TRAVEL MEDICINE
EVALUATION OF FEVER AND
MEDICAL EMERGENCIES IN
THE RETURNING TRAVELER
Outline of Travel Medicine
Issues
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Evaluation of Fever in the Returning
Traveler
Medical Emergencies in Travelers
Traveler’s Diarrhea
Prevention of Infection: Vaccines and
Antibiotic Prophylaxis
Geographic Infections : Abroad and at
Home
Overview of Travel Related Illness
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20 to 70 % of 50 million travelers to
the developing world report illness
associated with travel.
1 to 5 % end up seeking medical
care
1 in 100,000 dies of a travel related
illness
Evaluation of Fever in the
Returning Traveler
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Careful documentation regarding
Time of onset of symptoms
Travel locales and accommodations
Activities and exposures
Host factors – medical /immune
status
Evaluation of Fever – Time Factor
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Timing of exposures –a powerful tool
Calculation of incubation periods
Duration of total travel- probability of an
infection increases with stay ( ie. relative
risk of malaria is 80 fold for stays of >6
mos compared to a week)
Short-term travel rarely leads to
helminthic infections; seen more
commonly in immigrants
Fevers due to infection occurring more
than one year after travel is distinctly
uncommon.
Incubation Periods
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Less than 2 weeks
Malaria
Ricketsiae
Dengue
Typhoid
Diarrheal illnesses.
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6 weeks or more
Malaria
TB
Hepatitis B
Leishmaniasis
Rabies
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Two – Six weeks
Malaria
Hepatitis A, E
Leptospirosis
Amebic abscess
Schistosomiasis
Evaluation of Fever:
Prophylaxis History
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Detailed vaccine/prophylaxis historyThis does not exclude certain illnesses
(ie: efficacy of yellow fever vaccine is
greater than typhoid vaccine)
Malarial prophylaxis regimen may fail based
on resistance patterns and patient
compliance
Evaluation of Fever:
Exposures
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Food and Beverage Intake
Arthropod and Animal contacts
Recreational Activities- Hiking, Water
exposures –fresh and salt water
Sexual contacts
Evaluation of Fever - Workup
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Physical exam should carefully focus on:
Skin for lesions, rash, genital lesions
Lymph node, spleen and liver enlargement
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Laboratory Tests:
CBC with diff., LFT’s, Blood cultures, CXR and
malarial smears x 3
Stool studies if symptomatic- O&P, cultures for
enteric pathogens (SSCY)
Serology if indicated by LFT’s (Hepatitis A,B,E, or
E.Histolytica).
Fever and Eosinophilia
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Peripheral eosinophilia is associated
with helminthic infections that
migrate through tissues - rarely with
luminal infections
Acute Schistosomiasis
Acute Trichinosis
Acute Strongyloides
Lymphatic Filariasis
Evaluation of Fever
Emergencies
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Hemorrhagic Fevers
Meningococcus
Rickettsiae
Leptospirosis
Plague- Yersinia
*Dengue
Other viral hemorrhagic fevers (Lassa, Rift
Valley, Congo-Crimean)
Hemorrhagic Fevers:
Dengue Fever
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Endemic in Caribbean, Central and South
America and South Asia
Estimated 100 million cases/yr, with
symptoms ranging from mild fever to
shock and death.
Four distinct serotype (1-4) of this
flavivirus, transmitted by mosquito
Prior exposure increases risk of DHF-shock
Dengue:Clinical Picture
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Incubation period of 3-10 days
Fever, retro-orbital headache, myalgiasarthralgias –”break-bone fever”
Rash occurs 2- 5 days post fever onset,seen in
50%
GI symptoms in about 50%
Thrombocytopenia, leukopenia - 16-55%
Hemorrhagic Fever- seen with vascular leak and
shock state
Serologic studies
Treatment is supportive only
Evaluation of Fever
Emergencies
Fever and Confusion and lethargy
P.falciparum malaria (cerebral form)
N.meningococcus
Rickettsiae – R. conori, proweseki
Malaria
Fever in traveler from malarial region
 Highest after rainy season; uncommon at altitude
>2000 ft
 Over 1,500 cases in US /yr
 Appropriate prophylaxis is about 80% effective.
 Incubation period varies by speciesP.falciparum- 12-14 d
P. vivax/ovale -up to 2 mos, can be years
P.malariae- 35 days
*P. knowlesi- transmitted in SE Asia; endemic in
monkeys
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Malaria:Evaluation and Rx
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Fever associated with sweats, headache,
myalgias.
Anemia, thrombocytopenia
Thick smears q 6-12 hours for 48 hrs.
First smear + in 95%.
Parasitemia of greater than 3% should be
hospitalized; greater than 5% have
significant mortality when treated.
Malaria:Treatment
For Chloroquine-sensitive species
(P.vivax/ovale/malariae):
• Chloroquine 600mg, followed by 300mg at 6, 24 ,
48 hrs.
For Chloroquine-Resistant P.falciparum
Quinine+Doxycycline -7 days
Malarone – 3 days (if no malarone prophylaxis)
Mefloquine – 1250 mg in divided doses
Evaluation of Fever
Emergencies
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Respiratory Distress
Malaria
Hanta virus
Influenza
SARS
Avian Influenza.
Travelers’ Diarrhea
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Travel to the developing world carries a 40-60% risk
of diarrhea- usually benign and self-limited.
More than 90% is bacterial, and food/water borne.
Most common pathogen – Enterotoxin E.coli (ETEC).
Parasitic enteritis requires a more contaminated
environment than usually encountered by tourists.
Note: Airline food is prepared in departure city.
Travelers’ Diarrhea- Risk
Factors
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Low Risk (<10%) – N.Europe,Australia, US,
Canada-but note high Giardia risk in US
West/NE mountains
Moderate Risk (up to 20%) – Caribbean,
Mediterranean, and Israel
High Risk (>30%) – Asia, Africa, Mexico,
Central and South America
Gastric bypass and resection, histamine
blockers will allow bacteria to survive to small
bowel.
Travelers’ Diarrhea:
Clues to Pathogens
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Watery and Afebrile
Most common pathogen is ETEC- the
prototype travelers’ diarrhea is self limited
 Bloody Diarrhea with Fever
Salmonella, Shigella, Campylobacter and
Yersina are invasive; E.histolytica.
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Vibrio cholerae will cause a profound
secretory diarrhea (“rice water”), with highest
risk of dehydration/death.
Travelers’ Diarrhea:
Therapy
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Prevention: prophylactic antibiotics are not
recommended unless a person’s medical
condition or dehydration risk is severeIBD Renal Immunosuppresion AIDS
Empiric Abx- quinolones; for convenience,
consider qd dosing with levofloxacin indicated
in cases of fever, blood or pus, and > 4 daily
stools.
Skin Lesions in Travelers
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Arthopod BitesMyiasis -botfly larvae
will penetrate skin and
mature leading to a
nodule.
Tungiasis (sand flea
larvae are expelled
under skin after a
blood meal).
Rickestiae will see a
necrotic ulcer
Skin Lesions in Travelers
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Atypical Mycobacterial
Creeping Eruptions
Cutaneous larva
migrans
(hookworm larva)
Endemic fungal
Loiasis
STD’s –genital ulcersSyphilis, LGV,Chanchroid
Strongyloidiasis.
Skin Ulcers
Tularemia
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Cutaneous Leishmaniasis
Preventable Traveler’s
Infections
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Yellow Fever – viral, mosquito-borne,lethal
Malaria – parasitic, mosquito-borne, lethal
Typhoid Fever –bacterial, foodborne,contagious
Hepatitis A – viral, food-borne, contagious
Meningococcus – bacterial, contagious, lethal,
seasonal and epidemic.
Japanese Encephalitis- viral, mosquito-borne,
seasonal, lethal, low-risk for short-term
travelers
Yellow Fever Prevention
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An Equatorial infection in both East/West
A live-virus vaccine
Only vaccination legally required by certain
countries for entry.
Four reported cases of vaccine-related multiorgan failure, with three deaths in 1996-98 in
USA.
Contraindicated for pregnant and
immunodeficient persons (live-virus).
Single IM dose; booster every ten years
Malaria Prevention
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Nearly 300 million cases worldwide each year,
with more than one million deaths.
Four species: Plasmodium falciparum, vivax,
ovale and malariae. Fatalities with falciparum.
Several hundred cases/year in US travelers.
During 1980-93, 3005 US cases with 51
deaths (1.7%).
Highest risk occurs in Sub-Saharan Africa.
Need to consider up-to-date resistance
patterns.
Malarial Prevention
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Prophylactic antibiotics are 90-95% effective.
Regimens routinely require starting pills 1-2
weeks prior to, and for 4 weeks following
exposure.
Chloroquine is the first-line agent for travel
to areas that still have chloroquine-sensitive
P.falciparum, restricted to Central America,
Middle East.
Chloroquine resistant strains of P.vivax have
now appeared in Africa and Asia
Malaria Prevention
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Topical insect repellants which include
(DEET). Can see dermatitis, and
neurotoxicity from absorption (caution with
children-use lower %)
Mosquito netting sprayed with permethrin.
Note: Yellow Fever is transmitted by
mosquitos that bite during daytime, malaria
transmitted at night.
PREGNANCY- Chloroquine is safe,
Mefloquine appears safe, Malarone data is
still insufficient.
Malaria Prevention for Travel to
Chloroquine Resistant (CR)Regions
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Mefloquine- 250 mg q week (-1 to 4+ travel)
active against all species, yet resistant strains
of P.falciparum now exist in Africa and in ThaiCambodian-Myanmar regions. Side effects
include neuropsychiatric and GI.
Malarone – combination of
atovaquone/proguanil. Taken qd 1-2 days prior
to,during, and one week post. Equivalent to
mefloquine vs. CR P.falciparum.
Doxycycline- 100 mg qd 1-2 days prior, 4 wks.
post travel. Issue of photosensitivity.
Typhoid Fever and Prevention
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Salmonella typhi is still prevalent in Asia,
Africa and Latin America.
Risk appears greatest in Indian subcontinent.
Vaccination is best advised for those going to
more remote regions, or during reported
outbreaks
Oral vaccine(Vivotif)- taken prior to travel qod
x 4, and can be boosted every 5 years.
Injectable(Typhim)- provides protection for 12 yrs
Both vaccinations provide about 50-80%
protection
Homeland Security Travel Medicine in the USA
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Endemic infections must be considered in
evaluation of fever after US travel.
Recreational activities increase the chance of
exposure to arthropods and the endemic fungi
Ticks – Babesios (New England coast/islands)
Lyme (Northeast coast, WI,CA)
RMSF (Appalachia, Northeast)
Erhlichiosis (Northeast, MO, AR)
Tick Paralysis ( Rocky Mts.)
US Travel Medicine
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Endemic Mycoses – Pulmonary/Systemic
Blastomycosis – LA, WI, Miss. River valley
Histoplasmosis – Ohio, St.Lawrence and
Mississippi river valleys
Coccidiomycosis - desert SW, San Joaquin
Hanta Virus Pulmonary SyndromeNM,CO,AZ
 Plague- flea bite, AZ bubonic not pneumonic
Prevention of Infections Related
to Travel – Abroad and At Home
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Potential exposures should signal a
series of immunizations and
prophylaxis.
Resources:
WWW. ISTM.org.
WWW. Cdc.gov
WWW. Tropnet.net
Travel Medicine Clinics
BON VOYAGE
Be Careful Out There