scholarly journals Comparative Analysis of Infection by Rickettsia rickettsii Sheila Smith and Taiaçu Strains in a Murine Model

Pathogens ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 744
Author(s):  
Eliane Esteves ◽  
Chanida Fongsaran ◽  
Ingeborg M. Langohr ◽  
Sean P. Riley ◽  
Marcelo B. Labruna ◽  
...  
Keyword(s):  
United States ◽  
Spotted Fever ◽  
Case Fatality ◽  
Rocky Mountain ◽  
The United States ◽  
Rocky Mountain Spotted Fever ◽  
Rickettsia Rickettsii ◽  
Virulent Strains ◽  
Life Threatening ◽  
Tick Borne Disease

Rocky Mountain spotted fever (RMSF) is a life-threatening tick-borne disease caused by Rickettsia rickettsii, which is widely distributed throughout the Americas. Over 4000 cases of RMSF are recorded annually in the United States, while only around 100 cases are reported in Brazil. Conversely, while case fatality rates in the United States oscillate around 5%, in Brazil they can surpass 70%, suggesting that differences in tick vectoring capacity, population sensitivity, and/or variability in virulence of the rickettsial strains may exist. In this study, we compared the susceptibility of C3H/HeN mice to two highly virulent strains of R. rickettsii, one from the United States (Sheila Smith) and the other from Brazil (Taiaçu). Animals inoculated with the Taiaçu strain succumbed to infection earlier and exhibited severe histological lesions in both liver and spleen sooner than mice infected with the Sheila Smith strain. These differences in survival and signs of the disease are not related to a greater proliferation of the Taiaçu strain, as there were no significant differences in the rickettsial load in mice tissues inoculated with either strain. The present study is the first step to experimentally assess differences in fatality rates of RMSF in two different regions of the American continent.

scholarly journals The Ability of the Invasive Asian Longhorned Tick Haemaphysalis longicornis (Acari: Ixodidae) to Acquire and Transmit Rickettsia rickettsii (Rickettsiales: Rickettsiaceae), the Agent of Rocky Mountain Spotted Fever, Under Laboratory Conditions

2020 ◽  
Vol 57 (5) ◽  
pp. 1635-1639 ◽  
Author(s):  
Hannah M Stanley ◽  
Shelby L Ford ◽  
Alyssa N Snellgrove ◽  
Kris Hartzer ◽  
Emily B Smith ◽  
...  
Keyword(s):  
United States ◽  
Spotted Fever ◽  
Life Stage ◽  
Low Frequency ◽  
Rocky Mountain ◽  
The United States ◽  
Haemaphysalis Longicornis ◽  
Rocky Mountain Spotted Fever ◽  
Rickettsia Rickettsii ◽  
Laboratory Conditions

Abstract The invasive Asian longhorned tick, Haemaphysalis longicornis Neumann, was first detected in the United States in 2017. It has since been found in 12 states, and there is concern that the tick’s parthenogenetic ability and wide variety of host species may allow for broader dissemination. Of the tick-borne diseases endemic to the United States, Rocky Mountain spotted fever (RMSF), a rapidly progressive and potentially fatal disease caused by Rickettsia rickettsii, is the most severe. There is considerable geographical overlap between spotted fever rickettsioses cases, which include RMSF, and the currently known distribution of H. longicornis, providing the potential for this tick to encounter this pathogen. We have evaluated the ability of H. longicornis to acquire and transmit R. rickettsii under laboratory conditions. Haemaphysalis longicornis as larvae and nymphs acquired the pathogen while feeding on infected guinea pigs. The infection persisted through every life stage, all of which were able to transmit R. rickettsii to naïve hosts. The pathogen was also transmitted at a low frequency between generations of H. longicornis through the ova. While H. longicornis was demonstrated to be a competent vector for R. rickettsii under laboratory conditions, the probability of its involvement in the maintenance and transmission of this pathogen in nature, as well as its potential impact on human health, requires further study.

Mosquito and Tick-borne Illnesses in the United States. Guidelines for the Recognition and Empiric Treatment of Zoonotic Diseases in the Wilderness.

2019 ◽  
Vol 19 (3) ◽  
pp. 238-257
Author(s):  
Suresh Antony
Keyword(s):  
United States ◽  
Lyme Disease ◽  
Spotted Fever ◽  
Disease Process ◽  
Rocky Mountain ◽  
The United States ◽  
Health Care Facilities ◽  
Diagnostic Tools ◽  
Rocky Mountain Spotted Fever ◽  
Number Of Patients

Background:In the United States, tick-borne illnesses account for a significant number of patients that have been seen and treated by health care facilities. This in turn, has resulted in a significant morbidity and mortality and economic costs to the country.Methods:The distribution of these illnesses is geographically variable and is related to the climate as well. Many of these illnesses can be diagnosed and treated successfully, if recognized and started on appropriate antimicrobial therapy early in the disease process. Patient with illnesses such as Lyme disease, Wet Nile illness can result in chronic debilitating diseases if not recognized early and treated.Conclusion:This paper covers illnesses such as Lyme disease, West Nile illness, Rocky Mountain Spotted fever, Ehrlichia, Tularemia, typhus, mosquito borne illnesses such as enteroviruses, arboviruses as well as arthropod and rodent borne virus infections as well. It covers the epidemiology, clinical features and diagnostic tools needed to make the diagnosis and treat these patients as well.

scholarly journals Dermacentor variabilis is the Predominant Dermacentor spp. (Acari: Ixodidae) Feeding on Dogs and Cats Throughout the United States

2021 ◽  
Author(s):  
Kathryn T Duncan ◽  
Meriam N Saleh ◽  
Kellee D Sundstrom ◽  
Susan E Little
Keyword(s):  
United States ◽  
Spotted Fever ◽  
Rocky Mountain ◽  
The United States ◽  
Dermacentor Variabilis ◽  
Western United States ◽  
Its2 Region ◽  
Rrna Gene ◽  
Rocky Mountain Spotted Fever ◽  
Dermacentor Albipictus

Abstract Throughout North America, Dermacentor spp. ticks are often found feeding on animals and humans, and are known to transmit pathogens, including the Rocky Mountain spotted fever agent. To better define the identity and distribution of Dermacentor spp. removed from dogs and cats in the United States, ticks submitted from 1,457 dogs (n = 2,924 ticks) and 137 cats (n = 209 ticks) from veterinary practices in 44/50 states from February 2018-January 2020 were identified morphologically (n = 3,133); the identity of ticks from regions where Dermacentor andersoni (Stiles) have been reported, and a subset of ticks from other regions, were confirmed molecularly through amplification and sequencing of the ITS2 region and a 16S rRNA gene fragment. Of the ticks submitted, 99.3% (3,112/3,133) were Dermacentor variabilis (Say), 0.4% (12/3,133) were D. andersoni, and 0.3% (9/3,133) were Dermacentor albipictus (Packard). While translocation of pets prior to tick removal cannot be discounted, the majority (106/122; 87%) of Dermacentor spp. ticks removed from dogs and cats in six Rocky Mountain states (Montana, Idaho, Wyoming, Nevada, Utah, and Colorado) were D. variabilis, suggesting this species may be more widespread in the western United States than is currently recognized, or that D. andersoni, if still common in the region, preferentially feeds on hosts other than dogs and cats. Together, these data support the interpretation that D. variabilis is the predominant Dermacentor species found on pets throughout the United States, a finding that may reflect recent shifts in tick distribution.

Rocky Mountain Spotted Fever in the United States, 1997–2002

2006 ◽  
Vol 6 (2) ◽  
pp. 170-178 ◽  
Author(s):  
Alice S. Chapman ◽  
Staci M. Murphy ◽  
Linda J. Demma ◽  
Robert C. Holman ◽  
Aaron T. Curns ◽  
...  
Keyword(s):  
United States ◽  
Spotted Fever ◽  
Rocky Mountain ◽  
The United States ◽  
Rocky Mountain Spotted Fever

Fatal Cases of Rocky Mountain Spotted Fever in the United States, 1981?1988

1990 ◽  
Vol 590 (1 Rickettsiolog) ◽  
pp. 246-247 ◽  
Author(s):  
DANIEL B. FISHBEIN ◽  
MARIA G. FRONTINI ◽  
ROSE GILES ◽  
LOIS L. VERNON
Keyword(s):  
United States ◽  
Spotted Fever ◽  
Rocky Mountain ◽  
The United States ◽  
Rocky Mountain Spotted Fever

Rocky Mountain Spotted Fever in the United States, 1997-2002

2006 ◽  
Vol 1078 (1) ◽  
pp. 154-155 ◽  
Author(s):  
A. S CHAPMAN ◽  
S. M MURPHY ◽  
L. J DEMMA ◽  
R. C HOLMAN ◽  
A. T CURNS ◽  
...  
Keyword(s):  
United States ◽  
Spotted Fever ◽  
Rocky Mountain ◽  
The United States ◽  
Rocky Mountain Spotted Fever

Rocky Mountain spotted fever in the United States, 1993-1996.

2000 ◽  
Vol 63 (1) ◽  
pp. 21-26 ◽  
Author(s):  
T A Treadwell ◽  
M J Clarke ◽  
J W Krebs ◽  
J E Childs ◽  
C D Paddock ◽  
...  
Keyword(s):  
United States ◽  
Spotted Fever ◽  
Rocky Mountain ◽  
The United States ◽  
Rocky Mountain Spotted Fever

scholarly journals Fatal Rocky Mountain Spotted Fever along the United States–Mexico Border, 2013–2016

2017 ◽  
Vol 23 (10) ◽  
pp. 1621-1626 ◽  
Author(s):  
Naomi A. Drexler ◽  
Hayley Yaglom ◽  
Mariana Casal ◽  
Maria Fierro ◽  
Paula Kriner ◽  
...  
Keyword(s):  
United States ◽  
Spotted Fever ◽  
Rocky Mountain ◽  
The United States ◽  
Rocky Mountain Spotted Fever ◽  
United States Mexico Border ◽  
Mexico Border ◽  
United States Mexico
Sign in / Sign up

Export Citation Format

Share Document