Seroprevalence studies
Seroprevalence studies in asymptomatic populations have revealed presence of anti-ehrlichial or anti-anaplasma antibodies in both children and adults. In some endemic areas, seroprevalence ranges from 2% to 22% for human monocytotropic/monocytic ehrlichiosis (HME) and 15% to 36% for human granulocytotropic/granulocytic anaplasmosis (HGA). These cases most likely represent past infections with pathogenic Ehrlichia or exposure to nonpathogenic Ehrlichia through tick bites.[24]Bakken JS, Goellner P, Van Etten M, et al. Seroprevalence of human granulocytic ehrlichiosis among permanent residents of northwestern Wisconsin. Clin Infect Dis. 1998 Dec;27(6):1491-6.
http://www.ncbi.nlm.nih.gov/pubmed/9868666?tool=bestpractice.com
[74]Comer JA, Nicholson WL, Olson JG, et al. Serologic testing for human granulocytic ehrlichiosis at a national referral center. J Clin Microbiol. 1999 Mar;37(3):558-64.
https://journals.asm.org/doi/10.1128/JCM.37.3.558-564.1999
http://www.ncbi.nlm.nih.gov/pubmed/9986812?tool=bestpractice.com
[114]Bakken JS, Krueth J, Tilden RL, et al. Serological evidence of human granulocytic ehrlichiosis in Norway. Eur J Clin Microbiol Infect Dis. 1996;15:829-832.
http://www.ncbi.nlm.nih.gov/pubmed/8950565?tool=bestpractice.com
[115]Dumler JS, Dotevall L, Gustafson R, et al. A population-based seroepidemiologic study of human granulocytic ehrlichiosis and Lyme borreliosis on the west coast of Sweden. J Infect Dis. 1997;175:720-722.
http://www.ncbi.nlm.nih.gov/pubmed/9041353?tool=bestpractice.com
[116]Brouqui P, Dumler JS. Serologic evidence of human monocytic and granulocytic ehrlichiosis in Israel. Emerg Infect Dis. 2000;6:314-315.
http://www.ncbi.nlm.nih.gov/pubmed/10827125?tool=bestpractice.com
[117]Heo EJ, Park JH, Koo JR, et al. Serologic and molecular detection of Ehrlichia chaffeensis and Anaplasma phagocytophila (human granulocytic ehrlichiosis agent) in Korean patients. J Clin Microbiol. 2002 Aug;40(8):3082-5.
https://journals.asm.org/doi/10.1128/JCM.40.8.3082-3085.2002
http://www.ncbi.nlm.nih.gov/pubmed/12149387?tool=bestpractice.com
[118]Park JH, Heo EJ, Choi KS, et al. Detection of antibodies to Anaplasma phagocytophilum and Ehrlichia chaffeensis antigens in sera of Korean patients by western immunoblotting and indirect immunofluorescence assays. Clin Diagn Lab Immunol. 2003 Nov;10(6):1059-64.
https://journals.asm.org/doi/10.1128/CDLI.10.6.1059-1064.2003
http://www.ncbi.nlm.nih.gov/pubmed/14607867?tool=bestpractice.com
[119]Guillaume B, Heyman P, Lafontaine S, et al. Seroprevalence of human granulocytic ehrlichiosis infection in Belgium. Eur J Clin Microbiol Infect Dis. 2002;21:397-400.
http://www.ncbi.nlm.nih.gov/pubmed/12072927?tool=bestpractice.com
[120]Heppner DG, Wongsrichanalai C, Walsh DS, et al. Human ehrlichiosis in Thailand. Lancet. 1997;350:785-786.
http://www.ncbi.nlm.nih.gov/pubmed/9298007?tool=bestpractice.com
Asymptomatic populations are not screened, since this is an acute disease with no known chronic progression in humans, as opposed to zoonotic hosts where chronic infections are the rule.