scholarly journals Detection of Aedes-borne viruses from field-caught mosquitoes and consideration for establishment of persistent DENV transmission cycles in Japan

2020 ◽  
Vol 71 (2) ◽  
pp. 85-90
Author(s):  
Daisuke Kobayashi ◽  
Toshinori Sasaki ◽  
Haruhiko Isawa
Keyword(s):  
Transmission Cycles

scholarly journals Triatomine Feeding Profiles and Trypanosoma cruzi Infection, Implications in Domestic and Sylvatic Transmission Cycles in Ecuador

Pathogens ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 42
Author(s):  
Sofía Ocaña-Mayorga ◽  
Juan José Bustillos ◽  
Anita G. Villacís ◽  
C. Miguel Pinto ◽  
Simone Frédérique Brenière ◽  
...  
Keyword(s):  
Blood Meal ◽  
Mitochondrial Gene ◽  
Intestinal Content ◽  
Human Infection ◽  
Dispersal Capacity ◽  
Transmission Cycle ◽  
Rhodnius Ecuadoriensis ◽  
Transmission Cycles ◽  
Endemic Areas ◽  
Southern Highland

Understanding the blood meal patterns of insects that are vectors of diseases is fundamental in unveiling transmission dynamics and developing strategies to impede or decrease human–vector contact. Chagas disease has a complex transmission cycle that implies interactions between vectors, parasites and vertebrate hosts. In Ecuador, limited data on human infection are available; however, the presence of active transmission in endemic areas has been demonstrated. The aim of this study was to determine the diversity of hosts that serve as sources of blood for triatomines in domestic, peridomestic and sylvatic transmission cycles, in two endemic areas of Ecuador (central coastal and southern highland regions). Using conserved primers and DNA extracted from 507 intestinal content samples from five species of triatomines (60 Panstrongylus chinai, 17 Panstrongylus howardi, 1 Panstrongylus rufotuberculatus, 427 Rhodnius ecuadoriensis and 2 Triatoma carrioni) collected from 2006 to 2013, we amplified fragments of the cytb mitochondrial gene. After sequencing, blood meal sources were identified in 416 individuals (146 from central coastal and 270 from southern highland regions), achieving ≥ 95% identity with GenBank sequences (NCBI-BLAST tool). The results showed that humans are the main source of food for triatomines, indicating that human–vector contact is more frequent than previously thought. Although other groups of mammals, such as rodents, are also an available source of blood, birds (particularly chickens) might have a predominant role in the maintenance of triatomines in these areas. However, the diversity of sources of blood found might indicate a preference driven by triatomine species. Moreover, the presence of more than one source of blood in triatomines collected in the same place indicated that dispersal of vectors occurs regardless the availability of food. Dispersal capacity of triatomines needs to be evaluated to propose an effective strategy that limits human–vector contact and, in consequence, to decrease the risk of T. cruzi transmission.

scholarly journals Impact of transmission cycles and vector competence on global expansion and emergence of arboviruses

2017 ◽  
Vol 27 (5) ◽  
pp. e1941 ◽  
Author(s):  
Ankita Agarwal ◽  
Manmohan Parida ◽  
Paban Kumar Dash
Keyword(s):  
Vector Competence ◽  
Global Expansion ◽  
Transmission Cycles

Evaluation of two artificial infection methods of live ticks as tools for studying interactions between tick-borne viruses and their tick vectors

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Camille Victoire Migné ◽  
Vaclav Hönig ◽  
Sarah Irène Bonnet ◽  
Martin Palus ◽  
Sabine Rakotobe ◽  
...  
Keyword(s):  
Virus Transmission ◽  
Artificial Feeding ◽  
Ixodid Ticks ◽  
Control Methods ◽  
Feeding System ◽  
Artificial Infection ◽  
Tick Borne Encephalitis ◽  
Transmission Cycles ◽  
Tick Vectors ◽  
Virus Interactions

AbstractUp to 170 tick-borne viruses (TBVs) have been identified to date. However, there is a paucity of information regarding TBVs and their interaction with respective vectors, limiting the development of new effective and urgently needed control methods. To overcome this gap of knowledge, it is essential to reproduce transmission cycles under controlled laboratory conditions. In this study we assessed an artificial feeding system (AFS) and an immersion technique (IT) to infect Ixodes ricinus ticks with tick-borne encephalitis (TBE) and Kemerovo (KEM) virus, both known to be transmitted predominantly by ixodid ticks. Both methods permitted TBEV acquisition by ticks and we further confirmed virus trans-stadial transmission and onward transmission to a vertebrate host. However, only artificial feeding system allowed to demonstrate both acquisition by ticks and trans-stadial transmission for KEMV. Yet we did not observe transmission of KEMV to mice (IFNAR−/− or BALB/c). Artificial infection methods of ticks are important tools to study tick-virus interactions. When optimally used under laboratory settings, they provide important insights into tick-borne virus transmission cycles.

scholarly journals Investigation about the Occurrence of Transmission Cycles of Arbovirus in the Tropical Forest, Amazon Region

Viruses ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 774 ◽  
Author(s):  
Pedro A. Araújo ◽  
Maria O. Freitas ◽  
Jannifer Oliveira Chiang ◽  
Franko Arruda Silva ◽  
Liliane Leal Chagas ◽  
...  
Keyword(s):  
Viral Genome ◽  
Cell Monolayer ◽  
Virus Genome ◽  
Field Trips ◽  
National Forest ◽  
Human Populations ◽  
Newborn Mouse ◽  
Viral Isolation ◽  
Transmission Cycles ◽  
Potential Area

Because of its ecological characteristics, the Caxiuanã National Forest (FLONA) is a potential area of arbovirus circulation. The present study aimed to investigate the occurrence of arbovirus transmission cycles at FLONA de Caxiuanã. Five field trips were performed to capture mosquitoes and sylvatic vertebrates. For these vertebrates, we attempted viral isolation by cell monolayer inoculation from blood, and hemagglutination inhibition and further seroneutralization assays from sera. For mosquitoes, we performed tests of viral genome detection. A total of 338 vertebrates were captured, and the greatest representative was birds (251/74.26%). A total of 16,725 mosquitoes were captured, distributed among 56 species. There were no viruses isolated by newborn mouse inoculation. Among birds, antibodies against Ilheus virus were the most prevalent. Catu virus, Caraparu virus, and Mucambo virus were the most prevalent among mammals and reptiles. Fragments of Mucambo virus, Ilheus virus, Bussuquara virus, and Rocio virus genome were detected in a pool of mosquito samples. These results of the study suggest the occurrence of arbovirus transmission cycles in the FLONA of Caxiuanã. The proximity of human populations with elements, involved in transmission cycles, makes surveillance necessary in this population to avoid dispersion of arboviruses to naïve locations.

scholarly journals Epidemiology and hypothetical transmission cycles of Trichinella infections in the Greater Kruger National Park of South Africa: an example of host-parasite interactions in an environment with minimal human interactions

Parasite ◽  
2020 ◽  
Vol 27 ◽  
pp. 13
Author(s):  
Louis J. La Grange ◽  
Samson Mukaratirwa
Keyword(s):  
South Africa ◽  
Protected Areas ◽  
National Parks ◽  
National Park ◽  
Feeding Habits ◽  
Kruger National Park ◽  
Sub Saharan Africa ◽  
Ecological Niches ◽  
Transmission Cycles ◽  
Sub Saharan

Knowledge on the epidemiology, host range and transmission of Trichinella spp. infections in different ecological zones in southern Africa including areas of wildlife-human interface is limited. The majority of reports on Trichinella infections in sub-Saharan Africa were from wildlife resident in protected areas. Elucidation of the epidemiology of the infections and the prediction of hosts involved in the sylvatic cycles within specific ecological niches is critical. Of recent, there have been reports of Trichinella infections in several wildlife species within the Greater Kruger National Park (GKNP) of South Africa, which has prompted the revision and update of published hypothetical transmission cycles including the hypothetical options based previously on the biology and feeding behaviour of wildlife hosts confined to the GKNP. Using data gathered from surveillance studies and reports spanning the period 1964–2019, confirmed transmission cycles and revised hypothesized transmission cycles of three known Trichinella species (T. zimbabwensis, Trichinella T8 and T. nelsoni) are presented. These were formulated based on the epidemiological factors, feeding habits of hosts and prevalence data gathered from the GKNP. We presume that the formulated sylvatic cycles may be extrapolated to similar national parks and wildlife protected areas in sub-Saharan Africa where the same host and parasite species are known to occur. The anecdotal nature of some of the presented data confirms the need for more intense epidemiological surveillance in national parks and wildlife protected areas in the rest of sub-Saharan Africa to unravel the epidemiology of Trichinella infections in these unique and diverse protected landscapes.

scholarly journals NaturalLeishmania(Viannia) infections of phlebotomines (Diptera: Psychodidae) indicate classical and alternative transmission cycles of American cutaneous leishmaniasis in the Guiana Shield, Brazil

Parasite ◽  
2017 ◽  
Vol 24 ◽  
pp. 13 ◽  
Author(s):  
Adelson Alcimar Almeida de Souza ◽  
Iorlando da Rocha Barata ◽  
Maria das Graças Soares Silva ◽  
José Aprígio Nunes Lima ◽  
Yara Lúcia Lins Jennings ◽  
...  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Guiana Shield ◽  
American Cutaneous Leishmaniasis ◽  
Transmission Cycles

Potential Transmission Cycles of Leishmania tropica in a Historic Disease Focus of Cutaneous Leishmaniasis in Southeast Tunisia

2020 ◽  
Vol 55 (1) ◽  
pp. 38
Author(s):  
Ahmed Tabbabi ◽  
Nadia Bousslimi ◽  
Adel Rhim ◽  
Ines Ben Sghaier ◽  
Jamila Ghrab ◽  
...  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Leishmania Tropica ◽  
Transmission Cycles ◽  
Southeast Tunisia ◽  
Disease Focus
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