Travelers’ Health

April 2004 Dr. Tim Cook

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/

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?

INFECTIOUS

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

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)

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

DENGUE

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

INFECTIOUS

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

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

INFECTIOUS

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

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?)

VACCINES?

ROUTINE RECOMMENDED REQUIRED

ROUTINE VACCINES

TdP MMR

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

DUKORAL

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

REQUIRED

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

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

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

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 travel hajj single dose to these travellers 10 - 14 days pre-

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

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

PRESCRIPTIONS

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

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?

FEVER IN RETURNING TRAVELER

MALARIA, MALARIA, MALARIA DENGUE TYPHOID “DEVELOPED WORLD DISEASES” INFLUENZA, PNEUMONIA, UTI etc

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!