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Dermacentor variabilis, a common human-biting tick found throughout the eastern half and along the west coast of the United States, is a vector of multiple bacterial pathogens. Historically, D. variabilis has been considered a primary vector of Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever. A total of 883 adult D. variabilis, collected between 2012 and 2017 from various locations in 12 states across the United States, were screened for rickettsial DNA. Tick extracts were evaluated using three real-time PCR assays; an R. rickettsii-specific assay, a Rickettsia bellii-specific assay, and a Rickettsia genus-specific assay. Sequencing of ompA gene amplicons generated using a seminested PCR assay was used to determine the rickettsial species present in positive samples not already identified by species-specific real-time assays. A total of 87 (9.9%) tick extracts contained R. bellii DNA and 203 (23%) contained DNA of other rickettsial species, including 47 (5.3%) with Rickettsia montanensis, 11 (1.2%) with Rickettsia amblyommatis, 2 (0.2%) with Rickettsia rhipicephali, and 3 (0.3%) with Rickettsia parkeri. Only 1 (0.1%) tick extract contained DNA of R. rickettsii. These data support multiple other contemporary studies that indicate infrequent detection of R. rickettsii in D. variabilis in North America.

Dermacentor variabilis, a common human-biting tick found throughout the eastern half and along the west coast of the United States, is a vector of multiple bacterial pathogens. Historically, D. variabilis has been considered a primary vector of Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever. A total of 883 adult D. variabilis, collected between 2012 and 2017 from various locations in 12 states across the United States, were screened for rickettsial DNA. Tick extracts were evaluated using three real-time PCR assays; an R. rickettsii-specific assay, a Rickettsia bellii-specific assay, and a Rickettsia genus-specific assay. Sequencing of ompA gene amplicons generated using a seminested PCR assay was used to determine the rickettsial species present in positive samples not already identified by species-specific real-time assays. A total of 87 (9.9%) tick extracts contained R. bellii DNA and 203 (23%) contained DNA of other rickettsial species, including 47 (5.3%) with Rickettsia montanensis, 11 (1.2%) with Rickettsia amblyommatis, 2 (0.2%) with Rickettsia rhipicephali, and 3 (0.3%) with Rickettsia parkeri. Only 1 (0.1%) tick extract contained DNA of R. rickettsii. These data support multiple other contemporary studies that indicate infrequent detection of R. rickettsii in D. variabilis in North America.

Routine biosurveillance efforts at the Naval Station Guantanamo Bay, Cuba, on 18 June 2019, detected two unusual mosquitos in a CO2-baited CDC light trap. Morphological and molecular analysis confirmed the presence of Aedes (Fredwardsius) vittatus (Bigot, 1861) - the first record of the Old World dengue, chikungunya, Zika and yellow fever virus vector into the Americas - and provides evidence for its establishment in Cuba. Newly submitted GenBank sequences from Dominican Republic further evidence its establishment in the Caribbean, and a median-joining network analysis using mitochondrial COI gene sequences clearly supports multiple introductions of Ae. vittatus into the Caribbean from the Indian subcontinent. It was determined that many Ae. vittatus COI barcode sequences in GenBank are currently misidentified as Aedes (Fredwardsius) cogilli Edwards, 1922.

Ticks are the most significant vectors of infectious diseases in the United States, inspiring many researchers to study aspects of their biology, ecology, and their effects on public health. However, regional differences in tick abundance and pathogen infection prevalence result in the inability to assume results from one area are relevant in another. Current local information on tick ranges, infection rates, and human cases is needed to assess tick-borne disease risk in any given region. The Mid-Atlantic Tick Summit III brought together over 100 area experts and researchers to share regional updates on ticks and their associated pathogens. We report some meeting highlights here. Regional meetings foster cross-disciplinary collaborations that benefit the community, and open novel lines of inquiry so that tick-bite risk can be reduced and tick-borne diseases can be treated effectively.

Loxosceles rufescens (Dufour), a relatively cosmopolitan, synanthropic species commonly known as the Mediterranean recluse spider, inhabits numerous government buildings in the Washington, D.C. area. Like the closely related brown recluse spider ( L. reclusa Gertsch and Mulaik ) in the south-central United States, L. rufescens can be extremely abundant with in a structure. Unlike L. reclusa , D.C. populations of L. rufescens are essentially troglophilic, concentrated mainly in basements, foundation walls, and other man-made subterranean habitats, typically in close association with Periplaneta americana (L.) and/or Reticulitermes spp. It has not been observed either outdoors or in smaller, residential buildings. Since this spider is often misidentified as L. reclusa by entomologists who are unaware of L. rufescens ' widespread distribution and potential for persistent and dense local populations, we present photographs to aid in distinguishing the adults of these two similar species.

We evaluated the potential for Ochlerotatus j. japonicus (Theobald), a newly recognized invasive mosquito species in the United States, to transmit eastern equine encephalitis (EEE) virus. Aedes albopictus (Skuse) and Culex pipiens (L.) were similarly tested for comparison. Ochlerotatus j. japonicus and Ae. albopictus became infected and transmitted EEE virus by bite after feeding on young chickens 1 d after they had been inoculated with EEE virus (viremias ranging from 10(7.0-8.7) plaque-forming units [PFU]/ml of blood). No Cx. pipiens (n = 20) had detectable levels of virus 14 d after feeding on an EEE-virus infected chicken with a viremia of 10(8.1) PFU per ml of blood. Depending on the viral titer in the donor chicken, infection rates ranged from 55-100% for Oc. j. japonicus and 93-100% for Ae. albopictus. In these two species, dissemination rates were identical to or nearly identical to infection rates. Depending on the viral titer in the blood meal, estimated transmission rates ranged from 15 to 25% for Oc. j. japonicus and 59-63% for Ae. albopictus. Studies of replication of EEE virus in Oc. j. japonicus showed that there was an "eclipse phase" in the first 4 d after an infectious blood meal, that viral titers peak by day 7 at around 10(5.7) per mosquito, and that virus escaped the mid-gut as soon as 3 d after the infectious blood meal. These data, combined with the opportunistic feeding behavior of Oc. j. japonicus in Asia and the reported expansion of its range in the eastern United States, indicate that it could function as a bridge vector for EEE virus between the enzootic Culiseta melanura (Coquillett)-avian cycle and susceptible mammalian hosts.

Pagac, Benedict B., Ranum, Katrina L., Knisley, C. Barry, McCann, James M., Moser, George A., McGowan, Peter C. (2017): Discovery of the Puritan Tiger Beetle, Ellipsoptera puritana (G. Horn) (Coleoptera: Carabidae), Along the Severn River, Maryland. The Coleopterists Bulletin 71 (2): 357-360, DOI: 10.1649/0010-065X-71.2.357, URL: http://dx.doi.org/10.1649/0010-065x-71.2.357

We found that 14.3% (15/105) of Amblyomma maculatum and 3.3% (10/299) of Dermacentor variabilis ticks collected at 3 high-use military training sites in west-central Kentucky and northern Tennessee, USA, were infected with Rickettsia parkeri and Rickettsia montanensis, respectively. These findings warrant regional increased public health awareness for rickettsial pathogens and disease.

Recent outbreaks of mysterious skin lesions on multiple personnel at several military facilities were initially blamed on spiders. Requests were made for pest inspection and control to remedy the situation. Greater scrutiny of the situation led to a hypothesis that instead of spiders, an infectious outbreak of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) should be investigated as the etiology. Subsequent culturing of the lesions on personnel at one facility confirmed this bacterial etiology. Barracks, as well as other close quarter military living conditions, are ripe environments for the establishment, persistence, and spread of CA-MRSA. Military medical personnel should consider CA-MRSA as a more likely etiologic agent than spider bites for cutaneous eruptions in which there are multiple lesions on one person or multiple patients with similar lesions.

A statewide survey of Ixodes dammini Spielman was done in November 1991 as a follow-up to a study in 1989. In total, 3,434 adult ticks were collected from 922 hunter-killed white-tailed deer processed at 22 check stations (1 per county in 22 of 23 counties in the state). Significantly more male than female ticks were collected. Tick infestation was significantly heavier on male than female deer. The pattern of tick distribution was similar to that in 1989, with low prevalence (percentage tick-infested deer) and abundance (mean ticks per deer) in the Appalachian region, moderate values in the Piedmont, and high values in the western and eastern Coastal Plains regions. The pattern of tick infection with Borrelia burgdorferi spirochetes (determined by polyclonal immunofluorescence assay) was similar to the tick distributional pattern. Overall, tick prevalence and abundance were higher in 1991 than in 1989, as was the spirochete infection rate in ticks. Multiple regression analysis of tick prevalence against six selected physical and biotic parameters (elevation, rainfall, summer and winter temperature, percentage of forest land, deer density) showed a significant relationship with rainfall and elevation in 1989 and elevation alone in 1991. A more extensive study in Caroline and Dorchester counties in the eastern Coastal Plains region (which showed exceptionally low tick density indices in a generally tick-abundant region in 1989) demonstrated that I. dammini was well established in Caroline but not in Dorchester County.

Aedes japonicus japonicus was collected via gravid trapping in Wisconsin in the summers of 2004 and 2005 at Fort McCoy, Monroe County. Subsequently, in the summer of 2007, Ae. japonicus was captured in a human landing catch in Dane County, Madison, WI. Additional collections were made at this site in the spring of 2008. Invasion is in progress, but significant population increases have not yet been confirmed.

The United States faces many existing and emerging mosquito-borne disease threats, such as West Nile virus and Rift Valley fever. An important component of strategic prevention and control plans for these and other mosquito-borne diseases is forecasting the distribution, timing, and abundance of mosquito vector populations. Populations of many medically important mosquito species are closely tied to climate, and historical climate-population associations may be used to predict future population dynamics. Using 2003-2005 U.S. Army Center for Health Promotion and Preventive Medicine mosquito surveillance data, we looked at populations of several known mosquito vectors of West Nile virus, as well as possible mosquito vectors of Rift Valley fever virus, at continental U.S. military installations. We compared population changes with concurrent patterns for a satellite-derived index of climate (normalized difference vegetation index) and observed instances of population changes appearing to be direct responses to climate. These preliminary findings are important first steps in developing an automated, climate-driven, early warning system to flag regions of the United States at elevated risk of mosquito-borne disease transmission.

We used geospatial techniques to study the potential impact of 2 exotic mosquitoes, Aedes albopictus and Ochlerotatus japonicus japonicus, on the epidemiology of West Nile virus in Maryland. These 2 species have established populations in Maryland over the past 15 years. Larvae of both mosquito species are found in natural and artificial water-holding cavities and containers, particularly water in tires. Therefore, we used locations of licensed tire dealers and of tire dumps scheduled for clean up as an index for potential sources of mosquito vectors. This index was expected to underestimate the actual population of source habitats. West Nile virus activity in Maryland during 1999, 2000, and 2001 was indicated by the presence of dead, infected birds, particularly American crows and other corvids; infected pools of mosquitoes; and human and horse infections. Adult females of both mosquito species are aggressive, opportunistic feeders that have been observed to take blood meals from avian and mammalian hosts. Susceptible vertebrate hosts, particularly birds, are ubiquitously distributed throughout the developed areas of the state. This analysis demonstrated a spatial convergence of the virus, the exotic mosquito vectors, and susceptible hosts. This conjunction indicated that these 2 mosquito species have a high potential to serve as bridge vectors and thus, impact the epidemiology of West Nile virus under favorable environmental and climatic conditions. Positive mosquito pools were collected from only the Baltimore-Washington metropolitan corridor, suggesting a newly created enzootic focus for this virus. Land-cover analysis of the sites where virus activity had been detected showed predominantly developed land uses. Analyses of the environmental justice aspects (social, economic, and housing characteristics) of block groups with human West Nile fever cases or with positive mosquito pools were equivocal. Human cases seemed to occur in developed block groups with lower income levels.

An epizootic of eastern equine encephalitis (EEE) at the Patuxent Wildlife Research Center (PWRC), Laurel, Maryland (USA), in 1989 provided an opportunity to determine if EEE immunization protected whooping cranes (Grus americana). Based on seroconversion of 31% of sympatric hatch-year sandhill cranes, Grus canadensis, and a previous 35% case fatality rate in whooping cranes, 17 (37%) of the 46 susceptible whooping cranes should have been exposed to virus and six should have died. As there were no deaths in these birds, the EEE vaccination program appeared to be efficacious in this whooping crane population.