figure 2. life stages of the kissing bug triatoma gerstaekeri, from eggs (far left) through five nymphal stages to adult male and female (right). all nymph stages and adults feed on blood and can transmit the Chagas parasite. (photo by Dr. edward Wozniak)
inch), mostly nocturnal, blood feeding insects. These bugs are found through- out the Americas, and multiple species are established in at least 28 states of the southern half of the United States, as far north as Maryland, Northern Cali- fornia, Illinois, Indiana, Ohio, and Penn- sylvania; though the Chagas parasite has not yet been found in all of these states where further research is need- ed. (CDC, February 19, 2016). In Texas, over 50% of kissing bugs are infected with the Chagas parasite (Curtis-Robles et al., 2015). Kissing bugs develop into adults after a series of immature life stages called nymphs (see Fig. 2), and both nymphs and adults feed on blood. Unlike many insect-borne diseases, Chagas disease is not passed directly through the bite of the bug. The para- site lives in the digestive tract of the bug and is shed in the feces. Transmission of the parasite occurs when infectious bug fecal material contacts the mam- mal’s mucous membranes (eyes, nose, mouth) or the bug bite wound. Dogs are likely to become infected through consumption of infected bugs or their fecal material. Chagas disease can also be passed congenitally through the pla- centa from an infected mother to her offspring, passed through blood trans- fusion, and passed through transplan- tation of infected organs. Congenital transmission is of special concern to
from the many common look-alike species that pose no health risk. First is the long narrow head, or “nose” of the bug, which gives it the alternative name cone-nosed bug. Second, there is a characteristic flattened band around the outer edge of the body, which is almost always striped with orange or red markings. Other related species are similar in appearance to kissing bugs but feed on plants and other insects rather than blood and do not carry the Chagas parasite. Examples of common insects that are often confused with kissing bugs include leaf-footed bugs and wheel bugs (see Figs. 3 and 4). Kiss- ing bugs, unlike the leaf-footed bug, have uniformly thin legs with no areas that flare out or bulge. Wheel bugs can be differentiated from kissing bugs by the spiky ridge down the upper part of their back, which kissing bugs do not have. More information and additional
dog breeders, as there is a risk in breed- ing an infected dam that some of the puppies will be born infected and pos- sibly will die. Other than congenital transmission, the disease is not known to be spread easily from dog to dog or dog to human. This would require direct blood-to- blood or blood-to-mucous membrane contact with a dog that has the para- site actively circulating in the blood (thought to be a short period of time after infection). The presence of an infected dog in a home should serve as a warning indicator of the local environ- mental risk: that kissing bugs are likely present and are likely to be carrying the Chagas parasite.
identification of kissing Bugs
Key features aid in identification of kissing bugs and differentiating them
figure 3. leaf-footed bug, commonly misidentified as a kissing bug. notice the flared out areas on the rear legs that give this bug its name. (photo by michael merchant)
figure 4. Wheel bug, commonly misidentified as a kissing bug. notice the spiky ridge on the upper back and overall gray color. (photo by michael merchant) 5 01 / 05$) 5 0:4 . ": t
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