e = well tolerated (GI upset), methemoglobinemia (Rare), hemolysis with G6PD deficiency

• Pros:

  1. good for last min travellers (only need to start 1-2 days before travel)

  2. good for short trips (only require 7 days of post travel treatment)

  3. most effective for P. vivax (drug of choice for this strain)

• Cons:

  1. CONTRAINDICATION in severe G6PD deficiency (cost and delays to being tested for this)

  2. AVOID IN PREGNANCY/ BREASTFEEDING and children

  3. gastrointestinal s/e often leads to d/c of therapy —> best taken with food

hydroxychloroquine

• useful when heading to area without chloroquine resistance

• directions:

  • start 1 week before entering malaria risk area

  • take 1 tablet weekly throughout travel and

  • continue for 4 weeks after leaving malaria risk area

• Adults = 400mg weekly

• Children = 6.5/kg weekly

• s/e = GI upset (nausea, vomiting, abdominal pain), HA, blurred vision, pruritus, dizziness

  • Administer with food

• C/I:

  • psoriasis

  • seizures

• Pros:

  1. good for long trips (patients only require weekly dose)

  2. safe in pregnancy/ breastfeeding = drug of choice

• Cons:

  1. Many endemic areas are known to be chloroquine-resistant

  2. must take medication for 4 weeks post-travel

  3. not good for last min travellers (must be started 1 week before travel)

  4. AVOID IN PT WITH PSORIASIS OR SEIZURES!

  5. Potential caution in those with G6PD deficiency due to risk of hemolytic anemia

doxycycline

• 100mg

• directions:

  • begin 1-2 days before travelling and

  • continue for 28 days (4 weeks) after leaving malaria risk area

• s/e = photosensitivity, N/V, GI upset, staining of teeth in children and fetuses, candida vaginitis (use fluconazole for self-treatment)

• take with food and LOTS OF WATER while remaining upright position to avoid esophageal ulceration

• Pros:

  1. good for last minute travellers (only need to start 1-2 days before travel)

  2. least expensive option

• Cons:

  1. risks of photosensitivity - use sunscreens to block UV radiation

  2. contraindicated in PREGNANCY, BREASTFEEDING or CHILDREN <8

  3. Must take for 28 days after malaria risk area

Mefloquine

• use in areas sensitive to this!

• directions:

  • 250mg tab weekly

  • begin 1 week before travel and

  • continue for 4 weeks after return

    • Administer with food and with at least 240 mL of water

• 1st time users = recommended to start 2-3 weeks before leaving if time permits to assess for s/e

• s/e = dizziness, nausea, vomiting, diarrhea, headaches, sinus bradycardia, nightmares, insomnia, mood alteration, anxiety, irritability, Vivid dreams/ nightmares

  • rare = psychosis and seizures

• CI in many Psychiatric disorders (depression, seizures, anxiety)

• Pros:

  1. Good for long trips (only need weekly dosing)

  2. can be initiated within 1 week of travel

  3. SAFE in pregnancy (Drug of choice in chloroquine resistant areas)

  4. weight based dosing for pediatrics

• Cons:

  1. areas of mefloquine resistance

  2. Avoid in Hx of seizures and psychosis

  3. Must take for 4 weeks after travel

  4. known to have severe side effects leading to discontinuation

malaria prophylaxis summary

dengue fever

• acute febrile illness caused by virus transmitted by Aedes mosquitos

• prevention is key = use insect repellent and wear tight clothing

• most common symptom = fever with GI sx, rash (2 days after fever) or aches/pains (joint pain)

  • sx begins 4-7 days after exposure

• can develop severe dengue

• supportive care

chikungunya

• spread by Aedes mosquito

• vaccine available

• prevention is key = use insect repellents and wear tight clothing

• most common sx = fever and joint pain

• clinical presentation = HA, rash, Joint pain (can persist for years causing chronic disability), sx begin 3-12 days after exposure

• mimics dengue fever

• supportive care = acetaminophen for fever and muscle pain, rest and fluids

zika virus

• caused by Aedes mosquito

• no specific treatment or vaccine

• can be passed from pregnant woman to fetus

  • pregnant women should avoid areas endemic to this

• Avoid conception x 2 months (woman traveled to high risk/ outbreak areas) after leaving affected area

• clinical presentation = fever, rash, joint pain, can cause microencephalopathy and congenital brain abnormalities in fetus

water and food safety

• risk of neglecting recommendations = travelers diarrhea

• education is important —> esp in Pregnant, young, old and immunocompromised

• always boil, cook and peel food

• drinking unsafe or untreated water —> exposure to harmful pathogens (cholera, E. coli, Typhoid) —> high risk of disease (cholera, typhoid fever) and symptoms (diarrhea, fever)

• Boiling water = MOST RELIABLE and preferred method!

• Iodination = recommended only for short term (< 2 weeks) if unable to boil

  • CI in pregnant women and children or thyroid disease patients

  • tincture of 2% iodine (5 drops/L) then let stand for 30 mins

• chorine bleach = LEAST RELIABLE —> 2 drops chorine household bleach to 1 L water and let sit for 30 mins

thrombosis prevention

• risk during long flights and following the flight

• anyone travelling >4 hrs by air, car or bus = at risk of blood clot

• Patients with Hx of DVT/PE due to flying will need an evaluation by physician regarding anticoagulant therapy for flights >2 hrs

• risk factors:

  • duration of travel (8 hrs has strongest association)

  • previous patient risks (VTE, cancer, pregnancy, age, surgery, injury, clotting)

  • meds = oral contraceptives, HRT

  • immobility on fight

  • greatest risk first 2 weeks after travel, then slowly back to baseline by 8 weeks

• non-pharm:

  • Avoid alcohol

  • contract muscles in calves regularly or get up often to walk around (every 1-2 hrs)

  • below knee compression stockings = not routinely recommended for those with no risk factors (recommended for long distance travellers at increased risk of VTE)

  • avoid constrictive clothing

thrombosis prevention medications

• ASA does NOT reduce risk of travel related blood clots

• LMWH or DOACs = recommended after physician assessment for long distance travel with baseline risk factors for VTE

• if no increased risk for VTE: prophylactic anticoagulants not recommended

• if already on prophylactic or treatment anticoagulant or antiplatelet = no additional treatment needed

jet lag

• clinical presentation:

  • Malaise

  • Fatigue

  • Disruption of sleep-wake cycles

  • Irritability and impaired cognitive abilities

• travelling eastward = more severe than westward

• takes 1 day for every hr of time difference to acclimatize

• Non-pharm:

  • adjust sleep patterns to destination prior to departure

  • stay well hydrated during flight —> avoid alcohol, large meals

  • remain active during flight by stretching, walking )also helps to stay awake to adjust to new time zone)

• Pharm:

  • Melatonin = made by the body at nighttime by pineal gland to assist body with sleep

    • effective in reducing symptoms

    • dosing = 3-5 mg QHS —> IR formulation is most effective

    • take at first night after arrival (before nocturnal sleep in new time zone)

    • s/e = abdominal cramps, dizziness, HA, irritability, drowsiness