Utilization of serology for the diagnosis of suspected Lyme borreliosis in Denmark: survey of patients seen in general practice

TY - JOUR

T1 - Utilization of serology for the diagnosis of suspected Lyme borreliosis in Denmark: survey of patients seen in general practice

AU - Dessau, Ram B

AU - Bangsborg, Jette M

AU - Ejlertsen, Tove

AU - Skarphedinsson, Sigurdur

AU - Schønheyder, Henrik C

PY - 2010/11/1

Y1 - 2010/11/1

N2 - Background: Serological testing for Lyme borreliosis (LB) is frequently requested by general practitioners for patients with a wide variety of symptoms.Methods: A survey was performed in order to characterize test utilization and clinical features of patients investigated for serum antibodies to Borrelia burgdorferi sensu lato. During one calendar year a questionnaire was sent to the general practitioners who had ordered LB serology from patients in three Danish counties (population 1.5 million inhabitants). Testing was done with a commercial ELISA assay with purified flagella antigen from a Danish strain of B. afzelii.Results: A total of 4,664 patients were tested. The IgM and IgG seropositivity rates were 9.2% and 3.3%, respectively. Questionnaires from 2,643 (57%) patients were available for analysis. Erythema migrans (EM) was suspected in 38% of patients, Lyme arthritis/disseminated disease in 23% and early neuroborreliosis in 13%. Age 0-15 years and suspected EM were significant predictors of IgM seropositivity, whereas suspected acrodermatitis was a predictor of IgG seropositivity. LB was suspected in 646 patients with arthritis, but only 2.3% were IgG seropositive. This is comparable to the level of seropositivity in the background population indicating that Lyme arthritis is a rare entity in Denmark, and the low pretest probability should alert general practitioners to the possibility of false positive LB serology. Significant predictors for treating the patient were a reported tick bite and suspected EM.Conclusions: A detailed description of the utilization of serology for Lyme borreliosis with rates of seropositivity according to clinical symptoms is presented. Low rates of seropositivity in certain patient groups indicate a low pretest probability and there is a notable risk of false positive results. 38% of all patients tested were suspected of EM, although this is not a recommended indication due to a low sensitivity of serological testing.

AB - Background: Serological testing for Lyme borreliosis (LB) is frequently requested by general practitioners for patients with a wide variety of symptoms.Methods: A survey was performed in order to characterize test utilization and clinical features of patients investigated for serum antibodies to Borrelia burgdorferi sensu lato. During one calendar year a questionnaire was sent to the general practitioners who had ordered LB serology from patients in three Danish counties (population 1.5 million inhabitants). Testing was done with a commercial ELISA assay with purified flagella antigen from a Danish strain of B. afzelii.Results: A total of 4,664 patients were tested. The IgM and IgG seropositivity rates were 9.2% and 3.3%, respectively. Questionnaires from 2,643 (57%) patients were available for analysis. Erythema migrans (EM) was suspected in 38% of patients, Lyme arthritis/disseminated disease in 23% and early neuroborreliosis in 13%. Age 0-15 years and suspected EM were significant predictors of IgM seropositivity, whereas suspected acrodermatitis was a predictor of IgG seropositivity. LB was suspected in 646 patients with arthritis, but only 2.3% were IgG seropositive. This is comparable to the level of seropositivity in the background population indicating that Lyme arthritis is a rare entity in Denmark, and the low pretest probability should alert general practitioners to the possibility of false positive LB serology. Significant predictors for treating the patient were a reported tick bite and suspected EM.Conclusions: A detailed description of the utilization of serology for Lyme borreliosis with rates of seropositivity according to clinical symptoms is presented. Low rates of seropositivity in certain patient groups indicate a low pretest probability and there is a notable risk of false positive results. 38% of all patients tested were suspected of EM, although this is not a recommended indication due to a low sensitivity of serological testing.

KW - Adolescent

KW - Adult

KW - Animals

KW - Antibodies, Bacterial

KW - Bites and Stings

KW - Borrelia burgdorferi Group

KW - Child

KW - Child, Preschool

KW - Denmark

KW - Enzyme-Linked Immunosorbent Assay

KW - Female

KW - General Practice

KW - General Practitioners

KW - Humans

KW - Immunoglobulin G

KW - Immunoglobulin M

KW - Infant

KW - Lyme Disease

KW - Male

KW - Middle Aged

KW - Questionnaires

KW - Ticks

KW - Young Adult

U2 - 10.1186/1471-2334-10-317

DO - 10.1186/1471-2334-10-317

M3 - Journal article

C2 - 21040576

SN - 1471-2334

VL - 10

SP - 317

JO - B M C Infectious Diseases

JF - B M C Infectious Diseases

ER -