scholarly journals High Rate of Non-Human Feeding by Aedes aegypti Reduces Zika Virus Transmission in South Texas

Viruses ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 453 ◽  
Author(s):  
Mark F. Olson ◽  
Martial L. Ndeffo-Mbah ◽  
Jose G. Juarez ◽  
Selene Garcia-Luna ◽  
Estelle Martin ◽  
...  

Mosquito-borne viruses are emerging or re-emerging globally, afflicting millions of people around the world. Aedes aegypti, the yellow fever mosquito, is the principal vector of dengue, Zika, and chikungunya viruses, and has well-established populations across tropical and subtropical urban areas of the Americas, including the southern United States. While intense arboviral epidemics have occurred in Mexico and further south in the Americas, local transmission in the United States has been minimal. Here, we study Ae. aegypti and Culex quinquefasciatus host feeding patterns and vertebrate host communities in residential environments of South Texas to identify host-utilization relative to availability. Only 31% of Ae. aegypti blood meals were derived from humans, while 50% were from dogs and 19% from other wild and domestic animals. In Cx. quinquefasciatus, 67% of blood meals were derived from chicken, 22% came from dogs, 9% from various wild avian species, and 2% from other mammals including one human, one cat, and one pig. We developed a model for the reproductive number, R0, for Zika virus (ZIKV) in South Texas relative to northern Mexico using human disease data from Tamaulipas, Mexico. We show that ZIKV R0 in South Texas communities could be greater than one if the risk of human exposure to Ae. aegypti bites in these communities is at least 60% that of Northern Mexico communities. The high utilization of non-human vertebrates and low risk of human exposure in South Texas diminishes the outbreak potential for human-amplified urban arboviruses transmitted by Ae. aegypti.

2020 ◽  
Vol 14 (12) ◽  
pp. e0008867
Author(s):  
José Guillermo Estrada-Franco ◽  
Nadia A. Fernández-Santos ◽  
Adeniran A. Adebiyi ◽  
María de J. López-López ◽  
Jesús A. Aguilar-Durán ◽  
...  

Background Aedes aegypti mosquito-borne viruses including Zika (ZIKV), dengue (DENV), yellow fever (YFV), and chikungunya (CHIKV) have emerged and re-emerged globally, resulting in an elevated burden of human disease. Aedes aegypti is found worldwide in tropical, sub-tropical, and temperate areas. The characterization of mosquito blood meals is essential to understand the transmission dynamics of mosquito-vectored pathogens. Methodology/principal findings Here, we report Ae. aegypti and Culex quinquefasciatus host feeding patterns and arbovirus transmission in Northern Mexico using a metabarcoding-like approach with next-generation deep sequencing technology. A total of 145 Ae. aegypti yielded a blood meal analysis result with 107 (73.8%) for a single vertebrate species and 38 (26.2%) for two or more. Among the single host blood meals for Ae. aegypti, 28.0% were from humans, 54.2% from dogs, 16.8% from cats, and 1.0% from tortoises. Among those with more than one species present, 65.9% were from humans and dogs. For Cx. quinquefasciatus, 388 individuals yielded information with 326 (84%) being from a single host and 63 (16.2%) being from two or more hosts. Of the single species blood meals, 77.9% were from dogs, 6.1% from chickens, 3.1% from house sparrows, 2.4% from humans, while the remaining 10.5% derived from other 12 host species. Among those which had fed on more than one species, 11% were from dogs and humans, and 89% of other host species combinations. Forage ratio analysis revealed dog as the most over-utilized host by Ae. aegypti (= 4.3) and Cx. quinquefasciatus (= 5.6) and the human blood index at 39% and 4%, respectively. A total of 2,941 host-seeking female Ae. aegypti and 3,536 Cx. quinquefasciatus mosquitoes were collected in the surveyed area. Of these, 118 Ae. aegypti pools and 37 Cx. quinquefasciatus pools were screened for seven arboviruses (ZIKV, DENV 1–4, CHIKV, and West Nile virus (WNV)) using qRT-PCR and none were positive (point prevalence = 0%). The 95%-exact upper limit confidence interval was 0.07% and 0.17% for Ae. aegypti and Cx. quinquefasciatus, respectively Conclusions/significance The low human blood feeding rate in Ae. aegypti, high rate of feeding on mammals by Cx. quinquefasciatus, and the potential risk to transmission dynamics of arboviruses in highly urbanized areas of Northern Mexico is discussed.


2017 ◽  
Vol 86 (1) ◽  
pp. 50-83 ◽  
Author(s):  
Sarah K.M. Rodriguez

Between 1820 and 1827 approximately 1,800 U.S. citizens immigrated to northern Mexico as part of that country’s empresario program, in which the federal government granted foreigners land if they promised to develop and secure the region. Historians have long argued that these settlers, traditionally seen as the vanguard of Manifest Destiny, were attracted to Mexico for its cheap land and rich natural resources. Such interpretations have lent a tone of inevitability to events like the Texas Revolution. This article argues that the early members of these groups were attracted to Mexico for chiefly political reasons. At a time when the United States appeared to be turning away from its commitment to a weak federal government, Mexico was establishing itself on a constitution that insured local sovereignty and autonomy. Thus, the Texas Revolution was far from the result of two irreconcilable peoples and cultures. Moreover, the role that these settlers played in the United States’ acquisition of not just Texas, but ultimately half of Mexico’s national territory, was more paradoxical than inevitable.


Author(s):  
Rebecca A Zimler ◽  
Donald A Yee ◽  
Barry W Alto

Abstract Recurrence of local transmission of Zika virus in Puerto Rico is a major public health risk to the United States, where mosquitoes Aedes aegypti (Linnaeus) and Aedes mediovittatus (Coquillett) are abundant. To determine the extent to which Ae. mediovittatus are capable of transmitting Zika virus and the influence of viremia, we evaluated infection and transmission in Ae. mediovittatus and Ae. aegypti from Puerto Rico using serial dilutions of infectious blood. Higher doses of infectious blood resulted in greater infection rates in both mosquitoes. Aedes aegypti females were up to twice as susceptible to infection than Ae. mediovittatus, indicating a more effective midgut infection barrier in the latter mosquito species. Aedes aegypti exhibited higher disseminated infection (40–95%) than Ae. mediovittatus (<5%), suggesting a substantial midgut escape barrier in Ae. mediovittatus. For Ae. aegypti, transmission rates were low over a range of doses of Zika virus ingested, suggesting substantial salivary gland barriers.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Bingyi Yang ◽  
Angkana T. Huang ◽  
Bernardo Garcia-Carreras ◽  
William E. Hart ◽  
Andrea Staid ◽  
...  

AbstractNon-pharmaceutical interventions (NPIs) remain the only widely available tool for controlling the ongoing SARS-CoV-2 pandemic. We estimated weekly values of the effective basic reproductive number (Reff) using a mechanistic metapopulation model and associated these with county-level characteristics and NPIs in the United States (US). Interventions that included school and leisure activities closure and nursing home visiting bans were all associated with a median Reff below 1 when combined with either stay at home orders (median Reff 0.97, 95% confidence interval (CI) 0.58–1.39) or face masks (median Reff 0.97, 95% CI 0.58–1.39). While direct causal effects of interventions remain unclear, our results suggest that relaxation of some NPIs will need to be counterbalanced by continuation and/or implementation of others.


Author(s):  
Robyn M Nadolny ◽  
Ashley C Kennedy ◽  
James M Rodgers ◽  
Zachary T Vincent ◽  
Hannah Cornman ◽  
...  

Abstract During September–December 2018, 25 live ticks were collected on-post at Fort Leavenworth, Kansas, in a home with a history of bat occupancy. Nine ticks were sent to the Army Public Health Center Tick-Borne Disease Laboratory and were identified as Carios kelleyi (Cooley and Kohls, 1941), a species that seldom bites humans but that may search for other sources of blood meals, including humans, when bats are removed from human dwellings. The ticks were tested for numerous agents of human disease. Rickettsia lusitaniae was identified by multilocus sequence typing to be present in two ticks, marking the first detection of this Rickettsia agent in the United States and in this species of tick. Two other Rickettsia spp. were also detected, including an endosymbiont previously associated with C. kelleyi and a possible novel Rickettsia species. The potential roles of C. kelleyi and bats in peridomestic Rickettsia transmission cycles warrant further investigation.


PEDIATRICS ◽  
1994 ◽  
Vol 94 (1) ◽  
pp. 118-118
Author(s):  
J. F. L.

Harlington, TX, July 19 (AP)—Federal agricultural officials say that the honey bees that killed an 82-year-old rancher last week were the Africanized variety known as "killer bees." "Our lab has confirmed that the bees are Africanized," said Kim Kaplan, a Spokeswoman for the Federal Department of Agriculture in Greenbelt, MD. Final autopsy results are not yet available, but the pathologist who did the autopsy listed the preliminary cause of death as acute fluid buildup in the lungs caused by insect stings. If the cause of death is confirmed, the rancher, Lino Lopex, would be the first person killed by Africanized bees in the United States since the aggressive variety migrated into Texas in 1990. Harlington, TX, in South Texas, is about 15 miles from the Mexican border. Mr. Lopez apparently tried to drive the bees out of a wall in an abandoned house by poking the hive with a stick wrapped with a burning burlap sack. He was dead on arrival at the hospital, with about 40 stingers still attached to his body, officials said.


2018 ◽  
Vol 94 ◽  
Author(s):  
M. García-Varela ◽  
C.D. Pinacho-Pinacho

AbstractMembers of the genusNeoechinorhynchusStiles & Hassall, 1905 are endoparasites of freshwater fishes, brackish water fishes, and freshwater turtles distributed worldwide. In North America, 33 species have been described. One of the most widely distributed species in the eastern United States and Canada isNeoechinorhynchus (Neoechinorhynchus) cylindratus,a common acanthocephalan that infects centrarchid fishes. In the current study, adult specimens ofN. (N) cylindratuswere collected from largemouth bass (Micropterus salmoides) from the Purificación River in northern Mexico. In the same freshwater system, two additional congeneric species (Neoechinorhynchus (Neoechinorhynchus) emyditoidesandNeoechinorhynchus (Neoechinorhynchus) panucensis) were collected and analysed. Sequences of the large subunit, internal transcribed spacers ITS1 and ITS2, 5.8S from nuclear DNA, and sequences of the cytochromecoxidase subunit I (cox1) from mitochondrial DNA were generated and aligned with other sequences obtained from GenBank. Maximum likelihood and Bayesian inference analyses inferred for each dataset showed thatN. (N) panucensis,N. (N) emyditoidesandN. (N) cylindratuswere nested within several clades, indicating that these species do not share a common ancestor. Our phylogenies also revealed that the genusNeoechinorhynchusis paraphyletic, requiring further taxonomic revision using phylogenetic systematics and re-examination of morphological and ecological data. The presence of severalN. (N) cylindratusadults in northern Mexico allowed us to typify this species for the first time using a combination of morphological and molecular characteristics. The current record shows a wide distribution range ofN. (N) cylindratusacross Canada, the United States and Mexico in the Nearctic region.


2018 ◽  
Vol 2018 (1) ◽  
Author(s):  
Shahir Masri ◽  
Jianfeng Jia ◽  
Chen Li ◽  
Guofa Zhou ◽  
Ming-Chieh Lee ◽  
...  

2016 ◽  
Vol 2 (1) ◽  
pp. e6-e7
Author(s):  
Susan Ricci ◽  
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