Concordance of the point-of-care circulating cathodic antigen test for the diagnosis of intestinal schistosomiasis in a low endemicity area.

BACKGROUND: The Kato-Katz technique is recommended worldwide for the diagnosis of intestinal schistosomiasis, detecting parasite eggs in feces of infected people. However, new tests have been developed in order to facilitate diagnosis, e.g. by detection of specific antigens secreted by schistosomes, such as the circulating cathodic antigen (CCA). The aim of this study was to evaluate the performance of the point-of-care circulating cathodic antigen test (POC-CCA) compared to the Kato-Katz technique in a low prevalence area in the Amazon Region, located in the municipality of Primavera, State of Pará, Brazil. METHODS: Positivity rates of the POC-CCA test and the Kato-Katz technique were calculated. The sensitivity, specificity, accuracy and kappa coefficient were determined by comparing both methods. The reference standard was established using 16 Kato-Katz slides, 12 of the first fecal sample, two of the second and two of the third one. The study also included the concordance between POC-CCA results and different numbers and combinations of Kato-Katz slides. RESULTS: The prevalence of schistosomiasis according to the reference standard or POC-CCA test reached a rate of 9.4% or 23.9%, respectively, among a total of 372 participants. The positivity rates by the Kato-Katz technique increased from 2.4 to 9.4%, according to the increase in the number of slides examined and fecal samples collected. A sensitivity of 55.6%, specificity 76.9%, accuracy 76% and κ coefficient of 0.06 was observed by comparing one slide of the first sample and POC-CCA. Comparing 6 slides from three different samples, two slides of each, with POC-CCA resulted in a sensitivity of 58.3%, specificity 78.4%, accuracy 77% and κ coefficient of 0.16. Finally, the comparison of 16 slides from three different samples with POC-CCA revealed a sensitivity of 65.7%, specificity 80.4%, accuracy 79%, and κ coefficient of 0.27. CONCLUSIONS: The immunochromatographic test has the potential to be an important tool to combat schistosomiasis because of its practicality and applicability but should be applied with caution in low prevalence areas and in programs that aim to eliminate this disease. TRIAL REGISTRATION: CAAE#21824513.9.0000.5091 . January 31st, 2014.

Fruit flies (diptera, tephritidae) in municipalities with a risk mitigation system for anastrepha grandis macquart / Moscas-das-frutas (Diptera, Tephritidae) em municípios com sistema de mitigação de risco para Anastrepha Grandis Macquart

The objective of this study was verify the presence of A. grandis and identify other fruit-fly species collected in MacPhail traps, installed in areas of Cucurbitaceae under a risk mitigation system for Anastrepha grandis Macquart in the Vale do São Patrício Region, state of Goiás, Brazil, from November 2004 to October 2009. A total of 812 specimens of Anastrepha were captured, of which 639 were males (78.7%) and 173 were females (21.3%). Fourteen species of Anastrepha were identified occurring in all seasons of the year. A. dissimilis Stone, A. quiinae Lima and A. pickeli Lima were recorded for the first time in the state of Goiás, and A. grandis and was recorded for the first time, with a low prevalence, in the municipalities of Jaraguá and Uruana, which belong to the risk mitigation system area, indicating good conditions for maintaining an area of low prevalence status. A. manihoti Lima (34.10%) was the most frequent species in the region, followed by A. obliqua (Macquart) (19.65%) and A. pickeli Lima (13.87%).

O objetivo do estudo foi verificar a presença de Anastrepha grandis e identificar demais espécies de moscas-das-frutas coletadas em armadilhas modelo MacPhail instaladas em áreas de cucurbitáceas sob Sistema de Mitigação de Risco (SMR) para A. grandis na região Vale do São Patrício, GO, de novembro de 2004 a outubro de 2009. Um total de 812 espécimes de Anastrepha foram capturadas, sendo 639 machos (78,7%) e 173 fêmeas (21,3%). Destas foram identificadas 14 espécies de Anastrepha, ocorrentes em todas as estações do ano. A. dissimilis Stone, A. quiinae Lima e A. pickeli Lima foram registradas pela primeira vez em Goiás e primeiro registro de A grandis, com baixa prevalência, nos municípios de Jaraguá e Uruana, constituintes da área de SMR, indicando ótimas condições para manutenção de área de baixa prevalência. A. manihoti Lima (34,10%) foi a espécie mais frequente na região, seguidade A. obliqua (Macquart) (19,65%) e A. pickeli (13,87%).