Department of Neuroscience, College of Science, University of Arizona, Tucson, 85721-0077, USA.
Am J Trop Med Hyg. 2011 Oct;85(4):648-56. doi: 10.4269/ajtmh.2011.11-0137.
Chagas disease is caused by the parasite Trypanosoma cruzi, which is transmitted to humans by blood-sucking triatomine insects. This disease is endemic throughout Mexico and Central and South America, but only a few autochthonous cases have been reported in the United States, despite the fact that infected insects readily invade houses and feed on humans. Competent vectors defecate during or shortly after feeding so that infective feces contact the host. We thus studied the feeding and defecation behaviors of the prevalent species in southern Arizona, Triatoma rubida. We found that whereas defecation during feeding was frequent in females (93%), it was very rare in immature stages (3%), and absent in males. Furthermore, more than half of the immature insects that exhibited multiple feeding bouts (62%) defecated during interruptions of feeding, i.e., while likely on or near the host. These results indicate that T. rubida potentially could transmit T. cruzi to humans.
恰加斯病由寄生虫克氏锥虫引起，通过吸血的三锥虫传播给人类。这种疾病在墨西哥和中美洲、南美洲流行，但在美国只有少数本地病例报告，尽管感染的昆虫很容易侵入房屋并以人类为食。有能力的传播媒介在进食期间或之后不久就会排便，因此感染性粪便会接触到宿主。因此，我们研究了在亚利桑那州南部流行的物种——红三锥虫的进食和排便行为。我们发现，雌性（93%）在进食时经常排便，但在不成熟阶段（3%）很少排便，雄性则没有。此外，超过一半的表现出多次进食的未成熟昆虫（62%）在进食中断时排便，即在可能在或靠近宿主时排便。这些结果表明，红三锥虫可能会将克氏锥虫传播给人类。
