travel associated infections sunanda gaur, md. travelers’ health risks of 100,000 travelers to a...
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Travel Associated Infections
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Sunanda Gaur, MD
Travelers’ Health Risks
Of 100,000 travelers to a developing country for 1 month:– 50,000 will develop some health problem – 8,000 will see a physician– 5,000 will be confined to bed– 1,100 will be incapacitated in their work– 300 will be admitted to hospital– 50 will be air evacuated– 1 will dieSteffen R et al. J Infect Dis 1987; 156:84-91 (ISTM)
Infectious Disease Risks to the Traveler
• Malaria• Diarrhea• Leishmaniasis• Rabies• Dengue• Meningococcal
Meningitis• Hepatitis A
• Schistosomiasis• Tuberculosis• Leptospirosis• Polio• Yellow Fever• Measles• JEV
ETC.
Diseases in Returning Travelers
• Fever : Malaria, Dengue ,Typhoid, nonspecific
• Diarrhea : Giardiasis, Amebiasis, bacterial, non specific
• Dermatologic : Insect bites, CLM, allergic rashes
• Non diarrheal Intestinal disorders : Hepatitis, Strongyloidosis
N Engl J Med 2006; 354:119-130
Fever in the Returned TravelerGeosentinal sites studyCID 2007 44: 1560-8 ( n=6957)
• Malaria 21%• Acute Diarrheal Disease 15%• Respiratory Illness 14%• Dengue 6%• Salmonella Infections 2%• Tick borne Illness 2%• 3% had vaccine preventable illness ( Hep
A, Typhoid Fever, Influenza )
Causes of imported fever by region Africa Asia Americas
Malaria 35% Unknown etiology 19% Unknown etiology 33%
Unknown etiology 25% Respiratory 13% Respiratory 16%
Respiratory 10% Dengue 12% Dengue 9%
Bacterial enteritis 5% Malaria 11% Bacterial enteritis 9%
Rickettsial 4% Bacterial Enteritis 9%, Typhoid 3%
Malaria 4 %
Bottieau et al Arch Int Med 166: 1642, 2005
Travel Health Resources
• CDC Travelers’ Health Website– www.cdc.gov/travel
• World Health Organization – www.who.int/int
• State Department – travel.state.gov
• International Society of Travel Medicine– www.istm.org
• Health Information for International Travel– CDC “Yellow Book”
• International Travel and Health– WHO “Green Book”
Travelers’ Health Websitewww.cdc.gov/travel
Traveler's Diarrhea
• In general, up to 50% of travelers develop at least one episode of diarrhea during a two week stay
• Onset usually within 2-3 days of arrival, > 90% occur within the first two weeks
• A self limiting illness with significant morbidity
Causes of Traveler’s DiarrheaCause Percent Isolation
Bacteria 50-75
Escherichia coli
Enterotoxigenic
Enteroadhesive
Enteroinvasive
5-70
5-70
?
?
Campylobacter spp. 0-30
Salmonella spp. 0-15
Shigella 0-15
Aeromonas 0-10
Plesiomonas 0-5
Other 0-5
Causes of Traveler’s DiarrheaCause Percent Isolation
Protozao
Giardia lamblia
Entamoeba histolytica
Cryptosporidium ssp.
Cyclospora cayetanensis
0-5
0-5
0-5
?
?
Viruses
Rotavirus
Enterovirus
0-20
0-20
?
No pathogen isolated 10-40
Food and Beverage Precautions
Boil it , peel it, cook it or FORGET IT !!
Food and Water Precautions
• Bottled water
• Selection of foods– well-cooked and hot
• Avoidance of – salads, raw vegetables– unpasteurized dairy products– street vendors– ice
Traveler’s Diarrhea
• Prevention : Antimicrobial prophylaxis is not recommended.
• Early self therapy is recommended• Oral rehydration• Fluoroquinolones remain drug of choice• Resistance is developing in some regions• Azithromycin ( Mexico , Thailand, Morocco ), ? preferable• Rifaximin ( non bloody stools, no fever)• Non specific agents ( Bismuth subsalycilate, loperomide)
Destination Specific VaccinesVaccine Risk Region
Yellow fever Parts of Africa and South America. (travel.state.gov)
Hepatitis B SE Asia, parts of Africa, Middle East, Pacific Islands, parts of South America
Hepatitis A All except Japan, Australia, New Zealand, north and west Europe, North America (except Mexico)
Typhoid Developing countries
Meningococcal Sub Saharan Africa
Japanese Encephalitis
Indian Subcontinent, SE Asia
Cholera Outbreak setting
Rabies South and SE Asia, Mexico, parts of South and Central America and Africa
Plague Outbreak Setting
The Meningococcal Meningitis Belt
Don’t Forget the “Routine Vaccines”
• MMR
• dT ( New dTaP )
• Varicella
• IPV
• Hepatitis B
Malaria
Malaria
MALARIA
• Plasmodium vivax*
• Plasmodium falciparum*
• Plasmodium ovale
• Plasmodium malariae
* most common
Malaria Risk
• Oceania 1: 5 ( chloroquin res Vivax)
• Sub-Saharan Africa 1:50 ( falciparum)
• South Asia 1:250 ( mainly vivax)
• SE Asia 1:2500 ( multi res falciparum)
• Mexico/Central Am 1:10,000 ( Chloroquin sens)
Malaria life cycle
Malaria
• All febrile returning travelers should be considered to have malaria until proven otherwise
• Serial blood smears (thick and thin) every 8-12 hours in the first 24 – 48 hours
• Thick smears are 10 – 40 times more sensitive than thin smears. Thin smears important for quantitation of parastemia
• Important to identify the species
Fatal Malaria
• 45 fatal cases between 1980 – 1992• 98% caused by P. falciparum• 82% acquired in Sub-Saharan Africa• Most cases were associated with lack of
chemoprophylaxis, suboptimal chemoprophylaxis, delay in seeking medical attention, and delay in diagnosis
“ABCD” of malaria reduction
– A Awareness of risk– B Bite prevention– C Chemoprophylaxis– D Diagnosis
Mosquito Bite Prevention
Vector Precautions
• Covering exposed skin• Insect repellent containing DEET 30 – 50%• Treatment of outer clothing with permethrin• Use of permethrin-impregnated bed net• Use of insect screens over open windows• Air conditioned rooms • Use of aerosol insecticide indoors• Use of pyrethroid coils outdoors• Inspection for ticks
Malaria Prophylaxis
Drug Mefloquine
Usage In areas with chloroquine resistant Plasmodium falciparum and vivax. Highly effective
Adult Dose 22mg base (250 mg salt) orally, once/week, continue for 1 week after return
Side effects 25% mild headache, GI upset, malaise, anxiety
1/250-1/500 nightmares, irritability, depression
Comments Contraindicated in persons allergic to mefloquine. Not recommended for persons with epilepsy and other seizure disorders; with severe psychiatric disorders; or with cardiac conduction abnormalities.
Malaria Prophylaxis
Drug Doxycycline
Usage An alternative to mefloquine
Adult Dose 100 mg orally, once/day
Pediatric Dose
>8 years of age: 2mg/kg of body weight orally/day
up to adult dose of 100 mg/day
Comments Contraindicated in children < 8 years of age, pregnant women, and lactating women.
MalariaProphylaxis
Drug Chloroquine phosphate
Usage In areas with chloroquine sensitive Plasmodium flaciparum
Adult Dose 300 mg base (500 mg salt) orally, once/week
Pediatric Dose
5 mg/kg base (8.3 mg/kg (salt)) orally once/week up to maximum adult dose of 300 mg base
Comments
Malarone (Atovaquone and Proguanil Hydrochloride)
• Atovaquone - a broad spectrum antiprotozoal inhibits the parasites mitochondrial electron transport.
• Treatment with Atovaquone alone results in rapid development of resistance.
• Atovoquone and Proguanil are synergistic against multi drug resistant P. falciparum
• Several studies have demonstrated the efficacy of this combination in treatment and prophylaxis of multidrug resistant P. falciparum
• Daily dosing ( 2-3 days prior, 7 days after), high cost• Occasional headache, GI upset
Typhoid Fever
• Caused by S.typhi or S. paratyphi• In US 445 cases/year between 1967 – 1994• 72% of cases in the recent years (1985-1994) occurred in returning
travelers• Travel to Mexico and India account for >50% of cases• Fever, chills, headache, malaise, abdominal pain, and constipation
are common symptoms.• Blood cultures positive in 40-66%, bone marrow culture positive in
90%• Increasing antibiotic resistance – particularly in India – consider
Ceftriaxone or Ciprofloxacin as first line therapy
Commercially Available Typhoid Vaccines Available in the United States
DrugDrug Ty21a ViCPS
TypeType Live Attenuated Polysaccharide
RouteRoute Oral IM
Min Age of ReceiptMin Age of Receipt 6 2
No. DosesNo. Doses 4 1
Booster frequency,yBooster frequency,y 5 2
Side Side Effects(incidence)Effects(incidence)
<5% <7%
Oral Ty21a Vaccine
• Live attenuated vaccine• Enteri coated capsule – 1 cap every other day x 4 doses• Efficacy – 65%• Minimal to no side effects• Contraindicated in immune compromised individuals• Mefloquine can inhibit growth of Ty21a in vitro; delay
vaccine at least 24 hours before or after Mefloquine• Concommitant or antimicrobials may effect vaccine
efficacy
GEOGRAPHIC DISTRIBUTION OF HEPATITIS A VIRUS INFECTION
Hepatitis A Vaccine
• Inactivated Vaccine• Approved for children 2-18 years old and adults• Highly Immunogenic
– 88 – 90% seroconversion in 2 weeks– 99% seroconversion after 2nd dose
• Duration of protection – under evaluation• Indicated for:
– Foreign travel– Residence in communities with high endemicity – Patients with chronic liver disease– Homosexual/bisexual men– IVDU– Occupational risk
Yellow fever Endemic Zones
Yellow Fever Vaccine
• Live vaccine• Required if entering endemic area or going from an
endemic region to non-endemic region• Approved for children > 9 months old• Do not administer simultaneously with cholera vaccine• Under 4 months – unsafe (high incidence of post
vaccination encephalitis)• Adverse effect ( viscerotropic disease) : 1 in 2-3 million
World Distribution of Dengue 1999
Areas infested with Aedes aegyptiAreas with Aedes aegypti and recent epidemic dengue
Travel related Tick-Borne Diseases
Tick Borne Relapsing Fever
Israel, Africa, South Asia
Every 3-5 days fever episodes
African TBF Southern Africa Fever, h/a ,eschars
Mediterranean Spotted fever
Mediterranean , South Asia, E&S Africa
Similar to African TBF, more severe
TBE Central and E Europe Fever, Meningo-encephalitis
Lyme Borreliosis Europe Rash, 7th nerve palsy, aseptic meningitis
Bloodborne and STD Precautions• Prevalence of
– STDs – Hepatitis B– Hepatitis C– HIV
• Unprotected sexual activity• Commercial sex workers• Tattooing and body piercing• Auto accidents • Blood products• Dental and surgical procedures
Post Exposure HIV prophylaxis
• Assess likelihood of exposure• Assess degree of exposure• Begin ARV prophylaxis within 12-24 hrs.• 2-3 drug combinations recommended depending
on exposure risk . To be continued for 4 weeks.• http://www.cdc.gov/mmwr/PDF/rr/rr5409.pdf or
http://www.ucsf.edu/hivcntr/hotlines/PEPline
Pre Travel Check ListRoutine immunization
Hepatitis A Immune Dose 1 Dose 2
Polio Immune One dose IPV
Meningococcal One dose Booster
Typhoid Oral 4 doses One dose IM Booster
Malaria Chloroquin Mefloquin Malarone Doxy
Diarrhea Loperamide Ciprofloxacin Azithromycin Oral rehydration
Allergy Antihistamine Epi Pen
Soft tissue infection Cefalexin bacitracin
Motion sickness/GERD Dramamine/H2 blocker
Food and water precautions Instruction
Adventure/long stay Rabies Yellow fever JE
Special problems Asthma Diabetes
Mantoux status
Travel Emergency Kit
• Copy of medical records and extra pair of glasses• Prescription medications• Over-the counter medicines and supplies
– Analgesics– Decongestant, cold medicine, cough suppressant– Antibiotic/antifungal/hydrocortisone creams – Pepto-Bismol tablets, antacid– Band-Aids, gauze bandages, tape, Ace wraps– Insect repellant, sunscreen, lip balm– Tweezers, scissors, thermometer
Kibera, Nairobi
Post-Travel Care
• Post-travel checkup– Long term travelers– Adventure travelers– Expatriates in developing world
• Post-travel care– Fever, chills, sweats– Persistent diarrhea– Weight loss
Rabies
• Rabies in travelers – an underestimated risk• 1980 – 1997 12/36 (33%) of human rabies deaths in US have been
related to rabid animals outside the US• Canine rabies in endemic in the Indian Subcontinent, China, SE
Asia, Philippines, Latin America, Africa and the former Soviet Union• In many rabies endemic countries, only Equine RIG and older
Semple rabies vaccines are available• Equine RIG – significant risk of serum sickness• Semple type rabies vaccine is not as effective, and theoretical
danger of allergic myeloencephalitis exists• Pre-exposure prophylaxis should be considered in selected cases
Japanese Encephalitis Vaccine
• Inactivated vaccine• Efficacy = 91%• Booster every 3 years• Not approved for children under 3 years• Side effects
– Local reaction (10-25%)– Fever (10-25%)– Hypersensitivity reaction (0.6%)
• Indications– Expatriates living in Asia– Travel to endemic regions for >30 days during transmission
season, especially travel to rural areas