Travelers’ Health

1. Travelers’ Health April 2004 Dr. Tim Cook

2. USEFUL WEBSITES • Health Canada http://www.hc-sc.gc.ca/pphb-dgspsp/tmp-pmv/index.html • CDC Travelers' Health http://www.cdc.gov/travel/ • Morbidity and Mortality Weekly Report http://www.cdc.gov.mmwr/

3. CASE • Healthy recently graduated physician joins MSF and immediately deploys to CAR (Central African Republic) • What health risk mitigation information should he be given? • Vaccines? • Rx?

4. INFECTIOUS • VECTOR-BORNE DISEASE • MALARIA • DENGUE FEVER • NEMATODES • FILARIASIS, ONCHOCERCIASIS, LOAIASIS • TRYPANOSOMIASIS • YELLOW FEVER • RICKETTSIAE (Ticke-borne) • (JAPANESE ENCEPHALITIS – not in Africa)

5. PPM (PERSONAL PROTECTION MEASURES) • DEET • 28% lasts 6-8 hours • 6% lasts < 1 hr • 95% no longer available • Slow-release better (Ultrathon, Sawyer’s) • LONG SLEEVES, PANTS • BEDNETS (Permethrin-impregnated)

6. MALARIA CHEMOPROPHYLAXIS • MALARONE (Atovaquone + Proguanil) • Daily, day before until 1 wk after departing • S/E Mild GI, HeadAches • Safe in aircrew, drivers etc. • EXPENSIVE ($5/DAY) • MEFLOQUINE • DOXYCYCLINE • PRIMAQUINE

7. DENGUE • Throughout tropics • Day biting Aedes Egypti mosquito • therefore use DEET night AND day • No vaccine (yet!) • PPM only

8. INFECTIOUS • HUMAN-BORNE • TB – two step Mantoux recommended • STDs incl Hep B / HIV • Influenza • yr round in tropics • Meningococcus

9. INFECTIOUS • FOOD / WATER-BORNE • Typhoid (salmonella) • Non-typhoid salmonella • ETEC – commonest cause of travelers’ diarrhea • Toxin = secretory diarrhea • Cholera – similar toxin as ETEC • Other bacteria (shigella / campylobacter / yersinia • Virus - Hepatitis A (Norwalk, Rota) less common • Parasites (E.Histolytica, Cyclospora , Cryptosporidia) <3% of TD but more common in persistent diarrhea • Schistosomiasis – DON’T SWIM IN FRESHWATER

10. INFECTIOUS • ZOONOSES (Animal – borne) • Q fever (rickettsia) • Brucellosis • Tularemia • Rabies • Many others ALL RARE

11. NON-INFECTIOUS • FLORA • FAUNA …. AVOID! • ACCLIMATIZATION • ALTITUDE SICKNESS (hikes Kilimanjaro!) • Climb high, sleep low, go slow • Acetazolamide (Diamox) 250 mg OD • Carbonated beverages taste flat! • Does not prevent HAPE, HACE – emergent descent or pressure bag, O2, steroids, nifedipine, supportive care • NEEDLE STICK INJURY (Bring triple therapy?)

12. VACCINES? • ROUTINE • RECOMMENDED • REQUIRED

13. ROUTINE VACCINES • TdP • MMR

14. RECOMMENDED • HEPATITIS A – 2 doses, > 10 yrs • HEPATITIS B – 3 doses, > 10 yrs • TWINRIX – both A & B, 3 doses • INFLUENZA – annually / pre-travel • TYPHOID • Typhum Vi – 1 dose, lasts 3 yrs, 75% effective • Vivotif – oral, 4 doses, lasts 5 yrs, similar efficacy • RABIES • MENINGOCOCCUS

15. DUKORAL • New (Aug 2003) • Oral vaccine against toxin of ETEC and cholera • 2 doses 1 wk apart • ~75% effective • Only lasts 3 months • $$ (75)

16. REQUIRED • YELLOW FEVER • MENINGOCOCCUS (only req’d for participation in the Hajj, travel to Mecca)

17. YELLOW FEVER • monkey zoonosis transmitted to humans by mosquitoes • Classic (but more severe than ususal) clinical manifestations: Fever, headache, abdo pain and vomiting; Short period of improvement; Then liver and kidney failure, shock +/- bleeding

19. YELLOW FEVER CONT’D • certain countries require vaccination for entry • live attenuated virus; may be safe in asymptomatic HIV; patients should be given choice • single dose • if egg anaphylaxis, two options: • Intradermal skin testing with the vaccine • Letter documenting contraindication --> waiver from embassy

20. TYPHOID • most important in Indian subcontinent • use in travellers going outside of tourist areas or to places with known typhoid epidemics • capsular polysaccharide vaccine; single injection • MENINGOCOCCUS • frequent epidemics in sub-Saharan Africa (belt across the middle of the continent from Guinea to Ethiopia); patient at risk if there >3 weeks or not staying in hotels • risk in pilgrims going to Mecca for the hajj • single dose to these travellers 10 - 14 days pre-travel

21. HEPATITIS A • fecal to oral • prevalent in MANY countries; all of Africa and South America, SE Asia • 0.3% per month risk of infection in developing countries if patient is careful where they eat • vaccine is inactivated virus • safe, very effective • protection after four weeks • booster in 6 - 12 months (depending on formulation) • can use Immune Globulin for prophylaxis in patients who can’t be vaccinated • NOTE: other major indication for HAV vaccine is all patients with chronic liver disease

22. Japanese encephalitis • mosquito-borne arbovirus • important in late summer -- autumn in much of East Asia except urban China/Japan or Singapore • consider in patients going in Summer/Fall, esp. to rural areas or for a prolonged stay in urban areas • three doses over the course of a month • Measles • if born after 1970, with no proof of vaccination, if travelling to endemic area

23. PRESCRIPTIONS • ANTI-MALARIAL • STANDBY FOR TRAVELERS’ DIARRHEA • Azithromycin – 1 g all at once • Cipro – 1 g at once • Acetazolamide

24. CASE 2 • 2 days after returning to Canada the physician calls you complaining that he has a fever (38.5) and some diarrhea? • What are your recommendations?

25. FEVER IN RETURNING TRAVELER • MALARIA, MALARIA, MALARIA • DENGUE • TYPHOID • “DEVELOPED WORLD DISEASES” • INFLUENZA, PNEUMONIA, UTI etc

26. WHAT TO DO? • Consider it a medical emergency! • CBC (anemia, thrombocytopenia in malaria and dengue) • Thick and thin smears (malaria) • Blood cultures (typhoid) • LDH (hemolysis - malaria) • Stool cultures • Treat as P.Falciparum until proven otherwise!