Abstract
Rickettsioses have nonspecific clinical manifestations, making them difficult to diagnose in a clinical setting. Laboratory testing is usually needed to confirm the diagnosis.
Rickettsial isolation is a sensitive and specific diagnostic technique, but the hazards associated with handling pathogenic rickettsiae usually preclude isolation attempts in most laboratories. Rickettsiae can also be detected in infected tissues by fluorescein-labeled antisera or by immunoperoxidase staining, but these techniques lack sensitivity, except when applied to postmortem tissue specimens. However, rickettsial DNA can be detected in acute phase blood specimens by polymerase chain reaction (PCR) technology, and this technique offers the prospect of prompt diagnosis and treatment.
Serologic testing remains the most frequently used approach to diagnosis, although antibody tests usually fail to identify rickettsioses early enough to affect the management of individual patients. Available serologic techniques vary considerably in their sensitivity and specificity. Enzyme-linked immunosorbent assays (ELISA) are extremely sensitive, but the general unavailability of specific diagnostic antigens reduces the specificity of this and other serologic techniques. Molecular characterization of rickettsial antigens may soon allow the production of peptide antigens that are specific for each species and could maximize the specificity of test results.
No diagnostic technique has any value unless it is applied successfully to the appropriate patient population. Improved surveillance of rickettsial diseases is urgently needed to identify specific areas in which rickettsioses are endemic. Such surveillance data would promote awareness of rickettsioses among local physicians and increase the probability that individual patients with rickettsioses would be identified promptly and receive appropriate therapy early in the course of their illness.
Similar content being viewed by others
References
AndersonG.W.Jr. and OstermanJ.V. (1980): Host defenses in experimental rickettsialpox: genetics of natural resistance to infection - Infect. Immun. 28: 132–136.
AudyJ.R. (1968): Red mites and typhus - Althone Press, London.
BuhlesW.C., HuxsollD.L., RuchG., KenyonR.H. and ElisbergB.L. (1975): Evaluation of primary blood monocyte and bone marrow cell cultures for the isolation of Rickettsial rickettsii - Infect. Immun. 12: 1457–1463.
CarlM., TibbsC.W., DobsonM.E., PaparelloS. and DaschG.A. (1990): Diagnosis of acute typhus infection using the polymerase chain reaction - J. Infect. Dis. 161: 791–793.
CoxH.R. (1938): Use of yolk sac of developing chick embryo as medium for growing rickettsiae of Rocky Mountain spotted fever and typhus groups - Public Health Rep. 53: 2241–2247.
ElisbergB.L. and BozemanF.M. (1979): The rickettsiae. In: Diagnostic procedures for viral, rickettsial and chlamydial infections. E. Lennette and N.J. Schmidt (eds) - American Public Health Association, Washington, D.C., pp. 1061–1108.
GalenR.S. (1986): Use of predictive value theory in clinical immunology. In: Manual of Clinical Laboratory Immunology - 3rd ed. N.R. Rose, H. Friedman and J.L. Fahey (eds) - American Society for Microbiology, Washington, D.C., pp. 966–970.
GimenezD.F. (1964): Staining rickettsiae in yolk-sac cultures - Stain Technol. 39: 135–140.
GrovesM.G. and OstermanJ.V. (1978): Host defense in experimental scrub typhus: genetics of natural resistance to infection - Infect. Immun. 19: 583–588.
HahonN. (1968): Selected papers on the pathogenic rickettsiae - Harvard University Press, Cambridge, Massachussetts.
IlstrupD.M. (1990): Statistical methods in microbiology - Clin. Microbiol. Rev. 3: 219–226.
JohnsonJ.W. and PedersenC.E.Jr. (1978): Plaque formation of spotted fever rickettsiae in monolayer cultures of various cell types - J. Clin. Microbiol. 7: 389–391.
MarchetteN.J. and StillerD. (1982): Ecological relationships and evolution of the rickettsiae, Vol. I. CRC Press, Boca Raton, Florida.
McDadeJ.E. (1990): Ehrlichiosis — a disease of animals and humans - J. Infect. Dis. 161: 609–617.
McDadeJ.E. and FishbeinD.B. (1988): Rickettsiaceae: the rickettsiae. In: Laboratory diagnosis of infectious diseases: principles and practice. E. Lennette, P. Halonen and F.A. Murphy (eds) - Springer Verlag, New York, pp. 864–890.
NicolleC., ComteC. and ConseilE. (1909): Experimental transmission of exanthematic typhus through body lice - C.R. Acad. Sci. 149: 486–489.
PhilipR.N. and CasperE.A. (1981): Serotypes of spotted fever group rickettsiae isolated from Dermacentor andersoni (Stiles) ticks in Western Montana - Am. J. Trop. Med. Hyg. 30: 230–238.
PlotzH. (1934): Complement fixation in rickettsial diseases - Science 97: 20–21.
RickettsH.T. (1907): Further experiments with the wood tick in relation to Rocky Mountain spotted fever - J. Am. Med. Assoc. 49: 1278–1281.
RickettsH.T. and WilderR.M. (1910): The etiology of typhus fever (tabardillo) of Mexico City - J. Am. Med. Assoc. 54: 1373–1375.
ToppingN.H. and ShearM.J. (1945): Studies of typhus fever vaccines: III. Studies of antigens in infected yolk sacs - NIH Bull. 183: 13–17.
TzianabosT., AndersonB.E. and McDadeJ.E. (1989): Detection of Rickettsia rickettsii DNA in clinical specimens by using polymerase chain reaction technology - J. Clin. Microbiol. 27: 2866–2868.
WalkerD.H., CainB.G. and OlmsteadP.M. (1978): Laboratory diagnosis of Rocky Mountain spotted fever by immunofluorescent demonstration of Rickettsia rickettsii in cutaneous lesions - Am. J. Clin. Pathol. 69: 619–623.
WeilE. and FelixA. (1916): On serological diagnosis of spotted fever - Wien. Klin. Wochenschr. 13: 33–35.
WilsonJ. W. (1910): The etiology of typhus fever - J. Hyg. 10: 155–176.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
McDADE, J.E. Diagnosis of rickettsial diseases: A perspective. Eur J Epidemiol 7, 270–275 (1991). https://doi.org/10.1007/BF00145676
Issue Date:
DOI: https://doi.org/10.1007/BF00145676