Page 252 - parasitology for medical and clinical laboratoryprofessionals

232 CHAPTER 11

presence of a dorsal plate, or scutum. There are over avoiding attachment. Preventive practices such as body
200 member species of the genus Ixodes and a number of searches should be scrupulously performed for effec-
separate species are capable of transmitting Lyme disease tiveness. For this reason, a thorough body check should
to humans. Hard ticks die after producing a clutch of include special attention to hairy areas, including the
eggs, whereas soft ticks can produce eggs over a period head, chest, underarms, and pubic regions, in order to
of several years. find adult ticks before they attach and begin to feed.
Nymphs and larvae may not be as easily seen as adult
Avoiding the Contraction of ticks because they are quite small and practically trans-
Disease from Tick Bites parent in some species, so extreme care should be exer-
cised in searching for these forms. In addition, to further
Several methods exist for avoiding tick bites and the avoid the multitude of infections that may be contracted
possibility of becoming infected through contact with a by pets from a tick bite, a daily examination of a pet’s
tick, some of which will be practiced concurrently. First, body is also necessary when the pet has visited an area
and most important, avoiding habitats such as the edges in or near woods or fields.
of brushy fields frequented by ticks and proper body When considering the use of an insect repellent,
searches will eliminate many ticks. Staying away from one of the best tick repellents is called DEET
certain habitats where ticks are prevalent during the peak (N,N- diethyl-m-toluamide). Products containing 10
of tick season is perhaps the best way to prevent tick bites to 35 percent DEET, an effective and versatile insect
and potential infections. In most areas of the country, this repellent, will provide sufficient protection under nor-
time period is usually from early April into early fall. But mal conditions when used according to instructions.
depending upon the temperature of the various latitudes, Insect repellents that contain DEET have stood the
this period may vary by several weeks and starts earlier test of time, as they have been in existence for more
in the more southerly latitudes and will end a few weeks than 40 years and are especially effective when used in
later than in the northern zones. Extremely cold weather conjunction with protective clothing. If these practices
in the early fall serves to lower a population of ticks that are followed, the chances of becoming bitten by ticks is
may overwinter in the larval stage and emerge to breed greatly minimized (Figure 11-7). They have been used
the following spring. by people throughout the world in order to avoid a host
The second most important means of preventing of insects and other related organisms, which include
tick bites and perhaps subsequent infections, is by wear- not only ticks but other important vectors and pests that
ing protective clothing. If it is necessary to enter a tick include flies, mosquitoes, fleas, and chiggers, to name a
habitat, wearing light-colored clothing, including a long- few. DEET preparations are available in many forms that
sleeved shirt tucked into trousers and long-legged pants
tucked into socks, is beneficial. This will not only help to
prevent ticks from reaching your body, but as ticks roam
the body they are easier to see against a light background.
It is quite simple to remove these ticks before they find a
way to reach the skin. DO NOT wear flea and tick col-
lars around ankles to prevent ticks from attaching to the
skin. This practice can be extremely dangerous, because
the insecticide is absorbed through the skin and into Source: Centers for Disease Control and Prevention (CDC)
the body. In addition, do not crush these ticks between
unprotected fingers, as this may release infectious patho-
genic organisms.
The third method of prevention of tick bites
requires the help of a friend. Because both male and
female adult ticks tend to explore the body of a host for FIGURE 11-7 Wear long sleeves with trousers tucked
sometimes up to several hours before they attach them- into socks during peak tick season. Spray DEET
selves to the skin, body searches are quite effective in directly onto clothes