Jungle Survival

Leeches : The Facts
Have you ever felt that shiver crawl up your back after you pull off your
sock and there IT is - thick, black, shiny and fattened on your blood? The
next repulsive thought is how to get it off.

Leeches didn't always suffer from such a poor image - in the early-1800s
they were used as a cure-all for everything from indigestion to syphilis,
with very limited success in either situation.

Leeches find their host by detecting vibrations and heat with tiny sense
organs. They have suckers on each end as a means of locomotion, but one
end contains a mouth. Once attached to their host they use their saw-like
jaws to pierce the skin and suck.

Land or aquatic
Australia and South-East Asia are the only known places where leeches live
on land, usually in wet or moist forests. These are the kinds most likely
to attach themselves to you! The bulk of the world's recorded leech
species are aquatic and become attached when paddling in creeks or rivers.

Australia's known land species are found on the east coast, east of the
Great Dividing Range. It is difficult to distinguish land or aquatic
leeches by sight alone and many species are brightly coloured and marked.
Australia's land leeches only have two jaws whereas the world's other
species have three jaws.

Leeches contain a component in their saliva which prevents blood from
clotting and allows them to have their fill before dropping off. This
anticoagulant can cause a wound to bleed slightly after the leech has been
detached. It's said a leech can suck up to 10 times its own body weight in
blood.

Removal
Unlike ticks, leeches do not burrow into the skin nor will they leave a
poisonous head in the wound. Despite this, many myths abound about
removing leeches. The simplest way is with salt: a shake onto the body and
most will quickly drop off. Tea tree oil or vinegar dabbed onto the body
are also effective alternatives. Less queasy victims may prefer to scorch
them with cigarettes or lighters. Otherwise, simply pull the little
bloodsuckers off!

It is probably a good idea to get a fresh wad of cotton wool and dab a
little tea tree oil onto the open wound to prevent infection. While
leeches are not known to spread disease, a particular type of bacteria has
been identified in their stomachs which may be passed onto the host.

Uses
Today leeches are being used to assist in reducing swelling and clotting
in some surgical procedures, particularly microsurgery. For example, when
reattaching a severed finger tiny blood vessels in the finger can be
blocked by clotted blood. Leeches have been used to remove excess blood
and their anticoagulant serum allows the blood vessels to flow freely.
More research is needed to fully exploit the potential of the leech.

Deterrents
To avoid leeches try rubbing vulnerable areas with lotions such as tea
tree oil-based creams as well as cream insect-repellents. Alternatively,
try wearing gatters or wear long pants tucked into your socks.

How to cross a Rapid River
If necessary, you can safely cross a deep, swift river or rapids. To swim across a deep, swift river, swim with the current, never fight it. Try to keep your body horizontal to the water. This will reduce the danger of being pulled under.

In fast, shallow rapids, lie on your back, feet pointing downstream, finning your hands alongside your hips. This action will increase buoyancy and help you steer away from obstacles. Keep your feet up to avoid getting them bruised or caught by rocks.

In deep rapids, lie on your stomach, head downstream, angling toward the shore whenever you can. Watch for obstacles and be careful of backwater eddies and converging currents, as they often contain dangerous swirls. Converging currents occur where new watercourses enter the river or where water has been diverted around large obstacles such as small islands.

To ford a swift, treacherous stream, apply the following steps:

• Remove your pants and shirt to lessen the water's pull on you. Keep your footgear on to protect your feet and ankles from rocks. It will also provide you with firmer footing.

• Tie your pants and other articles to the top of your rucksack or in a bundle, if you have no pack. This way, if you have to release your equipment, all your articles will be together. It is easier to find one large pack than to find several small items.

• Carry your pack well up on your shoulders and be sure you can easily remove it, if necessary. Not being able to get a pack off quickly enough can drag even the strongest swimmers under.

• Find a strong pole about 7.5 centimeters in diameter and 2.1 to 2.4 meters long to help you ford the stream. Grasp the pole and plant it firmly on your upstream side to break the current. Plant your feet firmly with each step, and move the pole forward a little downstream from its previous position, but still upstream from you. With your next step, place your foot below the pole. Keep the pole well slanted so that the force of the current keeps the pole against your shoulder.

• Cross the stream so that you will cross the downstream current at a 45-degree angle.