[Public Health] Bed Bugs & Ticks On The Rise

The admonition of "Sleep tight — don’t let the bed bugs bite," is again proving applicable and should be taken more seriously than just a song at bedtime. According to Harold Harlan, senior entomologist of the National Pest Management Association in Dunn Loring, Va., the incidence of bed bug occurrences is rising. In addition, the conditions last year were just right for a resurgence of deer ticks. (Harlan gave a presentation on the topic at the NPMA convention last October.)

A few factors have led to the rise of bed bugs. Pest control operators have stopped using non-repellent residual pesticides they used in the past and now are primarily using pyrethroids for indoor treatments. Many of these are repellent and since bed bugs can sense even minute amounts of repellents, they will avoid them. Additionally, baits generally used for roaches and ants will not effect bed bugs, since bed bugs only have sucking mouthparts to feed on blood.

INSPECTIONS ARE IMPORTANT. Harlan says that a positive identification of the pest during an inspection is vital; too often, any bites that cannot be assigned to any other pest may automatically be assumed to be from bed bugs. During inspections, pest management professionals should look for the following: Bed bugs are typically 3/16-inch long, oval, flat, a reddish-brown color and have vestigial wings. All areas near sleeping quarters must be inspected, including the mattress, box springs, nightstands, dressers, upholstered and wooden furniture, picture frames and even outlet boxes. Normally bed bugs don’t move far from their hosts, mammals (including humans) and birds. They often hide in cracks and crevices near their blood meal source.

"It is nearly impossible to find all the bed bugs during one inspection," Harlan said. "I would strongly recommend budgeting two visits." During the first visit, he says, the PCO should vacuum any bugs that are found or he or she can collect the pests and put them into rubbing alcohol or soapy water. Any of these methods will kill the bugs. Additionally, PCOs should use their least repellent insecticide to treat the harborage sites and seal any cracks or crevices. In preparation for a second visit, monitors should be placed near harborage sites to check for additional bugs.

Outbreaks or infestations are not limited to single-family housing. "Several regional technical experts have been reporting them in homes, hotels, hostels and long-term care medical facilities," Harlan says, "as well as in university dormitories." A mitigating factor in this instance is the mobility of our society. It is possible to transport bed bugs in luggage, furniture or packages, during business travel, vacation or while moving. This fact also underlines the truism that outbreaks can keep occurring even after one infestation is eradicated.

One important aspect to remember is that bed bugs, even though they have been found to be infected with up to 20 or more human pathogens, have not been proven as vectors of any disease.

While bed bugs harbor inside near their hosts, ticks (which are outdoor pests), are vectors that are poised to have a resurgence this year.

TICKS. Warm, wet weather in the United States last summer provided fertile conditions for deer ticks (Ixodes scapularis), the carriers of Lyme disease (see related story on page 82). Hot weather curtails activity in ticks, while moisture abets the survival of ticks. In fact, 85 percent of ticks die from lack of moisture.

The life cycle of a deer tick is two years. Thus, eggs that hatched last spring into optimum conditions for survival became larvae. These larvae attached to hosts, such as mice, chipmunks or other small animals. The hosts may already have been infected with the bacterium that causes Lyme disease and the disease is transmitted to the tick. "It’s important to remember that once a tick feeds on an infected host, the tick remains infected for life," Harlan said. "It will then infect the next host it feeds on."

After the larvae feed, they drop off the host, usually in mid to late summer and they burrow into leaf litter where they remain inactive over the winter. In early spring, the larvae molt and become nymphs. The nymphs must find a host for a blood meal in order to molt into adulthood. At this point, nymphs usually select larger animals, such as birds, cats, dogs, squirrels or humans. The host is selected purely by opportunity — the nymphs cannot fly or jump, so they transfer to a host whenever a mammal is close enough to their habitat. The peak feeding time frame for nymphs is May and June, but it also can extend into August.

After the blood meal, the nymphs will molt into the adult state usually by late summer and will remain active through the winter. Once again, an adult must partake of a blood meal in order to lay eggs. The adult ticks prefer deer and other large animals. "With the deer population expanding, there is the viability for a larger number of tick eggs," Harlan explains.

MANAGEMENT. Pest management professionals should be aware of the conditions favored by ticks — leaf litter, brush, vines, tall grass — and educate their clients about reducing harborage sites. An attempt should be made to control the hosts preferred by ticks, including mice and small rodents, by exclusion methods. Additionally, pest management professionals can use insecticides at common harborage sites.

Customers must also be responsible and learn proper outdoor prevention techniques. These would include wearing long pants tucked into socks; wearing light-colored clothing to make it easier to see ticks; staying in the center of hiking paths; using a repellent on clothing and exposed skin; and checking for ticks and removing any immediately, followed by a disinfectant.

Pest management professionals can also relate the warning signs of Lyme disease to their customers. In the early stages of the disease, an infected person can experience headache and flu-like symptoms, swelling of joints and a bulls-eye rash. A physician should be consulted immediately if symptoms like this develop.

Although they reside in different habitats, both bed bugs and ticks may be poised to trigger an increased number of service calls in 2004.

The author is a freelance writer from Cleveland, Ohio. She can be reached via e-mail at dtaylor@pctonline.com.