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Rocky Mountain Spotted Fever

Updated : February 29, 2024





Background

Rickettsia rickettsii is a bacterium that causes Rocky Mountain spotted fever (RMSF), an acute febrile disease.
This is North America’s most severe and common rickettsial infection.

Epidemiology

R. rickettsia is transmitted from infected ticks to human hosts. Humans are not suitable vectors for this disease. Rickettsia does not harm the tick. Transmission occurs most frequently in the United States following a bite from dermacentor andersoni, dermacentor variabilis, or rhipicephalus sanguineus.

Due to its link with tick bites, the prevalence of this disease is high in summers, especially among people who are frequently outdoors. Contrary to its name, this condition is more prevalent in the Southeast and south-central US. In patients residing in or traveling to an endemic area, a lack of history of tick bites should not exclude this diagnosis.

Anatomy

Pathophysiology

With Rocky Mountain spotted fever, Rickettsia preferentially infects the vascular endothelial cells lining small and medium capillaries throughout the body, causing systemic symptoms and a high mortality rate.

Endothelial cell infection causes loss of brain function, altered vascular permeability in the body, and systemic inflammation.

This condition can lead to symptoms such as headaches, confusion, rashes, cardiovascular instability, and myalgia. Researchers are investigating how these organisms rapidly enter into the cell and how immune pathways are downregulated, allowing infection to persist for long periods.

Etiology

Rickettsia rickettsii, the most well-known and dangerous member of the spotted group rickettsiae, causes Rocky Mountain spotted fever.

It is an intracellular, obligate, and coccobacillary organism that infects human hosts following a tick bite.

It is hypothesised that transmission occurs rapidly following a tick bite, with fast entry of the germs into the cells of the endothelium.

Genetics

Prognostic Factors

Clinical History

Physical Examination

Age group

Associated comorbidity

Associated activity

Acuity of presentation

Differential Diagnoses

Laboratory Studies

Imaging Studies

Procedures

Histologic Findings

Staging

Treatment Paradigm

by Stage

by Modality

Chemotherapy

Radiation Therapy

Surgical Interventions

Hormone Therapy

Immunotherapy

Hyperthermia

Photodynamic Therapy

Stem Cell Transplant

Targeted Therapy

Palliative Care

Medication

Media Gallary

References

https://www.ncbi.nlm.nih.gov/books/NBK430881/

Rocky Mountain Spotted Fever

Updated : February 29, 2024




Rickettsia rickettsii is a bacterium that causes Rocky Mountain spotted fever (RMSF), an acute febrile disease.
This is North America’s most severe and common rickettsial infection.

R. rickettsia is transmitted from infected ticks to human hosts. Humans are not suitable vectors for this disease. Rickettsia does not harm the tick. Transmission occurs most frequently in the United States following a bite from dermacentor andersoni, dermacentor variabilis, or rhipicephalus sanguineus.

Due to its link with tick bites, the prevalence of this disease is high in summers, especially among people who are frequently outdoors. Contrary to its name, this condition is more prevalent in the Southeast and south-central US. In patients residing in or traveling to an endemic area, a lack of history of tick bites should not exclude this diagnosis.

With Rocky Mountain spotted fever, Rickettsia preferentially infects the vascular endothelial cells lining small and medium capillaries throughout the body, causing systemic symptoms and a high mortality rate.

Endothelial cell infection causes loss of brain function, altered vascular permeability in the body, and systemic inflammation.

This condition can lead to symptoms such as headaches, confusion, rashes, cardiovascular instability, and myalgia. Researchers are investigating how these organisms rapidly enter into the cell and how immune pathways are downregulated, allowing infection to persist for long periods.

Rickettsia rickettsii, the most well-known and dangerous member of the spotted group rickettsiae, causes Rocky Mountain spotted fever.

It is an intracellular, obligate, and coccobacillary organism that infects human hosts following a tick bite.

It is hypothesised that transmission occurs rapidly following a tick bite, with fast entry of the germs into the cells of the endothelium.

https://www.ncbi.nlm.nih.gov/books/NBK430881/