Persistent spatial clustering and predictors of pediatric La Crosse virus neuroinvasive disease risk in eastern Tennessee and western North Carolina, 2003-2020.

The combined region of eastern Tennessee and western North Carolina has a persistently high risk of pediatric La Crosse virus neuroinvasive disease (LACV-ND). To guide public health intervention in this region, the objectives of this retrospective ecological study were to investigate the geographic clustering and predictors of pediatric LACV-ND risk at the ZIP code tabulation area (ZCTA) level. Data on pediatric cases of LACV-ND reported between 2003 and 2020 were obtained from Tennessee Department of Health and North Carolina Department of Health and Human Services.

Utilization of a zoo for mosquito (Diptera: Culicidae) diversity analysis, arboviral surveillance, and blood feeding patterns.

Zoos provide a unique opportunity to study mosquito feeding ecology as they represent areas where exotic animals, free-roaming native animals, humans, and mosquito habitats overlap. Therefore, these locations are a concern for arbovirus transmission to both valuable zoo animals and human visitors. We sampled mosquitoes in and around The Nashville Zoo at Grassmere in Tennessee, USA, over 4 months in 2020 using 4 mosquito trap methods and 12 sampling locations.

West Nile Virus and Epizootic Hemorrhagic Disease Virus Co-Infection in a Novel Host at the Nashville Zoo.

On August 30, 2017, one of five bontebok in a mixed-species exhibit at the Nashville Zoo at Grassmere exhibited acute hind-limb ataxia and altered demeanor. Pathological examination demonstrated meningoencephalitis and spinal myelitis. Coinfection of West Nile virus (WNV) and epizootic hemorrhagic disease virus (EHDV) was revealed by quantitative real-time and traditional reverse transcription-polymerase chain reaction assays and virus isolation/whole genome sequencing from brain tissue, respectively.

La Crosse virus spread within the mosquito population in Knox County, TN.

In Appalachia, La Crosse virus (LACV) is a leading pediatric arbovirus and public health concern for children under 16 years. LACV is transmitted via the bite of an infected Aedes mosquito. Thus, it is imperative to understand the dynamics of the local vector population in order to assess risk and transmission.

Isothermal Recombinase Polymerase Amplification-Lateral Flow Point-of-Care Diagnostic Test for Heartland Virus.

The detection of novel or re-emergent pathogens necessitates the development of rapid, easy-to-use diagnostic tests that can be readily adapted and utilized in both clinical laboratories and field settings. Heartland virus (HRTV) is the first pathogenic responsible for serious and fatal cases in the United States. We developed a qualitative test based on recombinase-polymerase-amplification coupled with lateral flow reading (RPA-LF) for rapid detection of HRTV.

Assessment of Risk Factors and Outcomes of Severe Ehrlichiosis Infection.

Importance: Ehrlichiosis cases in the US have increased more than 8-fold since 2000. Up to 57% of patients with ehrlichiosis require hospitalization and 11% develop a life-threatening complication; however, risk factors for serious disease are not well documented.

Objective: To examine risk factors associated with severe ehrlichiosis.

Targeted Metagenomics for Clinical Detection and Discovery of Bacterial Tick-Borne Pathogens.

Tick-borne diseases, due to a diversity of bacterial pathogens, represent a significant and increasing public health threat throughout the Northern Hemisphere. A high-throughput 16S V1-V2 rRNA gene-based metagenomics assay was developed and evaluated using >13,000 residual samples from patients suspected of having tick-borne illness and >1,000 controls. Taxonomic predictions for tick-borne bacteria were exceptionally accurate, as independently validated by secondary testing.

Heartland Virus in Lone Star Ticks, Alabama, USA.

We detected Heartland virus (HRTV) in lone star nymphs collected in 2018 in northern Alabama, USA. Real-time reverse transcription PCR selective for the small segment of the HRTV genome and confirmatory sequencing of positive samples showed high identity with HRTV strains sequenced from Tennessee and Missouri.

One Confirmed and 2 Suspected Cases of Heartland Virus Disease.

Heartland virus is a tickborne phlebovirus first identified in Missouri in 2009; 11 human cases have been reported in the literature. Reported hallmarks of infection have included fever, malaise, anorexia, gastrointestinal complaints, thrombocytopenia, neutropenia, and aminotransferase elevations. We report 1 confirmed and 2 suspected cases and discuss implications for case-finding.

A standardized method for the construction of a tick drag/flag sampling approach and evaluation of sampling efficacy.

Drag sampling and flagging are two of the most effective and widely applied techniques to monitor tick populations. Despite the importance of this sampling strategy, there is a lack of standardized protocols for the construction of an inexpensive tick drag/flag. To this end, we provide a step-by-step protocol that details the construction of a tick drag/flag.

Chagas Disease Surveillance Activities - Seven States, 2017.

Chagas disease, a potentially life-threatening disease caused by the protozoan parasite Trypanosoma cruzi, has become a concern in the United States as a result of human emigration from Latin America where Chagas disease is endemic (1). It is estimated that as many as 8 million people living in Mexico, and Central and South America have Chagas disease.* Most cases of Chagas disease in the United States are chronic infections; however, rare cases of acute congenital infections and autochthonous vectorborne transmission have been reported (2).

Evaluation of a Spotted Fever Group Public Health Surveillance System in Tennessee.

Spotted fever group (SFG) rickettsioses are endemic in Tennessee, with ∼2,500 cases reported during 2000-2012. Because of this substantial burden of disease, we performed a three-part evaluation of Tennessee's routine surveillance for SFG rickettsioses cases and deaths to assess the system's effectiveness. Tennessee Department of Health (TDH) SFG rickettsioses surveillance records were matched to three patient series: 1) patients with positive serologic specimens from a commercial reference laboratory during 2010-2011, 2) tertiary medical center patients with positive serologic tests during 2007-2013, and 3) patients identified from death certificates issued during 1995-2014 with SFG rickettsiosis-related causes of death.

Novel Clinical and Pathologic Findings in a Heartland Virus-Associated Death.

We describe an investigation into a Heartland virus (HRTV)-associated death in Tennessee with novel clinical and pathologic findings. HRTV can cause rapidly fatal, widely disseminated infection with multisystem organ failure in patients without substantial comorbidities. We identified viral antigen in multiple organ tissues where it was not detected previously.

Challenges to Arboviral Surveillance in Tennessee: Health-Care Providers' Attitudes and Behaviors.

Surveillance of arboviruses depends on health-care providers' ability to diagnose and report human cases of disease. The purposes of this study were to assess Tennessee providers' 1) self-efficacy toward diagnosis and management, 2) clinical practices, and 3) variation in these measures by provider characteristics. A survey was e-mailed to 13,851 providers, of which 916 (7%) responded.

Human Infections by Multiple Spotted Fever Group Rickettsiae in Tennessee.

Rocky Mountain spotted fever is the most common tick-borne disease in Tennessee. However, Rickettsia rickettsii has rarely been isolated from endemic ticks, suggesting rickettsioses may be caused by other species. A total of 56 human serum samples that were serologically positive for exposure to Rickettsia were obtained from commercial laboratories in 2010 and 2011.

La Crosse Encephalitis Virus Infection in Field-Collected Aedes albopictus, Aedes japonicus, and Aedes triseriatus in Tennessee.

La Crosse virus (LACV) is a mosquito-borne virus and a major cause of pediatric encephalitis in the USA. La Crosse virus emerged in Tennessee and other states in the Appalachian region in 1997. We investigated LACV infection rates and seasonal abundances of the native mosquito vector, Aedes triseriatus, and 2 recently introduced mosquito species, Ae.

Comparative sequence analyses of La Crosse virus strain isolated from patient with fatal encephalitis, Tennessee, USA.

We characterized a La Crosse virus (LACV) isolate from the brain of a child who died of encephalitis-associated complications in eastern Tennessee, USA, during summer 2012. We compared the isolate with LACV sequences from mosquitoes collected near the child's home just after his postmortem diagnosis. In addition, we conducted phylogenetic analyses of these and other sequences derived from LACV strains representing varied temporal, geographic, and ecologic origins.

Cemeteries are effective sites for monitoring la crosse virus (LACv) and these environments may play a role in LACv infection.

La Crosse encephalitis (LAC) is the leading arboviral disease among children, and was previously limited to the upper Midwest. In 2012 nine pediatric cases of LAC occurred in eastern Tennessee, including one fatal case. In an attempt to identify sites near an active LACv infection and describe the abundance and distribution of potential LACv vectors near a fatal LAC case in the Appalachian region, we initiated an end of season study using a combination of questing and oviposition mosquito traps placed at forty-nine sites consisting of cemeteries and houses within 16 radial kilometers of two pediatric infections.

Dengue among American missionaries returning from Jamaica, 2012.

Dengue is an acute febrile illness caused by any of four mosquito-transmitted dengue virus (DENV) types. Dengue is endemic in Jamaica, where an epidemic occurred in 2012. An investigation was conducted by multiple agencies for 66 missionaries traveling from nine US states to Jamaica after 1 missionary from the group was confirmed to have dengue.

Seroepidemiologic study of human infections with spotted fever group Rickettsiae in North Carolina.

Increasing entomologic and epidemiologic evidence suggests that spotted fever group rickettsiae (SFGR) other than Rickettsia rickettsii are responsible for spotted fever rickettsioses in the United States. A retrospective seroepidemiologic study was conducted on stored acute- and convalescent-phase sera that had been submitted for Rocky Mountain spotted fever testing to the North Carolina State Laboratory of Public Health. We evaluated the serologic reactivity of the paired sera to R.

Inadequacy of IgM antibody tests for diagnosis of Rocky Mountain Spotted Fever.

Among 13 suspected Rocky Mountain spotted fever (RMSF) cases identified through an enhanced surveillance program in Tennessee, antibodies to Rickettsia rickettsii were detected in 10 (77%) patients using a standard indirect immunofluorescent antibody (IFA) assay. Immunoglobulin M (IgM) antibodies were observed for 6 of 13 patients (46%) without a corresponding development of IgG, and for 3 of 10 patients (30%) at least 1 year post-onset. However, recent infection with a spotted fever group rickettsiae could not be confirmed for any patient, based on a lack of rising antibody titers in properly timed acute and convalescent serologic specimens, and negative findings by polymerase chain reaction testing.

An outbreak of bed bug infestation in an office building.

Since 2000, resurgence in bed bugs has occurred in the U.S. Reports of infestations of homes, hospitals, hotels, and offices have been described.

Diversity of piroplasms detected in blood-fed and questing ticks from several states in the United States.

Piroplasms in the genera Babesia, Theileria, and Cytauxzoon are tick-borne parasites that may be animal and human pathogens. Most piroplasms with known life cycles are transmitted by ixodid ticks; however, for many species, the vector is unknown. This study was conducted to determine the prevalence and diversity of piroplasms in ticks from several US states.

Environmental investigation following the first human case of babesiosis in Tennessee.

Babesiosis is an emerging tick-borne zoonotic disease in the United States caused by Babesia parasites. In 2009, the first case of babesiosis was documented in Tennessee. Environmental investigation at the reported site of tick exposure included collection of ticks and specimens from eastern cottontail rabbits (Sylvilagus floridanus) and white-tailed deer ( Odocoileus virginianus ) that were tested for piroplasms by molecular and serologic methods.