Volume 91, Issue 4
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645



Among 13 suspected Rocky Mountain spotted fever (RMSF) cases identified through an enhanced surveillance program in Tennessee, antibodies to were detected in 10 (77%) patients using a standard indirect immunofluorescent antibody (IFA) assay. Immunoglobulin M (IgM) antibodies were observed for 6 of 13 patients (46%) without a corresponding development of IgG, and for 3 of 10 patients (30%) at least 1 year post-onset. However, recent infection with a spotted fever group rickettsiae could not be confirmed for any patient, based on a lack of rising antibody titers in properly timed acute and convalescent serologic specimens, and negative findings by polymerase chain reaction testing. Case definitions used in national surveillance programs lack specificity and may capture cases that do not represent current rickettsial infections. Use of IgM antibodies should be reconsidered as a basis for diagnosis and public health reporting of RMSF and other spotted fever group rickettsiae in the United States.


Article metrics loading...

The graphs shown below represent data from March 2017
Loading full text...

Full text loading...



  1. Openshaw JJ, Swerdlow DL, Krebs JW, Holman RC, Mandel E, Harvey A, Haberling D, Massung RF, McQuiston JH, , 2010. Rocky Mountain spotted fever in the United States, 2000–2007: interpreting contemporary increases in incidence. Am J Trop Med Hyg 83: 174182. Erratum 83: 729–730.[Crossref] [Google Scholar]
  2. Paddock CD, , 2006. Rickettsia parkeri as a paradigm for multiple causes of tick-borne rickettsioses in the Western Hemisphere. Ann N Y Acad Sci 1063: 315326.[Crossref] [Google Scholar]
  3. Shapiro MR, Fritz CL, Tait K, Paddock CD, Nicholson WL, Abramowicz KF, Karpathy SE, Dasch GA, Sumner JW, Adem PV, Scott JJ, Padgett KA, Zaki SR, Eremeeva ME, , 2010. Rickettsia 364D: a newly recognized cause of eschar-associated illness in California. Clin Infect Dis 50: 541548.[Crossref] [Google Scholar]
  4. Beeler E, Abramowicz KF, Zambrano ML, Sturgeon MM, Khalaf N, Hu R, Dasch GA, Eremeeva ME, , 2011. A focus of dogs and Rickettsia massiliae-infected Rhipicephalus sanguineus in California. Am J Trop Med Hyg 84: 244249.[Crossref] [Google Scholar]
  5. McQuiston JH, Zemtsova G, Perniciaro J, Hutson M, Singleton J, Nicholson WL, Levin ML, , 2012. Afebrile spotted fever group Rickettsia infection following a bite from a Dermacentor variabilis tick infected with Rickettsia montanensis . Vector Borne Zoonotic Dis 12: 10591061.[Crossref] [Google Scholar]
  6. Apperson CS, Engbar B, Nicholson WL, Mead DG, Engel J, Yabsley MJ, Dail K, Johnson J, Watson DW, , 2008. Tick-borne disease in North Carolina: is “Rickettsia amblyommii” a possible cause of rickettsiosis reported as Rocky Mountain spotted fever? Vector Borne Zoonotic Dis 8: 597606.[Crossref] [Google Scholar]
  7. Adejemian JZ, Krebs J, Mandel E, McQuiston J, , 2008. Spatial clustering by disease severity among reported Rocky Mountain spotted fever cases in the United States, 2001–2005. Am J Trop Med Hyg 80: 7277. [Google Scholar]
  8. Nicholson WL, Comer JA, Sumner JW, Gingrich-Baker C, Coughlin RT, Magnarelli LA, Olson JG, Childs JE, , 1997. An indirect immunofluorescence assay using a cell culture-derived antigen for the detection of antibodies to the agent of human granulocytic ehrlichiosis. J Clin Microbiol 35: 15101516. [Google Scholar]
  9. Kato CY, Chung IH, Robinson LK, Austin AL, Dasch GA, Massung RF, , 2013. Assessment of real-time PCR assay for detection of Rickettsia spp. and Rickettsia rickettsii in banked clinical samples. J Clin Microbiol 51: 314317.[Crossref] [Google Scholar]
  10. National Notifiable Disease System for Surveillance (NNDSS), 2010. Case definition for Spotted fever rickettsiosis. Available at: http://wwwn.cdc.gov/NNDSS/script/casedef.aspx?CondYrID=853&DatePub=1/1/2010. Accessed December 23, 2013.
  11. Raoult D, Dash GA, , 1995. Immunoblot cross-reactions among Rickettsia, Proteus spp. and Legionella spp. in patients with Mediterranean spotted fever. FEMS Immunol Med Microbiol 11: 1318.[Crossref] [Google Scholar]
  12. Teysseire N, Raoult D, , 1992. Comparison of western immunoblotting and microimmunofluorescence for diagnosis of Mediterranean spotted fever. J Clin Microbiol 30: 455460. [Google Scholar]
  13. Vardi M, Petersil N, Keysary A, Rzotkiewicz S, Laor A, Bitterman H, , 2011. Immunological arousal during acute Q fever infection. Eur J Clin Microbiol Infect Dis 30: 15271530.[Crossref] [Google Scholar]
  14. Fournier PE, Jensenius M, Laferl H, Vene S, Raoult D, , 2002. Kinetics of antibody responses in Rickettsia africae and Rickettsia conorii infections. Clin Diagn Lab Immunol 9: 324328. [Google Scholar]

Data & Media loading...

  • Received : 27 Feb 2014
  • Accepted : 06 May 2014
  • Published online : 01 Oct 2014

Most Cited This Month

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error