Bed Bugs Bounce Back - But Do They Transmit Disease?

Jerome Goddard, PhD

In This Article

Abstract and Introduction

Bed bugs had nearly disappeared in developed countries, but they have had a rapid resurgence in recent years. Their bites typically go undetected, but in some persons the bites may produce welts and local inflammation. While there is controversy about the ability of bed bugs to transmit disease, there appears to be no solid evidence that they are able to do so.

The common bed bug, Cimex lectularius, has been an associate of humans for thousands of years. The word Cimex is derived from the Roman designation for bug, and lectularius from the Latin name for couch or bed.[1] Bed bugs are common in eastern European and third world countries, especially in areas of extreme poverty. The blood-sucking parasites had nearly disappeared in developed countries until recently; in the last 5 to 10 years, they have been making a rapid comeback. The parasites have recently been reported as increasingly common inside US hotel rooms.[2]

Bed bugs are cosmopolitan in distribution, found in temperate re gions worldwide.[3] Another bed bug species, Cimex hemipterus, is also wide spread but is found mostly in the tropics. Several other bed bug species are found on bats, but they do not bite people.[3] Adult bed bugs are approximately 5 mm long, oval, and flattened. They somewhat resemble unfed ticks or small cockroaches. Adults are reddish brown (chestnut) (Figure 1); immature bugs resemble adults but may be yellowish white. Bed bugs have a pyramid-shaped head with prominent compound eyes, slender antennae, and a long proboscis tucked backward underneath the head and thorax. The prothorax (dorsal side, first thoracic segment) bears rounded, winglike lateral horns on each side.

Bed bug adult and cast skin. (Photograph by Jerome Goddard, PhD.)

Bed bugs possess stink glands and emit an odor. Homes heavily infested with the bugs have this distinct odor. Bed bugs feed at night, hiding in crevices during the day. Hiding places include seams in mattresses, crevices in box springs, and spaces under baseboards or loose wallpaper. There are 5 nymphal stages that must be passed before development to adulthood. Once an adult, the bed bug has a life span of 6 to 12 months. At each nymphal stage, the bed bug must take a blood meal (Figure 2) in order to complete development and molt to the next stage. The bugs take about 5 to 10 minutes to ingest a full blood meal. Bed bugs can survive long periods without feeding, and when their preferred human hosts are absent they may take a blood meal from any warm-blooded animal.

Bed bug nymph feeding on author's arm. (Photograph by Jerome Goddard, PhD.)

Bed bugs have piercing/sucking mouthparts typical of the insect order Hemiptera. Accordingly, bites from the bugs may produce welts and local inflammation, probably from allergic reactions to saliva injected during feeding.[4,5,6,7] On the other hand, in many persons the bite is nearly undetectable. Bed bug bite reactions are generally self-limited and require little specific treatment other than antiseptic or antibiotic creams or lotions to prevent infection.