Entamoeba histolytica: detection of coproantigens by purified antibody in the capture sandwich ELISA

A sensitive and specific Capture Sandwich ELISA (CSE) was developed using polyclonal purified rabbit antibodies against three different axenic strains of Entamoeba histolytica: CSP from Brazil and HM1 - IMSS from Mexico, for the detection of coproantigens in fecal samples. Immunoglobulin G (IgG) againstis E. histolytica was isolated from rabbits immunized with throphozoites whole extract in two stages: affinity chromatography in a column containing E. histolytica antigens bound to Sepharose 4B was followed by another chromatography in Sepharose antibodies 4B-Protein A. A Capture Sandwich ELISA using purified antibodies was able to detect 70ng of amebae protein, showing a sensitivity of 93% and specificity of 94%. The combination of microscopic examination and CSE gave a concordance and discordance of 93.25% and 6.75%, respectively. It was concluded that CSE is highly specific for the detection of coproantigens of E. histolytica in feces of infected patients, is quicker to perform, easier and more sensitive than microscopic examination.

Entamoeba histolytica: fecal antigen capture immunoassay for the diagnosis of enteric amebiasis by a monoclonal antibody

Amebiasis continues to be of epidemiological importance in underdeveloped countries. Clinical diagnosis and epidemiological setting in a region are based on the fecal microscopic identification of cysts or trophozoites. This procedure requires well trained personnel, is laborious, of low sensitivity and frequently yields false-positives results. The present study was designed to develop an immuno-enzymatic fecal 96 kDa antigen capture test (COPROELISA-Eh) more sensitive and specific than microscopic diagnosis of amebiasis. Triplicates of 177 stool samples processed by the formol-ether concentration method, were defined as positive or negative by three experienced microscopic observers. Another aliquot was submitted to the antigen capture test by a monoclonal antibody against a specific membrane antigen of pathogenic strains of Entamoeba histolytica. Optical densities were interpreted as positive when they exceeded the mean value of negative samples plus two standard deviations. COPROELISA-Eh showed a 94.4% sensitivity, 98.3% specificity, 96.2% positive predictive value and 97.6% negative predictive value for the detection of E. histolytica in feces. COPROELISA-Eh is more sensitive and specific than microscopic examination, does not require specially trained personnel and allows the simultaneous processing of a large number of samples.

Geographical distribution and intra-domiciliary capture of sylvatic triatomines in La Convención province, Cusco, Peru

The geographical distribution and intra-domiciliary capture of sylvatic triatomines in three districts of the province of La Convención, Cusco, Peru are presented. In the district of Vilcabamba, eight adults of Rhodnius pictipes and five adults of Panstrongylus geniculatus were found. In the district of Ocobamba, 19 adults, 14 nymphs, and eggs of P. rufotuberculatus were found. In the district of Echarate, six adults and 10 nymphs of Eratyrus mucronatus, an adult of R. pictipes and P. geniculatus, and a nymph of P. rufotuberculatus were also found. The geographical distribution of E. mucronatus has extended to Cusco. This is the first report in Peru of household colonization by this triatomine.

Comparison of capture methods for the diagnosis of adult anopheline populations from State of Mato Grosso, Brazil

INTRODUCTION: The present study compares human landing catches of primary malaria vectors with two alternative methods of capture: the Shannon trap and the Mosquito magnet. METHODS: This study used regression models to adjust capture data to a negative binominal distribution. RESULTS: Capture numbers and relative percentages obtained from the three methods vary strongly between species. The highest overall captures were obtained for Anopheles triannulatus with captures for the Shannon trap and the Mosquito magnet measuring more than 330% higher than captures obtained by human landings. For Anopheles darlingi, captures by the Shannon trap and the Mosquito magnet were about 14% and 26% of human landing catches, respectively. Another species with malaria transmission potential that was not sampled by human landing captures weascaptured by the Shannon trap and the Mosquito magnet (Anopheles oswaldoi). Both alternative sampling techniques can predict the human landing of Anopheles triannulatus, but without proportionality. Models for Anopheles darlingi counts, after totaling daily captures, are significant and proportional, but prediction models are more reliable when using the Shannon trap compared with the Mosquito magnet captures. CONCLUSIONS: These alternative capture methods can be partially recommended for the substitution of human landing captures or, at least, as complementary forms of monitoring for malarial mosquitoes.

Capture of Triatoma arthurneivai (Hemiptera: Reduviidae) using a new luminous trap in Southeast Brazil

INTRODUCTION: Triatomine bug captures in the wild are laborious and time-consuming. Some traps may assist in this task. We report a new trap design and the capture of a specimen of a triatomine rarely found. METHODS: Two luminous traps were installed in the city of Diamantina, State of Minas Gerais, and surveyed weekly for a year. RESULTS: A Triatoma arthurneivai female and other triatomine bugs were caught. CONCLUSIONS: A new trap design may be used in triatomine bugs field captures, mainly in low density areas. We assume the center of endemism of Triatoma arthurneivai is the Espinhaço Mountain range.

Hybrid capture II and PapilloCheck® tests for detection of anal high-risk human papillomavirus

Introduction This study evaluated the level of concordance between hybrid capture II (HCII) and PapilloCheck® for the detection of high-risk human papillomavirus (HPV) in anal samples. Methods Anal cell samples collected from 42 human immunodeficiency virus (HIV)+ patients were analyzed. Results Considering only the 13 high-risk HPV types that are detectable by both tests, HCII was positive for 52.3% of the samples, and PapilloCheck® was positive for 52.3%. The level of concordance was 80.9% (Kappa = 0.61). Conclusions Good concordance was observed between the tests for the detection of high-risk HPV.

Water depth selection during foraging and efficiency in prey capture by the egrets Casmerodius albus and Egretta thula (Aves, Ardeidae) in an urban lagoon in Rio de Janeiro State, Brazil

This study aimed to evaluate the water depth selection during foraging, the efficiency in prey capture, and the food items captured by Casmerodius albus (Linnaeus, 1758) and Egretta thula (Molina, 1782). The work was conducted at an urban lagoon, Lagoa Rodrigo de Freitas, Rio de Janeiro. Four transects were made each month (two in the morning and two in the afternoon) for six months. When the birds were detected foraging, the water depth and the types of prey captured were recorded. There was no significant relationship between the foraging efficiencies of the two species. However, they differed in relation to the water depth when foraging, and also in the food items captured. Casmerodius albus captured mainly fishes while Egretta thula captured mainly invertebrates. The results suggest that the differences in water depth when foraging and the food items captured allow a differential use of the food resources available by C. albus and E. thula at Lagoa Rodrigo de Freitas.

Capture of Caliptrate flies with different breeding substrates on beaches in Rio de Janeiro, RJ, Brazil

Muscidae flies belonging to four Familia and 13 species in a total number of 3.652 specimens were collected from beaches at Ilha do Governador, Rio de Janeiro, Brazil using different breeding substrates, and subsequently bred in the laboratory. Captures were done from April to November 1989, using in a first phase different substrates: fruits (banana and papaya), vegtable (tomato), animal viscera (bovine liver), marine animals (fish, crab, shrimp, squid), mouse carcass and feaces (human and canine). The species collected more often were: Fannia sp. (subgroup pusio), Chrysomya megacephala, Phaenicia eximia, Synthesiomyia nudiseta, Peckya chrysostoma, Musca domestica and Atherigona orientalis. In a later phase, only fish was used, as bait and placed directly on the beach sand. From a total of 189 pupae, the following adult specimen were obtained: Peckia chrysostoma (58.06%), Chrysomya megacephala (30.64%) and in lesser numbers Synthesiomyia nudiseta and Phaenicia eximia.

Frequency of Infection of Lutzomyia Phlebotomines with Leishmania braziliensis in a Brazilian Endemic Area as Assessed by Pinpoint Capture and Polymerase Chain Reaction

Leishmania infected of Lutzomyia spp. are rare in endemic areas. We tested the hypothesis that there is clustering of infected vectors by combining pinpoint capture with sensitive L. braziliensis kDNA minicircle specific PCR/dot blot in an endemic area in the State of Bahia. Thirty out of 335 samples (10 to 20 sand flies/sample; total of 4,027 female sand flies) were positive by PCR analysis and dot blot leading to a underestimated overall rate of 0.4% positive phlebotomines. However, 83.3% of the positive samples were contributed by a single sector out of four sectors of the whole studied area. This resulted in a rate of 1.5% Leishmania positive phlebotomines for this sector, far above rates of other sectors. Incidence of American cutaneous leishmaniasis cases for this sector was about twice that for other sectors. Our results show that there is a non-homogeneous distribution of Leishmania-infected vectors. Such a clustering may have implications in control strategies against leishmaniasis, and reinforces the necessity of understanding the ecological and geographical factors involved in leishmanial transmission.

Modification of Disney trap for capture of sand flies (Diptera: Psychodidae: Phlebotominae)

This paper describes the modifications made to the original model of the Disney trap, with a view to easier handling of the same, greater practicability in the collection of sand flies, protection of the animal bait and durability of the trap in the field.

Are light traps baited with kairomones effective in the capture of Lutzomyia longipalpis and Lutzomyia intermedia? An evaluation of synthetic human odor as an attractant for phlebotomine sand flies (Diptera: Psychodidae: Phlebotominae)

Phlebotomine sand flies are often captured with human bait and/or light traps, either with or without an animal bait. More recently, synthetic attractants have been used as bait in traps to improve the capture of phlebotomine sand flies as well as other insects of medical and veterinary importance. The aim of the present study was to evaluate the effects of the kairomone 1-octen-3-ol (octenol) and the synthetic human odor BG-Mesh LureTM (BGML - lactic acid, caproic acid and ammonia) baited in modified CDC light traps on the capture of phlebotomine sand flies. The experiments followed the 5x5 Latin square design. Among the species caught, Lutzomyia intermedia apparently presented a dose-dependent response to octenol. The response obtained with the BGML, alone or in combination with octenol (5 mg/h), indicated some degree of attractiveness of these baits to different phlebotomine sand fly species. Octenol seems to be more attractive to L. intermedia than to Lutzomyia longipalpis, while the BGML presented a higher success in capturing L. longipalpis. When the components of the BGML were used separately, there was no increase in catching the female of L. intermedia. Apparently, there was no synergistic effect between the octenol and the BGML. In conclusion, the octenol and the BGML were demonstrated to be possible baits to attract some phlebotomine sand fly species.

Mosquito traps designed to capture Aedes aegypti (Diptera: Culicidae) females: preliminary comparison of Adultrap, MosquiTRAP and backpack aspirator efficiency in a dengue-endemic area of Brazil

In this report, the efficiency of Adultrap under field conditions is compared to a CDC backpack aspirator and to MosquiTRAP. An urban dengue-endemic area of Rio de Janeiro was selected to evaluate the efficiency of mosquito traps in capturing Aedes aegypti females. Adultrap and aspirator captured similar numbers of Ae. aegypti females, with the former showing high specificity to gravid individuals (93.6%). A subsequent mark-release-recapture experiment was conducted to evaluate Adultrap and MosquiTRAP efficiency concomitantly. With a 6.34% recapture rate, MosquiTRAP captured a higher mean number of female Ae. aegypti per trap than Adultrap (Ç2 = 14.26; df = 1; p < 0,05). However, some MosquiTRAPs (28.12%) contained immature Ae. aegypti after 18 days of exposure in the field and could be pointed as an oviposition site for female mosquitoes. Both trapping methods, designed to collect gravid Ae. aegypti females, seem to be efficient, reliable and may aid routine Ae. aegypti surveillance.

Risk of dengue occurrence based on the capture of gravid Aedes aegypti females using MosquiTRAP

We assessed the risk classification of dengue fever based on the capture of Aedes aegypti adults using MosquiTRAP, a type of sticky trap, in comparison with traditional larval infestation indices. A total of 27 MosquiTRAPs were installed, with one trap per block, and were inspected weekly between November 2008-February 2009. Infestation baseline data were obtained from a survey conducted prior to trap installation. The index generated by MosquiTRAP and house index (HI) classified the area "in alert situation". The set for risk of dengue occurrence proposed by the use of MosquiTRAP classify areas in the same way of the traditional HI.

Development of the BG-Malaria trap as an alternative to human-landing catches for the capture of Anopheles darlingi

Although the human-landing catch (HLC) method is the most effective for collecting anthropophilic anophelines, it has been increasingly abandoned, primarily for ethical considerations. The objective of the present study was to develop a new trap for the collection of Anopheles darlingi . The initial trials were conducted using the BG-Sentinel trap as a standard for further trap development based on colour, airflow direction and illumination. The performance of the trap was then compared with those of the CDC, Fay-Prince, counterflow geometry trap (CFG) and HLC. All trials were conducted outdoors between 06:00 pm-08:00 pm. Female specimens of An. darlingi were dissected to determine their parity. A total of 8,334 anophelines were captured, of which 4,945 were identified as An. darlingi . The best trap configuration was an all-white version, with an upward airflow and no required light source. This configuration was subsequently named BG-Malaria (BGM). The BGM captured significantly more anophelines than any of the other traps tested and was similar to HLC with respect to the number and parity of anophelines. The BGM trap can be used as an alternative to HLC for collecting anophelines.