By Sandi Funke, Education Director

According to the Centers of Disease Control and Prevention
Lyme disease is caused by the bacterium Borrelia
burgdorferi and is transmitted to humans through the bite of infected black
legged ticks. Typical symptoms include fever, headache, fatigue, and a
characteristic skin rash called erythema
migrans which makes a bulls eye pattern. If left untreated, the infection
can spread to joints, the heart, and the nervous system. Some believe Lyme
disease can also cause long term chronic symptoms, though there is no complete
consensus in the medical establishment on this.

Unfortunately, the western black legged tick is the most
abundant of the 47 species of ticks known to live in California. It is very
small. The nymphs are only the size of a poppy seed and the adult females are
only about 1/8 of an inch. The nymphs transmit most of the disease in
California. Nymphs are found in forests and woodlands carpeted with leaf litter
or fir needles. They occur within the leaf litter and crawl onto tree trunks
and logs. They tend to transmit the disease from March to July.
Adult ticks occur on low vegetation most commonly in
grasslands or chaparral. Strangely, they are also more abundant on the uphill
margins of hillside trails. More adults are also found in the margins between
different habitats. Adults transmit the disease November to July. Adults tend
to be active in the early morning and late afternoon.
There are several steps we can take to avoid getting bit by
a tick. When in forests and woodlands avoid sitting on logs or leaning against
tree trunks - bring a chair! If you are hiking in a potentially tick infested
area, stay towards the middle of trails and stick to the downhill margin of the
trail. Wearing long sleeved shirts and pants and tucking in pant legs and shirt
tails can also help. Dr. Lane recommends considering use of repellant - some
have been shown to be up to 85% effective. You should also always do a tick
check after hiking paying special attention to exposed areas of skin on arms,
legs, behind ears, and on the scalp. If you have pets you should also check
your pet for ticks.
It may not be possible to completely eliminate all risks of
exposure to Lyme disease in California. However, we can take certain steps to
reduce contact to ticks. By getting more informed we can all feel a little
safer exploring and working outdoors in California.