BACKGROUND: Since 2000, the reported prevalence of tick-borne spotted fever rickettsiosis has increased considerably. We compared the level of antibody reactivity among healthy blood donors from 2 widely separated regions of the United States and evaluated the impact of antibody prevalence on public health surveillance in one of these regions. METHODS: Donor serum samples were evaluated by indirect immunofluorescence antibody assay to identify immunoglobulin G (IgG) antibodies reactive with Rickettsia rickettsii. The Georgia Department of Public Health (GDPH) analyzed characteristics of cases from 2016 surveillance data to evaluate the utility of laboratory surveillance for case assessment. RESULTS: Of the Georgia donors (n = 1493), 11.1% demonstrated antibody titers reactive with R. rickettsii at titers ≥64, whereas 6.3% of donors from Oregon and Washington (n = 1511) were seropositive. Most seropositive donors had a titer of 64; only 3.1% (n = 93) of all donors had titers ≥128. During 2016, GDPH interviewed 243 seropositive case patients; only 28% (n = 69) met inclusion criteria in the national case definition for spotted fever rickettsiosis. CONCLUSIONS: These findings suggest that a single IgG antibody titer is an unreliable measure of diagnosis and could inaccurately affect surveillance estimates that define magnitude and clinical characteristics of Rocky Mountain spotted fever and other spotted fever rickettsioses. Published by Oxford University Press for the Infectious Diseases Society of America 2019.
BACKGROUND: Since 2000, the reported prevalence of tick-borne spotted fever rickettsiosis has increased considerably. We compared the level of antibody reactivity among healthy blood donors from 2 widely separated regions of the United States and evaluated the impact of antibody prevalence on public health surveillance in one of these regions. METHODS:Donor serum samples were evaluated by indirect immunofluorescence antibody assay to identify immunoglobulin G (IgG) antibodies reactive with Rickettsia rickettsii. The Georgia Department of Public Health (GDPH) analyzed characteristics of cases from 2016 surveillance data to evaluate the utility of laboratory surveillance for case assessment. RESULTS: Of the Georgia donors (n = 1493), 11.1% demonstrated antibody titers reactive with R. rickettsii at titers ≥64, whereas 6.3% of donors from Oregon and Washington (n = 1511) were seropositive. Most seropositive donors had a titer of 64; only 3.1% (n = 93) of all donors had titers ≥128. During 2016, GDPH interviewed 243 seropositive case patients; only 28% (n = 69) met inclusion criteria in the national case definition for spotted fever rickettsiosis. CONCLUSIONS: These findings suggest that a single IgG antibody titer is an unreliable measure of diagnosis and could inaccurately affect surveillance estimates that define magnitude and clinical characteristics of Rocky Mountain spotted fever and other spotted fever rickettsioses. Published by Oxford University Press for the Infectious Diseases Society of America 2019.
Authors: Amanda Brown Marusiak; Brandon D Hollingsworth; Haley Abernathy; Aidin Alejo; Victor Arahirwa; Odai Mansour; Dana Giandomenico; John Schmitz; Carl Williams; Alexis M Barbarin; Ross M Boyce Journal: JAMA Netw Open Date: 2022-05-02
Authors: Anne M Kjemtrup; Kerry Padgett; Christopher D Paddock; Sharon Messenger; Jill K Hacker; Tina Feiszli; Michael Melgar; Marco E Metzger; Renjie Hu; Vicki L Kramer Journal: PLoS Negl Trop Dis Date: 2022-09-15
Authors: James M Wilson; Edward B Breitschwerdt; Nicholas B Juhasz; Henry S Marr; Joao Felipe de Brito Galvão; Carmela L Pratt; Barbara A Qurollo Journal: Emerg Infect Dis Date: 2020-12 Impact factor: 6.883