Browsing by Autor "Eva H. Clark"

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Biomarkers and Mortality in Severe Chagas Cardiomyopathy
(Elsevier BV, 2015) Jacqueline E. Sherbuk; Emi Okamoto; Morgan A. Marks; Enzo Fortuny; Eva H. Clark; Gerson Galdos‐Cardenas; Angel Vasquez-Villar; Antonio B. Fernández; Thomas Crawford; Q. Rose
Severe Chagas cardiomyopathy is associated with high short-term mortality. BNP, NT-proBNP, CK-MB, and MMP-2 have added predictive value for mortality, even in the presence of decreased ejection fraction and other clinical signs of congestive heart failure.
Hyperendemic Chagas Disease and the Unmet Need for Pacemakers in the Bolivian Chaco
(Public Library of Science, 2014) Eva H. Clark; Jacqueline E. Sherbuk; Emi Okamoto; Malasa Jois; Gerson Galdos‐Cardenas; Julio Vela-Guerra; Gilberto Silvio Menacho-Mendez; Ricardo W. Bozo-Gutierrez; Antonio B. Fernández; Thomas Crawford
Morbidity and mortality from Chagas cardiomyopathy have declined over the last three decades because of disruption of domestic vector-borne transmission, improved Trypanosoma cruzi infection treatment programs, and increasing availability of advanced cardiac care. However, the Gran Chaco, an ecological zone that includes parts of Argentina, Bolivia, and Paraguay, continues to struggle with extremely high rates of vector infestation and T. cruzi infection. In addition, this region is one of the poorest in the world, with most individuals living on less than US$2 per day. We estimate that thousands of patients are in need of pacemakers secondary to advanced Chagas cardiomyopathy. However, the vast majority of these individuals lack the resources to obtain these life-saving devices. A collaborative effort must be made by pacemaker donation programs, local implantation hospitals, and the governments of countries affected by Chagas disease to address this unmet need. With the necessary cooperation and infrastructure, pacemaker reuse programs have the potential to offer thousands of low-cost devices to impoverished patients with advancing Chagas cardiomyopathy.
Toxicological, Enzymatic, and Molecular Assessment of the Insecticide Susceptibility Profile of<i>Triatoma infestans</i>(Hemiptera: Reduviidae, Triatominae) Populations From Rural Communities of Santa Cruz, Bolivia
(Oxford University Press, 2016) Pablo Luis Santo‐Orihuela; Claudia Vassena; Guillermo Carvajal; Eva H. Clark; Silvio Menacho; Ricardo Bozo; Robert H. Gilman; Caryn Bern; Paula L. Marcet
A wide range of insecticide resistance profiles has been reported across Bolivian domestic and sylvatic populations of Triatoma infestans (Klug, 1834) (Hemiptera, Reduviidae), including some with levels proven to be a threat for vector control. In this work, the insecticide profile of domestic T. infestans was studied with standardized toxicological bioassays, in an area that has not undergone consistent vector control. F1 first-instar nymphs hatched in laboratory from bugs captured in three communities from the Santa Cruz Department were evaluated with different insecticides. Moreover, the enzymatic activity of esterases and cytochrome P450 monooxygenases was measured in individual insects to evaluate the possible mechanism of metabolic resistance to pyrethroids. In addition, the DNA sequence of sodium channel gene (kdr) was screened for two point mutations associated with pyrethroid resistance previously reported in T. infestans.All populations showed reduced susceptibility to deltamethrin and α-cypermethrin, albeit the RR50 values varied significantly among them. Increased P450 monooxygenases and permethrate esterases suggest the contribution, as detoxifying mechanisms, to the observed resistance to deltamethrin in all studied populations. No individuals presented either mutation associated to resistance in the kdr gene. The level of susceptibility to α-cypermethrin, the insecticide used by the local vector control program, falls within an acceptable range to continue its use in these populations. However, the observed RR50 values evidence the possibility of selection for resistance to pyrethroids, especially to deltamethrin. Consequently, the use of pyrethroid insecticides should be closely monitored in these communities, which should be kept under entomological surveillance and sustained interventions.