Transcript Wilderness Medicine Pearls

Health, Hygiene & Sanitation
in Remote Areas
Remote Areas Emergency Medicine and Survival
Preventative medicine
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Preplanning
Environment
Temp / terrain
 Pathogens / vectors
 Social / legal
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Water
Food
Toilet
Preplanning
Detailed risk assessments and planning to counter
identified health threats
Preplanning example
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Bangladesh.
-viral illness in airport
-Traffic accidents- use local drivers, use American,
Toyota, Mercedes vehicles only.
-Malaria- doxycycline prophylaxis, DEET, permetherin,
educate on S/S
-parasites- no swimming in fresh water
-violence- terrorist, criminal, quasi police, food riots
Focus on real risks not
sensationalism
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“On a typical trip to Everest base camp traffic
accidents enroute from the airport to the start of
the walk are a greater risk than the climb”. -Paul
Auerbach, MD July 08
North American Wilderness Summer
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Minor trauma, orthopedics
Contact dermatitis, sunburn
Food / water / hand washing
contamination
major trauma auto, quad, motorcycle, falls,
logging, aircraft
Heart attack, stroke, seizure etc…
Heat/cold injury/exposure/dehydration
Drowning / technical rescue environment
Penetrating trauma, logging, criminals,
animals, snakebite
Exotic: lightning, west nile, diving, altitude
Sources of information for international travel
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Local newspapers
Missionary groups, NGO
Local physicians
Ministry of health publications
Remember to focus on regions regardless of borders.
Local info is the best, sometimes local treatments may
be better
CDC Yellow book
WHO essential drugs list
Evacuation plans
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Primary
Alternate
Contingency plans
Emergency
P air travel with visa
A maritime travel or paid driver to border country.
Hired medical evac service
C consulate, shelter in place, local hospital
E local clothes, stow away on train, boat
Planning on the spot
Check own pulse first, often you have time
Size up the whole situation
Undue haste makes waste
Remember where you are
Vanquish fear and panic
Improvise
Value living
Act like the locals
Learn skills before the crisis, rehearse
actions
Stinging Insects avoid or eradicate
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Mosquitoes: West Nile virus, Yellow fever, Malaria, Dengue Fever, Filariasis,
Encephalitis, Eastern Equine Encephalitis and Japanese Encephalitis. deet
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Sand Flies: Oroya fever, Leishmaniasis, pappataci fever virus, kala azar, Oriental
sore, espundia, and bartonellosis Permetherin
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Tsetse Flies: Sub-Saharan Trypanosomiasis (African Sleeping Sickness) picardin,
deet.
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Black Flies: tropics and subtropics filariasis
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Biting Midges: visceral filariasis.
Bot Flies: vaseline
Ants: premetherin paint
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picardin, deet.
Permetherin
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Ticks: Lyme disease, African tickbite fever, Aneruptive fever, Australian
spotted fever, Far Eastern spotted fever, Flinders Island spotted fever, Thai
tick typhus, Lymphangitis associated rickettsiosis, Maculatum infection,
Mediterranean spotted fevers, North Asian tick typhus, Oriental spotted
fever, Queensland tick typhus, Rocky Mountain spotted fever, Sao Paulo
exanthematic typhus, Minas Gerais exanthematic typhus, Brazilian spotted
fever, Tick-borne lymphadenopathy (TIBOLA), Dermacentor- borne necrosis
and lymphadenopathy (DEBONEL), Unnamed rickettsiosis, Q fever,
Ehrlichosis and Anaplasmosis.permetherin
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Mites:
Rickettsialpox and Scrub typhus, Scabies, Chiggers Lindane Permethrin
5% Sulphur 4% Malathion
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Fleas:
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Lice: Epidemic typhus, Sylvatic typhus and Trench fever
Spiders: premetherin paint or string
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Plague, Epidemic typhus, Sylvatic typhus, Cat flea rickettsiosis,
Murine typhus and Cat-scratch disease. Bug bomb
RID,
Diptera: big fancy word for mosquito
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Many problems can be easily mitigated by
proper insect control measures
Worldwide, mosquitoes transmit diseases to
700,000,000 annually
Malaria kills 3,000,000 annually
Mosquitoes will cause the deaths of 1 out of 17
people now alive
Skin products
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Deet 50% or greater in standard formulation reapply q 4 hours.
Cumulative absorption. Increased absorption with sunscreen (in
monkeys)
Lower % in controlled release. Lasts longer less absorbed
In Queensland rainforest field trial:
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Picaridin 19% gave 95% protection > 9 hr
Picaridin 9% gave 95% protection > 2 hr
DEET 20% (Sawyer) 95% protection > 6 hr (Scheinfeld. J Drugs Dermatol 3:59,
2004)
Eucalyptus very weak for 2-3 hours (controversial)
Bite blocker, 97% protection against Aedes 3.5 hours after
application (U Guelph, Ontario, Canada)
DEET
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Complete protection from Aedes aegypti:
OFF 23.8% DEET
 Controlled Release 20% DEET
 Soybean Oil 2%
 Citronella 10%
 Avon SSS Bath Oil
 DEET wristband 9.5%
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15 Volunteers, Arm-in-Cage Design (Fradin & Day NEJM 2002)
302 min
234 min
95 min
20 min
10 min
0.2 min
Permethrin on clothing
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Long lasting. Persists after washing. Light stable
Nongreasy. Nearly odorless
Skin transfer .0006 mg/kg/d (Snodgrass ’92)
Rapidly metabolized. No tissue accumulation
Not carcinogenic. Not mutagenic
In clothing provides 74% protection against chiggers
(Breeden et al ‘92)
In clothing more effective than DEET against ticks
(Evans et al ‘90)
Permethrin
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Sheep dip permethrin (non FDA) on outer
clothing. Mix solution dunk and dry
(swartz and team 08
Bangladesh no bites, we lived)
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May spray window screens, bednets, door
sills, twine around sleeping, paint strip, tent,
sleeping pad, ER/OR, shoes, etc…
Sawyer products also has spray on
premetherin (FDA aproved)
Permethrin bug bombs (raid) for rooms.
Hang your clothes out in room
Mechanical barriers
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Bed nets with permethrin
Window screens with permethrin
Insect tents for food preparation areas and toilet
areas
Lids, bags
Eat food right after preparation
Traps
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Mosquito traps (CO2 and attractant)
Fly bait
UV light for flies in eating areas and at entrances
Good old fly swatter for that pesky one that got
in anyway
SumiOne Emanators
• Metofluthrin (SumiOne), a vapor-active
pyrethroid effective against mosquitoes
• Metofluthrin impregnated paper emanators
placed 1.2 m to sides of volunteers in field
• Pre and post-tx bite counts after 10-30 min
– In FL >90% reduction Ochlerotatus bites
– In WA >95% reduction Aedes bites
(Lucas et al. J Am Mosq Contr Assoc, 2007)
An Effective combo
Alaska study
-control 1,188bites in 1 hour
-Permethrin on clothes and DEET on skin 1 bite
in 1 hour
-99.9% effective over 8 hours
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(Lillie et al. J Med Entomol ‘88)
Mosquito reduction
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Remove or treat standing water ½ mile
-Tablets in water
-Vegetable oil clogs breathing of larvae in H2O
-Fuel oil may contaminate drinking water
Large scale permethrin fogger around buildings, camp.
somewhat effective
Ducks, fish
Muscovy ducks for flies, guinea hens/chickens for ticks
Future…. Transgenic mosquitoes?
Bigger Critters
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Mice
Rats
Bats
Snakes and lizards
Skunks, feral cats, dogs
Monkeys and bears
Oh my!
Mice & Rats
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Food/medicine contamination
Hantavirus
Plague
Destruction of equipment/packs
Poison & traps
Metal containers for supplies (paint cans)
Bats
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Rabies, lethal if symptomatic
Pre vaccinate in endemic areas/cavers
If bat is found and someone has been sleeping
must vaccinate if not done and must give
immune globulin also
Sleeping in the open discouraged
By far most North American rabies is from bats
Snakes and Lizards
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Painful bites
Poisonous bites
Salmonella, wash hands after touching before
eating or preparing raw food
Encourage a no touch policy
Tetanus vaccine
Skunks, feral cats, wild dogs
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Avoid contact
Secure food…solves most problems
.22 semi automatic rifle with scope, pistol if
trained (Katrina)
Gopher poison in cat food (non selective)
Skunk, cat, bat, and canine bite = rabies
prophylaxis
Monkeys, Raccoons, and Bears
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Secure food
Secure it some more
Really secure it
Elevation and metal containers
Monkey and racoon bite = rabies prophylaxis
Bear = trauma center or body bag
Field Water Treatment
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HAND WASHING!
Boiling
Chemical disinfection
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- Chlorine
-Iodine
-Chlorine dioxide
Filtration
UV
Sedimentation, Coagulation/flocculation, Granular activated
charcoal
SODIS 35 deg lat
Water and Sanitation
Globally
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1.1 billion persons without access to potable water
2.4 billion persons without adequate sanitation
4 billion episodes of diarrhea/year
2.2 million deaths/year (most under 5 years-old)
Safe water, sanitation, and hygiene can:
reduce diarrhea disease mortality by 65%
reduce mortality by 26%
WHO and UNCF Global water supply and sanitation assessment 2000 report
Sierra Nevada Water
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55 lakes and streams in National Parks
40% positive for coliforms
Most very low levels
31 lakes and streams in Wilderness areas
45 % positive for coliforms
high levels at 8 sites
Correlated with human and animal (beaver) activity
Derlet RW et al. Wild Environ Med 2004
Toilets
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Pre prepared: park service, hand washing, floor washing
Blue lagoon! (blue water backsplash)
5 gal pail with liner and lid
Ziplock skills
Slit trench, fenced areas
Paper, water, Rock, leaf, wipe plan (cultural)
Surface deployed poop next to water (what most people
and all animals do)
Helping you “go green!”
Bacterial
Viral
17-130 days in
H2O
Protozoan
Parasitic
E coli
Hepatitis A
Giardia
2-3 months in
H2O
Ascaris
Shigella
Norwalk E
histolytica
T solium
Campylobacter
3-5 weeks in H2O
Polio virus
Cryptosporidium
12 months in H2O
Liver fluke
V cholera
4-5 weeks in H2O
Hepatitis E
Cyclospora
Dracunculosis
S typhi
More than 120
enteric viruses
Blastocystis
Y enterocolitica
I belli
B coli
Water treatment is secondary to good
hygiene
Individual Practices:
-hand-washing, bathing, toilet practices
Group Practices
-campsite selection, group toilets, food / water
choice and preparation, food waste disposal, dish
washing
Water treatment should accompany a comprehensive
approach to hygiene
Handwashing camp sanitation
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After toilet
Before eating
Simple foot pump device
In large camps must be enforced
Liquid soap can be dispensed by monitor in line
Toilets need bleach water spray QD to QID based on use. Not
in toilets unless cholera outbreak.
Spray toilets with permethrin for flies
Garden sprayers work great
Bathe, do laundry, wash dishes, away from the well head.
Benefits of hygiene with students in
a large outdoor training program
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NOLS data covers a well studied group before and
after program wide interventions. Rates of
gastrointestinal illnesses (nausea, vomiting, and
diarrhea) dropped from 0.51 per 1000 program days
to 0.22 per 1000 program days over the same time
period.
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These hygiene issues include emphasizing hand
washing and camp hygiene, educating students, and
instructors on food-born illnesses, expecting all
wilderness drinking water to be disinfected, and
repeatedly restating the hygiene expectations to the
course participants.
Military applications
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More died in WWI from disease than combat
Soviets in Afghanistan: disease degraded war
fighting capability greater than all other causes
combined. Examples include entire battalions
hospitalized from food borne Hepatitis A from
one cook.
Boiling water
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Fuel and time intensive
Works great at most elevations
Most pathogens die well before boiling
Rolling boil is the only reliable temp, small
bubbles are not consistant
Time at boil shown not to be significant just
getting to a boil is reliably adequate
Thermal Death
-Water pasteurized at a boil
Giardia, E histolytica cysts
-2-3 minutes at 60º C (140º F)
 Cryptosporidium oocysts
-2 minutes at 64º C
-1 minute at 72º C
 Enteric viruses
-Seconds at 80º -100º C
 Hepatitis A
-1 minute at 85º C
 Enteric bacteria
-1 minute at 65º C
-Seconds at 100º C
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Elevation Boiling
Point
-10,000 ft. 90º C
-14,000 ft 86º C
-19,000 ft 81º C
WATER TREATMENT
Choice of Methods: Chemicals
Iodine and Chlorine:
-widely used and inexpensive
-ineffective against cryptosporidium
-effectiveness decreases with lower temperatures and higher turbidity
-byproducts a concern
Chlorine Dioxide (ClO2):
-stronger disinfectant than both chlorine and iodine: more resistant to low
temperatures and high turbidity
-some effectiveness against cryptosporidium (with extremely long contact
times)
-byproducts a concern
Mixed Oxidants:
-on-site generated combination of chlorine, chlorine dioxide, and ozone
-similar to ClO2 in effectiveness, but more susceptible to turbidity
-fewer byproducts than ClO2
Iodine/chlorine
May miss cryptosporidium. (Illinois river)
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Safe Water System CDC, WHO,
PAHO
International Network to
Promote Household Water
Treatment and Safe Storage
Sodium hypochlorite and closed
mouth containers with spigot
Reduced diarrhea
24% in Bangladesh
25% in Guatemala
30% among persons with HIV
infection in rural Uganda
-Inexpensive
-Widely available
-Flexible dosing
-Large volumes
-Multiple variables (temp, sediment,
concentration, time, pathogen
sensitivity, ph)
-Taste
-Potential toxicity? No evidence
-Corrosive, stains
-Requires contact time
-Cryptosporidium
resistance
Chlorine tips
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Differential Dx of diarrhea and or nausea
too much chlorine or iodine.
Chlorine at 1-2 ppm is bacteriostatic
4-5 ppm it gives you the “quick step”
Carry a few pool test strips to check camp
water where chlorine is routinely used
Allow over treated water to sit and off gas
the chlorine or add more water
Filters
May need back up halogen for viruses especially in
areas with slow water and lots of people.
(Bangladesh, Illinois river)
 New viral filters 0.2 micron now available however
how do you do quality control?
 USACHPPM website (http://chppm-www.apgea.army.mil/)
for testing overview of most models on the market
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New stuff
Steri-Pen Ultraviolet
-Effective against virtually all
pathogens
-leaves no byproducts
-requires power
-turbidity absorbs and scatters light;
essential that source water is clear
or pre-filtered
-leaves no residual disinfectant in
water; re-growth and repair are
possible
-UV light is harmful to our eyes;
devices must be used properly to
avoid damage
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Chlorine Dioxide less taste,
improved cold water performance,
cryptosporidium coverage
Miox Pen multiple chemicals
derived from salt, requires power
Sawyer/MSR Microfiltration?
Unproven
Sedimentation
Large inorganic particles
like sand and clay settle
by gravity
 Let water sit for 30-120
minutes
 Decant or filter clear
water
 Does not disinfect
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Coagulation - Flocculation
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Clarifies
Removes Colloids (fine
suspended matter)
Partially removes
Microorganisms
Metallic compounds and
minerals
Dissolved chemicals
(phosphates)
Bad taste, smell, color
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Use small amounts of
alum
Found in grocery store
for pickling
Removes up to 90% of
bacteria
Removes up to 89% of
viruses
Alum flocculation
Granular Activated Charcoal
Action
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Adsorbs dissolved chemicals, pesticides, oil,
uranium?
Improves taste, odor, color
Does not disinfect
Finite capacity for adsorption
Filtration
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Simple process
No taste imparted
Special equipment
Pore size limitation
Gradual clogging
Organism Maximum pore size (um)
Parasitic eggs and larvae 20
Giardia, E histolytica
5
Cryptosporidium
1
Enteric bacteria
0.2-0.4
Viruses
0.01
Common micro-filters 0.1-0.4
SODIS
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Contaminated water is filled into
transparent plastic bottles and
exposed to the full sunlight for 6
hours.
UV-A radiation SODIS, Solar
water disinfection is a simple
method to improve the quality of
drinking water by using sunlight to
inactivate pathogens causing
diarrhoea(wavelength 320-400nm)
of the sunlight destroys the
pathogens.
A synergy of UV-A and
temperature occurs, if the water
temperature rises above 45°C.
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SODIS requires relatively clear
water (turbidity less than 30 NTU)
SODIS is not useful to treat large
volumes of water
Regions well suited for SODIS are
locatedbetween latitude 35°N and
35°S
6 hours under bright or up to 50%
cloudy sky
2 consecutive day under 100%
cloudy sky
During days of continuous rainfall,
SODIS does not perform
satisfactorily.
Water boiling or rainwater
harvesting is recommended during
these days.
Solar box cooker
WATER TREATMENT
Risk Assessment
Factors to Consider:
-potential pathogens (protozoa, bacteria, viruses)
-potential toxins
-location (wilderness, rural, urban, farmland)
-local knowledge, awareness
-group characteristics (duty, age, susceptibility, immune status,
medical conditions, expectations)
-characteristics of trip (length, difficulty, medical support,
remoteness)
Water summary
Understand the advantages and disadvantages of each
system and apply them appropriately to your situation
Heat
Ultraviolet
Chlorine Dioxide
Filtration+Halogenation or UV
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Dish washing
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Wash Rinse Sanitize
Sources of “grocery outlet”
syndrome
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Washing dishes and bathing
at the wellhead.
Drying dishes in
contaminated areas.
Cutting salad and raw meat
together.
First in-last out storage.
Bare feet.
No soap.
Actually okay!
Remember:
A fly has six legs…
that’s six bad things on
your food!
And:
Keep your rice off the
ground…
and your butt off the
rice!!