13 - Travel Infections Flashcards
What 2 infections are we focusing on?
1) Traveller’s diarrhea
2) Malaria
_____ is the biggest cause of GI illnesses in travellers
Giardia
VFR
visiting friends and relatives
Why are VFR traveller’s more likely to get sick?
-they believe that if they used to live there, they won’t get sick when they go back
What are numerator factors?
-traveller has returned home before S & S develop, mild symptoms may not be reported, multiple locations visited making it difficult to know where disease was contracted
What are denominator factors?
Knowing the # of travellers to a specific location may be difficult to know accurately
What is TD (traveller’s diarrhea) ?
- Diarrhea associated with travel
- Most predictable travel-related illness
- Affects 30-70% of travellers, depending on destination and season
Mild (acute) TD
- diarrhea that is tolerable
- it is not distressing (no blood in stool or fever)
- does not interfere with planned activities
Moderate (acute) TD
-diarrhea that is distressing or interferes with planned activities
Severe (acute) TD
- diarrhea that is incapacitating or completely prevents planned activities
- all dysentery is considered severe
Describe the etiology of TD
-Contaminated food and/or water
_____ are the most common cause of TD (80-90%)
Bacteria (most commonly E. coli)
____ pathogens are the 2nd most common cause of TD
Viral
Bacterial and viral TD present with a sudden onset of bothersome symptoms - such as ?
- mild cramps
- urgent loose stools
- severe abdominal pain
- fever
- vomiting
- bloody diarrhea
With ______, vomiting may be more prominent
norovirus
Untreated bacterial diarrhea usually lasts ____ days
3-7
Viral diarrhea generally lasts ____ days
2-3
_____ pathogens are the least common cause of TD (less than 5%)
Protozoal
____ is the main protozoal pathogen found in TD
Giardia
Protozoal pathogens:
Incubation period is generally ____ weeks and may persist for weeks to months if not treated
1-2
Low risk areas for TD include ?
- US
- Canada
- Australia
- New Zealand
- Japan
- Northern and Western Europe
Intermediate risk areas for TD include ?
- Eastern Europe
- South Africa
- some Caribbean islands
High risk areas for TD include ?
- Asia
- Middle east
- Africa
- Mexico
- Central and South American
Low risk area incidence rate
8%
Intermediate risk area incidence rate
8-20%
High risk area incidence rate
> 20%
What are some patient related risk factors for TD ?
- TD occurs equally in male and female travellers and is more common in young adult travellers than in older travellers
- Very young travellers are at high risk of severe and/or prolonged TD
- The highest risk is observed with patients with immunocompromised conditions, achlorhydria, IBD, and people with chronic debilitating medical conditions
- More common in travellers from low TD risk (ex. Canada) travelling to moderate or high risk countries (ex. Mexico)
What are the destination related risk factors for acquiring TD ?
- Environments in warmer climates where access to modern pluming is low, the amount of stool contamination in the environment will be higher and more accessible to flies
- Inadequate electric capacity may lead to frequent blackouts and poor fridge function
- Lack of safe water
- Handwashing may not be social norm
- Risk regions (ex. Mexico, Africa, South America, etc.)
What foods are considered higher risk for TD ?
- raw or undercooked food such as meat, fish, shellfish
- salads, uncooked vegetables, unpasteurized fruit juices, unpasteurized milk or cheese
- raw fruits that are eaten unpeeled (such as berries)
- Food/bev from street vendors
- Tap water (including fountain drinks or ice made from tap water)
What is the saying to remember to prevent TD ?
boil it, peel it, cook it, or forget it !!!
What is the safest way to feed an infant < 6 months ?
breastfeed exclusively
What if an infant is formula fed ?
formula should be reconstituted with hot water at a temp of > 70
List 3 non-Rx options for prevention
- Bismuth subsalicylate
- Probiotics
- Dukoral
Bismuth Subsalicylate:
dose ?
524 mg PO QID
Bismuth Subsalicylate:
Safe for prevention for up to a ______ period
3 week
Bismuth Subsalicylate:
Disadvantages?
- inconvenient dosing
- possible salicylate toxicity
- cannot be used in anyone under 18 or pregnant women
Bismuth Subsalicylate:
Drug interactions ?
- salicylates
- blood thinners
- meds used in GOUT (methotrexate)
Bismuth Subsalicylate:
Caution in ppl with ?
renal impairement
Bismuth Subsalicylate:
__% reduction in TD from studies done in travellers to Mexico
50%
Probiotics (Lactobacillus GG and Saccharomyces boulardii):
Effective in prevention of TD?
- studies are inconclusive
- insufficient evidence to recommend use
Dukoral:
Describe it
- Oral, inactivated TD and cholera vaccine
- No Rx required
- 2 doses, separated by 1 week and is effective 1 week after the 2nd dose.
- Protection against TD lasts for 3 months.
- A booster every 5 years will remain protection
Dukoral:
Indicated for ?
children 2 yrs and up and adults who want protection from E. coli and/or cholera
Dukoral:
Effective?
effectiveness not been documented
Dukoral:
Safe ?
yes
Dukoral:
Price ?
around $100
Dukoral:
Who do you think would be interested ?
backpackers, immunocompromised, ppl with IBS, ppl with low acid production
When is it appropriate to use antibiotics as prophylaxis for TD ?
- Patients at high-risk for serious infections or complications such as immunocompromised patients
- Travellers who are travelling for a short period of time who can tolerate any down time (diplomats high level athletes, professionals presenting at a conference)
What antibiotics are used as prophylaxis in TD ?
FQ’s
Cipro or Levo
Goals of treatment of TD ?
- Prevent dehydration and replace fluids (oral rehydration therapy)
- Decrease duration and severity of symptoms
- Minimize impact of travel
List 3 agents that can be used to treat TD
1) Loperamide
2) BSS
3) Antibiotics
Loperamide for TD:
Describe it
- symptomatic relief
- useful adjust to antibiotics
- antimotility and antisecretory properties
- not recommended for patients with blood in the stools or those with a fever if used alone
Loperamide for TD:
Dose for adults
4 mg stat then 2mg after each loose stool (max 16 mg/day)
Loperamide for TD:
Dose for ages 3-5
1-2 mg PO initially, then 1-2 mg after each loose stool
max 3 mg daily
Loperamide for TD:
Dose for ages 5-8
1-2 mg PO initially, then 1-2 mg after each loose stool
max 4 mg daily
Loperamide for TD:
Dose for ages 8-12
1-2 mg PO initially, then 1-2 mg after each loose stool
max 6 mg daily
BSS for TD:
dose
524 mg q30 mins
Max 8 doses/day
Antibiotics for TD:
If prophylactic antibiotics were used and TD occurs, can you repeat treatment with the same antibiotic ?
No - a different AB needs to be used for treatment
Antibiotics for TD:
2 first line options ?
Cipro
Levo
Antibiotics for TD:
Dose of Cipro
500 mg BID x 3 days
or
750 mg QD x 1 dose
Antibiotics for TD:
Dose of Levo
500 mg QD x 3 days
or
1000 mg QD x 1 dose
Antibiotics for TD:
Who might Azithromycin be preferred in?
certain patients (allergies, pregnancy, children and breastfeeding) and regions because of resistance
Antibiotics for TD:
Dose of Azithro for adults
500mg QD x 3 days
or
1000mg x 1 dose
Antibiotics for TD:
Dose of Azithro for children
5-10 mg/kg QD x 3 days
max daily = 500 mg
Antibiotics for TD:
When might SMP-TMX be considered?
It is 3rd line due to resistance and should only be considered if other options are CI and there region is known to NOT exhibit resistance
Antibiotics for TD:
Dose of TMP-SMX for adults
800/160mg BID x 3 days
or
1600/320 mg x 1 dose
Antibiotics for TD:
Dose of TMP-SMX for children
20-25 mg/kg SMX
4-5 mg/kg TMP
BID x 3 days
Describe the therapy of mild TD
- Antibiotic treatment not recommended
- Loperamide or BSS may be considered
Describe the therapy of moderate TD
- Antibiotics may be used
- Loperamide may be used as adjunctive therapy or monotherapy
When would you not use Loperamide as monotherapy ?
if there’s fever or blood in the stools
Describe the therapy for severe TD
- Antibiotics should be used
- Azithromycin is preferred
What important non-pharm advice for TD ?
Be cautious about what he’s eating and drinking, hand hygiene is also important
What non-Rx items are available to prevent TD?
- BSS
- Dukoral
**loperamide is to treat, not to prevent
Is Azithromycin safe in pregnancy ?
yes
Malaria:
Human disease caused by ___ protozoan parasites of the genus “Plasmodium”
5
Malaria:
Symptoms ?
- fever
- flu-like symptoms
- chills
- headache
- myalgias
- malaise
Malaria:
Uncomplicated disease may be associated with ?
- anemia
- jaundice
Malaria:
In severe disease, may have ?
seizures, mental confusion, kidney failure, acute respiratory distress, syndrome, coma and death may occur
Malaria:
Symptoms can develop as early as ____ days after initial exposure
7 days
usually > 14 days
Malaria:
The parasite is transmitted by the bite of an infected female ______ mosquito
Anopheles
Malaria:
Anopheles female mosquitos must take a blood meal to develop her eggs and she hunts from ?
dusk until dawn
Dusk til dawn feeds normally bite when?
at night
Malaria:
Transmission may rarely occur by ?
blood transfusion, organ transplantation, needle sharing or congenitally from mother to fetus
Antimalarial medications:
Do these medications stop a person from becoming infected?
NO - these meds do NOT stop a person from becoming infected with the parasites that cause the disease, but rather eliminate the parasites during their different life cycles either in the liver or in the RBC
_____ or _____ may remain dormant in the body for months of years after initial infection
P. vivax
P. ovale
Infections caused by ______ are the most likely to progress to severe, potentially fatal forms therefore when the decision is being made on which antimalarial medicine to choose, the main focus is on providing protection against _______
(same word)
P. falciparum
Non-pharms to dealing with malaria
- window and door screens
- loose fitting and long-sleeved shirts and long pants in light colors
- mosquito repellent
- pyrethrin insecticides
- bed nets, preferably treated with permethrin
When do you refer malaria?
- ASAP
- malaria can be fatal
Read malaria prevention notes
okay
