Download 10. Tropical hygiene

The lecture
Tropical hygiene.
Hygienic description of climate and weather of hot
and low latitudes (features of sun radiation,
vibrations of days and seasonal parameters of
microclimate). Features of influencing of tropical
climate are on the terms of life, capacity and health of
population.Hygienic,toxicological
and epidemiologys problems in feeding of population
of tropical regions. Hygiene of water and feature of
water-supply of population in the conditions of
tropical climate
.
Prepared by O.Sopel
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THE PLAN
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Introduction
Hygienically characteristic of the
climate
The heating microclimate and its
influence on the human organism
Diarrhea in the returning traveler.
Poisonous plants and fish.
Mushroom poisoning.
World Climates
Koeppen climate classification
The Köppen system recognizes five major climate types based on the annual and
monthly averages of temperature and precipitation. Each type is designated by a
capital letter.
A - Moist Tropical Climates are known for their high temperatures year round and
for their large amount of year round rain.
B - Dry Climates are characterized by little rain and a huge daily temperature
range. Two subgroups, S - semiarid or steppe, and W - arid or desert, are used with
the B climates.
C - In Humid Middle Latitude Climates land/water differences play a large part.
These climates have warm, dry summers and cool, wet winters.
D - Continental Climates can be found in the interior regions of large land masses.
Total precipitation is not very high and seasonal temperatures vary widely.
E - Cold Climates describe this climate type perfectly. These climates are part of
areas where permanent ice and tundra are always
World map with the tropics
highlighted in red
Tropical Moist Climates (rainforest)
Rainfall is heavy in all months. The total annual
rainfall is often more than 250 cm. There are
seasonal differences in monthly rainfall but
temperatures of 27°C (80°F) mostly stay the same.
Humidity is between 77 and 88%.
High surface heat and humidity cause cumulus
clouds to form early in the afternoons almost
every day.
The climate on eastern sides of continents are
influenced by maritime tropical air masses. These
air masses flow out from the moist western sides
of oceanic high-pressure cells, and bring lots of
summer rainfall. The summers are warm and
very humid. It also rains a lot in the winter
oAverage temperature: 28 °C
oAnnual Precipitation: 262 cm.
oLatitude Range: 10° S to 25 ° N
oGlobal Position: Amazon Basin; Congo Basin of
equatorial Africa; East Indies, from Sumatra to New
Guinea.
Wet-Dry Tropical Climates (savanna)
A seasonal change occurs between wet
tropical air masses and dry tropical air
masses. As a result, there is a very wet
season and a very dry season. Trade winds
dominate during the dry season. It gets a
little cooler during this dry season but will
become very hot just before the wet season.
Temperature Range: 16 °C
Annual Precipitation: 0.25 cm. (0.1 in.).
All months less than 0.25 cm. (0.1 in.)
Latitude Range: 15 ° to 25 ° N and S
Global Range: India, Indochina, West Africa,
southern Africa, South America and the
north coast of Australia
Dry Tropical Climate desert biome )
These desert climates are found in low-latitude deserts
approximately between 18° to 28° in both hemispheres.
these latitude belts are centered on the tropics of Cancer
and Capricorn, which lie just north and south of the
equator. They coincide with the edge of the equatorial
subtropical high pressure belt and trade winds. Winds are
light, which allows for the evaporation of moisture in the
intense heat. They generally flow downward so the area is
seldom penetrated by air masses that produce rain. This
makes for a very dry heat. The dry arid desert is a true
desert climate, and covers 12 % of the Earth's land
surface.
Temperature Range: 16° C
Annual Precipitation: 0.25 cm (0.1 in). All months less
than 0.25 cm (0.1 in).
Latitude Range: 15° - 25° N and S.
Global Range: south-western United States and
northern Mexico; Argentina; north Africa; south Africa;
central part of Australia.
Dry Midlatitude Climates (steppe)
Characterized by grasslands, this is a semiarid climate. It
can be found between the desert climate (BW) and more
humid climates of the A, C, and D groups. If it received less
rain, the steppe would be classified as an arid desert. With
more rain, it would be classified as a tallgrass prairie.This
dry climate exists in the interior regions of the North
American and Eurasian continents. Moist ocean air masses
are blocked by mountain ranges to the west and south.
These mountain ranges also trap polar air in winter, making
winters very cold. Summers are warm to hot.
Temperature Range: 24° C (43° F).
Annual Precipitation: less than 10 cm (4 in) in the
driest regions to 50 cm (20 in) in the moister steppes.
Latitude Range: 35° - 55° N.
Global Range: Western North America (Great Basin,
Columbia Plateau, Great Plains); Eurasian interior,
from steppes of eastern Europe to the Gobi Desert
and North China.
Mediterranean Climate
This is a wet-winter, dry-summer climate. Extremely
dry summers are caused by the sinking air of the
subtropical highs and may last for up to five
months.
Plants have adapted to the extreme difference in
rainfall and temperature between winter and
summer seasons. Chlorophyll plants range in
formations from forests, to woodland, and scrub.
Eucalyptus forests cover most of the chaparral
biome in Australia.
Fires occur frequently in Mediterranean climate
zones.
oTemperature Range: 7 °C (12 °F)
oAnnual Precipitation: 42 cm (17 in).
oLatitude Range: 30° - 50° N and S
oGlobal Position: central and southern
California; coastal zones bordering the
Mediterranean Sea; coastal Western Australia
and South Australia; Chilean coast; Cape Town
region of South Africa.
Processes of Thermal Transfer
Thermoregulation
of
.
human organism on 85 %
is realized through the
skin.
The most way of the heat
losses
of organism
by
radiation is 45 %,
by
convection
and
conduction 30 %,
by
evaporation
(perspiration) 10 % .
Hyperthermia
Hyperthermia in its advanced state
referred to as heat stroke or sunstroke,
is an acute condition which occurs when
the body produces or absorbs more heat
than it can dissipate. It is usually due to
excessive exposure to heat. The heatregulating mechanisms of the body
eventually become overwhelmed and
unable to effectively deal with the heat,
and
body
temperature
climbs
uncontrollably
Signs and symptoms of heat stroke and
heat exhaustion
Heat Stress Hazards
Cause
Heat
Rash
Hot humid
environment;
plugged sweat
glands.
Sunburn Too much
exposure to
the sun.
Symptoms
Treatment
Prevention
Red bumpy rash
with severe
itching.
Change into dry
Wash regularly to
clothes and avoid keep skin clean
hot
and dry.
environments.
Rinse skin with
cool water.
Red, painful, or
blistering and
peeling skin.
If the skin
blisters, seek
medical aid. Use
skin lotions
(avoid topical
anaesthetics)
and work in the
shade.
Work in the
shade; cover skin
with clothing;
apply skin lotions
with a sun
protection factor
of at least 15.
People with fair
skin should be
especially
cautious.
Heat Stress Hazards
Fainting
Cause
Symptoms
Treatment
Prevention
Fluid loss
and
inadequate
water
intake.
Sudden fainting
after at least two
hours of work;
cool moist skin;
weak pulse.
GET MEDICAL
ATTENTION.
Assess need
for CPR. Move
to a cool area;
loosen clothing;
make person
lie down; and if
the person is
conscious, offer
sips of cool
water. Fainting
may also be
due to other
illnesses.
Reduce activity
levels and/or
heat exposure.
Drink fluids
regularly.
Workers should
check on each
other to help
spot the
symptoms that
often precede
heat stroke.
Heat
Exhaustio
n
Fluid loss and
inadequate salt
and water
intake causes a
person's body's
cooling system
to start to break
down.
Heavy sweating; cool
moist skin; body
temperature over
38°C; weak pulse;
normal or low blood
pressure; person is
tired and weak, and
has nausea and
vomiting; is very
thirsty; or is panting
or breathing rapidly;
vision may be
blurred.
GET MEDICAL AID.
This condition can
lead to heat stroke,
which can kill. Move
the person to a cool
shaded area;
loosen or remove
excess clothing;
provide cool water
to drink; fan and
spray with cool
water.
Reduce activity
levels and/or heat
exposure. Drink
fluids regularly.
Workers should
check on each
other to help spot
the symptoms that
often precede heat
stroke.
Heat
Stroke
If a person's
body has used
up all its water
and salt
reserves, it will
stop sweating.
This can cause
body
temperature to
rise. Heat stroke
may develop
suddenly or
may follow from
heat
High body
temperature (over
41°C) and any one of
the following: the
person is weak,
confused, upset or
acting strangely; has
hot, dry, red skin; a
fast pulse; headache
or dizziness. In later
stages, a person
may pass out and
have convulsions.
CALL
AMBULANCE. This
condition can kill a
person quickly.
Remove excess
clothing; fan and
spray the person
with cool water;
offer sips of cool
water if the person
is conscious.
Reduce activity
levels and/or heat
exposure. Drink
fluids regularly.
Workers should
check on each
other to help spot
the symptoms that
often precede heat
stroke.
Traveler's
Diarrhea
Traveler's
diarrhea
affects some 30 to 50% of
visitors
to
developing
countries.
In general, travelers at
risk for diarrhea commonly
come from industrialized
nations and travel to highrisk areas that are primarily
within developing or less
industrialized nations of the
world,
including
Latin
America, Africa, the Middle
East and Asia. Areas of
lesser risk include China and
some Caribbean nations.
What causes traveler's
diarrhea?
is contracted by the ingestion of
contaminated food or water
caused by bacteria
The single most important bacterium is
enterotoxigenic E. coli which has been
estimated to account for up to 70% of all
cases.
Also the CAUSES OF traveler's diarrhea ARE:
Campylobacter jejuni
Shigella
Salmonella
Viruses (including Rotavirus, Norwalk virus and other
enteric viruses) less commonly are causes
of travelers' diarrhea.
CLINICAL SYMPTOMS
Diarrhea in travelers is usually between 5 and 15 days after
arrival.
Main symptoms:
Malaise
anorexia
diarrhea
nausea
occasional vomiting
Fever
Inflammatory processes that
may warrant bacterial
culture or parasite
examinations include high
fever, tenesmus, bloody
dysentery, and prolonged
illnesses with weight loss.
If there is any suspicion of an
inflammatory, bloody, or prolonged
diarrheal illness, a prompt microscopic
examination of fresh samples for fecal
leukocytes (with methylene blue or
Gram's stain) and for parasites should be
done.
DIAGNOSIS
The increasing frequency of AIDS
should also broaden the
considerations of diarrhea causes
to include additional viruses as
well as parasites (especially
Cryptosporidium), bacteria (e.g.,
Salmonella, Campylobacter, and
even fungi (e.g., Candida) agents.
Although one may see motile
trophozoites of Giardia lamblia or
Entamoeba histolytica, special stains
for amebae (e.g., trichrome stain,
with micrometer measurements of
parasite size), Cryptosporidium and
Isospora belli, or Strongyloides may
be necessary
PREVENTION
The prevention of traveler's diarrhea includes the
avoidance of
 salads,
 raw vegetables,
 untreated or unboiled water or ice,
 dairy products
 uncooked meat or seafood
which can reduce risk, even in highly endemic areas.
Even bottled, non-carbonated water or beverages
may not be safe, as outbreaks of cholera and typhoid
fever have been traced to bottled drinks.
FISH
POISONING
Most common fish poisonings are:
CIGUATERA POISONING
TETRAODON POISONING
SCOMBROID POISONING
CIGUATERA POISONING
is the most important type of poisoning.
Types of fish which may contain the toxin at
unpredictable times include ciguatera fish, red
snapper, grouper, amberjack, sea bass, and a
wide range of tropical reef fish.
Ciguatera fish
Clinical Manifestations and Prognosis
Clinical manifestations of poisoning occurs 4 to 30 hours after
ingestion.
The Symptoms:
gastrointestinal and neurological
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with nausea (and, on occasion, a metallic taste in the mouth),
vomiting
diarrhea
abdominal pain
cramps
paresthesia around the mouth (and in some cases the fingers and toes),
cold-to-hot sensory reversal dysesthesia
increased salivation
dilatation of the pupils
strabismus, ptosis, weakness, myalgia of the legs, incoordination, and even
paralysis.
TETRAODON POISONING
Tetrodotoxin, also called pufferfish poisoning or fugu
poisoning, is a much more rare form of fish poisoning, but
is potentially very serious.
Tetraodon-toxin, a neurotoxin, is widely distributed among the
order Tetraodontoidea (Plectognathi). This includes puffers
(blowfish, toadfish, fugu), ocean sunfish, and porcupine fish.
Those kinds of fish are characterized by
having very small scales.
The toxin concentrates mainly in:
the liver,
ovaries,
intestine, and
skin of the fish.
Puffer musculature is generally considered
nonpoisonous. Toxicity is related to the
reproductive cycle, being highest just before
spawning in late spring or early summer.
Symptoms generally appear between 20 minutes to 3
hours after eating the poisonous pufferfish.
The most common symptoms of pufferfish poisoning are:
• numbness of lips, tongue, throat and late, the limbs
• abdominal pain
• dizziness
• headache
• vomiting
• diarrhea
• sweating
• extensive muscle weakness
There is a tachycardia, hypotension, and, increasing
difficulty with breathing, which may be complicated by a
general flaccid ascending paralysis, leading to respiratory
failure, convulsions, and death in 6 to 24 hours.
Treatment for pufferfish
poisoning (TETRAODON POISONING ):
Treatment for pufferfish poisoning
consists of limiting the body's
absorption of the toxin, relieving
symptoms,
and
treating
lifethreatening complications. There is
no known antidote for tetrodotoxin.
SCOMBROID POISONING
•Scromboid poisoning occurs after
eating fish that contain high levels
of histamine.
•These fish, which include mahi
mahi (dolphin fish), albacore tuna,
bluefin and yellowfin tuna,
mackerel, and sardines, have high
amounts of histidine.
•As a result of inadequate
refrigeration or preservation,
bacteria (Proteus, Salmonella,
Clostridium, and Escherichia coli)
convert the histidine to
histamine, and this leads to
scromboid poisoning.
Clinical Symptoms:
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Signs and symptoms occur about 3 hours after ingestion of the
fish.
• an acute allergic or histamine-like reaction, with headache;
flushing of the head and upper trunk;
generalized urticaria;
swelling of the eyelids,
periorbital tissue, lips, tongue, and throat;
muscular weakness;
myalgia;
diarrhea.
Recovery usually takes place in about 3 to 16
hours, although occasional deaths have been reported.
OTHER FISH POISONINGS
I. Elasmobranch Poisoning
This occurs after ingestion of the liver or skeletal muscles
of sharks and rays.
The symptoms usually occurs after 30 minutes.
These are usually mild following ingestion of the musculature
and include some abdominal pain but mainly diarrhea.
Symptoms are more severe after ingestion of the liver and include,
in addition to diarrhea and abdominal pain, nausea, vomiting,
headache, tingling around the mouth, and a burning sensation of
the tongue. In severe cases, this may progress to ataxia, visual
disturbances, difficulty with breathing, coma, and death.
Most patients, however, recover completely in 5 to 20 days.
I. Hallucinatory Fish Poisoning
This may occur after ingestion of certain species of
mullet. Signs and symptoms begin about 2 hours after ingestion
of the fish and are all neurologic, e.g., incoordination,
nightmares, ataxia, and hallucinations. No fatalities have been
recorded, and cathartics are recommended in treatment.
I. Miscellaneous
Other intoxications have been described, e.g., fish roe poisoning,
fish blood poisoning, and fish liver poisoning.
The contamination of the sea and its fauna by metallic wastes,
particularly mercury, has been described in Japan, i.e., Minamata
disease.
SHELLFISH POISONING
Clinically, there are 3 types of shellfish poisoning
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GASTROINTESTINAL
• ALLERGIC
• PARALYTIC
GASTROINTESTINAL SHELLFISH
POISONING
The symptoms:
nausea
vomiting
diarrhea
abdominal pain
occur 8 to 12 hours after ingestion.
ALLERGIC SHELLFISH POISONING
The symptoms :
skin rash and itching, nasal congestion, dryness of the
throat, and edema of the tongue, causing potentially fatal
respiratory distress,
occur 30 minutes to 6 hours after ingestion.
PARALYTIC SHELLFISH POISONING
This is an acute poisoning due to
saxitoxin, a powerful curare like
neurotoxin that is produced by
toxic species of planktonic
dinoflagellates and concentrated in
filter-feeding mollusks
oysters
mussels
clams
scallops
PARALYTIC SHELLFISH POISONING
The symptoms are:
paresthesia starts in the lips and tip of the tongue
and spreads to involve the face, scalp, neck, and extremities.
weakness of the limbs
ataxia
incoherent speech
tightness of the throat and chest
aphonia
increased salivation
the pulse is thready; superficial reflexes may be lost
PLANT POISONING
Atropa
Belladonna
Datura stramonium
(Jimson-weed;
moon-lily;
Jamestown weed )
POISONOUS PARTS: All parts are poisonous, especially seeds and leaves. Lethal
dosages for cattle may be 10-14 oz (0.06-0.09% of the animal's body weight). It is
SYMPTOMS:
intense
thirst
visual
disturbance
flushed
skin
central
nervous
system
hyperirritability
Heart beat may be rapid with elevated temperature.
Victims become delirious, incoherent, and perform insensible
antics. Subjects may be prone to violence, hallucination,
convulsions, coma, and death.
POISONOUS PRINCIPLES:
Solanaceous alkaloids (tropane configuration) including
atropine, hyosayamine (isomeric with atropine),
and hyoscine (scopolamine).
Datura alkaloids are useful in medicine.
Total content of alkaloids in a plant may be high, varying from
0.25-.0.7%.
Concentration varies in different parts of the plant,
during various stages of development,
and under varied growing conditions.
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