Lyme disease during pregnancy

Lyme disease is an increasingly recognized tick-borne illness caused by a spirochete, Borrelia burgdorferi. Because the etiologic agent of Lyme disease is a spirochete, there has been concern about the effect of maternal Lyme disease on pregnancy outcome. We reviewed cases of Lyme disease in pregnant women who were identified before knowledge of the pregnancy outcomes. Nineteen cases were identified with onset between 1976 and 1984. Eight of the women were affected during the first trimester, seven during the second trimester, and two during the third trimester; in two, the trimester of onset was unknown. Thirteen received appropriate antibiotic therapy for Lyme disease. Of the 19 pregnancies, five had adverse outcomes, including syndactyly, cortical blindness, intrauterine fetal death, prematurity, and rash in the newborn. Adverse outcomes occurred in cases with infection during each of the trimesters. Although B burgdorferi could not be implicated directly in any of the adverse outcomes, the frequency of such outcomes warrants further surveillance and studies of pregnant women with Lyme disease.     

The association of thrombocytopaenia and Lyme disease.

The association of asymptomatic thrombocytopaenia in six patients with acute Lyme disease is described. Recovery from thrombocytopaenia occurred shortly following antibiotic therapy. Patients residing in endemic areas for Lyme disease who present with flu-like symptoms and laboratory findings of thrombocytopaenia should prompt suspicion of acute Lyme disease. Appropriate clinical studies should be undertaken to confirm the diagnosis.     

Role of serology in the diagnosis of Lyme disease.

Numerous concerns regarding the potential for misdiagnosis of Lyme disease using commercial assays have been voiced by the US Food and Drug Administration (FDA). We attempted to clarify the clinical value of serologic testing for Lyme disease using the results of commonly marketed assays for detecting antibody to Borrelia burgdorferi, the organism that causes Lyme disease. We reviewed published studies on B burgdorferi test performance published through 1998, package insert labeling from FDA-cleared test kits for B burgdorferi, and Lyme Disease Survey Set LY-A from the College of American Pathologists. We assessed the sensitivity and specificity of commercial serologic tests (enzyme-linked immunosorbent assay [ELISA], immunofluorescence antibody [IFA], and immunodot) for diagnosis of Lyme disease. To reduce this risk of misdiagnosis, it is important that clinicians understand the performance characteristics and limitations of these tests. These tests, in common use in clinical or commercial laboratories, should be used only to support a clinical diagnosis of Lyme disease, not as the primary basis for making diagnostic or treatment decisions. Serologic testing is not useful early in the course of Lyme disease because of the low sensitivity of tests in early disease. Serologic testing may be more useful in later disease, at which time sensitivity and specificity of the test are improved. Positive or equivocal results on an ELISA, IFA, or immunodot assay requires supplemental testing with a Western blot assay. A negative result on the Western blot or ELISA indicates that there is no serologic evidence of infection by B burgdorferi at the time the sample was drawn.     

Investigation of Lyme disease in Xinjiang.

From April through July 1988, an epidemiological investigation on Lyme disease was carried out in Nalati Xanyuan, Xinjiang Uygur Autonomous Region, China. Of 150 Ixodes persulcatus ticks examined by darkfield microscopy, 42 (28%) were found to have spirochetes. Two strains of spirochetes were isolated from I. persulcatus with BSK medium. Rabbits inoculated with the spirochetes showed erythema chronicum migrans at the sites of inoculation and the spirochetes were found in the cerebrospinal fluid by darkfield microscopy. Serum samples from 63 patients were examined for antibodies to B. burgdorferi by IFA test and 11 of them were positive with a titer of 1:64. Upon these results, it may be concluded that natural focus of Lyme disease exists in Xinjiang, China.