Resumo
Rabies is a vaccine-preventable disease that causes acute encephalitis in mammals, and it is still a significant public health problem in numerous countries. Infected dogs represent the main vectors involved in human rabies. Additionally, cattle rearing close to geographic areas where vampire bats are found presents an important connection with rural epidemiology. We applied two "in-house" enzyme-linked immunosorbent assay (ELISA) methodologies, considered alternatives to measure antibodies from vaccinated dogs and cattle, without employing the gold standard approach. The ELISA assays were performed on individual serum samples taken from domestic adult dogs and cows compulsory vaccinated against rabies (147 urban dogs and 64 cows; n = 211). The sandwich and liquid-phase competitive ELISA (scELISA and lpcELISA), considered "in-house" assays, were performed according to previous works. The only statistical methodology that allows this study is the Bayesian approach, developed to replace the conventional Hui-Walter paradigm. For conditional independent Bayesian model (one population, two tests and no gold standard) the prior information for sensitivity and specificity of each test, mode, prevalence and transformed (á, â) were submitted to Bayesian inference. The "in-house" lpcELISA revealed 16 - out of 261 serum samples - negative results, whereas in scELISA all results were positive. The Bayesian approach showed that prior information was specified for all parameters; posterior medians were Se scELISA 89%, Sp scELISA 88%, Sp lpcELISA 95% Se lpcELISA 98%, and prevalence (pi) of 99%, without the use of gold standard analysis to measure specific anti-rabies antibodies.
Resumo
ABSTRACT The present study describes the methodology used for evaluating the mortality of Boophilus microplus larvae submitted to treatments with acaricide products. The technique presented allows for the daily observation of individuals of the same treatment, for at least 20 days, without any significant change in the mortality percentages of the control group. It can be used in any experiment made to observe the total or cumulative mortality of larvae treated with chemical products, plant extracts or entomopathogenic agents.
RESUMO O presente estudo descreve metodologia para avaliação de mortalidade de larvas de Boophilus microplus submetidas a tratamentos com produtos carrapaticidas. A técnica apresentada permite a observação diária de indivíduos de um mesmo tratamento por, pelo menos, 20 dias, sem que haja alteração significativa nos percentuais de mortalidade do grupo controle. Pode ser utilizada em qualquer experimento conduzido com o objetivo de se observar a mortalidade total ou acumulada de larvas tratadas com produtos químicos, extratos vegetais ou agentes entomopatogênicos.