Field Isolation and Laboratory Vector-Host Studies of Brazoran Virus (Peribunyaviridae: Orthobunyavirus) from Florida.

Brazoran virus was first isolated from Culex mosquitoes in Texas in 2012, yet little is known about this virus. We report the isolation of this virus from Culex erraticus from southern Florida during 2016. The Florida strain had a nucleotide identity of 96.

Introducing an environmental microbiome to axenic mosquitoes documents bacterial responses to a blood meal.

The blood meal of the female mosquito serves as a nutrition source to support egg development, so is an important aspect of its biology. Yet, the roles the microbiome may play in blood digestion are poorly characterized. We employed axenic mosquitoes to investigate how the microbiome differs between mosquitoes reared in the insectary versus mosquitoes that acquire their microbiome from the environment.

Increased blood meal size and feeding frequency compromise Aedes aegypti midgut integrity and enhance dengue virus dissemination.

Aedes aegypti is a highly efficient vector for numerous pathogenic arboviruses including dengue virus (DENV), Zika virus, and yellow fever virus. This efficiency can in part be attributed to their frequent feeding behavior. We previously found that acquisition of a second, full, non-infectious blood meal could accelerate virus dissemination within the mosquito by temporarily compromising midgut basal lamina integrity; however, in the wild, mosquitoes are often interrupted during feeding and only acquire partial or minimal blood meals.

The known unknowns of Powassan virus ecology.

Powassan virus (POWV; Family: Flaviviridae, Genus: Flavivirus) is the sole North American member of the tick-borne encephalitis sero-complex. While associated with high rates of morbidity and mortality, POWV has historically been of little public health concern due to low incidence rates. However, over the last 20 yr, incidence rates have increased highlighting the growing epidemiological threat.

Jamestown Canyon virus comes into view: understanding the threat from an underrecognized arbovirus.

This review examines the epidemiology, ecology, and evolution of Jamestown Canyon virus (JCV) and highlights new findings from the literature to better understand the virus, the vectors driving its transmission, and its emergence as an agent of arboviral disease. We also reanalyze data from the Connecticut Arbovirus Surveillance Program which represents the largest dataset on JCV infection in mosquitoes. JCV is a member of the California serogroup of the genus Orthobunyavirus, family Peribunyaviridae, and is found throughout much of temperate North America.

Three species of axenic mosquito larvae recruit a shared core of bacteria in a common garden experiment.

In this study, we describe the generation of two new species of axenic mosquito, and . Along with , axenic larvae of these three species were exposed to an environmental water source to document the assembly of the microbiome in a common garden experiment. Additionally, the larvae were reared either individually or combinatorially with the other species to characterize the effects of co-rearing on the composition of the microbiome.

Comparison of acarological risk metrics derived from active and passive surveillance and their concordance with tick-borne disease incidence.

Tick-borne diseases continue to threaten human health across the United States. Both active and passive tick surveillance can complement human case surveillance, providing spatio-temporal information on when and where humans are at risk for encounters with ticks and tick-borne pathogens. However, little work has been done to assess the concordance of the acarological risk metrics from each surveillance method.

EVIDENCE OF PROTOZOAN AND BACTERIAL INFECTION AND CO-INFECTION AND PARTIAL BLOOD FEEDING IN THE INVASIVE TICK HAEMAPHYSALIS LONGICORNIS IN PENNSYLVANIA.

The Asian longhorned tick, Haemaphysalis longicornis, an invasive tick species in the United States, has been found actively host-seeking while infected with several human pathogens. Recent work has recovered large numbers of partially engorged, host-seeking H. longicornis, which together with infection findings raises the question of whether such ticks can reattach to a host and transmit pathogens while taking additional bloodmeals.

Dynamics of eastern equine encephalitis virus during the 2019 outbreak in the Northeast United States.

Eastern equine encephalitis virus (EEEV) causes a rare but severe disease in horses and humans and is maintained in an enzootic transmission cycle between songbirds and Culiseta melanura mosquitoes. In 2019, the largest EEEV outbreak in the United States for more than 50 years occurred, centered in the Northeast. To explore the dynamics of the outbreak, we sequenced 80 isolates of EEEV and combined them with existing genomic data.

Mosquito Larvae and Pupae Transport from the Field.

Laboratory study of field-collected mosquitoes can allow researchers to better understand the ways variation within and among mosquito populations shapes burdens of mosquito-borne disease. The complex comprises the most important vectors of malaria, but it can be challenging to keep in the laboratory. For some species of mosquitoes, especially , it is very difficult to bring viable eggs into the laboratory.

Collecting, Storing, and Hatching Eggs.

Laboratory study of natural populations of mosquitoes can play a key role in determining the underlying causes of variation in burdens of mosquito-borne disease. is the main vector of the viruses that cause dengue, chikungunya, Zika, and yellow fever, making it a high priority for laboratory study. eggs provide an ideal starting point for new laboratory colonies.

Phylogeographic reconstruction of the emergence and spread of Powassan virus in the northeastern United States.

Powassan virus is an emerging tick-borne virus of concern for public health, but very little is known about its transmission patterns and ecology. Here, we expanded the genomic dataset by sequencing 279 Powassan viruses isolated from ticks from the northeastern United States. Our phylogeographic reconstructions revealed that Powassan virus lineage II was likely introduced or emerged from a relict population in the Northeast between 1940 and 1975.

Dynamics of Eastern equine encephalitis virus during the 2019 outbreak in the Northeast United States.

Eastern equine encephalitis virus (EEEV) causes a rare but severe disease in horses and humans, and is maintained in an enzootic transmission cycle between songbirds and mosquitoes. In 2019, the largest EEEV outbreak in the United States for more than 50 years occurred, centered in the Northeast. To explore the dynamics of the outbreak, we sequenced 80 isolates of EEEV and combined them with existing genomic data.

Anomalous morphologies in Ixodes scapularis feeding on human hosts.

Cases of anomalous morphologies in the blacklegged tick, Ixodes scapularis, have been reported in both field-collected and human-biting specimen in the Northeastern and Midwestern United States, complicating the identification of this medically important tick species. We herein describe four cases of morphological anomalies in I. scapularis females exhibiting nanism and abnormally small genital apertures.

Range Expansion of Native and Invasive Ticks: A Looming Public Health Threat.

Native and invasive tick species pose a serious public health concern in the United States. Range expansion of several medically important tick species has resulted in an increasing number of communities at risk for exposure to ticks and tick-borne pathogens.

Population Genetic Analysis of Mosquitoes From Sudan Revealed Recent Independent Colonization Events by the Two Subspecies.

Increases in arbovirus outbreaks in Sudan are vectored by raising the medical importance of this mosquito. We genotyped 12 microsatellite loci in four populations of from Sudan, two from the East and two from the West, and analyzed them together with a previously published database of 31 worldwide populations to infer population structure and investigate the demographic history of this species in Sudan. Our results revealed the presence of two genetically distinct subspecies of in Sudan.

Spatiotemporal distribution, abundance, and host interactions of two invasive vectors of arboviruses, Aedes albopictus and Aedes japonicus, in Pennsylvania, USA.

Background: Aedes albopictus and Aedes japonicus, two invasive mosquito species in the United States, are implicated in the transmission of arboviruses. Studies have shown interactions of these two mosquito species with a variety of vertebrate hosts; however, regional differences exist and may influence their contribution to arbovirus transmission.

Methods: We investigated the distribution, abundance, host interactions, and West Nile virus infection prevalence of Ae.

Seasonal Dynamics of Mosquito-Borne Viruses in the Southwestern Florida Everglades, 2016, 2017.

Mosquitoes were collected for 12 consecutive months beginning June 2016, from 11 locations in the Florida Everglades, Collier County, and tested for viruses by isolation in Vero cells and subsequent identification. One species complex and 31 species of mosquitoes were identified from 668,809 specimens. Ochlerotatus taeniorhynchus comprised 72.

Ecology and Epidemiology of Eastern Equine Encephalitis Virus in the Northeastern United States: An Historical Perspective.

In the current review, we examine the regional history, ecology, and epidemiology of eastern equine encephalitis virus (EEEV) to investigate the major drivers of disease outbreaks in the northeastern United States. EEEV was first recognized as a public health threat during an outbreak in eastern Massachusetts in 1938, but historical evidence for equine epizootics date back to the 1800s. Since then, sporadic disease outbreaks have reoccurred in the Northeast with increasing frequency and northward expansion of human cases during the last 20 yr.

Envenomation by Steatoda borealis (Araneae: Theridiidae) in Connecticut, USA.

We report a case of envenomation by Steatoda borealis (Hentz, 1850) in Connecticut in late spring 2021. The bitten subject was a 60-yr-old female Caucasian. The bite occurred upon disturbing some books in her basement.