Seventy-one clones from 11 bugs containing vertebrate blood were isolated and characterized. Blood meal sources were inferred by using BLAST ( ). 10 The polymerise chain reaction products were cloned and sequenced to isolate multiple blood meals within a single insect. Previous work established that assays based on the 12S gene detected more blood meal sources than an assay based on the mitochondrial cytochrome B gene. 10 By using universal vertebrate primers for the mitochondrial 12S ribosomal gene, 11, 12 a broad net was cast to potentially identify as many blood meals as possible. cruzi parasite infection 7 using primers from Moser et al 9 were determined for each insect as previously reported. Of the 134 insects captured at the ASDM, 8 were randomly chosen to include both sexes, species, and collection sites. Bugs were placed in individual vials with 95% ethanol + 5% glycerol. These are the 3 most common kissing bugs in southern Arizona. In addition, 2 wild adult Triatoma recurva were collected on a roadway in Bisbee, Arizona, and 1 was collected in Colossal Cave, Arizona. A total of 134 kissing bugs (121 Triatoma rubida and 13 Triatoma protracta) were collected using ultraviolet lights at the Arizona-Sonora Desert Museum (ASDM), Tucson, Arizona, in May and June 2009. Ultraviolet “black lights” were set up in the desert in areas providing a clear flight path for the insects from all directions to the light source. Our findings indicate that wild-caught bugs feed often on humans in addition to large and small vertebrates. Is it possible that kissing bugs, like mosquitoes, feed on people engaged in outside activities? To answer this question, we determined the blood meal sources of wild kissing bugs captured in a zoological park in close proximity to a variety of vertebrates. As mentioned, kissing bugs feed on humans when trapped in houses after a dispersal flight, but little is known about the feeding habits of wild, free-roaming bugs. 7Ĭontact between kissing bugs and humans is an important indicator of the potential risk for Chagas disease and can be determined by investigating the frequency of human blood feeding. However, the house was 29 years old and provided many gaps for entry of bugs. Neither nymphs nor eggs were found in the house, indicating that the home was not colonized. More than 20 adult kissing bugs were found in her home 56% harbored T. 6 A well-documented example of autochthonous Chagas disease is a 74-year-old woman in New Orleans Parish, Louisiana, who was acutely infected with Chagas ( T. 5 Five of the seven cases involved infants or young children who presumably were infected in the home or the immediate environs. Nevertheless, there are 7 well-documented autochthonous cases of Chagas disease in the United States. Furthermore, use of solid wall and roof construction, features not conducive to colonization by kissing bugs, is standard in construction. In contrast, home construction in the warmer parts of the United States where kissing bugs reside is different, with an emphasis on energy conservation and sealing of homes for air conditioning. In this setting, contact with humans occurs frequently and often leads to infection. Kissing bugs colonize these homes and peri-domestic structures and may achieve densities of more than 1000 bugs per home. Bottom: Proboscis folded ventrally when not feeding.Ĭhagas disease in Latin America is closely linked to house construction with thatch roofing and wattle and daub walls that provide numerous crevices for bugs to hide. Blood meals may take minutes to a half an hour to complete and are often interrupted by movement of the host. When starved of a blood meal for approximately 2 weeks, these voracious bugs immediately begin to feed, even disregarding handling and removal from their habitat. Top: Adult female Triatoma ruhida preparing to feed Kissing bugs are nuisances in homes in San Diego, California, and Phoenix and Tucson, Arizona. This occasionally leads to human anaphylaxis 4 or, rarely, infection, in the United States. 2Īdult kissing bugs in the Southwest undergo a dispersal flight before the monsoon rains during the hottest days of summer and are attracted to lights near and on houses, 3 which they may enter beneath door thresholds and through window casings and feed on pet and human inhabitants ( Figure 1). 1 Yet, with climate change and possible changes in the behavior of kissing bugs, there is a potential for an increase in the number of vector-transmitted human infections with T. Kissing bug home ranges extend northward into the bottom two thirds of the United States however, the nearest endemic area of Chagas disease in humans is in Mexico. Eleven species of hematophagous kissing bugs are found in the United States, and all potentially harbor Trypanosoma cruzi, the parasite that causes Chagas disease.
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