A new tactic for Triatoma infestans control: fabrics impregnated with beta-cypermethrin

Triatoma infestans is the most important vector of Chagas disease in Argentina. Experiences from Argentine national campaigns have shown indoor spraying to control triatomine bugs is both expensive and difficult. An alternative control method may be the use of pyrethroid- impregnated fabrics (PIFs), which could be both a practical and cheap complement to conventional control measures. In this study, a formulation of emulsifiable concentrate of beta-cypermethrin [a-cyano-3-phenoxybenzyl-3- (2,2-dichlorovinyl) -2,2-dimethylcyclopropanecarboxilate] pyrethroid was used to impregnate different fabrics. The fabrics were then tested for their efficacy and persistence in killing Triatoma infestans. Insects attempting to penetrate or grasp the fabric in search of blood meals were poisoned by the exposure to the absorbed pyrethroid. Laboratory bioassays showed that the insecticidal effect of the PIFs with a dosage of 0.2 g/m² lasted longer on wool than on cotton or rayon. Eight months after impregnation, a residual efficacy of 100% was found for wool, 80% for rayon-cotton fabrics, and 50% for rayon- polyester fabrics. In addition, beta-cypermethrin-impregnated fabrics showed a better repellency effect than did fabrics impregnated with either deltamethrin or cypermethrin. For field trials, fabrics were impregnated either in the laboratory or "in situ" at a dosage of 1 g beta-cypermethrin/m² and then dried. The PIFs were placed inside homes, either under the roof or under the bed mattress. The field trials showed the PIF approach to be very effective in keeping dwellings free of triatomine bugs for at least one year and found a high degree of acceptability among the houses residents

Non-Compaction Cardiomyopathy. Risk Stratification of Sudden Death for Automatic Cardioverter Defibrillator Implantation

Non-compaction cardiomyopathy is a rare disease. Its natural history includes heart failure, thromboembolic events, arrhythmias and sudden death (SD). In the absence of data from randomized studies or records, the ACC / AHA / HRS 2008 guidelines recommend the automatic implantable cardioverter defibrillator (AICD) in all patients with non-compaction cardiomyopathy to reduce the risk of suden death.ObjectiveDescribe the outcomes of patients with non-compaction cardiomyopathy according to selected criteria for risk stratification of sudden death to decide the implantation of an AICD.Material and MethodsA total of 80 patients were analyzed. The diagnosis was established by echocardiography and nuclear cardiac magnetic resonance imaging criteria.The criteria for implantation of an AICD as a secondary prevention included sudden death and sustained ventricular tachycardia (SVT); as primary prevention included left ventricular ejection fraction (LVEF) < 30% or ≥ 2 risk factors (family history of sudden death [FHSD], syncope and non-sustained VT).   Introducción La miocardiopatía no compactada es una entidad rara. Su historia natural incluye insuficiencia cardíaca, eventos tromboembólicos, arritmias y muerte súbita (MS). En ausencia de datos de estudios aleatorizados o registros, las Guías ACC/AHA/HRS 2008 recomiendan el cardiodesfibrilador automático implantable (CDAI) en todos los pacientes con miocardiopatía no compactada para reducir el riesgo de muerte súbita. ObjetivoDescribir la evolución de pacientes con miocardiopatía no compactada de acuerdo con criterios seleccionados de estratificación de riesgo de muerte súbita para decidir el implante de un CDAI.Material y métodosSe analizaron 80 pacientes. El diagnóstico se estableció mediante criterios ecocardiográficos y de resonancia magnética nuclear cardíaca. Los criterios para el implante de un CDAI como prevención secundaria incluyeron muerte súbita y taquicardia ventricular sostenida (TVS); como prevención primaria comprendieronfracción de eyección del ventrículo izquierdo (FEVI) < 30% o ≥ 2 factores de riesgo (antecedentes familiares de muerte súbita [AFMS], síncope y TV no sostenida).  (resumen completo en pdf

Incoordination, Paralysis and Recovery after Pyrethroid Treatment on Nymphs III of Triatoma infestans (Hemiptera: Reduviidae)

Symptoms of poisoning for deltamethrin and cis-permethrin on nymphs III of Triatoma infestans were described. The time required for incoordination and paralysis were determined. Deltamethrin was equal or more rapid in the onset of the first effect (accordingly to dose), and cis-permethrin in the onset of the second one. There were no significant differences between incoordination doses 50% (IncD50s) at different times for the two pyrethroids. They showed equivalent incoordination power, but the nymphs treated with deltamethrin recovered slightly more rapid and in greater amount than the nymphs treated with cis-permethrin. The recovery was inhibited by the simultaneus application of piperonyl butoxide. This result suggests that biotransformation by mixed-function microsomal oxidases are involved in the process of recover