Aedes aegypti

“ Therefore, methods of control for a species may not be accurate to control the other one. Furthermore, when the populations of A. aegypti is reduced, the opportunistic invasive A. albopictus may rapidly move into the area ( [63] ) .
Aedes aegypti and, to a lesser extent, A. albopticus are clearly involved in ZIKV transmission and spread, but other Aedes spp., such as A. polynesienis, are suspected to have also contributed to it, as it was the case during the 2013–2014 outbreak in the French Polynesia ( [64] ) . ”

“ Simulations indicate the highest mosquito abundance occurs in the Southeast and south Texas where locally acquired cases of Aedes-transmitted viruses have been reported previously. Cities in southern Florida and south Texas are at the nexus of high seasonal suitability for Aedes aegypti and strong potential for travel-related virus introduction. Higher poverty rates in cities along the U.S.-Mexico border may correlate with factors that increase human exposure to Aedes aegypti. ”

“ Aedes (Stegomyia) albopictus (Skuse, 1895) is nowadays the most notorious invasive Culicidae. From its native range in Asia, the species has spread throughout the Americas, Europe and Africa, mainly via international trade in used tires [1] . Its capacity to transmit a large number of arboviruses is well documented. Although less efficient than Aedes aegypti for the dengue viruses transmission, it was responsible for large dengue epidemics in Japan in 1942–1945 [2] , for the DEN-1 outbreak in Hawaii in 2001 [3] and for the DEN-2 outbreaks in La Reunion in 1977–78 and 2004 [4] , [5] . ”

“ Widely distributed throughout tropical areas of Asia and Africa, ZIKV is transmitted by a broad range of mosquito species, most of which are sylvatic or rural, Aedes aegypti, an anthropophilic and urban species, being considered the main ZIKV epidemic vector. ”

“ Mosquito abundance results were analyzed alongside travel and socioeconomic factors that are proxies of viral introduction and vulnerability to human-vector contact. Results: Meteorological conditions are largely unsuitable for Aedes aegypti over the U.S. during winter months (December-March) , except in southern Florida and south Texas where comparatively warm conditions can sustain low-to-moderate potential mosquito abundance. ”

“ Transmission Cycle Mosquitoes The arthropod vectors of the ZIKV natural transmission cycle are mosquitoes of the genus Aedes ( [54] ) . As mentioned early, the virus was first isolated from A. africanus ( [2] ) and, since then, ZIKV has been isolated from A. aegypti ( [47] ) , the main vector of the virus, and also from A. albopictus ( [55] ) , confirming that both species are competent vectors.
Aedes aegypti is currently distributed in Asia and Oceania, the Americas, and in a few regions of Africa and Europe (Madeira and the north-eastern Black Sea coast) 2 ”

“ Aedes aegypti from Senegal, West Africa (SenAae) have a low oviposition rate; those that do oviposit have a low fecundity and poor egg-to-adult survival. Furthermore rearrangements were detected on all three chromosomes in SenAae. These observations are consistent with the presence of at least two cryptic subspecies of Ae. aegypti in Senegal arising from reproductive isolation due to chromosome rearrangements. Genetic control strategies are being considered for the suppression of Ae. aegypti populations worldwide. Barriers to gene flow in African Ae. ”

“ Since Aedes spp. has very limited spatial dispersal, overlapping high population densities of mosquitoes and humans would be needed to sustain a focus of infection. However, as A. aegypti is distinctly anthropophilic, future control strategies for Zika should be considered in tandem with the continuing threat to human wellbeing that is presented by dengue, yellow fever and Japanese encephalitis, all of which are transmitted by the same vector species. ”

“ Human-filled containers can represent an important source of water for Ae. aegypti habitat in arid and semi-arid regions [37] . For both models, releasing new cohorts of eggs each month prevented extinction of mosquitoes, or (in the case of DyMSiM) when the population of any life stage reduced to zero. Releases ranged from 80-100 eggs per container. This choice essentially assumes that Aedes eggs are frequently reintroduced into areas through transportation networks [38] or that eggs are able to survive through periods when weather is unfavorable for development. ”

“ Using calculations and assumptions given in Focks et al. (2000) , we estimate that average pupae person-1 decreased in our treated area from 0.7 pre-treatment to 0.04 post-treatment, which in their model would be sufficient to prevent epidemic transmission under these conditions, or indeed under the most adverse conditions modelled for a naive population with 0% seroprevalence. The long-term goal for vector control should be to suppress below the transmission threshold even given low herd immunity [39] –our data indicate that release of OX513A males is able to achieve this goal. ”

“ Although Ae. albopictus is thought to be a competent vector of ZIKAV [14] , Ae. aegypti has been implicated as the primary transmitter of the virus in human populations in the ongoing outbreak in the Americas [15] . ”

“ Surveillance and monitoring of the species is thus an instrumental activity to be carried out to prevent infestation of new areas, to assess the risk of arbovirus transmission and to optimize control activities. Ovitrap is the simplest and most widely used monitoring device for Ae. albopictus, as well as of other container-breeding species such as Aedes aegypti, the major vector of yellow fever, dengue and Zika [3] . ”

“ An ongoing Zika virus pandemic in Latin America and the Caribbean has raised concerns that travel-related introduction of Zika virus could initiate local transmission in the United States (U.S.) by its primary vector, the mosquito Aedes aegypti.Methods: We employed meteorologically driven models for 2006-2015 to simulate the potential seasonal abundance of adult Aedes aegypti for fifty cities within or near the margins of its known U.S. range. ”

“ Male (“M”) alleles at the SDL are dominant so that males are “Mm” heterozygotes and females are homozygous recessive “mm.” Presgraves and Orr showed that for the most part Anopheline mosquitoes follow Haldane’s rule for sterility and inviability while Aedes mosquitoes only follow Haldane’s rule for sterility. The authors speculated that faster male evolution is driven by sexual selection which occurs irrespective of the sex determination mechanism. ”

“ Accordingly, spreading of the virus will coincide primarily with the geographical distribution of mosquitoes of this family as e.g. Aedes aegypti. On the other hand, some recent cases of ZIKV infections suggest sexual transmission of the virus by semen as well.
Quite recently, in Brazil microcephaly [1] and chorioretinopathy [2] , [3] as well as signs of in utero growth restriction [4] were found to be epidemiologically associated with either clinically suspected maternal ZIKV infections during pregnancy and/or positive qualitative RT-PCR tests for ZIKV in maternal blood, urine or both. ”

“ Dengue fever - mosquito-borne (Aedes aegypti) viral disease associated with urban environments; manifests as sudden onset of fever and severe headache; occasionally produces shock and hemorrhage leading to death in 5% of cases. Yellow fever - mosquito-borne viral disease; severity ranges from influenza-like symptoms to severe hepatitis and hemorrhagic fever; occurs only in tropical South America and sub-Saharan Africa, where most cases are reported; fatality rate is less than 20%. Japanese Encephalitis - mosquito-borne (Culex tritaeniorhynchus) viral disease associated with rural areas in Asia ”

“ However this situation is itself transient as death of OX513A heterozygous offspring will in time start to have an impact on the number of wild mosquitoes, depending on the numbers of OX513A males released and their mating competitiveness in relation to wild males. Females additionally have to blood feed and find oviposition sites. ”

“ Sterile Insect Technique 2005. p. 177–208 .1 2 3 Mayer DG, Atzeni MG, Stuart MA, Anaman KA, Butler DG. Mating competitiveness of irradiated flies for screwworm fly eradication campaigns. Preventive Veterinary Medicine. 1998;36 (1) :1–9 . pmid:96776231 2 3 Focks D, Brenner R, Hayes J, E D. Transmission thresholds for dengue in terms of Aedes aegypti pupae per person with discussion of their utility in source reduction efforts. ”

“ These cut points were chosen to provide a proxy of the lower quartile, the interquartile range, and the upper quartile with respect to Miami values. The “None to low” cut-point of 2% rules out extremely low abundance values that are unlikely to be sufficient to generate substantial risk for human contact.
Results of simulations of adult Ae. aegypti populations are referred to in terms of potential abundance in order to emphasize that they indicate meteorological suitability for the mosquito but not necessarily that it is present or will occur in a given location. ”

“ The present study describes the oral susceptibility of a Singapore field strain Ae. aegypti to ZIKV, under condition that simulate local climate.
Materials and Methods Mosquitoes Ae. aegypti, used for the experimental infection, were derived from eggs collected in the Western part of Singapore during a weekly ovitrap surveillance study to determine mosquito population density. Ovitraps were placed in public areas, mostly along the common corridors of public housing. The surveillance study was conducted by colleagues from the Environmental Health Institute. ”

“ Itching or itching rash has been suggested to be added to the case definition issued by the Pan American Health Organization (PAHO) .
Introduction Background
Since 2015, Brazil is faced with the challenge of three co-circulating arboviruses of major public health importance. For the last 30 years, dengue virus (DENV) infection has been the main mosquito-transmitted threat in the country, which has suffered several epidemics caused by all four serotypes, [1] , [2] fostered by the widespread presence of its main vector, Aedes aegypti, in densely populated urban areas. ”

“ While Ae. aegypti and Ae. albopictus are established across much of the southern United States (Fig. 1) , mosquito populations in many areas are only present seasonally. This seasonality varies according to local meteorological conditions, and thus can provide one measure of potential for ZIKAV transmission (i.e., local transmission may not be sustained if competent vector mosquitoes are not present) . ”

“ Conventional sterile insect based programs generally achieve greater efficiency by initiating releases in conjunction with reduced mosquito population, either by utilising naturally occurring seasonality or temporary knockdown with alternate control such as insecticide application. ”

“ The first evidence of the role of A. aegypti in the urban transmission cycle of ZIKV was suggested after its isolation from a pool of mosquitoes collected in 1966 in Malaysia, in what it was the first isolation from a mosquito other than A. africanus ( [47] ) .
Aedes albopictus, the so-called Asian tiger mosquito, is also widely distributed. ”

“ The current study, using a field strain of mosquitoes, showed that Singapore's Ae. aegypti are highly susceptible to ZIKV, with high midgut infection and salivary gland dissemination rates. By day 5 pe, 62% of the mosquitoes had detectable ZIKV in their salivary glands and by day 10 pe all mosquitoes were potentially infective. Based on the studies of Cornet et al. [27] , nearly all mosquitoes with ZIKV in their salivary glands are assumed to be able to transmit the virus. ”

“ With the goal of performing Quantitative Trait Locus (QTL) mapping of gene regions associated with DENV2 susceptibility, Aaa P1 laboratory strains that are known to be highly susceptible to DENV2 infection were crossed with Senegal Ae. aegypti (SenAae) that are refractory to DENV2 infection [29] to breed F1 intercross families. During this process reproductive incompatibilities were observed between Aaa collected outside Africa and SenAae. Furthermore reproductive incompatibilities were observed within and among SenAae collections. ”

“ Even though individuals belonging to cryptic taxa can mate with one another, they produce few or no eggs (Fig 2) and if eggs are produced, they have lower survival to adults.
The suggestion that one or more new cryptic subspecies exist in Senegal in no way contradicts the phylogenetic patterns among worldwide Ae.aegypti s.l. populations that have been derived over the last 35 years using allozyme markers [78] – [18] , microsatellites [25] , [26] , [27] , nuclear SNP loci [15] , [28] , [22] , mitochondrial DNA [20] , [26] and most recently a SNP-Chip [28] . ”

“ The critical test for cryptic species would be to identify a priori two or more types of mosquitoes based on genetic markers, cytogenetics or phenotype and then show that reproductive incompatibilities exist between these types and not within them. ”

“ Areas in the southern parts of Texas demonstrated higher rates of poverty than some other regions under study (Fig. 3) . Coupled with the higher levels of travel from areas where transmission is occurring and the history of Ae. aegypti –borne virus outbreaks, this suggests that southern Texas may be a vulnerable region for Zika transmission.
Even if Zika virus arrives in the United States, transmission can be mitigated and reduced through the use of vector control strategies. ”