Publications by authors named "Ravinder Sehgal"

Little is known about the behaviors of African equatorial rain forest mosquito species and their potential role as sylvatic and bridge-vectors of various pathogens of animal and public health. In 2016 and 2017, the diversity and sources of water supporting immature development of mosquitoes in Talangaye Rainforest (South West Cameroon) before, during and after deforestation were investigated. Mosquito eggs, larvae and pupae were collected from 12 natural, seminatural, and artificial water sources and reared to adults.

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The Wildlife Malaria Network (WIMANET) is a groundbreaking multinational collaboration focused on studying vector-borne haemosporidian parasites in wildlife. Unlike human malaria, wildlife malaria is found on all continents except Antarctica, with parasites being transmitted by a range of vectors. The complexity and diversity of these parasites makes it necessary to have an interdisciplinary approach to understand and mitigate their impacts.

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Using samples spanning 10-degrees of latitude in Alaska, we provide the first comparative assessment of avian haemosporidia distribution of Arctic Alaska with subarctic host populations for four species of grouse and three species of ptarmigan (Galliformes). We found a high overall prevalence for at least one haemospordian genus (88%; N = 351/400), with spruce grouse () showing the highest prevalence (100%; N = 54/54). and lineages were only observed within grouse, while species were found within both grouse and ptarmigan.

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Article Synopsis
  • Avian pox is an avian virus that causes skin lesions in birds, often underreported through traditional detection methods like visual inspections and histopathology.
  • This study compared visual observation to molecular techniques (like qPCR) using various samples (blood, feathers, etc.) to assess avian pox prevalence in hummingbirds across different locations.
  • Results showed significant differences in prevalence rates, indicating a higher infection rate in live-caught hummingbirds (32.5%) compared to banding data (1.5%), highlighting the importance of molecular methods for accurate disease surveillance in wildlife.
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Avian haemosporidian parasites can cause malaria-like symptoms in their hosts and have been implicated in the demise of some bird species. The newly described Matryoshka RNA viruses (MaRNAV1 and MaRNAV2) infect haemosporidian parasites that in turn infect their vertebrate hosts. MaRNAV2 was the first RNA virus discovered associated with parasites of the genus Leucocytozoon.

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Very little data exist on the biology of an afrotropical rainforest mosquito Eretmapodites (Er.) in a world undergoing dramatic changes due to deforestation. The aim was to assess the efficacy of different trapping methods in the collection of Er.

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The taxonomically diverse and relatively understudied avifauna of Papua New Guinea's (PNG) island archipelagos provide a unique ecological framework for studying haemosporidian parasite differentiation and geographic structure. We implemented molecular and phylogenetic analyses of partial mitochondrial DNA sequences to assess the host distribution of 3 genera of vector-transmitted avian blood parasites (Plasmodium, Leucocytozoon and Haemoproteus) across a range of islands off the southeastern tip of PNG. We identified 40 new lineages of haemosporidians, including five lineages belonging to Leucocytozoon, a genus not previously described in this region.

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Globally, zoonotic vector-borne diseases are on the rise and understanding their complex transmission cycles is pertinent to mitigating disease risk. In North America, Lyme disease is the most commonly reported vector-borne disease and is caused by transmission of sensu lato (s.l.

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Characterizing the diversity and structure of host-parasite communities is crucial to understanding their eco-evolutionary dynamics. Malaria and related haemosporidian parasites are responsible for fitness loss and mortality in bird species worldwide. However, despite exhibiting the greatest ornithological biodiversity, avian haemosporidians from Neotropical regions are quite unexplored.

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Hummingbirds (Trochilidae) are sensitive to environmental changes because of their extraordinary ecology, metabolism, and the highest red blood cell counts found in any vertebrate. These physiological attributes may render hummingbirds particularly susceptible to the effects of haemosporidian (blood parasite) infections. Much of the research on haemosporidians in hummingbirds has been conducted in South America; less is known about haemosporidian diversity and prevalence in North America.

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We describe Leucocytozoon polynuclearis n. sp. (Haemosporida: Leucocytozoidae) from two North American woodpeckers, the northern flicker (Colaptes auratus Linnaeus) and white-headed woodpecker (Dryobates albolarvatus Boie, 1826), based on the morphology of its blood stages and portions of the mitochondrial cytochrome b gene.

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Grey crowned cranes (Balearica regulorum) have been facing significant and long-term population declines in East Africa. Studies of Haemosporidian infections are essential to gain insight into pathogenic threats and help infer vector-host relationships, resolve parasite relationships, and support conservation efforts. As part of a program to reintroduce captive cranes in Rwanda back to their natural habitats, through health checks and initial microscopic examination, 120 grey crowned cranes were selected under suspicion of harboring Haemosporidian infections following initial peripheral blood smear examinations.

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Scientist Spotlights-curricular materials that employ the personal and professional stories of scientists from diverse backgrounds-have previously been shown to positively influence undergraduate students' relatability to and perceptions of scientists. We hypothesized that engaging students in authoring Scientist Spotlights might produce curricular materials of similar impact, as well as provide a mechanism for student involvement as partners in science education reform. To test this idea and investigate the impact of student-authored Scientist Spotlights, we developed a service-learning course in which teams of biology students partnered with an instructor to develop and implement Scientist Spotlights in a biology course.

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Parasites of the genus Haemoproteus are vector-borne avian haemosporidia commonly found in bird species of the world. Haemoproteus infections are typically considered relatively benign in birds. However, some Haemoproteus species cause severe disease and mortality, especially for captive birds removed from their original habitat.

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Species of Culex (Diptera: Culicidae) belonging to the subgenus Culiciomyia were collected in partially logged areas and in surrounding pristine forest (Talangaye Forest) in the Nguti Subdivision in the South-West Region of Cameroon. Mosquitoes were collected mainly by sweep netting through forest floor vegetation. Morphological species identification of African Culiciomyia relies almost exclusively on the structure of the male genitalia and the shapes of comb scales on the maxillary palpi of males.

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Background: Avian pox is a viral disease documented in a wide range of bird species. Disease-related detrimental effects can cause dyspnea and dysphagia, and birds with high metabolic requirements, such as hummingbirds, are thus especially vulnerable to the pathogen. Hummingbirds have a strong presence in California, especially in urban environments.

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Habitat change caused by deforestation can modify the interactions of many biotic and abiotic factors, and in turn influence patterns of diseases in wild birds. Whether deforestation directly or indirectly affects the prevalence of avian haemosporidian parasites through their hosts and/or vectors is still not well understood. We sampled understory bird communities (insectivorous, frugivorous, granivorous and nectarivorous birds) and mosquitoes in three habitats showing a gradient of deforestation (pristine forest, fragmented forest, and young palm oil plantation), to assess the effects of habitat changes on avian haemosporidian (Plasmodium and Haemoproteus) prevalence and its relationship to bird feeding guilds and mosquito abundance.

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Deforestation is a major threat to biodiversity but little data exist on how deforestation in real-time affects the overall mosquito species community despite its known role in the transmission of diseases. We compared the abundance and diversity of Culex mosquitoes before and after deforestation along a gradient of three different anthropogenic disturbance levels in a tropical rainforest in southwestern Cameroon. The collections were conducted in unlogged forest (January, 2016), selectively logged forest (January, 2017), and within a young palm plantation (October, 2017) using net traps, sweep nets, resting traps, and dipping for immature stages in water bodies.

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A juvenile White-headed woodpecker () fitted with a radio tag was located dead at approximately 22-days post-fledging in Yakima county in central Washington in July 2015. Postmortem examination revealed an enlarged liver and spleen plus evidence of iron sequestration. Microscopic examination observed young gametocytes within the cytoplasm of erythrocytes, and exo-erythrocytic meronts within the cytoplasm of capillary endothelial cells, hepatocytes, and myocytes, and free in the tissues.

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Over the past 10 years, much research has been done and remarkable discoveries have been made in various fields of research regarding wildlife malaria parasites (Plasmodium, Plasmodiidae) and related haemosporidians, the agents of infections, which affect all major groups of terrestrial vertebrates. Recent molecular studies show that these blood parasites cause more harm to wildlife than formerly believed, calling for new fundamental and applied research on this subject. The 4th International Conference on Malaria and Related Haemosporidian Parasites of Wildlife highlighted the recent accomplishments of many research groups throughout the world at the Beijing Normal University, with additional hosts being the Beijing Zoo and the China Ornithological Society.

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Parasites of the genus Plasmodium infect a wide array of hosts, causing malaria in all major groups of terrestrial vertebrates including primates, reptiles, and birds. Molecular mechanisms explaining why some Plasmodium species are virulent, while other closely related malaria pathogens are relatively benign in the same hosts, remain unclear. Here, we present the RNA sequencing and subsequent transcriptome assembly of two avian Plasmodium parasites which can eventually be used to better understand the genetic mechanisms underlying Plasmodium species pathogenicity in an avian host.

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Members of the order Haemosporida are protist parasites that infect mammals, reptiles and birds. This group includes the causal agents of malaria, Plasmodium parasites, the genera Leucocytozoon and Fallisia, as well as the species rich genus Haemoproteus with its two subgenera Haemoproteus and Parahaemoproteus. Some species of Haemoproteus cause severe disease in avian hosts, and these parasites display high levels of diversity worldwide.

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Many studies have used the avian hemosporidians (, , and ) to test hypotheses of host-parasite co-evolution, yet documented health and survival consequences of these blood parasites vary among studies and generalizations about their pathogenicity are debatable. In general, the negative effects of the hemosporidians are likely to be greatest during acute infections of young birds, yet most previous studies in wild passerines have examined chronic effects in adults. Here, we evaluated responses of nestling American crows () to acute infection (prevalence and burden), as well as its short- and long-term survival consequences.

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Currently, there are very few studies of avian malaria that investigate relationships among the host-vector-parasite triad concomitantly. In the current study, we experimentally measured the vector competence of several Culex mosquitoes for a newly described avian malaria parasite, Plasmodium homopolare. Song sparrow (Melospiza melodia) blood infected with a low P.

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Many efforts to improve science teaching in higher education focus on a few faculty members at an institution at a time, with limited published evidence on attempts to engage faculty across entire departments. We created a long-term, department-wide collaborative professional development program, Biology Faculty Explorations in Scientific Teaching (Biology FEST). Across 3 years of Biology FEST, 89% of the department's faculty completed a weeklong scientific teaching institute, and 83% of eligible instructors participated in additional semester-long follow-up programs.

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