Travel and Tropical Medicine - PowerPoint PPT Presentation

1 / 58
About This Presentation

Travel and Tropical Medicine


Helminths such as Amebiasis, echinococcus American trypanosomiasis (Chagas disease) Cutaneous and mucocutaneous Leishmaniasis Paragonimiasis ... – PowerPoint PPT presentation

Number of Views:700
Avg rating:3.0/5.0
Slides: 59
Provided by: RogerT83


Transcript and Presenter's Notes

Title: Travel and Tropical Medicine

Travel and Tropical Medicine
  • Roger Thomas, MD, Ph.D, CCFP. MRCGP

RISKS of Travel to Developing Countries
  • Diarrhea 34
  • (ETEC causes 30-60 of these cases)
  • Respiratory 26
  • Skin disorder 8
  • Acute mountain sickness 6
  • Accident and injury 5
  • Illness with fever 3

Mortality from travel in developing world
  • 50 is cardiovascular (older travelers with
    pre-existing cardiac condition), but rates are
    not increased by travel
  • In younger travelers injuries are main cause of
    death accidental death rate in 15-44 year olds
    is 2-3 times domestic rate (MVA, scooters,

Traffic accidents worldwide 2004
  • 1.7 million deaths, single major cause of death
    in males 15-45
  • gt 750 US citizens die, gt 25,000 injured annually
    on foreign roads, some are permanent residents
    abroad, (implying gt 75 Canadians and gt 2,500
  • 30 million injuries
  • Egypt, Kenya, India, S. Korea, Turkey, Morocco
    most dangerous
  • Advise do not drive at night, especially rural
    areas do not drive motorbike or bike

  • Take a history
  • past medical history, medications,
  • planned travel
  • unplanned excursions and sports
  • Bring childhood vaccinations up to date (MMR,
    polio, tetanus)
  • Vaccinations and medications needed for trip
  • Ask their understanding of risks your advice
  • Print off CDC data and have them read and
    underline it
  • Malaria prevention diagnosis treatment
  • Travellers diarrhea prevention diagnosis
  • Helminths 9. Other

Lets begin with a 60 year old going to Peru and
  • PMH HTN, hyperlipidemia, well controlled never
  • What are his/her travel plans?
  • Review CDC website
  • Identify risks and prescribe

60 year old visiting Peru and Ecuador
  • Update childhood vaccinations
  • Check for egg allergy if plan MMR, influenza,
    Yellow Fever vaccines
  • GI risk cholera? typhoid? Bacterial diarrhea?
    Hepatitis? (Twinrix) Helminths?
  • Yellow Fever?
  • Malaria risks?
  • High altitude sickness risks? (he/she is going to
    3,600 meters rapidly by plane, no slow ascent
    risks begin above 2,400 meters)
  • PE from air travel (5/million)

60 year old visiting Peru and Ecuador Other
  • Helminths such as Amebiasis, echinococcus
  • American trypanosomiasis (Chagas disease)
  • Cutaneous and mucocutaneous Leishmaniasis
  • Paragonimiasis (oriental lung fluke)
  • Brucellosis
  • Bartonellosis (Oroya fever) on western slopes of
    Andes up to 3000 m
  • Louseborne typhus in mountainous areas of Peru

28 year old veterinarian, visiting Malawi, South
Africa, advising for WHO
  • PMH LMP 6 weeks ago, rising ?HcG titres,
    planning to be in Africa during 1st and 2nd
  • GI risks?
  • Malaria risks?
  • Rabies risks?
  • Risks to pregnancy?

Live-attenuated vaccines in pregnancy
  • MMR and varicella are live-attenuated and
    contrandicated in pregnancy because of
    theoretical risk to fetus
  • However, no evidence of harm from inadvertent
    rubella vaccination
  • ?226 pregnant females 1971- 1989 in US
  • caused subclinical infection in 1-2 of
  • no evidence of congenital rubella
  • ?Motherisk found no evidence of increased
  • rate of fetal malformations in 94 women
  • vaccinated with rubella 3 months before
  • conception or during pregnancy

Live-attenuated vaccines in pregnancy
  • No evidence of harm from inadvertent varicella
  • ? in 362 women vaccinated during pregnancy, no
    cases of congenital varicella

Vaccines in pregnancy
  • No evidence of increased risk of adverse
    reactions, teratogenic or embryotoxic effects in
  • All classes of maternal IgG transported across
    placenta, mostly in 3rd trimester
  • maternal IgG has half life of 3-4 weeks in
    infant, waning after 6-12 months of life.
  • Strong evidence of benefits of vaccines

Canadian Immunization Guide Advice for pregnancy
  • Safe
  • ? Influenza (good idea as pregnant women have
    4 x hospitalisation rate for influenza compared
    to non-pregnant due to increased CVS volume, HR
    and O2 consumption)
  • ? Diptheria/tetanus
  • ? Polysaccharide meningococal vaccine (no
    evidence for conjugate vaccine)
  • ? Salk poliomyelitis vaccine

Canadian Immunization Guide Advice for pregnancy
  • No apparent risk, recommended in women at risk
  • ? Hepatitis B
  • No apparent risk, consider in high-risk
  • ? Hepatitis A
  • ? Pneumococcal polysaccharide
  • ?Cholera (no data)
  • ?Typhoid (no data)
  • ?Pertussis (no data)
  • ? Live Japanese encephalitis (no data)
  • Contraindicated (unless high risk travel
  • ? Yellow fever (6/million risk of visceral
    and 6/million risk of cerebral complications for
    all vaccinees)

  • Incubation for Plasmodium falciparum 7-14 days
    (up to 6 weeks)
  • Partial immunity from long-term residence is
    against erythrocytic stages and diminishes within
    6-12 months of leaving endemic area
  • Clinical presentation (clinical diagnosis is
    inaccurate as malaria is a great imitator must
    do thick and thin films)
  • Prodrome of tiredness, malaise and aching in the
    back, joints and abdomen, anorexia and nausea and
    vomiting. Tender splenomegaly. Conjunctivae
    suffused. Patient febrile for 2-3 hours before

  • Cold stage of rigors (15-60 minutes)
  • ? sudden feeling of cold and apprehension
  • ? pulse rapid and low volume
  • ? mild shivering turns into violent teeth
  • chattering and shaking of the whole
  • Patients try to cover themselves with
  • bedclothes
  • ? core temperature is high but peripheral
  • vasoconstriction with skin cold and
  • pimpled

  • Hot stage up to 104F (2-6 hours) (Ague
    attack resembles the endotoxin reactions of
    lobar pneumonia or pyelonephritis)
  • ? restless, unbearably hot, throws off all
  • bedclothes, excited
  • ? severe throbbing headache, palpitations,
  • tachypnea, postural syncope
  • ? may vomit
  • ? may become confused, convulse
  • ? skin dry flushed and burning
  • ? splenomegaly may be detected first the
    first time in this stage
  • sweating stage (2-4 hours) temperature returns
    to normal and patient sleeps

WHO criteria for Severe malaria
  • Identify patients with severe malaria for special
    treatment with one or more of
  • Cerebral malaria
  • Respiratory distress
  • Severe normocytic anemia
  • Renal failure
  • Hyperparasitemia
  • Pulmonary edema
  • Hypoglycemia
  • Circulatory collapse
  • Spontaneous bleeding
  • Generalised convulsions

Cerebral malaria (encephalitis)
  • impairment of consciousness or generalised
    convulsion followed by coma
  • high fever can cause irritability, obtundation,
    psychosis, and febrile convulsions (children) so
    urgently treat impairment of consciousness
  • may thrash or lie immobile with eyes open or have
    dysconjugate gaze

Cerebral malaria (encephalitis)
  • brainstem signs
  • ? dolls eyes (in children)
  • ? may be decorticate (flexion of elbows and
    wrists, supination of the arm) suggests severe
    bilateral damage to the midbrain
  • ? may be decerebrate (extension of wrists and
    elbows with pronation of the arms suggests damage
    to the midbrain or the caudal diencephalon)

Cerebral malaria (encephalitis)
  • children may have subtle convulsions (nystagmoid
    eye movements, salivation, shallow irregular
    respirations, clonic movements of an eyebrow,
    finger, toe or mouth)
  • with excellent care mortality is 15-20 death
    within hours for children
  • respiratory distress (compensation for metabolic
    acidosis), laboured breathing, intercostal
    recession, nasal flaring, accessory muscles of

Malarial Anemia (defined as lt 5 g/dl)
  • children with severe anemia usually have acidosis
    (deep Kussmaul breathing)
  • malarial anemia kills as many children as
    cerebral malaria (mortality 5-15 mortality
    from acidosis 24 mortality from severe anemia
    acidosis 35)
  • also common in pregnant women

Jaundice and hypoglycemia in malaria
  • Jaundice
  • 1/3 of adults associated with cerebral
    malaria, acute pulmonary edema
  • Hypoglycemia
  • Anxiety, breathlessness, lightheadedness,
    tachycardia, impairment of consciousness,
    seizures, abnormal posturing can be
    misinterpreted as due only to the malaria
  • Pregnant women
  • ? cell-mediated immunity is altered to favour
    survival of the fetus (more so in primigravidae),
    the placenta is heavily parasitized (the
    parasites adhere to chondriotin sulphate on the
    syncytiotrophoblast) The peripheral blood film
    may show no parasites
  • ?risk is greatest for primigravidae in areas
    of unstable malaria

Chemoprophylaxis of malaria
  • Causal prophylaxis atovaquone and primaquin act
    on exo-erythrocytic cycle in liver
  • Schizontocides atovaquone, mefloquine,
    chloroquine, doxycycline, proguanil act on
    intra-erythrocytic parasites
  • Terminal prophyaxis Primaquine acts on latent
    hypnozoites in liver to prevent relapses in P
    Ovale and P vivax

Chemoprophylaxis of malaria
  • Mefloquine PO (Begin 1 week before departure,
    continue 4 weeks after return)
  • 62.5 mg weekly children 3 months 5
  • years
  • 125 mg weekly 6-8 years
  • 187.5 mg 9-14 years
  • 250 mg weekly adults

Chemoprophylaxis of malaria
  • Doxycycline PO 1.5mg/kg daily. Do not use
    children lt 12 years and pregnant or lactating
    women can begin 2 days before enter malarious
  • Pyrimethamine-dapsone (Malaquine) PO 1 tablet
    12.5 mg pyrimethamine 100 mg dapsone
  • ¼ tablet weekly children 1-5 years
  • 1/2 tablet weekly children 6-11 years
  • 1 tablet weekly children gt11 years and

Prevention of malaria
  • Bednets clothes impregnated with pyrethroids.
  • Cochrane review by Gamble (2006) found for 4 RCTs
    of treated nets vs. no nets a reduction in
    relative risks
  • RR
  • ?placental malaria 0.79 0.63 to 0.98
  • ?low birth weight 0.77 0.61 to 0.98
  • Avoid going out at night, wear long sleeves and
    long trousers (80 of bites on ankles)
  • Compliance with medication

Treatment of Malaria
  • ARTEMISINS (halve parasite clearance time
    compared to quinine, but RCTs do not show
    reduction in mortality compared to quinine)
  • Uncomplicated disease artesunate or artemether
    by mouth 4mg/kg x 3 days. Give each day in
    divided doses. Artesunate suppositories are easy
    to use. Use with second drug (e.g. mefloquine) to
    prevent recrudescence)

Treatment of Malaria
  • Severe disease
  • ? Artesunate 2.4 mg/kg IV or IM then 1.2
    mg/kg IM daily.
  • To make artesunate dissolve 60 g in 0.6
    ml of 5 NaHCO3,
  • dilute to 5 ml with 5 dextrose and give
    IV or IM.
  • ? Artemether Loading dose 3.2 mg/kg IM then
    maintenance 1.6
  • mg/kg IM. Do not give artemether IV,
    only orally, by suppository
  • or IM. Complete the therapy with oral
  • sulfadoxine/pyrimethamine

Treatment of Malaria
  • Uncomplicated disease 10m/kg quinine SALT by
    mouth three times daily x 7 days. Once parasites
    eradicated, change to tetracycline 4mg/kg PO four
    times daily OR doxycycline 3mg/kg PO once daily
  • Severe disease starting dose 20mg/kg quinine
    SALT IV over 2-4 hours THEN 10mg/kg infused over
    2 hours every 8 hours until tolerates oral
    medication (sulfadxine/pyrimethamine). If given
    IM, dilute to 60mg/ml and split between sites if
    volume exceeds 5ml
  • Give IV doses in 500ml of 5 glucose
    over 4 hours
  • Reduce rate if cardiac arrhythmias
  • Pregnant women quinine is the drug of choice.

Falciparum strains adjust to antibiotic pressure
  • Treatment of malaria must take into account local
    sensitivity to medications and shifts in parasite
    genome due to antibiotic pressure
  • Zongo (Lancet 2007) showed in children older than
    6 months in a 28 day RCT in Burkina Faso that
    risk of recurrent malaria was
  • amodiaquine sulfadoxine-pyrimethamine 1.7

Large family going to Mexico for daughters
wedding. They are worried about getting
travellers diarrhea
  • Advise on risks, precautions and treatment

  • Hand washing 30 seconds with soap
  • Boil, cook or peel, eat when piping hot. Avoid
    salads, ice cubes, food vendors, cans cooled in
    water (probably from a stream), shellfish,
    undercooked seafood
  • ? However, most travelers commit a food
    indiscretion within the first 72 hours due to
    being tempted by the sight of snacks, pre-paid
    buffets and the unavailability of hot food
  • ?Studies of US naval ships abroad showed the
    more indiscretions ashore (salads, ice in drinks,
    food vendors ) the more were on sick parade the
    next day with diarrhea.

  • 3. Take a micropore filter. Cryptosporidium can
    pass through a 1 micropore filter, so needs
    subsequent halogenation
  • Chlorine is less effective in acid or alkaline or
    cool water, so lengthen contact time (2 hours for
    Giardia, 10 minutes for bacteria). Resistance to
    halogenation increases from bacteria, viruses,
    protozoan cysts, bacterial spores to parasitic
    ova and larvae
  • Potassium Permanganate to wash fruit and veg
  • Kettle to boil water (boiling for 1 minute kills
    even Cryptosporidium

  • 6. Pepto-bismol 2 tablets qid reduces risk by
    65 (children gt 3 years 1 tablet qid)
  • ? Indications Prophylactic Pepto-bismol for
    a short trip Consider if immunocompromised,
    HIV, severe inflammatory bowel disease, renal
    failure, poorly controlled insulin dependent
    diabetes. Or of you are a conference speaker or a
    musical performer who must be well at a specific
  • ? Contraindications
  • (a) 2 tablets have the salicylate content of
    one 325 mg aspirin, so contraindicated if allergy
    to aspirin, bleeding disorder, taking warfarin,
    history of GI bleed.
  • (b) If taking doxycycline Pepto-bismol inhibits
    absorption of doxycycline (an important

  • 7. Dukoral cholera vaccine provides 60
    cross-over protection against ETEC.
  • 8. Antibiotics considering side-effects, best to
    use antibiotics for treatment in the case of
    diarrhea rather than prophylaxis

  • On a 3 week trip the indiscreet traveler is most
    likely to get diarrhea in the first week, and
    will need guidance about self-treatment.
  • gt60 is bacterial Most common is E. Coli, then
    Shigella, Salmonella, Campylobacter
  • Attack rate remains same in long-term travelers
    and expatriates for several years

Diagnosis of Travellers Diarrhea by Clinical
Presentation Watery diarrhea (60)
  • Mostly enterotoxigenic E. Coli also Salmonella,
    Campylobacter, Vibrios. Parasites such as
    Giardia, Cryptosporidium, Cyclospora and Isospora
    can cause watery diarrhea. 10 is viruses.
  • Symptoms last 3-5 days and range from several
    watery stools per day to more explosive profuse
    but non-bloody diarrhea. Some may have nausea,
    cramps, vomiting, low grade fever.

Diagnosis of Travellers Diarrhea by Clinical
Presentation Dysentery (15)
  • Usually Shigella. Other causes Salmonella,
    Campylobacter, Yersinia, E. Coli serotype
    0157H7, more rarely amebiasis.
  • Symptoms small volume stools with mucous, high
    fever, abdominal pain and tenderness,
    prostration, feeling of incomplete evacuation.
    Blood seen in only 50 of patients.
  • Treatment Treat all bloody diarrhea with
    antibiotics fluids to prevent dehydration.

Diagnosis of Travellers Diarrhea by Clinical
Presentation Chronic diarrhea, lasting gt 1 month
  • Usually Giardia or Campylobacter. In many cases
    tests are negative and is attributed to
    postinfectious lactose intolerance and IBS.
  • Symptoms vague abdominal pain, bloating, nausea,
    weight loss, low grade fever.

Treatment of Diarrhea while Travelling
  • 1. Oral rehydration
  • Severe dehydration. WHO is glucose based,
    CeraLyte is rice based. If not available, make
    your own with 1 teaspoon salt and 2 tablespoons
    sugar or honey in 1 L water. Continue to drink
    even if vomiting.
  • Moderate drink 3 L water/day, add soup salty
    crackers, avoid dairy
  • Mild infants - continue usual breast
    feeding/formula/ fluids

Treatment of Diarrhea while Travelling
  • 2. Loperamide 2 mg. capsules two STAT then 1
    capsule for every loose stool, max 16 mg/day
    reduces frequency of stools and duration of
    illness by 80 due to anti-motility and
    anti-secretory actions.
  • Young children are more susceptible to side
    effects drowsiness, vomiting and paralytic
    ileus. Not approved for children lt 2 years.
  • 3. Pepto-bismol (do not exceed 16 tablets/day)
    reduces diarrhea by 50 because of
    anti-peristaltic and anti-secretary effects.

Treatment of Diarrhea while Travelling
  • 4. Antibiotics If copious or bloody stools, or
  • ? Ciprofloxacin 750 mg once or 500 mg bid.
    If unwell continue for a total of three days.
  • Resistance 90 in Thailand, 50 Nepal, 40
  • ? Alternatives
  • Levaquin 500 mg once or 500 mg daily x 3
  • Azithromycin 1000 mg once or 500 mg daily
    for 3
  • days (also effective against Shigella,
    Salmonella, E.
  • Coli, Campylobacter and typhoid fever.
    In Thailand
  • more effective against Campylobacter
  • ciprofloxacin.
  • ? Flagyl 250 mg tid x 5-7 days if you
    consider you may
  • have Giardia and cannot get medical
    help. Do not
  • use with alcohol.

Treatment of Diarrhea while Travelling
  • Treat all bloody diarrhea with antibiotics.
  • Treat pregnant women with ciprofloxacin, best
    alternative is azithromycin.
  • Consider whether the rapid diarrhea is limiting
    antibiotic absorption.

Returning travellers
  • how many will have symptoms?
  • Which symptoms are most frequent?

Returned travellers
  • Freedmans (NEJM 2006) study of 17,353 ill
    returned travellers from 30 GeoSentinel sites in
    developing countries
  • per 1000
  • Systemic febrile illness 226
  • Acute diarrhea 222
  • Dermatologic disorder 170
  • Chronic diarrhea 113
  • Nondiarrheal GI disorder 82
  • Respiratory disorder 77
  • Death 1

Returned travellers basic approach to diagnosis
  • Detailed history of symptoms
  • if persistent fever malaria thick and thin films
    and repeat in 12-24 hours
  • Detailed history of itinerary and exposures
  • Careful physical exam
  • CBC, LFTs, creatinine, electrolytes (if had
    diarrhea) (hepatitis Ags and Abs as appropriate)
  • 2 fresh stools

Investigation of prolonged diarrhea (gt 14 days)
  • 2 fresh stools for
  • Parasites Giardia, Cyclospora, Cryptosporidium,
    Microsporidum, Entamoeba histolytica
  • Bacteria Enteropathogenic E. Coli, Shigella,
    Salmonella, Aeromonas, enteroaggreagative E.
    Coli, noncholera Vibrios
  • If all tests negative, consider ciprofloxacin 500
    mg tid x 5 days if not yet given, then flagyl 250
    mg tid x 7 days
  • If diarrhea continues, sigmoidoscopy or upper GI
  • A few patients progress to IBS after Campylobacter

Investigation of persistent fever without focal
disease Blood cultures
  • Bacterial endocarditis
  • Bacterial sepsis
  • Bartonellosis
  • Brucellosis
  • Leptospirosis
  • Listeriosis
  • Meliodosis
  • Meningococcemia
  • typhoid

Investigation of persistent fever without focal
disease blood or CSF for parasites
  • Babesiosis
  • borreliae
  • African and American trypanosomiasis
  • malaria
  • microfilariae
  • visceral leishmaniasis
  • loiasis

Investigation of persistent fever without focal
disease serology
  • Cytomegalovirus
  • Epstein-Barr
  • viral hepatitis
  • Leptospirosis
  • Rickettsiae
  • viral hemorrhagic fevers
  • Dengue
  • syphilis
  • relapsing fever
  • toxoplasmosis

You are going to work as a physician in a
SubSaharan country (Sudan) for 2 years What can
you contribute?
  • Train health professionals
  • Be able to do and teach a safe C-section and
    vacuum delivery
  • Reduce infectious disease risks by public health
  • Involve other experts in increasing food
    production in each household
  • Encourage an organisation to come in and start
    small loans to households to start businesses
    (Gramin banks)

Sudan Infectious Diseases Arthropod borne
  • malaria (except above 2600 m)
  • filariasis
  • onchocerciasis (river blindness)
  • cutaneous and mucocutaeous leishmaniasis
  • visceral leishmaniasis
  • trypanosomiasis (sleeping sickness)
  • relapsing fever
  • louse- flea- and tick-borns typhus
  • Tungiasis
  • viral hemorrhagic fevers (from mosquitoes,
  • ticks, sand flies)
  • Yellow Fever

Sudan Food and water-borne infections
  • helminths
  • bacterial diarrhea typhoid
  • hepatitis A and E
  • hepatitis B
  • cholera

Sudan Food and water-borne infections Helminths
  • Metazoa
  • Flat worms Round worms

  • (nematodes)
  • Cestodes Trematodes
  • (tape worms) (flukes)

Sudan Food and water-borne infections
Helminths nematodes (round worms)
  • Ascaris lumbricoides
  • Trichuris trichiura
  • Enterobius vermicularis
  • Stronglyoides
  • Ancyclostoma duodenale
  • Necator americanus
  • Trichinella spiralis
  • Wucheria bancrofti
  • Loa loa
  • Onchocerca volvulus

Sudan Food and water-borne infections
Helminths Cestodes (tape worms)
  • Taenia solium
  • Taenia saginata
  • Echinococcus granulosus
  • Echinococcus multilocularis

Sudan Food and water-borne infections
Helminths Trematodes (flukes)
  • Schistosoma haematobium, mansoni and japonicum
Write a Comment
User Comments (0)