Ambulatory Conference: Travel Medicine

1. Ambulatory Conference: Travel Medicine Hollis Ray, MD June 6, 2011

2. Travel Clinic • Should be carried out by persons who have training in the field, particularly for travelers who have complex itinerariesor 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.

3. Travel Clinic • Epidemiology, transmission and prevention of travel-associated infectious diseases • A complete understanding of vaccine indications and procedures • Prevention and management of non-infectious travel health risks • Recognition of major syndromes in returned travelers (e.g., fever, diarrhea, and rash)

4. 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.

6. Most Common Diagnoses Short Incubation Period (<2 weeks) Malaria Typhoid fever Dengue Rickettsial disease Hepatitis A Long Incubation Period (>4 weeks) Malaria Tuberculosis

7. Malaria

8. 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

9. 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

11. 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

12. 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

13. Malaria Chemoprophylaxis Largely based on resistance patterns to chloroquine phosphate or hydroxychloroquine sulfate. (IDSA Travel Medicine Guidelines)

14. (IDSA Travel Medicine Guidelines)

15. (IDSA Travel Medicine Guidelines)

17. 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

18. 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

19. Typhoid Rash

23. 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

24. Dengue Fever • Diffuse erythema or nonspecific maculopapular or petechial rash • No specific treatment • IV fluids • Primary preventive approach: mosquito repellent and screens (NEJM 2002)

26. Travelers Diarrhea

27. 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 antacids.

28. 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

30. 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

32. 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

33. 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)

34. Rickettsial Diseases • Headache, fever, myalgias and often a truncal maculopapular or vesicular rash • Clinical clue: eschar at site of bite • Treatment: doxycycline, self-limited

36. 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)

38. Scabies • Due to Sarcoptes scabiei infection • Common in • Developing world • Adventurous backpackers • Sexually active travelers are those most commonly infected

39. (Foot of a person who had recently visited the Caribbean) (NEJM 2002)

40. 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

42. QUESTIONS

48. The End