Rocky Mountain Spotted Fever: Difference between revisions

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<div class="editorbox">
<div class="noeditbox">Welcome to [[Pathophysiology of Complex Patient Problems|PT 635 Pathophysiology of Complex Patient Problems]] This is a wiki created by and for the students in the School of Physical Therapy at Bellarmine University in Louisville KY. Please do not edit unless you are involved in this project, but please come back in the near future to check out new information!!</div> <div class="editorbox">
'''Original Editors ''' - David Grinnell [[Pathophysiology of Complex Patient Problems|from Bellarmine University's Pathophysiology of Complex Patient Problems project.]]  
'''Original Editors '''- David Grinnell [[Pathophysiology of Complex Patient Problems|from Bellarmine University's&nbsp;Pathophysiology of Complex Patient Problems project.]]  


'''Top Contributors''' - {{Special:Contributors/{{FULLPAGENAME}}}} &nbsp;
'''Top Contributors''' - {{Special:Contributors/{{FULLPAGENAME}}}}  
</div>  
</div>  
== Definition/Description  ==
== Definition/Description  ==


Rocky Mountain Spotted Fever (RMSF) is a tick borne disease, due to an intracellular pathogen known as Rickettsia rickettsi.<ref name="Lacz">Lacz NL, Schwartz RA, Kapila R. Rocky Mountain spotted fever. JEADV 2006, 20, 411-417.</ref>&nbsp;This pathogen is carried by ticks and is transmitted to humans via a bite from an infected tick; thus it is considered and infectious disease as well as a [[Zoonotic Diseases|zoonotic disease]].&nbsp;Three known ticks in the United States carry this pathogen: the American dog tick (Dermacentor variabilis), Rocky Mountain wood tick (Dermacentor andersoni) and the brown dog tick (Rhipicephalus sanguineous).&nbsp;The American dog tick carries the pathogen in the western United States, and the wood tick carries the pathogen in the eastern United States.<ref name="Dantas-Torres">Dantas-Torres F, Rocky Mountain spotted fever. Lancet Infectious Disease 2007;7:724-732</ref>&nbsp;This infection was first described in the Rocky Mountains in Idaho in 1896. Howard Ricketts found the causative agent in the early 1900’s.&nbsp;<ref name="Lacz" />&nbsp;This systemic infectious disease is treatable, however, if left untreated it can be fatal.  
Rocky Mountain Spotted Fever (RMSF) is a tick borne disease, due to an intracellular pathogen known as Rickettsia rickettsi.<ref name="Lacz">Lacz NL, Schwartz RA, Kapila R. Rocky Mountain spotted fever. JEADV 2006, 20, 411-417.</ref> This pathogen is carried by ticks and is transmitted to humans via a bite from an infected tick; thus it is considered and infectious disease as well as a [[Zoonotic Diseases|zoonotic disease]]. Three known ticks in the United States carry this pathogen: the American dog tick (Dermacentor variabilis), Rocky Mountain wood tick (Dermacentor andersoni) and the brown dog tick (Rhipicephalus sanguineous). The American dog tick carries the pathogen in the western United States, and the wood tick carries the pathogen in the eastern United States.<ref name="Dantas-Torres">Dantas-Torres F, Rocky Mountain spotted fever. Lancet Infectious Disease 2007;7:724-732</ref>&nbsp;This infection was first described in the Rocky Mountains in Idaho in 1896. Howard Ricketts found the causative agent in the early 1900’s.&nbsp;<ref name="Lacz" />&nbsp;This systemic infectious disease is treatable, however, if left untreated it can be fatal.  


== Prevalence  ==
== Prevalence  ==
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=== United States  ===
=== United States  ===


Between 1993 and 1996, there were 1253 reported cases of Rocky Mountain Spotted Fever (RMSF).<span style="">&nbsp;
Between 1993 and 1996, there were 1253 reported cases of Rocky Mountain Spotted Fever (RMSF). This amount of confirmed incidence is roughly 2.2 cases per million.&nbsp;<ref name="Lacz" /> Since that time period there has been some increase in confirmed cases. In 2008, the number of cases jumped to approximately 8 per million. However, the number of fatalities has decreased and currently is about 0.5%.  
</span>This amount of confirmed incidence is roughly 2.2 cases per million.&nbsp;<ref name="Lacz" /> Since that time period there has been some increase in confirmed cases.<span style="">&nbsp; </span>In 2008, the number of cases&nbsp; jumped to approximately 8 per million.<span style="">&nbsp;
</span>However, the number of fatalities has decreased and currently is about 0.5%.  


There is some distinction between race in the diagnosis of RMSF. Causcasians are two times more likey to be diagnosised that those of African American decent. Compared to the general population, American Indians are at the greatest risk for contracting the disease. For data that was collected between the years of 2001 and 2005, the American Indian incidence rate was calculated at 16.8 per million, while caucasians were at 4.2 per million, African Americans at 2.6 per million, and Asian/Pacific Islanders at 0.5 cases per million people.<ref name="Johnson">Johnson CD, Sinert RH. Tick-Borne Disease, Rocky Mountain Spotted Fever, http://emedicine.medscape.com/article/785659-overview. accessed 3/17/2011</ref><br>  
There is some distinction between race in the diagnosis of RMSF. Caucasians are two times more likely to be diagnosed that those of African American decent. Compared to the general population, American Indians are at the greatest risk for contracting the disease. For data that was collected between the years of 2001 and 2005, the American Indian incidence rate was calculated at 16.8 per million, while caucasians were at 4.2 per million, African Americans at 2.6 per million, and Asian/Pacific Islanders at 0.5 cases per million people.<ref name="Johnson">Johnson CD, Sinert RH. Tick-Borne Disease, Rocky Mountain Spotted Fever, http://emedicine.medscape.com/article/785659-overview. accessed 3/17/2011</ref><br>  


RMSF is more common in males than females; 1.7:1<ref name="Johnson" />  
RMSF is more common in males than females; 1.7:1<ref name="Johnson" />  
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<br>  
<br>  


[[Image:Rmsf month.jpg|500px|graph courtsey of:http://www.cdc.gov/rmsf/stats/]]<br>  
[[Image:Rmsf month.jpg|500px|graph courtesy of:http://www.cdc.gov/rmsf/stats/]]<br>  


<ref name="CDC">http://www.cdc.gov/rmsf/stats/</ref> <br>  
<ref name="CDC">http://www.cdc.gov/rmsf/stats/</ref> <br>  
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== Characteristics/Clinical Presentation  ==
== Characteristics/Clinical Presentation  ==


The R. ricketttsii pathogen can have numerous systemic manifestations affecting the: cardiac, pulmonary, gastrointestinal, renal, neurological, ocular, musclecoskeletal, and integumentary systems.<ref name="Dantas-Torres" /> If infected the individual may face moderate to severe illness. The initial symptoms usually will begin 2-14 days after being bitten by an infected tick.<ref name="Pubmed">Pub Med Health. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001677/. accessed 3/4/2011</ref><br>  
The R. ricketttsi pathogen can have numerous systemic manifestations affecting the: cardiac, pulmonary, gastrointestinal, renal, neurological, ocular, musculoskeletal, and integumentary systems.<ref name="Dantas-Torres" /> If infected the individual may face moderate to severe illness. The initial symptoms usually will begin 2-14 days after being bitten by an infected tick.<ref name="Pubmed">Pub Med Health. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001677/. accessed 3/4/2011</ref><br>  


<u>Initial symptoms include</u>&nbsp;<ref name="Lacz" /><ref name="Dantas-Torres" /><ref name="Johnson" /><ref name="CDC1">Centers for Disease Control and Prevention: http://www.cdc.gov/rmsf/symptoms/index.html. accessed 3/17/2011</ref>  
<u>Initial symptoms include</u>&nbsp;<ref name="Lacz" /><ref name="Dantas-Torres" /><ref name="Johnson" /><ref name="CDC1">Centers for Disease Control and Prevention: http://www.cdc.gov/rmsf/symptoms/index.html. accessed 3/17/2011</ref>  
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*Severe headache  
*Severe headache  
*Nausea  
*Nausea  
*Vomitting
*Vomiting
*Fatigue  
*Fatigue  
*Loss of appetite  
*Loss of appetite  
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<u>After completing a thorough examination, a patient's laboratory workup may show the following results:</u> <ref name="Dantas-Torres" />  
<u>After completing a thorough examination, a patient's laboratory workup may show the following results:</u> <ref name="Dantas-Torres" />  


*Normal periphearl WBC count  
*Normal peripheral WBC count  
*Thrombocytopenia  
*Thrombocytopenia  
*Elevated aminotransferase levels  
*Elevated aminotransferase levels  
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<br>  
<br>  


If an allergy to doxycycline exists or a if a women is pregnant, other medications are available as treatment.<ref name="CDC1" />&nbsp;Chlorampenicol is another antibiotic that may be prescribed, however, this medication has some adverse side effects such as: aplastic anemeia and grey baby syndrome.<ref name="CDC1" />&nbsp;Recommended dosing for Chloramphenicol is 500mg via IV divided 2 times per day for 7 days. General&nbsp; antibiotics have not been found to be effective against RMSF and sulfa drugs may actually worsen the infection.<ref name="CDC1" />  
If an allergy to doxycycline exists or a if a women is pregnant, other medications are available as treatment.<ref name="CDC1" />&nbsp;Chlorampenicol is another antibiotic that may be prescribed, however, this medication has some adverse side effects such as: aplastic anemia and grey baby syndrome.<ref name="CDC1" />&nbsp;Recommended dosing for Chloramphenicol is 500mg via IV divided 2 times per day for 7 days. General antibiotics have not been found to be effective against RMSF and sulfa drugs may actually worsen the infection.<ref name="CDC1" />  


<br>  
<br>  


Tetracyclines have been found to increase hypthrombiemic effects of anticoagulants, and they have also been found to decrease the effectiveness of common oral contratceptives.<ref name="Johnson" />  
Tetracyclines have been found to increase hypthrombiemic effects of anticoagulants, and they have also been found to decrease the effectiveness of common oral contraceptives.<ref name="Johnson" />  


== Diagnostic Tests/Lab Tests/Lab Values  ==
== Diagnostic Tests/Lab Tests/Lab Values  ==


Lab tests that will be completed if RMSF is suspected inlcuded the following:<ref name="Johnson" /><br>  
Lab tests that will be completed if RMSF is suspected included the following:<ref name="Johnson" /><br>  


*CBC count  
*CBC count  
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<br>  
<br>  


Overall, the initial diagnosis of RMSF is made based on the clincal signs and symptoms.<ref name="CDC1" /><ref name="Minniear" /><ref name="Lacz" />&nbsp;Data that is gathered later via specific laboratory tests will confirm the working diagnosis of RMSF. Thus it is extremely important to begin a course of antibiotic therapy if RMSF is suspected as soon as possible.  
Overall, the initial diagnosis of RMSF is made based on the clinical signs and symptoms.<ref name="CDC1" /><ref name="Minniear" /><ref name="Lacz" />&nbsp;Data that is gathered later via specific laboratory tests will confirm the working diagnosis of RMSF. Thus it is extremely important to begin a course of antibiotic therapy if RMSF is suspected as soon as possible.  


<br>  
<br>  


The gold standard for the diagnosis of RMSF is the indirect immunofluorescence assay (IFA) with the R.''ricettsii'' antigen.<ref name="CDC1" /> This method has a high sensitivity and specifity rated at 94%<ref name="Lacz" />. This is performed by obtaining two serum samples and then comparing the IgG and IgM antibody titers<ref name="CDC1" /><ref name="Lacz" /><ref name="Minniear" />. Ideally, the first serum test should be completed as early as possible when symptoms first set in, and the second sample be tested 2-4 weeks after the initial test.<ref name="CDC1" /> A four fold increase in these antibody titers confirms the diagnosis of RMSF.<ref name="CDC1" /><ref name="Minniear" /><ref name="Lacz" />  
The gold standard for the diagnosis of RMSF is the indirect immunofluorescence assay (IFA) with the ''R. ricettsii'' antigen.<ref name="CDC1" /> This method has a high sensitivity and specificity rated at 94%<ref name="Lacz" />. This is performed by obtaining two serum samples and then comparing the IgG and IgM antibody titers<ref name="CDC1" /><ref name="Lacz" /><ref name="Minniear" />. Ideally, the first serum test should be completed as early as possible when symptoms first set in, and the second sample be tested 2-4 weeks after the initial test.<ref name="CDC1" /> A four fold increase in these antibody titers confirms the diagnosis of RMSF.<ref name="CDC1" /><ref name="Minniear" /><ref name="Lacz" />  


== Etiology/Causes  ==
== Etiology/Causes  ==


RMSF is a possibly fatal tick-borne illness. Three known ticks in the United States carry the pathogen ''R. rickettsii:&nbsp;''the American dog tick (Dermacentor variabilis), Rocky Mountain wood tick (Dermacentor andersoni) and the brown dog tick (Rhipicephalus sanguineous). The American dog tick primarily carries the pathogen in the United States, primarily in the western United States. The Rocky Mountain wood tick primarily carries the pathogen in the eastern United States and the brown dog tick is thought to be the vector for the pathogen in Mexico. In addition, there are other tick species that are thought to carry the pathogen. In Central and South America, the Cayenne tick is thought to be the vector for the pathogen.<ref name="Dantas-Torres" />  
RMSF is a possibly fatal tick-borne illness. Three known ticks in the United States carry the pathogen ''R. rickettsii:''the American dog tick (Dermacentor variabilis), Rocky Mountain wood tick (Dermacentor andersoni) and the brown dog tick (Rhipicephalus sanguineous). The American dog tick primarily carries the pathogen in the United States, primarily in the western United States. The Rocky Mountain wood tick primarily carries the pathogen in the eastern United States and the brown dog tick is thought to be the vector for the pathogen in Mexico. In addition, there are other tick species that are thought to carry the pathogen. In Central and South America, the Cayenne tick is thought to be the vector for the pathogen.<ref name="Dantas-Torres" />  


''Rrickettsii''is transmitted to humans via a bite of an infected tick. The tick bites do not cause pain, and many don't know they were exposed to the ticks. The transmission process can be completed in as little as 4 hours extending up to 24 hours. Most cases of RMSF occur between the months of April and September and usually occur in rural settings, however, they are not confined to just the rural community.<ref name="Johnson" /><br>  
''R. rickettsii''is transmitted to humans via a bite of an infected tick. The tick bites do not cause pain, and many don't know they were exposed to the ticks. The transmission process can be completed in as little as 4 hours extending up to 24 hours. Most cases of RMSF occur between the months of April and September and usually occur in rural settings, however, they are not confined to just the rural community.<ref name="Johnson" /><br>  


<br>  
<br>  


'''R rickettsii&nbsp;'''<u>''<ref name="Dantas-Torres" />''</u> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;  
'''R. rickettsii'''<u>''<ref name="Dantas-Torres" />''</u> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;  


{| width="200" cellspacing="1" cellpadding="1" border="1"
{| width="200" cellspacing="1" cellpadding="1" border="1"
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<br>  
<br>  


If an attached tick is found, it is important to remove it as quickly as possible. Health professionals recommend that protective gloves be worn during this process . It is best to remove the tick via tweezers as close to the skin as possible and carefully pull it out. Take precaution to not squeeze&nbsp; or twist the tweezers upon removal. As soon as possible, disinfect the wound area as well as your hands. It is not advised to burn ticks out or the topical application of petroleum jelly <ref name="Dantas-Torres" />.<br>  
If an attached tick is found, it is important to remove it as quickly as possible. Health professionals recommend that protective gloves be worn during this process . It is best to remove the tick via tweezers as close to the skin as possible and carefully pull it out. Take precaution to not squeeze or twist the tweezers upon removal. As soon as possible, disinfect the wound area as well as your hands. It is not advised to burn ticks out or the topical application of petroleum jelly <ref name="Dantas-Torres" />.<br>  


<br> {{#ev:youtube|_8ziSYsh5lo|400}}<ref name="tick removal"> Tick removal. http://www.youtube.com/watch?v=_8ziSYsh5lo. accessed 4/1/2011</ref>  
<br> {{#ev:youtube|_8ziSYsh5lo|400}}<ref name="tick removal"> Tick removal. http://www.youtube.com/watch?v=_8ziSYsh5lo. accessed 4/1/2011</ref>  
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== Systemic Involvement  ==
== Systemic Involvement  ==


Rocky Mountain Spotted Fever is a systemic disease in nature. Infected individuals can presented with numerous signs and symptoms that will have an affect on the: integumentary, cardiac, pulmonary, gastrointestinal, renal, neurological, ocular, and musculoskeletal systems.<ref name="Dantas-Torres" /> The Rickettsia pathogen reproduces intracellularly after being introduced through the skin via a tick bite. The pathogen is then spread by the bloodstream and the body's lyphmatic system.<ref name="Johnson" /><br>  
Rocky Mountain Spotted Fever is a systemic disease in nature. Infected individuals can presented with numerous signs and symptoms that will have an affect on the: integumentary, cardiac, pulmonary, gastrointestinal, renal, neurological, ocular, and musculoskeletal systems.<ref name="Dantas-Torres" /> The Rickettsia pathogen reproduces intracellularly after being introduced through the skin via a tick bite. The pathogen is then spread by the bloodstream and the body's lymphatic system.<ref name="Johnson" /><br>  


<u>Integumentary syste</u><u>m manifestations</u>&nbsp;<ref name="Johnson" />  
<u>Integumentary system</u><u>m manifestations</u>&nbsp;<ref name="Johnson" />  


*1-5mm blanchable erthyemathematous macule and this will usually progress to a petechial rash
*1-5mm blanchable erthyemathematous macule and this will usually progress to a petechial rash


<u>Cardiacvascular system manifestations</u>&nbsp;<ref name="Johnson" />  
<u>Cardiovascular system manifestations</u>&nbsp;<ref name="Johnson" />  


*Myocarditis
*Myocarditis
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*Abdominal pain  
*Abdominal pain  
*Nausea  
*Nausea  
*Vomitting
*Vomiting
*Diarrhea  
*Diarrhea  
*Occult bloody stool
*Occult bloody stool
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Please see above section entitled "Medication".  
Please see above section entitled "Medication".  


== Physical Therapy Management (current best evidence)  ==
== Physical Therapy Management (Current Best Evidence)  ==


Rocky Mountain spotted fever is an infectious disease that a physical therapist can not diagnosis and treat. It is important for a physical therapist to recognize the signs and symptoms that are not congruent with a disorder of the musculoskeletal system so they can be referred to a physician for further examination. One important piece of subjective information a physical therapist needs to gather during the initial evaluation is if the individual has recently been out in the woods or other outdoor areas where ticks can thrive, or if they own pets that spend time outdoors as well as indoors. Pets can commonly bring the vectors of RMSF into the home.<br>  
Rocky Mountain spotted fever is an infectious disease that a physical therapist can not diagnosis and treat. It is important for a physical therapist to recognize the signs and symptoms that are not congruent with a disorder of the musculoskeletal system so they can be referred to a physician for further examination. One important piece of subjective information a physical therapist needs to gather during the initial evaluation is if the individual has recently been out in the woods or other outdoor areas where ticks can thrive, or if they own pets that spend time outdoors as well as indoors. Pets can commonly bring the vectors of RMSF into the home.<br>  
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== Case Reports/ Case Studies<br>  ==
== Case Reports/ Case Studies<br>  ==


#Stallings MD S. Rocky Mountain Spotted Fever and Pregnancy: A Case Report and Review of the Literature. Obstetrical and Gyneocological Survery 2001;56;1:37-42
#Stallings MD S. Rocky Mountain Spotted Fever and Pregnancy: A Case Report and Review of the Literature. Obstetrical and Gyneocological Surgery 2001;56;1:37-42


*[https://www.ncbi.nlm.nih.gov/pubmed/11140862 https://www.ncbi.nlm.nih.gov/pubmed/11140862]<br>
*[https://www.ncbi.nlm.nih.gov/pubmed/11140862 https://www.ncbi.nlm.nih.gov/pubmed/11140862]<br>
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<rss>http://eutils.ncbi.nlm.nih.gov/entrez/eutils/erss.cgi?rss_guid=1dwOEnJFpGXx0SHRMDID71ODxrY6oIBK4sERDXYJQ_XLHrAEaN|charset=UTF-8|short|max=10</rss>  
<rss>http://eutils.ncbi.nlm.nih.gov/entrez/eutils/erss.cgi?rss_guid=1dwOEnJFpGXx0SHRMDID71ODxrY6oIBK4sERDXYJQ_XLHrAEaN|charset=UTF-8|short|max=10</rss>  
</div>  
</div>  
== References  ==
== References  ==


Revision as of 07:57, 6 January 2017

Original Editors - David Grinnell from Bellarmine University's Pathophysiology of Complex Patient Problems project.

Top Contributors - David Grinnell, Admin, Elaine Lonnemann, Evan Thomas, Daniele Barilla, Lucinda hampton, Nupur Smit Shah, Rishika Babburu, Wendy Walker, WikiSysop and Kim Jackson

Definition/Description[edit | edit source]

Rocky Mountain Spotted Fever (RMSF) is a tick borne disease, due to an intracellular pathogen known as Rickettsia rickettsi.[1] This pathogen is carried by ticks and is transmitted to humans via a bite from an infected tick; thus it is considered and infectious disease as well as a zoonotic disease. Three known ticks in the United States carry this pathogen: the American dog tick (Dermacentor variabilis), Rocky Mountain wood tick (Dermacentor andersoni) and the brown dog tick (Rhipicephalus sanguineous). The American dog tick carries the pathogen in the western United States, and the wood tick carries the pathogen in the eastern United States.[2] This infection was first described in the Rocky Mountains in Idaho in 1896. Howard Ricketts found the causative agent in the early 1900’s. [1] This systemic infectious disease is treatable, however, if left untreated it can be fatal.

Prevalence[edit | edit source]

United States[edit | edit source]

Between 1993 and 1996, there were 1253 reported cases of Rocky Mountain Spotted Fever (RMSF). This amount of confirmed incidence is roughly 2.2 cases per million. [1] Since that time period there has been some increase in confirmed cases. In 2008, the number of cases jumped to approximately 8 per million. However, the number of fatalities has decreased and currently is about 0.5%.

There is some distinction between race in the diagnosis of RMSF. Caucasians are two times more likely to be diagnosed that those of African American decent. Compared to the general population, American Indians are at the greatest risk for contracting the disease. For data that was collected between the years of 2001 and 2005, the American Indian incidence rate was calculated at 16.8 per million, while caucasians were at 4.2 per million, African Americans at 2.6 per million, and Asian/Pacific Islanders at 0.5 cases per million people.[3]

RMSF is more common in males than females; 1.7:1[3]

RMSF has varying incidence rates when age is taken into account. The aging population, specially the 60-69 year old cohort and children between the ages of 5-9 have the highest incidence rate. [3]

  • 60-69 year old age group - 3.1 cases per million [3]
  • 5-9 year-old age group - 3.3 cases per million [3]

Even though the disease is known as Rocky Mountain spotted fever, it is more commonly found in the eastern United States. Georgia, Maryland, North Carolina, Oklahoma, South Carolina, Tennessee, and Virginia are among the states that have confirmed the largest number of cases. [3]

photo courtsey of: http://www.cdc.gov/rmsf/stats/

[4]


graph courtesy of:http://www.cdc.gov/rmsf/stats/

[5]

Worldwide[edit | edit source]

Other cases of RMSF have been confirmed in Canada, Mexico, Central America, Columbia, as well as Brazil. Currently, there haven’t been any confirmed cases of RMSF beyond the boarders of the American continents.[3]

Characteristics/Clinical Presentation[edit | edit source]

The R. ricketttsi pathogen can have numerous systemic manifestations affecting the: cardiac, pulmonary, gastrointestinal, renal, neurological, ocular, musculoskeletal, and integumentary systems.[2] If infected the individual may face moderate to severe illness. The initial symptoms usually will begin 2-14 days after being bitten by an infected tick.[6]

Initial symptoms include [1][2][3][7]

  • High fever - reaching temperatures to 102 degrees Fahrenheit (38.9 degrees Celsius) or greater
  • Chills
  • Severe headache
  • Nausea
  • Vomiting
  • Fatigue
  • Loss of appetite
  • Abdominal pain - may present as appendicitis
  • Conjunctival infection
  • Muscle pain

Additional signs and symptoms that may develop include the following:

  • A red-spotted rash that spreads to a majority of the body -this rash occurs in approximately 90% of those infected with RMSF and usually appears 2-5 days after the fever has been present
  • Restlessness
  • Diarrhea
  • Aches & pains
  • Delirium

After completing a thorough examination, a patient's laboratory workup may show the following results: [2]

  • Normal peripheral WBC count
  • Thrombocytopenia
  • Elevated aminotransferase levels
  • Hyponatremia
  • Anemia
  • Elevated bilirubin level
  • Elevated level of creatine kinase
  • Elevated CSF and WBC count with monocyte predominance
  • Serological tests negative until convalescence


Typical rash seen with Rocky Mountain spotted fever

[8]


[9]

Medications[edit | edit source]

Doxycycline is the standard medication prescribed when physicians are suspicious of RMSF.[7] Adults are prescribed to take 200mg by mouth or IV two times per day.[3] Children who weigh less than 100lbs are to take 2mg/lb by mouth and those children who weigh above 100lbs are suggested to take the same dosage as an adult, 200mg by mouth or IV, two times per day.[3] There has been some previous cause for concern that older medications such as tetracyclines may cause staining of a child's permanent adult teeth, however, recent treatment with doxycycline has not been shown to cause staining.[7][10] Medical treatment should be continued for a minimum of 3 days after one's fever had decreased. Typically, medical treatment of this disease will last anywhere from 7-14 days in length.[7]


If an allergy to doxycycline exists or a if a women is pregnant, other medications are available as treatment.[7] Chlorampenicol is another antibiotic that may be prescribed, however, this medication has some adverse side effects such as: aplastic anemia and grey baby syndrome.[7] Recommended dosing for Chloramphenicol is 500mg via IV divided 2 times per day for 7 days. General antibiotics have not been found to be effective against RMSF and sulfa drugs may actually worsen the infection.[7]


Tetracyclines have been found to increase hypthrombiemic effects of anticoagulants, and they have also been found to decrease the effectiveness of common oral contraceptives.[3]

Diagnostic Tests/Lab Tests/Lab Values[edit | edit source]

Lab tests that will be completed if RMSF is suspected included the following:[3]

  • CBC count
  • Electrolytes
  • Renal function tests
  • Liver function tests
  • Coagulation panel


Overall, the initial diagnosis of RMSF is made based on the clinical signs and symptoms.[7][10][1] Data that is gathered later via specific laboratory tests will confirm the working diagnosis of RMSF. Thus it is extremely important to begin a course of antibiotic therapy if RMSF is suspected as soon as possible.


The gold standard for the diagnosis of RMSF is the indirect immunofluorescence assay (IFA) with the R. ricettsii antigen.[7] This method has a high sensitivity and specificity rated at 94%[1]. This is performed by obtaining two serum samples and then comparing the IgG and IgM antibody titers[7][1][10]. Ideally, the first serum test should be completed as early as possible when symptoms first set in, and the second sample be tested 2-4 weeks after the initial test.[7] A four fold increase in these antibody titers confirms the diagnosis of RMSF.[7][10][1]

Etiology/Causes[edit | edit source]

RMSF is a possibly fatal tick-borne illness. Three known ticks in the United States carry the pathogen R. rickettsii:the American dog tick (Dermacentor variabilis), Rocky Mountain wood tick (Dermacentor andersoni) and the brown dog tick (Rhipicephalus sanguineous). The American dog tick primarily carries the pathogen in the United States, primarily in the western United States. The Rocky Mountain wood tick primarily carries the pathogen in the eastern United States and the brown dog tick is thought to be the vector for the pathogen in Mexico. In addition, there are other tick species that are thought to carry the pathogen. In Central and South America, the Cayenne tick is thought to be the vector for the pathogen.[2]

R. rickettsiiis transmitted to humans via a bite of an infected tick. The tick bites do not cause pain, and many don't know they were exposed to the ticks. The transmission process can be completed in as little as 4 hours extending up to 24 hours. Most cases of RMSF occur between the months of April and September and usually occur in rural settings, however, they are not confined to just the rural community.[3]


R. rickettsii[2]                                                                                     

Kingdom Bacteria
Phylum Proteobacterai
Class Alphaproeobacteria
Order Rickettsiales
Family Rickettsiaceae
Genus Rickettsia
Species Rickettsia rickettsii


photo courtsey of: http://search.creativecommons.org/?q=rocky%20mountain%20spotted%20fever#

[11]

Currently, there is no vaccine that will protect against RMSF[1] [2][3]. With precaution one can prevent the transmission of the disease by following these general recommendations:

  • Avoid habitats where ticks thrive - wooded, grassy areas, stream banks and trails
  • Take protective measure to limit tick exposure - wear light-colored long sleeves and pants, tuck pant legs into your socks, and wear insect repellents that contain DEET
  • Frequently examine yourself if you are in suspected tick infested areas


If an attached tick is found, it is important to remove it as quickly as possible. Health professionals recommend that protective gloves be worn during this process . It is best to remove the tick via tweezers as close to the skin as possible and carefully pull it out. Take precaution to not squeeze or twist the tweezers upon removal. As soon as possible, disinfect the wound area as well as your hands. It is not advised to burn ticks out or the topical application of petroleum jelly [2].


[12]

Systemic Involvement[edit | edit source]

Rocky Mountain Spotted Fever is a systemic disease in nature. Infected individuals can presented with numerous signs and symptoms that will have an affect on the: integumentary, cardiac, pulmonary, gastrointestinal, renal, neurological, ocular, and musculoskeletal systems.[2] The Rickettsia pathogen reproduces intracellularly after being introduced through the skin via a tick bite. The pathogen is then spread by the bloodstream and the body's lymphatic system.[3]

Integumentary systemm manifestations [3]

  • 1-5mm blanchable erthyemathematous macule and this will usually progress to a petechial rash

Cardiovascular system manifestations [3]

  • Myocarditis

Renal system manifestations [3]

  • Reduced glomerular filtration rate
  • Prerenal azotemia
  • Focal hepatocellular necrosis

Gastrointestinal system manifestations[3]

  • Abdominal pain
  • Nausea
  • Vomiting
  • Diarrhea
  • Occult bloody stool

Pulmonary system manifestations [3]

  • Noncardiogenic pulmonary edema
  • Interstitial pneumonia
  • Adult respiratory system distress

Neurological system manifestations [3]

  • Encephalitis
  • Meningoencephalitis
  • Seizure
  • Cranial nerve damage
  • Permanent blindness
  • Permanent deafness

Medical Management (current best evidence)[edit | edit source]

Please see above section entitled "Medication".

Physical Therapy Management (Current Best Evidence)[edit | edit source]

Rocky Mountain spotted fever is an infectious disease that a physical therapist can not diagnosis and treat. It is important for a physical therapist to recognize the signs and symptoms that are not congruent with a disorder of the musculoskeletal system so they can be referred to a physician for further examination. One important piece of subjective information a physical therapist needs to gather during the initial evaluation is if the individual has recently been out in the woods or other outdoor areas where ticks can thrive, or if they own pets that spend time outdoors as well as indoors. Pets can commonly bring the vectors of RMSF into the home.

Differential Diagnosis           
[edit | edit source]

  • Meningoceccemia[2][3]
  • Enteroviral infection[2]
  • Typhus[2]
  • Ehrlichiosis[2]                                              
  • Immune complex vasculitis[2][3]
  • Typhoid fever[2][3]
  • Leptospirosis[2]
  • Dengue[2]
  • Infectious mononucleosis[2][3]
  • Bacterial sepsis[2][3]
  • Gastroenteritis[2][3]
  • Bronchitis[2][3]
  • Pneumonia[2][3]
  • Hepatitis[3]
  • Idiopathic Thrombocytopenic Purpura[3]
  • Meningitis[3]
  • Henoch-Schonlein Purpura[3]
  • Kawasaki Disease[3]
  • Measles[3]
  • Rubella[3]
  • Syphilis[3]
  • Ehrlichiosis[3]
  • Lyme's Disease[3]
  • Q Fever[3]
  • Relapsing Fever[3]
  • Tularemia[3]
  • Toxic Shock Syndrome[3]
  • Influenza[3]
  • Entervirus infection[3]
  • Disseminated gonococcal infection[3]
  • Drug hypersensivity[3]
  • Staphylococcal sepsis[3]
  • Murine typhus[3]
  • Rickettsialpox[3]
  • Recrudescent typhus[3]
  • Sylvatic flying squirrel-associated Rickettsia prowazekii infection[3]

Case Reports/ Case Studies
[edit | edit source]

  1. Stallings MD S. Rocky Mountain Spotted Fever and Pregnancy: A Case Report and Review of the Literature. Obstetrical and Gyneocological Surgery 2001;56;1:37-42
  1. Bergeron JW, Braddon RL, Kaelin DL. Persisting impairment following Rocky Mountain Spotted Fever: a case report. Arch Phys Med Rehabilitation 1997; 78: 1277-80.

Resources
[edit | edit source]

Centers for Disease Control website:
http://www.cdc.gov/rmsf/

Mayo Clinic website:
http://www.mayoclinic.com/health/rocky-mountain-spotted-fever/DS00600

Emedicine website:
http://www.medicinenet.com/rocky_mountain_spotted_fever/article.htm

Medline plus website:
http://www.nlm.nih.gov/medlineplus/ency/article/000654.htm

WebMD website:
http://www.webmd.com/skin-problems-and-treatments/rocky-mountain-spotted-fever

Kids Health website:
kidshealth.org/parent/infections/skin/rocky.html

Recent Related Research (from Pubmed)
[edit | edit source]

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References[edit | edit source]

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Lacz NL, Schwartz RA, Kapila R. Rocky Mountain spotted fever. JEADV 2006, 20, 411-417.
  2. ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17 2.18 2.19 2.20 2.21 Dantas-Torres F, Rocky Mountain spotted fever. Lancet Infectious Disease 2007;7:724-732
  3. ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 3.20 3.21 3.22 3.23 3.24 3.25 3.26 3.27 3.28 3.29 3.30 3.31 3.32 3.33 3.34 3.35 3.36 3.37 3.38 3.39 3.40 3.41 3.42 3.43 3.44 3.45 3.46 3.47 3.48 3.49 3.50 3.51 Johnson CD, Sinert RH. Tick-Borne Disease, Rocky Mountain Spotted Fever, http://emedicine.medscape.com/article/785659-overview. accessed 3/17/2011
  4. ↑ CDC incidence map http://www.cdc.gov/rmsf/stats/
  5. ↑ http://www.cdc.gov/rmsf/stats/
  6. ↑ Pub Med Health. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001677/. accessed 3/4/2011
  7. ↑ 7.00 7.01 7.02 7.03 7.04 7.05 7.06 7.07 7.08 7.09 7.10 7.11 Centers for Disease Control and Prevention: http://www.cdc.gov/rmsf/symptoms/index.html. accessed 3/17/2011
  8. ↑ Typical rash of RMSF http://search.creativecommons.org/?q=rocky%20mountain%20spotted%20fever#
  9. ↑ Rocky Mountain spotted fever. http://www.youtube.com/watch?v=FFXh1wv2Nf4 accessed 4/1/2011
  10. ↑ 10.0 10.1 10.2 10.3 Minniear T, Buckingham S. Managing Rocky Mountain spotted fever. Expert Reviews. Anti Infect. Ther.7(9),1131-1137(2009)
  11. ↑ photo courtsey of: http://search.creativecommons.org/?q=rocky%20mountain%20spotted%20fever#
  12. ↑ Tick removal. http://www.youtube.com/watch?v=_8ziSYsh5lo. accessed 4/1/2011


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