Ambulatory Ambulatory Conference: Conference:

Travel Travel MedicineMedicine

Hollis Ray, MDHollis Ray, MD

June 6, 2011June 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 non-specialists 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 Epidemiology, transmission and prevention of travel-associated infectious prevention of travel-associated infectious diseasesdiseases

A complete understanding of vaccine A complete understanding of vaccine indications and proceduresindications and procedures

Prevention and management of non-Prevention and management of non-infectious travel health risksinfectious travel health risks

Recognition of major syndromes in Recognition of major syndromes in returned travelers (e.g., fever, diarrhea, returned travelers (e.g., fever, diarrhea, and rash)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

MalariaMalaria

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 leukocytosisCDC 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 MalariaSevere Malaria Cerebral malaria, with abnormal behavior, Cerebral malaria, with abnormal behavior,

impairment of consciousness, seizures, impairment of consciousness, seizures, coma, or other.coma, or other.

Severe anemia due to hemolysisSevere anemia due to hemolysis Hemoglobinuria Hemoglobinuria Pulmonary edema or ARDS, which may Pulmonary edema or ARDS, which may

occur even after the parasite counts have occur even after the parasite counts have decreased in response to treatment decreased in response to treatment

Abnormalities in blood coagulation and Abnormalities in blood coagulation and thrombocytopeniathrombocytopenia

Shock Shock

Treatment of Severe Malaria Treatment of Severe Malaria in the United States in the United States

ArtesunateArtesunate for hospitalized patients with for hospitalized patients with Severe malaria disease Severe malaria disease High levels of malaria parasites in the High levels of malaria parasites in the

blood blood Inability to take oral medications Inability to take oral medications Lack of timely access to intravenous Lack of timely access to intravenous

quinidine quinidine Quinidine intolerance or contraindications Quinidine intolerance or contraindications Quinidine failureQuinidine failure

Malaria Chemoprophylaxis

Largely based on resistance patterns to chloroquine phosphate or hydroxychloroquinesulfate.

(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)

TravelersDiarrhea

Travelers DiarrheaTravelers 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 antacids.

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 Tick transmitted,

occur throughout the world, typically named for geographic region– African tick bite

fever (sub-Saharan)– Meditterranean tick

bite fever (N. Africa and Middle East)

– Exception: RMSF

African tick typhus

(NEJM 2002)

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