First report of sheep naturally infected with Trypanosoma sp. in Ecuador / Primeiro relato de ovinos naturalmente infectados com Trypanosoma sp. no Equador

ABSTRACT: The prevalence of trypanosomiasis in sheep is of worldwide concern. It is a hemoparasitic disease caused by the protozoan Trypanosoma (T) spp., andthe biological cycle of transmission involves susceptible hosts and certain hematophagous flies, such as Tabanids and Stomoxys. The objective of this study was to determine the presence of Trypanosomasp. in sheep (Ovisaries). Through an applied, descriptive-prospective-cross-sectional qualitative study conducted between October 1, 2018, and January 29, 2019, blood samples extracted from the jugular vein were analyzed by the blood smear method using 2 Romanowsky staining techniques (Giemsa and Diff-Quick). Animals studied were between ages of 3 and 10 years, coming from 3 farms in the city of Colimes (Ecuador). Of 100 sampled and processed animals, 2 (2%) were positive for Trypanosoma sp., constituting the first report of this hemoparasite in sheep in Ecuador, and 1 case of Babesia spp. (1%) and 4 cases of Anaplasma marginale (4%) were also identified. However, none of these cases presented symptomatology of any hemotropic-parasitic disease. Subsequently, the positive animals were dewormed.The presence of these parasites wasconfirmedat the study site and,thus, could become a serious animal health problem.

RESUMO: A tripanossomíase em ovelhas é uma hemoparasitose globalmente prevalente causada pelo protozoário chamado Trypanosoma (T) sp. O ciclo de vida de transmissão envolve hospedeiros suscetíveis e alguns dípteros hematófagos como Tabanids e Stomoxys. O objetivo destetrabalho foi determinar a presença de Trypanosoma sp. em ovelhas (Ovisaries). Através de um estudo aplicado, com abordagem qualitativa, do tipo descritivo prospectivo-transversal, realizado entre o dia primeiro de outubro de 2018 e 29 de janeiro de 2019, foram analisadas amostras de sangue extraídas da veía jugular pelo método do esfregaço de sangue, utilizando duas técnicas de coloração Romanowski (Giensa e Diff-Quick). Os animais estudados tinham entre três e dez anos de idade, de três fazendas no municipio de Colimes (Equador). Dos 100 animais amostrados e processados, dois casos (2%) foram positivos para Trypanosoma sp., constituindo o primeiro relato deste hemoparasita em ovelhas no Equador. Além disso, um caso de Babesia sp. (1%) e quatro casos de Anaplasma marginale (4%); entretanto, em nenhum desses casos houve sintomas de qualquer doença hemotropicoparasitária. Animais positivos foram posteriormente desparasitados. A presença desses parasitas foi confirmada no local do estudo e, portanto, pode se tornar um sério problema de saúde animal.

The role of gallery forests in maintaining Phlebotominae populations: potential Leishmania spp. vectors in the Brazilian savanna

BACKGROUND Knowledge on synanthropic phlebotomines and their natural infection by Leishmania is necessary for the identification of potential areas for leishmaniasis occurrence. OBJECTIVE To analyse the occurrence of Phlebotominae in gallery forests and household units (HUs) in the city of Palmas and to determine the rate of natural infection by trypanosomatids. METHODS Gallery forests and adjacent household areas were sampled on July (dry season) and November (rainy season) in 2014. The total sampling effort was 960 HP light traps and eight Shannon traps. Trypanosomatids were detected in Phlebotominae females through the amplification of the SSU rDNA region, and the positive samples were used in ITS1-PCR. Trypanosomatid species were identified using sequencing. FINDINGS A total of 1,527 sand flies representing 30 species were captured in which 949 (28 spp.) and 578 (22 spp.) were registered in July and November, respectively. In July, more specimens were captured in the gallery forests than in the HUs, and Nyssomyia whitmani was particularly frequent. In November, most of the specimens were found in the HUs, and again, Ny. whitmani was the predominant species. Lutzomyia longipalpis was commonly found in domestic areas, while Bichromomyia flaviscutellata was most frequent in gallery forests. Molecular analysis of 154 pools of females (752 specimens) identified Leishmania amazonensis, L. infantum, and Crithidia fasciculata in Ny. whitmani, as well as L. amazonensis in Lu. longipalpis, Trypanosoma sp. and L. amazonensis in Pintomyia christenseni, and L. amazonensis in both Psathyromyia hermanlenti and Evandromyia walkeri. MAIN CONCLUSIONS These results show the importance of gallery forests in maintaining Phlebotominae populations in the dry month, as well as their frequent occurrence in household units in the rainy month. This is the first study to identify Leishmania, Trypanosoma, and Crithidia species in Phlebotominae collected in Palmas, Tocantins, Brazil.

The rising importance of Triatoma rubrofasciata

The migration of invasive vector species has contributed to the worldwide extension of infectious diseases such as dengue (Aedes aegypti) and chikungunya (Aedes albopictus). It is probably a similar behaviour for certain vectors of Chagas disease which allowed it to become a continental burden in Latin America. One of them, Triatoma rubrofasciata has also been spreading throughout the tropical and subtropical world. Here, the recent and massive peridomestic presence of T. rubrofasciata in Vietnam cities is reported, and tentatively explained, highlighting the need for improved entomological surveillance.