UPDATE (March 2019)- QUOTE CDC- " During 2010–2015, CDC received 16,807 case reports of SFR meeting the probable or confirmed case definition. The number of cases reported annually increased from 1,617 in 2010 to 2,275 in 2015. As the number of annual cases increased, the percentage of confirmed cases decreased from 1.9% in 2010 to 0.7% in 2015." https://www.cdc.gov/mmwr/volumes/68/wr/mm6810a3.htm?s_cid=mm6810a3_x
UPDATE (March 2019)- Spotted fever group Rickettsia antigens cross-react, and routine serologic assays cannot provide conclusive species-specific diagnoses. https://www.cdc.gov/mmwr/volumes/68/wr/mm6810a3.htm?s_cid=mm6810a3_x
UPDATE (March 2019)- According to the CDC, in 2000, 495 cases of spotted fever rickettsiosis were reported. In 2017, more than 6,248 cases were reported. https://www.cdc.gov/rmsf/stats/index.html
QUOTE (CDC)- "The goal of SFR surveillance is to provide information to health care providers and public health officials about the temporal, geographic, and demographic occurrence of SFR and to facilitate prevention and control (3). During 2010–2015, only 1.0% of SFR cases reported to CDC via case report forms met the criteria for a confirmed SFR case. The majority of probable cases were not confirmed because of incomplete serologic testing." https://www.cdc.gov/mmwr/volumes/68/wr/mm6810a3.htm?s_cid=mm6810a3_e
UPDATE- March 2017- There are a growing number of new Rickettsia strains (spotted fevers) being discovered in the US and foreign countries. Just in the past month (March 2017) seven more were reported from various countries.
UPDATE- May 2017- Five additional strains of spotted fever were documented.
QUOTE (CDC)- "People over the age of 40 years account for the highest number of reported cases, however, children under 10 years old represent the highest number of reported deaths." https://www.cdc.gov/rmsf/stats/index.html
"Long-term neurologic sequelae of RMSF include cognitive impairment; paraparesis; hearing loss; blindness; peripheral neuropathy; bowel and bladder incontinence; cerebellar, vestibular, and motor dysfunction; and speech disorders (7,110,121–124).
These complications are observed most frequently in persons recovering from severe, life-threatening disease, often after lengthy hospitalizations, and are most likely the result of R. rickettsii-induced vasculopathy. Cutaneous necrosis and gangrene (Figure 23) might result in amputation of digits or limbs (105)." (CDC- MMWR- May 2016)
Link Here- http://www.cdc.gov/mmwr/volumes/65/rr/pdfs/rr6502.pdf
QUOTE (CDC)- "The results of these tests (spotted fevers) can take weeks. If your healthcare provider thinks your illness might be RMSF, he or she should recommend antibiotic treatment before test results are available." https://www.cdc.gov/rmsf/diagnosis-testing/index.html
Rocky Mountain spotted fever, Rickettsia rickettsii, (RMSF) is the most common rickettsial disease in the United States. It is potentially fatal with a mortality rate as high as 30%. Early treatment with appropriate antibiotics is required to prevent the disease progression and should be started as soon as the disease is suspected.
The number of reported cases of many strains of spotted fevers are increasing in the United States. Untreated cases may result in death within 20 days after exposure. The hospitalization rate is over 70%, even in treated patients.
Update- September 2014- Study shows a tick attachment time can be as little as 10 minutes before Rocky Mountain Spotted Fever is transmitted.
A second study (2014) indicates various spotted fevers can be missed using tests to detect Rocky Mountain Spotted Fever. (More information on subpages below.)
Update- May 2016- See detailed information and photos below.
Update- March 2017- See New CDC Guidelines For Treating Spotted Fevers & Anaplasmosis Located Here. Older 2006 guidelines- Located Here.
Diagnostic tests for rickettsial diseases, particularly for RMSF, are usually not helpful in making a timely diagnosis during the initial stages of illness.
According to the CDC- Treatment decisions for rickettsial pathogens should never be delayed while awaiting laboratory confirmation. Delay in treatment can lead to severe disease and long-term sequelae or death.
Early signs and symptoms of tickborne rickettsial illnesses are nonspecific, and most cases of RMSF are misdiagnosed at the patient’s first visit for medical care, even in areas where awareness of RMSF is high.
Understand the availability, limitations, and usefulness of confirmatory diagnostic tests.
RMSF is the rickettsiosis in the United States that is associated with the highest rates of severe and fatal outcomes.
The highest incidence occurs in persons aged 60–69 years, and the highest case-fatality rate is among children aged <10 years, although illness occurs in all age groups (4).
Incidence varies considerably by geographic area ( Figure 1). During 2008–2012, 63% of reported SFG rickettsiosis cases originated from five states: Arkansas, Missouri, North Carolina, Oklahoma, and Tennessee (4). However, SFG rickettsiosis cases have been reported from each of the contiguous 48 states and the District of Columbia (4,9,12,14).
A history of a tick bite within 14 days of illness onset is reported in only 55%–60% of RMSF cases and 68% of ehrlichiosis cases. Therefore, absence of a recognized tick bite should never dissuade health care providers from considering tickborne rickettsial disease in the appropriate clinical context.
In fact, the absence of classic features, such as a reported tick bite, has been associated with delays in RMSF diagnosis and increased risk for death.
Temporally and geographically related clusters of illness have occurred among family members (including their pet dogs), coworkers, or persons frequenting a particular common area.
Described clusters include ehrlichiosis among residents of a golfing community, ehrlichiosis and RMSF among soldiers on field maneuvers, and RMSF among family members.
Infections with R. rickettsii and Ehrlichia species have been observed concurrently in humans and their pet dogs. Recognition of a dog’s death from RMSF has even prompted recognition and appropriate treatment of RMSF in the sick owner. Health care providers should ask ill patients about similar illnesses among family members, coworkers, community residents, and pet dogs.
Although the majority of persons have increased IgG titers by the second week of the illness, persons infected with certain Rickettsia species might have delayed development of significant antibody titers or produce none.
PETS- Tickborne rickettsial infection in dogs can range from inapparent to severe. RMSF in dogs manifests with fever, lethargy, decreased appetite, tremors, scleral injection, maculopapular rash on ears and exposed skin, and petechial lesions on mucous membranes.
Galaxy Lab- Galaxy Lab tests for at least 47 species of Bartonella, Ehrlichia, Rickettsia (spotted fevers) and Babesia. See which species are tested for each genus HERE.
RMSF- Infection with R. rickettsii leads to systemic vasculitis that manifests externally as characteristic petechial skin lesions.
If disease progresses untreated, it can result in end-organ damage associated with severe morbidity and death. Pathogen-mediated injury to the vascular endothelium results in increased capillary permeability, microhemorrhage, and platelet consumption.
Late-stage manifestations, such as noncardiogenic pulmonary edema (acute respiratory distress syndrome [ARDS]) and cerebral edema, are consequences of microvascular leakage. Hyponatremia occurs as a result of appropriate secretion of antidiuretic hormone in response to hypovolemia.
Spotted Fever symptoms can include:
Delay in diagnosis and treatment is the most important factor associated with increased likelihood of death.
Early empiric therapy is the best way to prevent RMSF progression.
Without treatment, RMSF progresses rapidly.
Patients treated after the fifth day of illness are more likely to die
Than those treated earlier in the course of illness.
Lab Findings- Total white blood cell count is typically normal or slightly increased in patients with RMSF. Increased numbers of immature neutrophils can be observed. Thrombocytopenia, slight elevations in hepatic transaminases (aspartate transaminase and alanine transaminase), and hyponatremia might be present.
Laboratory values cannot be relied on to guide early treatment decisions because they are often within or slightly deviated from the reference range early in the course of illness.
Indicators of diffuse tissue injury, such as elevated levels of creatine kinase or serum lactate dehydrogenase, might be present later in the course of illness. Disseminated intravascular coagulation (DIC) can occur.
When cerebrospinal fluid (CSF) is evaluated, a lymphocytic (or less commonly, neutrophilic) pleocytosis (usually <100 cells/µL) can be observed.
CSF protein might be moderately elevated (100–200 mg/dL). The glucose level is typically within normal range.
Testing for Spotted Fever
Quest
http://www.questdiagnostics.com/testcenter/TestDetail.action?ntc=6419
Rickettsia parkeri
The first manifestation in nearly all patients is an inoculation eschar (a dark, scabbed plaque overlying a shallow ulcer, typically 0.5–2 cm in diameter), which generally is nonpruritic, nontender or mildly tender, and surrounded by an indurated, erythematous halo and occasionally a few petechiae.
The presence of more than one eschar has been described.
Fever typically develops within a few days of the eschar. Shortly after the onset of fever (approximately 0.5–4 days later), a nonpruritic maculopapular or vesiculopapular rash can develop. The rash primarily involves the trunk and extremities and might involve the palms and soles in approximately half of patients and the face in <20% of patients.
Other common symptoms include myalgia (76%) and headache (86%). Regional lymphadenopathy is detected in approximately 25% of patients. Gastrointestinal manifestations, such as nausea or vomiting, can occur.
Mild thrombocytopenia has been observed in 40%, mild leukopenia in 50%, and modest elevation of hepatic transaminase levels in 78% of cases. Because the clinical description of R. parkeri infection is based on observations from a limited number of cases, the full clinical spectrum of illness is likely incomplete.
Rickettsia Species 364D
The first clinical description of a confirmed case of Rickettsia species 364D infection was published in 2010. Although the full spectrum of illness has yet to be described, 364D infection appears to be characterized by an eschar or ulcerative skin lesion with regional lymphadenopathy.
Fever, headache, myalgia, and fatigue have occurred among persons with confirmed infection. Rash has not been a notable feature of this illness. Illnesses among the few described patients can be relatively mild.
Ehrlichia chaffeensis Ehrlichiosis
Last Updated- February 2019
Lucy Barnes
