Larvoscopic study on Dictyocaulus sp. in the faeces of beef cattle in northeastern Brazil / Estudo larvoscópico de Dictyocaulus sp. em fezes de bovinos de corte do nordeste do Brasil

Abstract The lungworm Dictyocaulus viviparus has an important role in cattle health and productivity worldwide, since infections can lead to substantial economic losses. Despite its importance, few studies investigating the epidemiological aspects of infection by this parasite have been conducted. The aim of this study was to report the occurrence of lungworm infection in beef cattle herds reared in an area of livestock production in the northeastern region of Brazil. From September 2020 to August 2021, monthly fecal samples (n = 493) were collected from 46 beef cattle. Among all the animals assessed, lungworm larvae were detected in 8.7% (4/46). None of them presented any clinical sign suggestive of infection by lungworm parasites. Twenty larvae were retrieved, with the minimum number (n = 1) detected in October and December, and the maximum number (n = 13) in November. These presented a mean length of 363 μm (± 28.65 μm) and mean width of 19 μm (± 1.03 μm), and were morphologically similar to Dictyocaulus sp.. This study reports the occurrence of this parasite in this livestock production area. Lastly, local veterinarians need to be aware of inclusion of this parasite in the differential diagnosis of other respiratory infections in beef cattle.

Resumo O parasito pulmonar Dictyocaulus viviparus tem um papel importante na saúde e produtividade bovina em todo o mundo, uma vez que infecções podem levar a perdas econômicas. Além de sua importância, poucos estudos que investigam aspectos epidemiológicos das infecções por esse parasito têm sido realizados. Objetivou-se, nesta pesquisa, relatar a ocorrência de infecção por nematódeos pulmonares em rebanhos bovinos de corte, criados em uma importante área de produção pecuária, na região Nordeste do Brasil. De setembro de 2020 a agosto de 2021, foram coletadas, mensalmente, amostras fecais (n = 493) de 46 bovinos de corte. De todos os animais avaliados, larvas de nematódeos pulmonares foram detectadas em 8,7% (4/46). Os animais não apresentaram nenhum sinal clínico sugestivo de infecção por parasitos pulmonares. Vinte larvas foram recuperadas, com o número mínimo (n = 1) detectado em outubro e dezembro, e o número máximo (n = 13) em novembro. Apresentavam comprimento médio de 363 μm (± 28,65 μm), largura média de 19 μm (±1,03 μm) e eram morfologicamente semelhantes a Dictyocaulus sp.. Este estudo relata a ocorrência desse parasito nesta área. Logo, os veterinários locais devem estar atentos à inclusão desse parasito no diagnóstico diferencial de outras infecções respiratórias em bovinos de corte.

Larvicidal activity of Caesalpinia ferrea Mart. and Lippia origanoides Cham. Against Aedes aegypti (LINNAEUS, 1762) (Diptera: Culicidae)

The control of Aedes aegypti has been considered one of the most important public health challenges worldwide. Chemical compounds have long been used for this purpose, but resistance to these molecules has also increased. Therefore, over the last few years several studies have focused on the development of alternative tools, particularly those based on plant metabolites. The purpose of this study was to assess the larvicidal activity of Caesalpinia ferrea and Lippia origanoides against Ae. aegypti. Larvae (L3) of Ae. aegypti Liverpool and Rockefeller strains, as well as of the Recife population were exposed to different concentrations of C. ferrea (ranging from 13.1 to 105 mg/mL) and L. origanoides (ranging from 16.3 to 130 mg/mL), and the mortality rate was evaluated up to 48 hours after the beginning of the experiment. All tested groups and ontrol group were quadruplicated. For C. ferrea, mortality ranged from 42.5% to 100% for Ae. aegypti Liverpool strain, from 67% to 100% for Ae. aegypti Rockfeller strain, and 57% to 100% for Ae. aegypti Recife population after 48 hours of larval exposure. For L. origanoides, the larvicidal activity ranged from 75% to 100% for Ae. aegypti Liverpool strain, from 61.5% to 100% for Ae. aegypti Rockfeller strain, and from 60.5% to 100% for Ae. aegypti Recife population. The hydro ethanol extract of C. ferrea and L. origanoides presented larvicidal activity against Ae. aegypti.

Sandflies in an endemic area for Visceral Leishmaniasis in Northeastern Brazil / Flebotomíneos em uma área endêmica para Leishmaniose Visceral no Nordeste do Brasil

Abstract Phlebotomines of the genus Lutzomyia are important vector for species of Leishmania, the etiological agent of leishmaniasis. The aim of this study was to assess the diversity of sandflies in an endemic area for Visceral Leishmaniasis (VL). Sampling was performed in four localities on the coast of the municipality of Goiana, state of Pernambuco, Northeastern Brazil. Specimens were collected monthly on three consecutive nights, from November 2017 to October 2018. CDC light traps were installed at a height of 1.5 m above the ground, in two ecotypes (i.e. tree and animal facility), both in peridomestic areas. A total of 5,205 sandflies were collected, among which the species Lutzomyia longipalpis (99.85%; 5,197/5,205) was the most common, followed by Lutzomyia evandroi (0.13%; 07/5,205) and Lutzomyia whitmani (0.02%; 01/5,205). Specimens of L. longipalpis were collected throughout the study period and most of them were found near to the animal facilities. The findings from this research indicate that vectors for Leishmania infantum are present in the study area throughout the year, along with occurrences of vectors relating to Cutaneous Leishmaniasis (CL). Preventive vector control measures need to be implemented in Goiana to reduce the risk of infection for the human and animal populations.

Resumo Flebotomíneos do gênero Lutzomyia são importantes vetores de espécies de Leishmania, agente etiológico das leishmanioses. O objetivo deste estudo foi avaliar a diversidade de flebotomíneos em área endêmica para Leishmaniose Visceral (LV). As coletas foram realizadas em quatro localidades do litoral do município de Goiana, Pernambuco, Nordeste do Brasil. Os espécimes foram coletados mensalmente em três noites consecutivas de novembro de 2017 a outubro de 2018. Foram instaladas armadilhas luminosas modelo CDC a uma altura de 1,5 m acima do solo em dois ecótopos (ex. árvore e instalações de animais), ambos em áreas peridomiciliares. Um total de 5.205 flebotomíneos foi coletado, sendo Lutzomyia longipalpis (99,85%; 5.197/5.205) a mais comum, seguida por Lutzomyia evandroi (0,13%; 07/5.205) e Lutzomyia whitmani (0,02%; 01/5.205). L. longipalpis foi coletada durante todo o período do estudo. A maioria dos espécimes foi detectada perto das instalações dos animais. Os achados deste estudo indicam a presença de vetores de Leishmania infantum na área avaliada ao longo do ano, bem como a ocorrência de vetores relacionados à Leishmaniose Cutânea (LC). Medidas preventivas de controle vetorial devem ser implementadas em Goiana para reduzir o risco de infecção à população humana e animal.

Spatial distribution of Aedes aegypti (Diptera: Culicidae) in vulnerable areas for the transmission of arboviruses

Abstract INTRODUCTION: Areas at risk of transmission of arboviruses have been monitored using ovitraps. This study aimed to evaluate the spatial distribution of Aedes aegypti in vulnerable areas for the transmission of arboviruses and assess the influence of climatic conditions on the infestation of these culicids. METHODS: Ovitraps were installed in Agrestina, Pernambuco, Northeastern Brazil. RESULTS: Overall, 44,936 eggs were collected, and the indexes of infestation varied. Relative humidity was significantly associated with the infestations. CONCLUSIONS: Using ovitraps, entomologic indexes and analysis of climatic factors might be good strategies for monitoring vulnerable areas for the transmission of arboviruses.

Detection and molecular characterization of Trypanosoma (Duttonella) vivax in dairy cattle in the state of Sergipe, northeastern Brazil / Detecção e caracterização molecular de Trypanosoma (Duttonella) vivax em gado leiteiro no estado de Sergipe, no Nordeste do Brasil

Abstract Trypanosoma (Duttonella) vivax is an important cause of economic losses among feedlot cattle. These losses are related to the morbidity, mortality, reproductive issues and decreased production. It is known that the clinical signs observed in infections by this protozoon are similar to other hemoparasitosis, which difficult the diagnosis. Therefore, the aim of this study was to detect and molecularly characterize an outbreak of trypanosomiasis caused by T. (D.) vivax in dairy cattle in the municipality of São Miguel Aleixo, state of Sergipe, Brazil. Blood samples from cattle (n = 15) presenting clinical signs compatible with trypanosomiasis were collected and parasitological and molecular evaluated. Among the samples analyzed, 34% (5/15) were positive from blood smears, 60% (9/15) from the buffy coat method and 80% (12/15) from the molecular method. The DNA sequence obtained (659 bp) showed 99% similarity to T. (D.) vivax sequences that are available in the GenBank database. The presence of this protozoon in cattle herds is a problem for producers. Diagnosing trypanosomiasis is problematic because its evolution is similar to that of other parasitic blood diseases. In addition, this is the first report of infection by T. (D.) vivax in cattle in the state of Sergipe, northeastern Brazil.

Resumo Trypanosoma (Duttonella) vivax é responsável por consideráveis perdas econômicas na bovinocultura. Estas perdas estão relacionados à morbidade, mortalidade, problemas reprodutivos e declínio na produção. Sabe-se que os sinais clínicos apresentados em infecções por este protozoário se assemelha a outras hemoparasitoses, dificultando muitas vezes o diagnóstico. Portanto, objetivou-se com este estudo detectar a ocorrência de T. (D.) vivax em bovinos leiteiros no município de São Miguel Aleixo, Estado de Sergipe, Brasil. Para tanto, amostras de sangue (n = 15) foram coletadas e avaliadas através de métodos parasitológicos e moleculares. Do total das amostras analisadas, 34% (5/15) foram positivas no esfregaço sanguíneo, 60% (9/15) pelo método do Buffy Coat, enquanto na biologia molecular 80% (12/15) amplificaram um fragmento de DNA (659 pb) compatível com T. (D.) vivax (GenBank). Em conclusão a presença de T. (D.) vivax nos rebanhos bovinos caracteriza-se como um problema para os pecuaristas, como também para o diagnóstico, uma vez que essa tripanossomíase apresenta evolução semelhante a outras hemoparasitoses. Ademais, este é o primeiro relato de infecção por T. (D.) vivax em bovinos do estado de Sergipe, nordeste do Brasil.

Reliability of different methods of diagnosing intestinal parasites in horses

Parasitism by intestinal nematodes may cause serious injuries to equines affecting their performance, given that the parasites compete for food and cause irritation, internal bleeding and anaemia. The diagnostic methods currently available are not efficient in detecting all the species of parasites simultaneously, hampering reliable diagnosis. Therefore, the purpose of this study was to evaluate four diagnostic methods for detecting equine intestinal parasites in the southern hinterland of Pernambuco, Brazil. Fecal samples (n = 87) were collected and examined through flotation based methods (Willis-Mollay, modified centrifugal flotation and EPG/OPG) and sedimentation (Hoffman). Of the total number of samples examined, 77.0% (67/87) were positive by modified centrifugal flotation; 44.8% (39/87) were positive by the Willis-Mollay method; 34.5% (30/87) by the Hoffman method and 28.7% (25/87) by the EPG/ OPG method. The Kappa index indicated moderate concordance between the Willis-Mollay and modified centrifugal flotation techniques (K= 0.477); Willis-Mollay and EPG/OPG (K= 0.466); EPG/OPG and Hoffman (K= 0.425). In conclusion, modified centrifugal flotation presented high sensitivity for detection of parasites of the Strongylida order and Parascaris spp. It may, therefore, be used in association with the Willis-Mollay technique as a safe and accurate method of diagnosis.