Insecticide resistance in vector Chagas Disease: evolution, mechanisms and management

G. MOUGABURE CUETO; M.I. PICOLLO

ACTA TROPICA

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2015 vol. 149 p. 70 - 85

0001-706X

tChagas disease is a chronic parasitic infection restricted to America. The disease is caused by the proto-zoa Trypanosoma cruzi, which is transmitted to human through the feces of infected triatomine insects.Because no treatment is available for the chronic forms of the disease, vector chemical control repre-sents the best way to reduce the incidence of the disease. Chemical control has been based principallyon spraying dwellings with insecticide formulations and led to the reduction of triatomine distributionand consequent interruption of disease transmission in several areas from endemic region. However, inthe last decade it has been repeatedly reported the presence triatomnes, mainly Triatoma infestans, afterspraying with pyrethroid insecticides, which was associated to evolution to insecticide resistance. In thispaper the evolution of insecticide resistance in triatomines is reviewed. The insecticide resistance wasdetected in 1970s in Rhodnius prolixus and 1990s in R. prolixus and T. infestans, but not until the 2000s resis-tance to pyrthroids in T. infestans associated to control failures was described in Argentina and Bolivia. Themain resistance mechanisms (i.e. enhanced metabolism, altered site of action and reduced penetration)were described in the T. infestans resistant to pyrethrods. Different resistant profiles were demonstratedsuggesting independent origin of the different resistant foci of Argentina and Bolivia. The deltamethrinresistance in T. infestans was showed to be controlled by semi-dominant, autosomally inherited factors.Reproductive and developmental costs were also demonstrated for the resistant T. infestans. A discussionabout resistance and tolerance concepts and the persistence of T. infestans in Gran Chaco region are pre-sented. In addition, theoretical concepts related to toxicological, evolutionary and ecological aspects ofinsecticide resistance are discussed in order to understand the particular scenario of pyrethroid resistancein triatomines.