Transcript TRAVEL MEDICINE

Ambulatory
Conference:
Travel
Medicine
Hollis Ray, MD
June 6, 2011
Travel Clinic
Should be carried out by persons who
have training in the field, particularly for
travelers who have complex itineraries or
special health needs
 Primary care physicians and nonspecialists should be able to advise
travelers who are in good health and
visiting low-risk destinations with standard
planned activities.

Travel Clinic
Epidemiology, transmission and
prevention of travel-associated infectious
diseases
 A complete understanding of vaccine
indications and procedures
 Prevention and management of noninfectious travel health risks
 Recognition of major syndromes in
returned travelers (e.g., fever, diarrhea,
and rash)

Immunization


Update vaccines/boosters: tetanus, pertussis,
diphtheria, Haemophilus influenzae type b,
measles, mumps, rubella, varicella, Streptococcus
pneumoniae, and influenza
Hepatitis A and B, poliomyelitis, and Neisseria
meningitidis
– for travel as well as for routine health care.

Yellow fever vaccine: endemic zones (Africa and
S. America)
– some countries may require as a condition for entry

Vaccines against Japanese encephalitis, rabies,
tick-borne encephalitis and typhoid fever
– Administered based on a risk assessment
– Quadrivalent meningococcal vaccine is required by Saudi
Arabia for religious pilgrims to Mecca for the Hajj or
Umrah.
Most Common Diagnoses
 Short
Incubation Period (<2 weeks)
– Malaria
– Typhoid fever
– Dengue
– Rickettsial disease
– Hepatitis A
 Long
Incubation Period (>4 weeks)
– Malaria
– Tuberculosis
Malaria
Malaria




Largely preventable
Incubation period: 10
days to 1 year
Signs and symptoms:
GI symptoms, cyclical
fevers, anemia,
splenomegaly
Diagnosis: thick and
thin peripheral blood
smear
– Thrombocytopenia
without leukocytosis
CDC Public Health Image Library
Infecting Organisms

Plasmodium falciparum: potentially fatal
and considered an emergency
– Acquired in Africa = 3:1 likelihood
– 95% have clinical onset within 2 months
exposure
– Peripheral blood smear: parasitemia > 2%,
only ring forms, banana-shaped gametocyte,
erythrocytes of all sizes infected, erythrocytes
contain no Schuffner granules

Other species: P. vivax, P. ovale, P.
malariae, P. knowlesi
– fevers occurring at regular intervals of 48 to
72 hours
Severe Malaria
Cerebral malaria, with abnormal behavior,
impairment of consciousness, seizures,
coma, or other.
 Severe anemia due to hemolysis
 Hemoglobinuria
 Pulmonary edema or ARDS, which may
occur even after the parasite counts have
decreased in response to treatment
 Abnormalities in blood coagulation and
thrombocytopenia
 Shock

Treatment of Severe Malaria
in the United States
Artesunate for hospitalized patients with
 Severe malaria disease
 High levels of malaria parasites in the
blood
 Inability to take oral medications
 Lack of timely access to intravenous
quinidine
 Quinidine intolerance or contraindications
 Quinidine failure
Malaria
Chemoprophylaxis
Largely based on
resistance patterns to
chloroquine phosphate
or hydroxychloroquine
sulfate.
(IDSA Travel Medicine Guidelines)
(IDSA Travel Medicine Guidelines)
(IDSA Travel Medicine Guidelines)
Typhoid Fever
Typically present 1-3 weeks after
ingestion of food or water contaminated
with Samonella enterica serotype typhi
 Have visited Indian subcontinent, in the
Philippines, or in Latin America
 Fever and constitutional symptoms

– May have insidious onset
– Abdominal pain, cough, chills
– Diarrhea may eventually develop
Typhoid Fever
Diagnosis: identify
organism in urine,
blood, stool, or
bone marrow
 Vaccines partially
effective
 Treatment: 3rd
gen. cephalosporin,
floroquinolone, or
azithromycin

– Relapse: 2-3 weeks
after treatment
Typhoid Rash
Dengue Fever
 Primary
vector: Aedes mosquito
 Caused by one of four different
serotypes of Flavivirus
 Incubation period: 4-7 days
 Fever, severe myalgias, retro-orbital
pain
 Leukopenia and thrombocytopenia
 Dengue shock syndrome and dengue
hemorrhagic fever: second infection
with a different serotype
Dengue Fever
Diffuse erythema
or nonspecific
maculopapular or
petechial rash
 No specific
treatment

– IV fluids

Primary preventive
approach:
mosquito repellent
and screens
(NEJM 2002)
Travelers
Diarrhea
Travelers Diarrhea

Between 20%-50% international travelers
– Onset: usually first week of travel but may
occur later
Most common agent: enterotoxigenic
Escherichia coli (ETEC)
 Primary source of infection: ingestion of
fecally contaminated food or water.
 Most important risk determinant:
traveler's destination

– Latin America, Africa, the Middle East, and Asia
– High-risk: young adults, immunocompromised,
pts with inflammatory-bowel disease ,
diabetes, and persons taking H-2 blockers or
Travelers Diarrhea

Prevention: food and liquid hygiene and
provision for prompt self-treatment in the
event of illness
– Hydration, loperamide (if no fever >38.5
degrees C & no gross blood or mucus in stool)
– Short course (1 dose to 3 days) of a
fluoroquinolone, azithromycin or rifaximin
Usually resolves in 3-5 days
 Antibiotic prophylaxis is not recommended
for most travelers

Prolonged Diarrhea
 Greater
than 2 weeks
 Less likely to isolate specific
organism
 More likely to be parasitic
– Giardia lamblia, Cryptosporidium
parvum, Entamoeba histolytica, and
Cyclospora cayetanensis most
frequently identified
– detected in fewer than 1/3 travelers
with chronic diarrhea and in only 1-5%
travelers with acute diarrhea
Hepatitis A Virus
 Transmitted
through fecal
contimination of food and drink
 Treatment: supportive (no antivirals)
 Vaccination
– Should be immunized at least 2-4 weeks
prior to traveling
– Single dose: 100% protection by 4 wks
– 2nd dose administered 6 months later
results in antibody titers likely to last
many decades
Rickettsial Diseases

African tick typhus
(NEJM 2002)
Tick transmitted,
occur throughout
the world, typically
named for
geographic region
– African tick bite
fever (subSaharan)
– Meditterranean tick
bite fever (N. Africa
and Middle East)
– Exception: RMSF
Rickettsial Diseases
 Headache,
fever, myalgias and often
a truncal maculopapular or vesicular
rash
 Clinical clue: eschar at site of bite
 Treatment: doxycycline, self-limited
Fungal Infections
 Coccidioidomycosis:
Southwest US,
Mexico, and parts of South America
 Histoplasmosis: Ohio River valley,
Mexico, Central America
 Penicillium marneffei: Southeast
Asia, parts of China, Hong Kong, and
Taiwan
– Disseminated infection increasing in
immunocompromised patients (AIDS)
Scabies
 Due
to Sarcoptes scabiei infection
 Common in
– Developing world
– Adventurous backpackers
 Sexually
active travelers are those
most commonly infected
(Foot of a person who had recently visited the Caribbean)
(NEJM 2002)
Cutaneous Larva Migrans
Most frequent serpiginous lesion among
travelers
 Results from migration of animal
hookworms (e.g., Ancylostoma braziliense
and A. caninum) in superficial tissues
 Usually acquired after direct skin contact
with soil or sand contaminated with dog or
cat feces
 Lesions

– may initially be papular or vesicular
– Pruritic
– commonly found on the foot or buttock
QUESTIONS
The End