scholarly journals Sylvatic Mosquito Diversity in Kenya—Considering Enzootic Ecology of Arboviruses in an Era of Deforestation

Insects ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 342
Author(s):  
Gillian Eastwood ◽  
Rosemary C. Sang ◽  
Joel Lutomiah ◽  
Philip Tunge ◽  
Scott C. Weaver

As new and re-emerging vector-borne diseases are occurring across the world, East Africa represents an interesting location, being the origin of several arboviruses with a history of urbanization and global spread. Rapid expansion of urban populations and alteration of natural habitats creates the opportunity for arboviruses to host-switch from wild, sylvatic hosts or vectors into urban transmission affecting human populations. Although mosquito surveillance regularly takes place in urban areas of Kenya, for example identifying vectors of dengue virus or malaria viruses, little work has been carried out to determine the distribution and abundance of sylvatic vectors. Here, we describe the mosquito vector species and diversity collected at twelve forest habitats of rural Kenya. We conducted arbovirus screening of over 14,082 mosquitoes (47 species, 11 genera) as 1520 pools, and detected seven viruses (six bunyaviruses, and one flavivirus-bunyavirus co-infection) isolated from pools of Aedes dentatus, Anopheles funestus, Culex annulioris, and Cx. vansomereni. Awareness of sylvatic vector species and their location is a critical part of understanding the ecological foci and enzootic cycling of pathogens that may be of concern to public, animal or wildlife health. As natural ecosystems come under anthropogenic pressures, such knowledge can inform us of the One Health potential for spillover or spillback leading to outbreaks, and assist in vector control strategies.

2020 ◽  
Vol 4 (3) ◽  

Mosquitoes are very obnoxious insects and vectors of many diseases like malaria, filariasis, dengue, yellow fever, encephalitis etc. Among these, malaria is transmitted by Anopheles stephensi mainly in urban areas across the temperate country. So, there is an imperative requirement to imply some mechanisms to reduce the mosquito vector to facilitate the reduction of vector borne diseases throughout the globe. But, mosquito control strategies are now in front of a threat because mosquito populations get resistance against the available synthetic insecticides. Besides the chemical insecticides, several other ways to control the vector population proved unsuccessful in most of the cases. Now, various researchers are trying to develop an alternate effective approach to eradicate malaria from the earth by controlling its vector by using a product which is ecofreindly, cost effective, biodegradable, non-toxic and selective in nature. So, by the amalgamation of the two fields namely the nanotechnology and the vector managements, a new field is now opened up for decades, “the green synthesized nanoparticles as mosquito control agents”. The plant-based, fabricated nanoparticles are beneficial over the synthetic one since it is economical, eco-friendly and non-toxic to nature. Silver, gold, zinc, cobalt, copper etc. nanoparticles are green fabricated with different plant parts, fungi as well as bacteria. These nano-materials are of less than 100 nm in diameter and are currently used in various fields of industry. So, adapting the nano-biotechnology to control the mosquito vector is the need of the hour. In this present review we focused on potential role of nano-materials as mosquito control agent against An. stephensi at different life stages of it.


2020 ◽  
Author(s):  
Jeanine Vélez-Gavilán

Abstract Pteris vittata is a herbaceous fern native to the tropics and subtropics of the Old World. It is mostly found in disturbed and urban areas, usually growing on limestone substrates, including buildings walls, pavement cracks and tombs. Although no details are available on its introduction to areas outside its native range, the dispersal of the species occurs naturally through air-borne spores or by its occasional use as an ornamental. It is reported as an urban weed in the European Mediterranean region and in Lucknow in India. In Azerbaijan it is categorized as a species that has the ability to self-sustain for a certain period of time, but not invading natural ecosystems. P. vittata is categorized in Florida, USA as an exotic species that has increased in abundance or frequency but has yet to alter natural plant communities. P. vittata is reported as invasive on Diego García Island, Brunei Darussalam, Cambodia, Malaysia, Micronesia, Guam, Palau, USA (Florida and Hawaii), Cuba and Brazil. Although there are no data available on its effects on natural habitats or native species, it is still regarded as an invasive species due to the vast number of spores produced.


BMC Zoology ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Mariëtte Pretorius ◽  
Wanda Markotter ◽  
Mark Keith

Abstract Background Modification and destruction of natural habitats are bringing previously unencountered animal populations into contact with humans, with bats considered important zoonotic transmission vectors. Caves and cave-dwelling bats are under-represented in conservation plans. In South Africa, at least two cavernicolous species are of interest as potential zoonotic hosts: the Natal long-fingered bat Miniopterus natalensis and the Egyptian fruit bat Rousettus aegyptiacus. Little information is available about the anthropogenic pressures these species face around important roost sites. Both bats are numerous and widespread throughout the country; land-use changes and urban expansions are a rising concern for both conservation and increased bat-human contact. Results Our study addressed this shortfall by determining the extent of land-cover change around 47 roosts between 2014 and 2018 using existing land cover datasets. We determined the land-cover composition around important roost sites (including maternity, hibernacula and co-roosts), distances to urban settlements and assessed the current protection levels of roost localities. We detected an overall 4% decrease in natural woody vegetation (trees) within 5 km buffer zones of all roost sites, with a 10% decrease detected at co-roost sites alone. Agricultural land cover increased the most near roost sites, followed by plantations and urban land-cover. Overall, roosts were located 4.15 ± 0.91 km from urban settlements in 2018, the distances decreasing as urban areas expand. According to the South African National Biodiversity Institute Ecosystem Threat Status assessment, 72% of roosts fall outside of well-protected ecosystems. Conclusions The current lack of regulatory protection of cavernicolous bats and their roosts, increasing anthropogenic expansions and proximity to human settlements raises concerns about increased human-bat contact. Furthermore, uncontrolled roost visitation and vandalism are increasing, contributing to bat health risks and population declines, though the extent of roosts affected is yet to be quantified. In an era where pandemics are predicted to become more frequent and severe due to land-use change, our research is an urgent call for the formal protection of bat-inhabited caves to safeguard both bats and humans.


2021 ◽  
pp. 1-8
Author(s):  
Julieta Fernández ◽  
Marina F. Ponzio ◽  
Verónica I. Cantarelli ◽  
Julie A. Clennon ◽  
María Sol Gennuso ◽  
...  

The expansion of human populations associated with urbanization results in extensive modification of natural habitats. While many species cannot persist in these highly modified environments, some species adopt new strategies, which contribute to their survival. Several primate species have persisted in altered habitats, including members of the genus <i>Alouatta</i>. To improve our understanding of this interplay, we compared glucocorticoid (GCC) levels in male and female black and gold howler monkeys (<i>Alouatta caraya</i>) in urban and rural areas in northeastern Argentina. Fecal samples (<i>n</i> = 60) were collected from adults and hormone extracts were analyzed by enzyme immunoassays (EIA). Monkeys living in urban areas (females: 109.15 ± 18.83; males: 106.15 ± 10.48) had lower GCC<i></i>levels than monkeys living in rural areas (females: 152.01 ± 19.50; males:139,82 ± 10.85). Interestingly, males living in urban areas had lower GCC levels compared to those living in rural areas, whereas no differences were observed in GCC levels between females living in urban and rural areas. While these results suggest that urban areas may provide a release from intergroup competition for male howler monkeys, future work is needed to better understand the dynamics of this association to best inform management and conservation of this vulnerable species.


Animals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2837
Author(s):  
Biel Garcias ◽  
Laia Aguirre ◽  
Chiara Seminati ◽  
Nerea Reyes ◽  
Alberto Allepuz ◽  
...  

Wildlife has been suggested to be a good sentinel of environmental health because of its close interaction with human populations, domestic animals, and natural ecosystems. The alarming emergence of antimicrobial resistance (AMR) in human and veterinary medicine has activated/triggered the awareness of monitoring the levels of AMR pollution in wildlife. European hedgehogs (Erinaceus europaeus) are common wild species habiting urban areas in Europe. However, there are few studies conducted in hedgehogs as reservoirs of AMR bacteria or genes. The aim of this study was to assess the occurrence and distribution of ESBL, AmpC, and carbapenem-resistant enterobacteria and AMR genes in wild European hedgehogs in Catalonia, a densely populated region of NE Spain. A total of 115 hedgehogs admitted at the Wildlife Rehabilitation Center of Torreferrussa were studied. To our knowledge, this is the first description of β-lactam resistant enterobacteria in wild hedgehogs. Interestingly, 36.8% (42/114) of the animals were detected as carriers of β-lactamase/carbapenemase resistance genes. Klebsiella spp. (59.6%), and specifically K. pneumoniae (84.6%), were the bacteria with the highest proportion of resistance genes, followed by E. coli (34.6%) and C. freundii (5.8 %). The most frequently detected genetic variants were blaCTX-M-15 (19.3%), blaSHV-28 (10.5%), blaCMY-1 (9.7%), blaCMY-2 (8.8%), and blaOXA-48 (1.7%). In addition, 52% (27/52) of the isolates presented a multidrug resistance (MDR) phenotype and 31% had an extended drug resistance (XDR) profile. No clustering of animals with AMR genes within the study region was shown in the spatial analysis, nor differences in the proportion of positive animals among regions, were detected. The results of this study suggest that wild European hedgehogs could be good sentinels of AMR environmental pollution, especially in areas with a high human population density, because they either inhabit and/or feed in an anthropogenic environment. In conclusion, it is crucial to raise awareness of the strong interconnection between habitats and compartments, and therefore this implies that AMR issues must be tackled under the One Health approach.


2019 ◽  
Vol 116 (19) ◽  
pp. 9155-9163 ◽  
Author(s):  
Susan D. Jones ◽  
Bakyt Atshabar ◽  
Boris V. Schmid ◽  
Marlene Zuk ◽  
Anna Amramina ◽  
...  

Zoonoses, such as plague, are primarily animal diseases that spill over into human populations. While the goal of eradicating such diseases is enticing, historical experience validates abandoning eradication in favor of ecologically based control strategies (which reduce morbidity and mortality to a locally accepted risk level). During the 20th century, one of the most extensive plague-eradication efforts in recorded history was undertaken to enable large-scale changes in land use in the former Soviet Union (including vast areas of central Asia). Despite expending tremendous resources in its attempt to eradicate plague, the Soviet antiplague response gradually abandoned the goal of eradication in favor of plague control linked with developing basic knowledge of plague ecology. Drawing from this experience, we combine new gray-literature sources, historical and recent research, and fieldwork to outline best practices for the control of spillover from zoonoses while minimally disrupting wildlife ecosystems, and we briefly compare the Soviet case with that of endemic plague in the western United States. We argue for the allocation of sufficient resources to maintain ongoing local surveillance, education, and targeted control measures; to incorporate novel technologies selectively; and to use ecological research to inform developing landscape-based models for transmission interruption. We conclude that living with emergent and reemergent zoonotic diseases—switching to control—opens wider possibilities for interrupting spillover while preserving natural ecosystems, encouraging adaptation to local conditions, and using technological tools judiciously and in a cost-effective way.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
André B. B. Wilke ◽  
Catherine Chase ◽  
Chalmers Vasquez ◽  
Augusto Carvajal ◽  
Johana Medina ◽  
...  

Abstract Global increases in temperatures and urbanization are impacting the epidemiology of mosquito-borne diseases. Urbanization processes create suitable habitats for vector mosquitoes in which there are a reduced number of predators, and human hosts are widely available. We hypothesize that mosquito vector species, especially Aedes aegypti, are locally concentrated primarily in those specific habitats at the neighborhood levels that provide suitable conditions and environmental resources needed for mosquito survival. Determining how mosquito vector species composition and abundance depend on environmental resources across habitats addresses where different types of vector control need to be applied. Therefore, our goal was to analyze and identify the most productive aquatic habitats for mosquitoes in Miami-Dade County, Florida. Immature mosquito surveys were conducted throughout Miami-Dade County from April 2018 to June 2019, totaling 2,488 inspections. Mosquitoes were collected in 76 different types of aquatic habitats scattered throughout 141 neighborhoods located in the urbanized areas of Miami-Dade County. A total of 44,599 immature mosquitoes were collected and Ae. aegypti was the most common and abundant species, comprising 43% of all specimens collected. Aedes aegypti was primarily found in buckets, bromeliads, and flower pots, concentrated in specific neighborhoods. Our results showed that aquatic habitats created by anthropogenic land-use modifications (e.g., ornamental bromeliads, buckets, etc.) were positively correlated with the abundance of Ae. aegypti. This study serves to identify how vector mosquitoes utilize the resources available in urban environments and to determine the exact role of these specific urban features in supporting populations of vector mosquito species. Ultimately, the identification of modifiable urban features will allow the development of targeted mosquito control strategies optimized to preventatively control vector mosquitoes in urban areas.


2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Anthony Adducci ◽  
Jeremy Jasperse ◽  
Seth Riley ◽  
Justin Brown ◽  
Rodney Honeycutt ◽  
...  

Abstract Urbanization is increasing throughout the world, transforming natural habitats. Coyotes (Canis latrans) are found in highly urban, suburban, rural and undeveloped mountainous habitats, making them an exemplary model organism to investigate the effects of urbanization on animals. We hypothesized that coyotes in natural habitats are more genetically related to distant coyotes in similar natural habitats and less related to coyotes in urban areas due to natal habitat-biased dispersal. We also hypothesized that increasing urbanization would result in decreased genetic diversity due to habitat fragmentation, dispersal barriers and genetic drift. We analyzed 10 microsatellite genetic markers from 125 individual coyotes sampled across a spectrum of highly urban to highly natural areas in southern California. Most coyotes clustered into four distinct genetic populations, whereas others appeared to have admixed ancestry. Three genetic populations were associated primarily with urban habitats in Los Angeles and Orange Counties. In contrast, the remaining population was associated with more naturally vegetated land near the surrounding mountains. Coyotes living in natural areas formed a genetically distinct cluster despite long geographic distances separating them. Genetic diversity was negatively associated with urban/suburban land cover and local road density, and positively associated with the relative amount of natural vegetation. These results indicate that genetic differentiation and loss of genetic diversity coincided with the extremely rapid expansion of Greater Los Angeles throughout the 1900s. Thus, urbanization reduces gene flow and erodes genetic diversity even in a habitat generalist thought to be minimally impacted by land development.


2020 ◽  
Author(s):  
Emily Northridge ◽  
Mikaël J. A. Maes ◽  
Ben Milligan

Government organisations and other public sector bodies are compiling standardised environmental accounts to encourage more sustainable land use choices and improve management of the natural environment and associated benefits. While the United Nations System of Environmental-Economic Accounting Experimental Ecosystem accounting (SEEA EEA) provides such as framework, practical challenges remain in particular decision-making contexts. In urban areas, natural ecosystems have unique challenges because of anthropogenic pressures, providing a mix of ecosystem services (ES) that may be valued differently compared to non-urban natural ecosystems due to peoples proximity to these. It is unknown whether existing publicly available data sources for urban areas are compatible with the SEEA EEA framework and if these sources are sufficient for the development of an inclusive natural capital accounts. Here, we explore whether an inclusive urban natural capital account that includes a broad range of ES can be compiled from publicly available data sources for Greater London between 2007 and 2018. We showed that it was not possible to compile an inclusive urban natural capital account for London per year consistent with the SEEA EEA framework because of issues with (1) temporal inconsistencies, (2) land cover classifications and (3) lack of public access to certain data sources. Greater collaboration between institutions and other organisations could support our understanding of linkages between ecosystem extent, condition and ES flows. Overall, our findings suggest the need for renewed efforts to develop a cohesive source of publicly available data, which could be supported by making interdisciplinary work standard practise.


2013 ◽  
Vol 145 (6) ◽  
pp. 674-685 ◽  
Author(s):  
Michael J. Jackson ◽  
Jennifer L. Gow ◽  
Michelle J. Evelyn ◽  
T.J. Scott McMahon ◽  
Harlan Campbell ◽  
...  

AbstractStormwater catch basins form part of artificial drainage systems in urban areas and can provide larval habitat for mosquito vector species of West Nile virus (WNv), such asCulex pipiensLinnaeus (Diptera: Culicidae). We evaluated the impact of management techniques and targeted applications of larvicide on larval populations of this potential WNv mosquito vector species in catch basins from the Lower Mainland of Vancouver and on Vancouver Island of British Columbia, Canada. A mixed effects logistic regression model described the relationship between larval presence and larvicide treatment while controlling for other parameters. Parameter estimates showed that larvicide treatment reduced the odds of larvae presence by a factor of ∼7.23. The model also revealed relationships between larval presence and water temperature and adjacent land use but larvicide treatment consistently reduced the presence of larvae regardless of these other factors. This knowledge can now be used to prioritise and target control efforts to most efficiently reduce WNv mosquito vector populations, and most effectively reduce the risk of WNv transmission to humans. A similar research strategy could be applied to emerging threats from other potential mosquito vectors of disease around the world, to help lower the incidence of mosquito-borne disease.


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