1. Rocky Mountain Spotted Fever

2. Rocky Mountain Spotted Fever: First recognized in 1896 in the Snake River Valley of Idaho and was originally called "black measles" because of the characteristic rash. First recognized in 1896 in the Snake River Valley of Idaho and was originally called "black measles" because of the characteristic rash. Howard T. Ricketts established the identity of the infectious organism that causes this disease, Rickettsia rickettsii. Howard T. Ricketts established the identity of the infectious organism that causes this disease, Rickettsia rickettsii. He and others described the epidemiologic features of the disease, including the role of tick vectors. He and others described the epidemiologic features of the disease, including the role of tick vectors. Sadly, Dr. Ricketts died of typhus (another rickettsial disease) in Mexico in 1910. Sadly, Dr. Ricketts died of typhus (another rickettsial disease) in Mexico in 1910.

3. Epidemiology: A bit of a misnomer, this disease has been identified in almost all of the continental US, with perhaps the exception of Maine and Vermont A bit of a misnomer, this disease has been identified in almost all of the continental US, with perhaps the exception of Maine and Vermont Most cases reported in south Atlantic, southeastern and south central states Most cases reported in south Atlantic, southeastern and south central states 54% of cases were from NC, TN, OK, SC and Ark 54% of cases were from NC, TN, OK, SC and Ark

5. Transmission: Vector=tick Vector=tick Wood tick, dog tick and Lone Star tick Wood tick, dog tick and Lone Star tick Both dog and Lone Star ticks are found in NC Both dog and Lone Star ticks are found in NC Wood tick is primarily in western US, and Rocky Mountain area Wood tick is primarily in western US, and Rocky Mountain area

6. DOG TICK: Transmits DOG TICK: Transmits RMSF, but probably not RMSF, but probably notLyme LONE-STAR TICK: LONE-STAR TICK: Transmits RMSF, and Transmits RMSF, and human monocytic human monocytic ehrlichiosis ehrlichiosis

7. Two-thirds of RMSF cases occur in children younger than 15 years Two-thirds of RMSF cases occur in children younger than 15 years Males are infected more commonly (1.7-2.2:1) Males are infected more commonly (1.7-2.2:1) Caucasians are more common than African- Americans Caucasians are more common than African- Americans Peak months of infection are April-October Peak months of infection are April-October

9. R. rickettsii organisms are released through saliva during a feeding R. rickettsii organisms are released through saliva during a feeding Usually 12-24 hrs of attachment is required Usually 12-24 hrs of attachment is required Incubation period is 2-14 days Incubation period is 2-14 days Once organisms enter the body, they multiply within endothelial cell linings of small blood vessels Once organisms enter the body, they multiply within endothelial cell linings of small blood vessels

10. Signs and Symptoms: EARLY: EARLY: Fever, nausea, vomiting, severe headache, anorexia and malaise Fever, nausea, vomiting, severe headache, anorexia and malaise LATE: LATE: Rash, joint pain and diarrhea Rash, joint pain and diarrhea Classic triad=fever, rash and headache Classic triad=fever, rash and headache Rash: appears between day 2 to 5 of illness Rash: appears between day 2 to 5 of illness Blanching, erythematous macules arouond ankles feet, later wrists and hands; palms and soles often involved Blanching, erythematous macules arouond ankles feet, later wrists and hands; palms and soles often involved Petechiae on day 6 Petechiae on day 6 10-15% of infected patients are without rash 10-15% of infected patients are without rash

13. Important points: Only 40-60% of those infected have a history of tick bite Only 40-60% of those infected have a history of tick bite RMSF may be clinically indisginguishable from Human Monocytic ehrlichiosis RMSF may be clinically indisginguishable from Human Monocytic ehrlichiosis

14. Laboratory tests: Hyponatremia (20%) Hyponatremia (20%) Thrombocytopenia (33%) Thrombocytopenia (33%) Anemia, increased LFTs or BUN (25%) Anemia, increased LFTs or BUN (25%) CSF: monocytic pleocytosis, increased protein CSF: monocytic pleocytosis, increased protein

15. Diagnosis: Largely clinical Largely clinical Suspect if classic triad Suspect if classic triad Acute and convalescent titers (> 3 wks apart) Acute and convalescent titers (> 3 wks apart) Immunofluorescence assay Immunofluorescence assay PCR PCR Isolation of R rickettsii from clinical specimen Isolation of R rickettsii from clinical specimen

16. Treatment: Should be started immediately Should be started immediately Doxycycline, usually 7-10 days Doxycycline, usually 7-10 days 100 mg PO BID for adults 100 mg PO BID for adults 4 mg/kg/day div BID for children 4 mg/kg/day div BID for children Discontinue 72 hrs after defervescence Discontinue 72 hrs after defervescence Teeth staining if < 9 years old; probably requires 5-6 courses before staining appears Teeth staining if < 9 years old; probably requires 5-6 courses before staining appears

17. Prevention: Protective clothing Protective clothing Repellants Repellants Avoid DEET if under 12 months Avoid DEET if under 12 months Full body examinations Full body examinations

18. To remove attached ticks, use the following procedure: To remove attached ticks, use the following procedure: 1. Use fine-tipped tweezers or shield your fingers with a tissue, paper towel, or rubber gloves (Figure 17). When possible, persons should avoid removing ticks with bare hands. 1. Use fine-tipped tweezers or shield your fingers with a tissue, paper towel, or rubber gloves (Figure 17). When possible, persons should avoid removing ticks with bare hands. 2. Grasp the tick as close to the skin surface as possible and pull upward with steady, even pressure (Figure 18). Do not twist or jerk the tick; this may cause the mouthparts to break off and remain in the skin. (If this happens, remove mouthparts with tweezers. Consult your health care provider if infection occurs.) 2. Grasp the tick as close to the skin surface as possible and pull upward with steady, even pressure (Figure 18). Do not twist or jerk the tick; this may cause the mouthparts to break off and remain in the skin. (If this happens, remove mouthparts with tweezers. Consult your health care provider if infection occurs.) 3. Do not squeeze, crush, or puncture the body of the tick because its fluids (saliva, body fluids, gut contents) may contain infectious organisms. 3. Do not squeeze, crush, or puncture the body of the tick because its fluids (saliva, body fluids, gut contents) may contain infectious organisms. 4. After removing the tick, thoroughly disinfect the bite site and wash your hands with soap and water. 4. After removing the tick, thoroughly disinfect the bite site and wash your hands with soap and water. 5. Save the tick for identification in case you become ill. This may help your doctor make an accurate diagnosis. Place the tick in a plastic bag and put it in your freezer. Write the date of the bite on a piece of paper with a pencil and place it in the bag. 5. Save the tick for identification in case you become ill. This may help your doctor make an accurate diagnosis. Place the tick in a plastic bag and put it in your freezer. Write the date of the bite on a piece of paper with a pencil and place it in the bag.

19. Resources: Center for Disease Control and Prevention. Rocky Mountain spotted fever. Available at: http://www.cdc.gov/ncidod/dvrd/rmsf Center for Disease Control and Prevention. Rocky Mountain spotted fever. Available at: http://www.cdc.gov/ncidod/dvrd/rmsf http://www.cdc.gov/ncidod/dvrd/rmsf Pickering, L. Red Book; 26 th edition. pp. 532- 534. Pickering, L. Red Book; 26 th edition. pp. 532- 534. Razzaq, S. Rocky Mountain Spotted Fever: A Physician’s Challenge. Pediatrics in Review. Vol. 26, No. 4 April 2005. pp. 125-129. Razzaq, S. Rocky Mountain Spotted Fever: A Physician’s Challenge. Pediatrics in Review. Vol. 26, No. 4 April 2005. pp. 125-129.