Travel medicine Flashcards
How may international travel upset a person’s equilibrium making them susceptible to disease?
- sudden exposure to sig changes in altitude, humidity, microbial flora, sunlight, and temperature, exacerbated by stress and fatigue, may result in ill-health and an inability to achieve purpose of travel
What are key factors determining health risks to which travelers may be exposed?
- destinations
- duration of visit
- purpose of visit
- std of accommodation and food hygiene
- behavior of traveler
What are some pre-trop recommendations?
- basic medical kit
- analgesics (acetaminophenm aspirin, ibuprofen)
- abx for self-tx of diarrhea (chipper, azithro)
- anti-diarrheals: bismuth subsalicylate (pepto), loperamide (imodium)
- antihistamines
- antimalarials
- antinausea/motion sickness (benedryl, dramamine) meds
- sleeping meds
- insect repellent
- water purifier or tablets
- cold/sinus/cough med
- sunscreen
- wound dressings
- antiseptic
Pre-travel consultation with pt?
- risk assessment: itinerary
traveler demographics, emphasis on not traveling while sick - discussion with pt: vaccinations, prophylaxis, specific advice about self tx (traveler’s diarrhea), pre-tx of chronic health issues
Medical planning: determine destination?
- investigate specific risks associated with that region
- ID travel clinic that can acquire specific vaccines read
What enivironmental precautions should you be aware of?
- air travel
- jet lag (melatonin)
- sun protection
- extreme heat and cold: dehydration, heat stroke, hypothermia, frostbite
- altitude
- water recreation
Food and water precautions?
- bottled water!!!
- selection of foods: well cooked and hot
- avoid: salads, raw veggies, unpasteurized dairy products, street vendors, ice
Pre-existing health status concerns?
Flying:
CVD: less than 3 weeks post MI, longer “wait” following complicated courses, 2 weeks post CABG
pulmonary disease: 2-3 weeks post chest tube removal, PaO2:
What vaccines should be up to date?
- polio
- Hep A and B
- meningococcal
- influenza
- tetanus, diptheria, pertusis
- MMR
- Varicella
Vaccines you may need?
- Typhoid
- yellow fever
- rabies
- japanese Encephalitis
- cholera
- tick-borne encephalitis
- TB
When should you have Hep A vaccine?
endemic areas- Asia, central America, Africa, Mexico, caribbean
Motion sickness prophylaxis?
- meclizine
- promethazine (need Rx)
- Transdermal scopolamine (Rx)
- most must be taken before trip
- prometh. works after sxs start
- drowsiness can be sig
Why does jet lag occur?
- disturbance of circadian rhythms due to crossing time barriers
- sxs: fatigue, irritability, nausea, difficulty concentrating
Destination altitude sickness sxs?
- HA and one or more of the following:
- nausea
- vomiting
- fatigue
- malaise
- insomnia
- due to relative hypoxemia and delay in development of compensatory erythrocytosis
Acute mountain sickness?
- usually acclimatization occurs in 2-3 days
- 30% incidence at 3000 M, 75% at 4500 M
Prevention of altitude sickness?
- gradual ascent - 300 M/day
- spend a few days at intermediate altitudes
- slowly ascend at > 2500 m
- spend an extra night for every 600-900 m if continuing to ascend, climb high and sleep low
- avoid alcohol and sedative hypnotics
High altitude pulmonary edema (HAPE)
- combo of low hypoxic ventilatory drive and over perfusion
- young physically fit males most susceptible
sxs: weakness, decreased exercise performance, chest congestion, dyspnea, wheezing
signs: wheezing, crackles (rales), cyanosis, tachycardia - must have 2 signs and 2 sxs for dx
TX of HAPE?
- Rx: Diamox aka
- acetazolamide: mild diuretic that increases amount of excreted bicarb, which in turn increases the blood pH which in turn causes you to hyperventilate which increases O2 saturation.
- steroids: dexamethasone
- Nifedipine: decreases pulmonary hypertension, improves oxygen saturations
High altitude cerebral edema (HACE) signs and sxs?
- Hallucinations
- focal near signs
- seizures
- stupor
- coma
- MEDICAL emergency: pts need high flow O2 and prompt descent to lower altitude
- dexamethasone to reduce edema
- can have HACE and HAPE simultaneously
What are you worried about with snorkeling and diving?
- stings and envenomization
- coelenterate family:
sea urchins, jellyfish, anemones, portuguese man-o-war - release nematocysts from tentacles
- tx with vinegar
Tx for sea bathers eruption (sea lice)
- papulovesicular rash caused by larvae of coelenterates
Rx: shower, soak affected part in vinegar, throw away bathing suit, more susceptible after initial infestation: future infestations can cause severe allergic rxns
Where can you get cholera?
- 0-5 cases per year in US, major cause of epidemic diarrhea throughout the developing world. Its an ongoing global pandemic in Asia, Africa, and Latin America for the last four decades
Sign of cholera?
- rice water diarrhea
- vomiting, circulatory collapse and shock. Many infections may only have milder diarrhea or be asymptomatic
- prognosis: 5-50% typical cases are fatal if untx
Prevention of cholera?
routine immunization isn’t recommended for conventional travelers from US, although vaccination is approp. for aid and refugee workers to endemic areas in high risk situations
Prevention/tx of cholera?
- natural infection and currently available vaccines offer incomplete protection of relatively short duration, no multivalent vaccines available
- simple rehydration tx saves lives, but logistics of delivery in remote areas remains difficult during epidemic periods
- adjunct abx tx is helpful but may be difficult b/c of growing antimicrobial resistance
- natural reservoir in warm coastal waters makes eradication very unlikely
Locations of Hepatitis A and B
- worldwide: can be isolated cases or epidemic
- 1.25 million chronic Hep B infections in US
Signs of Hepatitis?
- jaundice, fatigue, abdominal pain, loss of appetite, nausea, vomiting, joint pain, 30% asymptomatic
Tx of Hep B?
- Adefovir, dipivoxil, interferons, lamivudine, entecavir, and telbivudine used for tx of chronic Hep B
- new txs: high cure rates -> Harvoni
Typhoid?
infection with salmonella typhi
- 16 mill cases & 600K deaths/year
- mainly in undeveloped countries with contaminated water supplies
sxs and tx of typhoid?
- high fever
- rose colored rash***
- abdominal pains
- diarrhea
- tx: ampicillin, SMX/TMP, cipro
locations of typhoid?
- greatest risk for travelers to S. Asia, developing countries in Asia, Africa, Caribbean, and Central and S. America (approx. 400 cases occur in US/ year 75% international travel)
Signs of typhoid?
high fever 103-104
- HA, malaise, anorexia, splenomegaly, rash of flat rose-colored spots and bradycardia
- many mild and atypical infections occur
Prognosis of Typhoid
- life threatening if left untx
Tx/prevention of typhoid?
- vaccination recommended for those who will be traveling in rural areas
- travelers should be cautioned that none of avail. vaccines are 100% effective
(not a sub. for careful selection of food and drink) - specific antimicrobrial therapy shortens clinical course and reduces risk of death.
How is typhoid spread?
- lives only in humans in intestinal tract and blood
- spread oral/fecal route: raw fruits and veggies, milk and shellfish
- small number of carriers: both ill and carriers can shed bacteria in their stool
Typhoid vaccines?
- injectable: contains inactivated polysaccharide ag
(given as single IM injection, single dose is adequate) - oral: live virus -> one enteric coated capsule in four doses
How long does immunity last with typhoid vaccine?
- IM: 2 years
- oral: 5 years, after 5 years get a booster
CIS and precautions of Typhoid vaccine?
- severe allergic reaction to vaccine component or following a prior dose
- immunosuppression
- moderate or severe acute illness: acute GI illness
- pregnancy
- age
Yellow Fever
- acute viral hemorrhagic disease
- RNA virus in the Flavivridae family
- transmitted by mosquitoes
- found in Africa, S. American with several epidemics in the 19th century
- 200,000 estimated cases of yellow fever/year
- 90% of infections occur in Africa
Signs of Yellow Fever
- infection ranges from asymptomatic (5-50% of cases) to hemorrhagic fever
- onset is Sudden with fever 39-40 C. Chills, HA, dizziness, and myalgias
- Pulse first tachycardic - gets bradycardic (facets sign*****)
- face will be flushed and eyes will be injected, N/V, constipation, severe prostration, restlessness, irritability are common.
Clinical features of Yellow Fever
- incubation period: 3-6 days
- 85% of cases will have only midl sxs including:
fever, HA, chills, back pain, N/V, loss of appetite - 15% will enter a second, toxic phase with recurring fever accompanied by other sxs
- toxic phase is fatal in approx 20-50% of cases
- surviving the infection results in life-long immunity and normally there is no permanent organ damage
Tx of Yellow fever?
- up to 20% mortality
- tx mainly supportive
- bleeding may be tx with Ca gluconate. Prophylaxis against GI bleeding with a proton pump inhibitor or H2 blocker
- prevention: reduce number of mosquitoes and limit mosquito bites by using DEET mosquito netting and protective attire
Yellow Fever vaccine recommendations?
- attenuated live vaccine
- single dose is adequate
- lasts 10 years
- recommended for pts traveling to affected areas over age of 9 months, people living in endemic areas b/t 9-12 months, lab personnel who might be exposed to virus or vaccine virus
- bed netting, mosquito repellant recommended
SEs of vaccine: HAs, fever, myalgias
CIs and precautions for Yellow Fever vaccine?
- immunosuppression
- thymic disorders
- age
Malaria?
- parasitic infection transmitted by mosquitoes: Plasmodium falciparum, P. Vivax, P. ovale, P. malariae
- > 1 mill deaths/year
- transmitted by anopheles mosquito
signs of malaria?
fever, chills, sweats, HAs, muscle pains, N/V, severe malaria caused by P. falciparum - confusion, coma, neuro focal signs, severe anemia, resp. difficulties, dx by direct visualization and Ag detection
Prophylaxis for malaria?
- bed nets tx with permethrin, insecticides, and antimalarial drugs:
Atovaquone/proguanil (malarone), cholorquine (some strains resistant), doxy (works well), Mefloquine (Larium): cause hallucinations
Clinical manifestations of Malaria?
- cyclic fevers
- anemia: erythrocyte destruction
- hepatosplenomegaly
- capillary occlusion
- intravascular hemolysis (blackwater fever)
- dormant sporozoites.. recurrent lapses
Dx of malaria?
- thick/thin smears
- serologic tests
Tx of malaria?
- Atovaguone/proguanil (Malarone)
- Artemether/Lumefantrine (coartem)
What is schistosomiasis?
- 200 million worldwide infected
- parasitic infection caused by trematodes (parasitic freshwater worms that live in snails)
Clinical picture of schistosomiasis?
- dermatitis
- katayama syndrome: fatigue, malaise, fever, cough, hepatosplenomegaly
- clinical manifestations may not show up for several weeks post exposure
- chronic infection can cause CNS disease, colon polyps, bloody diarrhea
Dx of schistosomiasis?
- thick stool smears reveal eggs
- eosinophilia on peripheral blood smear
- serologic testing- IFA available
Tx of schistosomiasis
- praziquantel-quinolone
- oxaminiquine
Fish (scrombroid) poisoning
- scrombroidea family: tuna, mackerel, albacore
- poor fish preservation causes decarboxylization of histidine to histamine
- illness begins 90 min and lasts for up to 12 hrs after ingestion
- flushing, tachycardia, N/V
Tx of Fish (scombroid) poisoning
supportive care, antihistamines, epi
non scrombroidea fish poisoning
- mainly in caribbean
- ciguatera poisoning from fish that have ingested dinoflagellates
- competitive inhibitors of Ca channels
- sxs occur w/in 24 hours: Gi- nausea, vomiting, diarrhea
neuro paresthesias: pruritus, tremors, fascicultations - ***temp reversal burning of skin exposed to cold is classic sx
Shellfish poisoning?
- caused by saxitoxin after algae blooms
- incubation hours to days
- dx made when 2 sensroy and 2 motor sxs are found in pts with approp. hx: sensory - numbness, dizziness, paresthesia, HA, dysethesia, pruritus
motor dysphagia: paralysis, paresis, dyspnea, diplopia, dysphonia - mortality rate: 2-20%
What is the biggest risk for travelers?
- travelers diarrhea
Traveler’s diarrhea?
- can be from parasites or other organisms
- most commonly from diff. strains of E. coli
- prevention and tx:
Pepto bismol
loperamide
cipro
azithro
Epidemiology of Travelers’ diarrhea
bacterial: 80-90%
viral: 5-10%
parasitic: >/10%
Signs of travelers’ diarrhea?
- onset usually w/in first week
- abrupt with increasing frequency and volume of stool
- 4-5 loose stools/day: also N/V, abdominal cramping, bloating, fever, urgency, malaise
- most resolve 1-2 days w/o tx
Cause of travelers diarrhea and what to avoid?
- bacterial enteropathogens: E. coli
prevention/avoid: street vendor foods/drinks, raw/undercooked meats, raw fruits and veggies
Prophylaxis for travelers’ diarrhea?
- bismuth subsalicylate (pepto)
antibacterial and antisecretory
Tx of travelers’ diarrhea?
- replacement fluids/electrolytes: mostly clear fluids
- antibiotics: N/V, cramping, bloody stools, fever
- anti motility agents
- loperamide (imodium): not for blood stool!!!! Reduces duration of diarrhea
rabies?
- caused by the rabies virus: almost always fatal
- RNA virus: part of Rhabdoviruses
- virus is transmitted through a bite or scratch from an infected animal. These are the most common species: raccoons, skunks, foxes, coyotes, bats
What country has the most rabies cases?
India has about half of all rabies cases worldwide
clinical features of rabies?
- prodrome: HA, fever, rhinorrhea, sore throat, myalgias, GI upset, back pain, and muscle spasms
- agitation and anxiety may result in dx of psychosis or intoxication
- paresthesias, pain or severe itching at site may be first near sx
- over several days symptoms progress
Two forms of rabies?
- furious/encephalitic forms: agitation, hydrophobia, extreme irritability, hyperexcitability periods fluctuate with lucidity: pt will exhibit: tachycardia, tachypnea, fever
- dumb or paralytic rabies: similar to Guillain-Barre
- prominent limb weakness. Consciousness initially spared
the 2 forms can overlap or progress from one to the other
- coma after one week of neuro sxs with death a few days after
Rabies vaccine:
inactivated vaccine, pre-exposure vaccine should be offered to people in high risk groups
(anyone who is likely to come in contact with rabid animals
- immediate access to approp. medical care is limited
Post-exposure vaccine is recommended for who?
- all individuals who have had contact with animal (bites or abrasions) that they believe may be or which is proven to be rabid
- unvaccinated: 4-5 doses in 2-4 weeks + RIG
- vaccinated: 2 doses, no rabies immunoglobulin
Rabies vaccine CIs and precautions
- hypersensitivity
- moderate or severe acute illness
- immunocompromised and pregnant women who are exposed to rabies may receive vaccine
What is Japanese encephalitis?
- mosquito borne flavivirus
- most common vaccine preventable cause of encephalitis in Asia
- RNA virus
- 35,000-50,000 cases annually (less than 1 case / year in US)
Clinical features of JE
- incubation period: 6-8 days
- most asymptomatic or mild signs
- acute encephalitis: HA, high fever, stiff neck, stupor
-severe encephalitis: paralysis, seizures, convulsions, coma and death
Neuropsychiatric sequelae: 45-70% of survivors - in utero infection possible: abortion of fetus
JE vaccine
- inactivated Vero Cell Culture - derived vaccine
- recommended for those at increased risk such as: lab workers, travelers spending more than one month in endemic/epidemic areas during transmission season
- 2 doses (days 0, 28)
TB
caused by bacteria Mycobacterium tb
- 2 types of infection: active or latent
- respiratory transmission: it is currently estimated that 1/3 of world pop is infected with TB (doesn’t mean it is active)
- with increased incidence of AIDS, TB #s have increased in US
Clinical features of TB
- cough, hemoptysis
- persistent fever/night sweats
- wt loss
- malaise
- adenopathy
- pleuritic chest pain
Complications with TB
- w/o tx may be fatal. Untx active disease typically affects the lungs but it can spread to other parts of body causing: pneumothorax bronchiectasis cardiac aneurysms meningitis renal failure
TB vaccine
- BCG live strain
- lasts 10 years
- given intradermally
Who should receive the TB vaccine?
- newborns and health care workers in countries where TB prevalence is moderate to high, close contacts of pts with TB
- in countries where prevalence is low, not recommended that health care workers get vaccine unless in close contact with pts from endemic countries
TB vaccine CIs and precautions
- hypersensitivity
- moderate or severe acute illness
- immunosuppression
- pregnancy is CI
- local skin reactions are common
Summary of recommendations for traveling
- follow recommendations for destination
- begin vaccinations early
- find travel clinic for immunizations
- plan ahead if you are traveling with children or have other special needs or chronic illnesses
