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Metropolitan Government of Nashville-Davidson (balance), TN, United States

McQuiston J.H.,Centers for Disease Control and Prevention | Wiedeman C.,Communicable and Environmental Disease Services | Singleton J.,Centers for Disease Control and Prevention | Carpenter L.R.,Centers for Disease Control and Prevention | And 6 more authors.
American Journal of Tropical Medicine and Hygiene | Year: 2014

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 postonset. 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. Case definitions used in national surveillance programs lack specificity and may capture cases that do not represent current rickettsial infections. Use of IgM antibodies should be reconsidered as a basis for diagnosis and public health reporting of RMSF and other spotted fever group rickettsiae in the United States. Copyright © 2014 by The American Society of Tropical Medicine and Hygiene. Source

Cohen S.B.,Vector Borne Diseases Section | Freye J.D.,Animal and Plant Health Inspection Service | Dunlap B.G.,Animal and Plant Health Inspection Service | Dunn J.R.,Communicable and Environmental Diseases Section | And 2 more authors.
Journal of Medical Entomology | Year: 2010

From April 2007 to September 2008,1,793 adult and nymphal ixodid ticks were collected from 49 counties in Tennessee. Six species were identified, including Dermacentor variabilis (Say), Amblyomma americanum (L.), Ixodes texanus (Banks), Ixodes cookei Packard, Ixodes scapularis (Say), and Amblyomma maculatum Koch, from 13 medium- to large-sized mammalian hosts and dragging through vegetation. Raccoons were the most common vertebrate source (198 captures), accounting for 60% of ticks collected. Dermacentor variabilis was the predominant species from raccoons with a prevalence of 92% and mean intensity of 5.3. A. americanum was predominated in white-tailed deer and drags with respective mean intensities of 3.1 and 14.1 and prevalence values of 94%. All tick species were identified between April and August, coinciding with the majority of animal captures. Only A. americanum, I. texanus, and I. cookei were identified from 22 animal captures from November to March. I. texanus and I. cookei were more common in the eastern portions of the state, but this may be a result of higher raccoon captures in those areas. Only four specimens of I. scapularis were collected in this study, which may reflect the absence of small mammal or reptile captures. Two A. maculatum were collected, and we report new distribution records in Tennessee for this species. Despite unequal sampling among ecoregions, the large numbers of D. variabilis and A. americanum from multiple host species suggest their widespread distribution throughout the state. These species of ticks can transmit multiple pathogens, including spotted fever group rickettsiae and ehrlichiae. © 2010 Entomological Society of America. Source

Fritzen C.,Vector Borne Diseases Section | Mosites E.,Vector Borne Diseases Section | Applegate R.D.,Vector Borne Diseases Section | Applegate R.D.,Tennessee Wildlife Resources Agency | And 6 more authors.
Journal of Parasitology | Year: 2014

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. One hundred and sixty-six Ixodes scapularis ticks and biological samples from 8 rabbits and 5 deer were collected. Ixodes scapularis were PCR positive for Babesia odocoilei (n = 7, 4%) and Theileria cervi (n = 24, 14%). Deer were seropositive for B. odocoilei and PCR positive for T. cervi. Rabbits were seropositive for B. odocoilei and Babesia sp. MO1, and 1 rabbit was PCR positive for Babesia sp. MO1. In summary, zoonotic Babesia sp. MO1 infection in rabbits is reported here for the first time in Tennessee as well as infection of deer and I. scapularis ticks with 2 other piroplasms of veterinary importance. © American Society of Parasitologists 2014. Source

Westby K.M.,Vector Borne Diseases Section | Westby K.M.,Washington University in St. Louis | Fritzen C.,Vector Borne Diseases Section | Paulsen D.,University of Tennessee at Knoxville | And 2 more authors.
Journal of the American Mosquito Control Association | Year: 2015

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. albopictus and Ae. japonicus, in an emerging disease focus in Tennessee. Mosquitoes were collected using multiple trapping methods specific for Aedes mosquitoes at recent human case sites. Mosquito pools were tested via reverse transcriptase-polymerase chain reaction (RT-PCR) of the S segment to detect multiple Bunyamwera and California serogroup viruses, including LACV, as well as real-time RT-PCR of the M segment. A total of 54 mosquito pools were positive, including wild-caught adult females and laboratory-reared adults, demonstrating transovarial transmission in all 3 species. Maximum likelihood estimates (per 1,000 mosquitoes) were 2.72 for Ae. triseriatus, 3.01 for Ae. albopictus, and 0.63 for Ae. japonicus. We conclude that Ae. triseriatus and Ae. albopictus are important LACV vectors and that Ae. japonicus also may be involved in virus maintenance and transmission. Copyright © 2015 by The American Mosquito Control Association, Inc. Source

Fritzen C.M.,Vector Borne Diseases Section | Huang J.,Vector Borne Diseases Section | Westby K.,Vector Borne Diseases Section | Freye J.D.,Animal and Plant Health Inspection Service | And 5 more authors.
American Journal of Tropical Medicine and Hygiene | Year: 2011

Rocky Mountain spotted fever, Lyme disease, and ehrlichiosis are tick-borne diseases that are reported annually in Kentucky. We conducted a survey to describe infection prevalence of tick-borne pathogens in Amblyomma americanum and Dermacentor variabilis ticks collected in Kentucky. During 2007-2008, we collected 287 ticks (179 D. variabilis and 108 A. americanum) from canine, feral hog, horse, raccoon, white-tailed deer, and human hosts in six counties in Kentucky. Ticks were screened for Rickettsia spp., Borrelia spp., and Ehrlichia spp. by using polymerase chain reaction. Forty-one (14.3%) ticks (31 A. americanum and 10 D. variabilis) were polymerase chain reaction-positive for a Rickettsia spp. Fourteen (4.9%) ticks (6 A. americanum and 8 D. variabilis) were positive for E. chaffeensis, and 4 A. americanum (1.4%) were positive for E. ewingii. One (0.4%) A. americanum was positive for Borrelia lonestari.Although Rocky Mountain spotted fever is diagnosed in Kentucky, no R. rickettsii was found in ticks in this study. Copyright © 2011 by The American Society of Tropical Medicine and Hygiene. Source

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