Experimental & Applied Acarology

, Volume 25, Issue 10–11, pp 881–897 | Cite as

Population-Based Evaluation of the Ehrlichia Ruminantium MAP 1B Indirect ELISA

  • Trevor F. Peter
  • Christopher J. O'Callaghan
  • Graham F. Medley
  • Brian D. Perry
  • Shalt M. Semu
  • Suman M. Mahan


The indirect MAP 1B ELISA based on the recombinant MAP 1B fragment of the immunodominant MAP 1 protein of Ehrlichia ruminantium is considered to be the most sensitive and specific assay for the serodiagnosis of heartwater. In this study, we evaluated its reliability in detecting exposure to E. ruminantium in field populations of domestic ruminants in Zimbabwe. Cattle and goat herds in endemically stable areas with high infection pressure and an expected close to 100% prevalence of E. ruminantium exposure were sampled. Bovine sera (858) and caprine sera (706) collected at seven locations representative of the two main production systems (communal lands and large scale commercial farms) in the two main agroecological zones of Zimbabwe (highveld and lowveld) were analysed. The prevalence of MAP 1B-specific antibodies in goats was similar and high, ranging from 67 to 100%, at all except one site (43%). Age-specific differences in goats (1, 2, 3, 4, 5 years) were not observed. In contrast, MAP 1B seroprevalence in cattle was significantly lower (P < 0.001), ranging from 46 to 61% in the lowveld communal area and from 24 to 33% in the remaining areas (P < 0.001). Age-specific differences in seroprevalence (1, 2, 3, 4, 5–7 + years) were similarly not evident in cattle (P < 0.15). Hence, the indirect MAP 1B ELISA may be an unreliable indicator of past exposure to heartwater in field-infected cattle in Zimbabwe. Although the reasons for this low response in field cattle are not fully understood, this study illustrates the need for field validation of the performance of new diagnostic tests prior to their use for epidemiological purposes.

Amblyomma Ehrlichia ruminantium rickettsia heartwater indirect MAP 1B ELISA serology 


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  1. Alexander, R.A.Neitz, W.O. andAdellar, T.F. 1946. Heartwater. Farm. S. Afr. 21: 548-552.Google Scholar
  2. Andrew, H.R. andNorval, R.A.I. 1989. The carrier status of sheep, cattle and African buffalo recovered from heartwater. Vet. Parasitol. 34: 261-266.Google Scholar
  3. Bowie, M.V.Reddy, G.R.Semu, S.M.Mahan, S.M. andBarbet, A.F. 1999. Potential value of major antigenic protein 2 for serological diagnosis of heartwater and related ehrlichial infections. Clin. Diag. Lab. Immunol. 6: 209-215.Google Scholar
  4. Camus, E. 1986. Contribution a l'etude epidemiologique de la cowdriose (Cowdria ruminantium) en Guadeloupe. DSc Thesis, University of Paris-Sud, Orsay.Google Scholar
  5. Camus, E.Barre, N.Martinez, D. andUilenberg, G. 1996. Heartwater (cowdriosis). A Review, 2nd ed. Office International des Epizooties, Paris.Google Scholar
  6. Chamboko, T.Mukhebi, A.W.O'Callaghan, C.J.Peter, T.F.Kruska, R.L.Medley, G.F.Mahan, S.M. andPerry, B.D. 1999. The control of heartwater on large scale commercial and smallholder farms in Zimbabwe: results of cross-sectional and longitudinal field studies. Prev. Vet. Med. 39: 191-210.Google Scholar
  7. Chamboko, T., Mukhebi, A.W.O'Callaghan, C.J.Peter, T.F.Kruska, R.L.Medley, G.F.Mahan, S.M. andPerry, B.D. 1999. Heartwater and the economics of livestock production on large scale commercial and smallholder farms in Zimbabwe: results of cross-sectional field studies. Rev. d'elev. Med. Vet. Pays Trop. 52: 313-323.Google Scholar
  8. Cowdry, E.V. 1925a. Studies on the etiology of heartwater. I. Observation of a rickettsia, Rickettsia ruminantium (n. sp.) in the tissues of infected animals. J. Exp. Med. 42: 253-274.Google Scholar
  9. Cowdry, E.V. 1925b. Studies on the etiology of heartwater. II. Rickettsia ruminantium (n. sp.) in the tissues of ticks transmitting the disease. J. Exp. Med. 42: 231-245.Google Scholar
  10. Deem, S.L.Norval, R.A.I.Yonow, T.Peter, T.F.Mahan, S.M. andBurridge, M.J. 1996. The epidemiology of heartwater: establishment and maintenance of endemic stability Parasitol. Today 12: 402-405.Google Scholar
  11. Dumler, J.S.Barbet, A.F.Bekker, C.P.Dasch, G.A.Palmer, G.H.Ray, S.C.Rikihisa, Y. andRurangirwa, F.R. 2001. Reorganization of genera in the families Rickettsiaceae and Anaplasmataceae in the order Rickettsiales: unification of some species of Ehrlichia with Anaplasma, Cowdria with Ehrlichia and Ehrlichia with Neorickettsia, descriptions of six new species combinations and designation of Ehrlichia equi and 'HGE agent' as subjective synonyms of Ehrlichia phagocytophila. Int. J. Syst. Evol. Microbiol. 51: 2145-2165.Google Scholar
  12. du Plessis, J.L. andMalan, L. 1987. The non-specific resistance of cattle to heartwater. Onderst. J. Vet. Res. 54: 333-336.Google Scholar
  13. du Plessis, J.L. andMalan, L. 1988. Susceptibility to heartwater of calves born to non-immune cows. Onderst. J. Vet. Res. 55: 235-237.Google Scholar
  14. du Plessis, J.L.Bezuidenhout, J.D.Brett, M.S.Camus, E.Jongejan, F.Mahan, S.M. andMartinez, D. 1993. The sero-diagnosis of heartwater: a comparison of five tests. Rev. d'elev. Med Vet. Pays Trop. 46: 123-129.Google Scholar
  15. Jongejan, Vries, N.Nieuwenhuijs, J.van Vliet, A.H.M. andWassink, L.A. 1993. The immunodominant 32-kilodalton protein of Cowdria ruminantium is conserved within the genus Ehrlichia. Rev. d'elev. Med. Vet. Pays Trop. 46: 145-152.Google Scholar
  16. Katz, J.B.Barbet, A.F.Mahan, S.M.Kumbula, D.Lockhart, J.M.Keel, M.K.Dawson, J.E.Olson, J.G. andEwing, S.A. 1996. A recombinant antigen from the heartwater agent (Cowdria ruminatium) reactive with antibodies in some southeastern United States whitetailed deer (Odocoileus virginianus), but not cattle, sera. J. Wild. Dis. 32: 424-430.Google Scholar
  17. Katz, J.B.Dewald, R.Dawson, J.E.Camus, E.Martinez, D. andMondry, R. 1997. Development and evaluation of a recombinant antigen, monoclonal antibody-based competitive ELISA for heartwater serodiagnosis. J. Vet. Diag. Investig. 9: 130-135.Google Scholar
  18. Keinbaum, D.G.Kupper, L.L.Muller, K.E. andNizam, A. 1998. Applied Regression Analysis and Other Multivariable Methods, 3rd edn. Duxbury Press, Pacific Grove.Google Scholar
  19. Kock, N.D.van Vliet, A.H.Charlton, K. andJongejan, F. 1995. Detection of Cowdria ruminantium in blood and bone marrow samples from clinically normal, free ranging Zimbabwean wild ungulates. J. Clin. Microbiol. 33: 2501-2504Google Scholar
  20. Logan, L.L.Holland, C.J.Mebus, C.A. andRistic, M. 1986. Serological relationship between Cowdria ruminantium and certain Ehrlichia. Vet. Rec. 119: 458-459.Google Scholar
  21. Mahan, S.M.Tebele, N.Mukwedeya, D.Semu, S.Nyathi, C.B.Wassink, L.A.Kelly, P.J.Peter, T. andBarbet, A.F. 1993. An immunoblotting diagnostic assay for heartwater based on the immunodominant 32-kilodalton protein of Cowdria ruminantium detects false positives in-field sera. J. Clin. Microbiol. 31: 2729-2737.Google Scholar
  22. Mahan, S.M., Semu, S.M.Peter, T.F. and Jongejan, F. 1998. Evaluation of the MAP-1B ELISA for cowdriosis with field sera from livestock in Zimbabwe. Ann. N.Y. Acad. Sci. 849: 259-261.Google Scholar
  23. Mahan, S.M.Allsopp, B.Kocan, K.M.Palmer, G.H. andJongejan, F. 1999. Vaccine strategies for Cowdria ruminantium infections and their application to other ehrlichial infections. Parasitol. Tod. 15: 290-294.Google Scholar
  24. Mattioli, R.C.Bah, M.Reibel, R. andJongejan, F. 2000. Cowdria ruminantium antibodies in acaricide-treated and untreated cattle exposed to Amblyomma variegatum ticks in The Gambia. Exp. Appl. Acarol. 24: 957-969.Google Scholar
  25. Mboloi, M.M.Bekker, C.P. J.Kruitwagen, C.Greiner, M. andJongejan, F. 1999. Validation of the indirect MAP1-B enzyme-linked immunosorbent assay for diagnosis of experimental Cowdria ruminantium infection in small ruminants. Clin. Diag. Lab. Immunol. 6: 66-72.Google Scholar
  26. Mondry, R.Martinez, D.Camus, E.Liebisch, A.Katz, J.B.Dewald, R.van Vliet, A.H.M. andJongejan, F. 1998. Validation and comparison of three enzyme-linked immunosorbent assays for the detection of antibodies to Cowdria ruminantium infection. Ann. N.Y. Acad. Sci. 849: 262-272.Google Scholar
  27. Mukhebi, A.W.Chamboko, T.O'Callaghan, C.J.Peter, T.F.Kruska, R.L.Medley, G.F.Mahan, S.M. andPerry, B.D. 1999. An assessment of the economic impact of heartwater (Cowdria ruminantium infection) and its control in Zimbabwe. Prev. Vet. Med. 39: 173-189.Google Scholar
  28. Neitz, W.O. andAlexander, R.A. 1941. The immunisation of calves against heartwater. J.S. Afr. Vet. Med. Assoc. 12: 103-111.Google Scholar
  29. Neitz, W.O.Alexander, R.A. andAdellar, T.F. 1947. Studies on immunity to heartwater. Onderst. J. Vet. Res. 21: 243-249.Google Scholar
  30. Nokes, D.J. andAnderson, R.M. 1988. The use of mathematical models in the epidemiological study of infectious diseases and in the design of mass immunisation programmes. Epidemiol. Infect. 101: 1-20.Google Scholar
  31. Norval, R.A.I.Perry, B.D. andYoung, A.S. (eds) 1992. The Epidemiology of Theileriosis in Africa. Academic Press, London.Google Scholar
  32. O'Callaghan, C.J. 1998. A study of the epidemiology of theileriosis on smallholder dairy farms in Kiambu District, Kenya. PhD Thesis, University of Guelph, Guelph, Canada.Google Scholar
  33. O'Callaghan, C.J.Medley, G.F.Peter, T.F. andPerry, B.D. 1998. Investigating the epidemiology of heartwater (Cowdria ruminantium infection) by means of a transmission dynamics model. Parasitol. 117: 49-61.Google Scholar
  34. O'Callaghan, C.J.Medley, G.F.Peter, T.F.Mahan, S.M. andPerry, B.D. 1999. The effect of vaccination on the transmission dynamics of heartwater (Cowdria ruminantium infection). Prev. Vet. Med. 42: 17-39.Google Scholar
  35. O'Callaghan, C.J.Peter, T.F.Medley, G.F. andPerry, B.D. 2001. Direct estimation of the attachment and detachment rates of Amblyomma hebraeum on cattle. (in preparation, draft manuscript available). No update available.Google Scholar
  36. Perry, B.D. andYoung, A.S. 1995. The past and future roles of epidemiology and economics in the control of tick-borne diseases of livestock in Africa: the case of theileriosis. Prev. Vet. Med. 25: 107-120.Google Scholar
  37. Peter, T.F.Perry, B.D.O'Callaghan, C.J.Medley, G.F.Shumba, W.Madzima, W.Burridge, M.J. andMahan, S.M. 1998a. Distributions of the vectors of heartwater, Amblyomma hebraeum and Amblyomma variegatum (Acari: Ixodidae) in Zimbabwe. Exp. Appl. Acarol. 22: 725-740.Google Scholar
  38. Peter, T.F.Perry, B.D.O'Callaghan, C.J.Medley, G.F.Shumba, W.Madzima, W.Burridge, M.J. andMahan, S.M. 1998b. The distribution of heartwater in the highveld of Zimbabwe: 1980-1997. Onderst. J. Vet. Res. 65: 177-187.Google Scholar
  39. Peter, T.F.Anderson, E.C.Burridge, M.J. andMahan, S.M. 1998c. Demonstration of a carrier state for Cowdria ruminantium in wild ruminants from Africa. J. Wild. Dis. 34: 567-575.Google Scholar
  40. Peter, T.F.Anderson, E.C.Burridge, M.J.Perry, B.D. andMahan, S.M. 1999a. Susceptibility and carrier status of impala, sable and tsessebe for Cowdria ruminantium infection (heartwater). J. Parasitol. 85: 468-472.Google Scholar
  41. Peter, T.F.Perry, B.D.O'Callaghan, C.J.Medley, G.F.Mlambo, G.Barbet, A.F. andMahan, S.M. 1999b. Prevalence of Cowdria ruminantium infection in Amblyomma hebraeum ticks from heartwater-endemic areas of Zimbabwe. Epidemiol. Infect. 123: 309-316.Google Scholar
  42. Reddy, G.R.Sulsona, C.R.Barbet, A.F.Mahan, S.M.Burridge, M.J. andAlleman, A.R. 1998. Molecular characterisation of a 28 kDa surface antigen gene family of the tribe Ehrlichiae. Biochem. Biophys. Res. Commun. 247: 636-643.Google Scholar
  43. Savadye, D.T.Kelly, P.J. andMahan, S.M. 1998. Evidence to show that an agent that crossreacts serologically with Cowdria ruminantium in Zimbabwe is transmitted by ticks. Exp. Appl. Acarol. 22: 111-122.Google Scholar
  44. Semu, S.M.Peter, T.F.Mukwedeya, D.Barbet A.F.Jongejan, F. andMahan, S.M. 2001. Antibody responses to MAP 1B and other Cowdria ruminantium antigens are down regulated in cattle challenged with tick-transmitted heartwater. Clin. Diagn. Lab. Immunol. 8: 388-396.Google Scholar
  45. Sulsona, C.R.Mahan, S.M. andBarbet, A.F. 1999. The map-1 gene of Cowdria ruminantium is a member of a multigene family containing both conserved and variable genes. Biochem. Biophys. Res. Commun. 257: 300-305.Google Scholar
  46. Thomas, A.D. andMansvelt, P.R. 1957. Immunisation of goats against heartwater. J.S. Afr. Vet. Med. Assoc. 28: 163-168.Google Scholar
  47. Uilenberg. G. 1971.Etudes sur la cowdriose a Madagascar. Premiere partie. Rev. d'elev. Med. Vet. Pays Trop. 24: 239-249.Google Scholar
  48. van Vliet, A.H.M.Jongejan, F. andvan der Zeijst, B.A.M 1992. Phylogenetic position of Cowdria ruminantium (Rickettsiales) determined by analysis of amplified 16 S ribosomal DNA sequences. Int. J. Sys. Bacteriol. 42: 494-498.Google Scholar
  49. van Vliet, A.H.M.van der Zeijst, B.A.M.Camus, E.Mahan, S.M.Martinez, D. andJongejan, F. 1995. Use of a specific immunogenic region on the Cowdria ruminantium MAP1 protein in a serological assay. J. Clin. Microbiol. 33: 2405-2410.Google Scholar

Copyright information

© Kluwer Academic Publishers 2001

Authors and Affiliations

  • Trevor F. Peter
    • 1
  • Christopher J. O'Callaghan
    • 2
  • Graham F. Medley
    • 2
  • Brian D. Perry
    • 3
  • Shalt M. Semu
    • 1
  • Suman M. Mahan
    • 1
  1. 1.UF/USAID/SADC, Heartwater Research ProjectCauseway, HarareZimbabwe
  2. 2.Ecology & Epidemiology Group, Department of Biological SciencesUniversity of WarwickCoventryUK
  3. 3.International Livestock Research InstituteNairobiKenya

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