Implementation of a proficiency testing program for Lyme disease in New York State.

Nine proficiency test events for Lyme disease (Borrelia burgdorferi) antibody were carried out from October 1988 to January 1992 by the New York State Department of Health, Albany, Overall sensitivity for the 846 participants averaged 95.4%, with varying sensitivities of 98.7% for users (71 laboratories) of immunofluorescence assays, 97.4% for users (144 laboratories) of solid-phase fluorescence immunoassays, and 94.6% for users (631 laboratories) of enzyme immunoassays. Thirty percent of the enzyme immunoassay laboratories tested at greater than or equal to 98.4% sensitivity by the DiaMedix test kit (DiaMedix Corp, Miami, Fla) and MarDx test kit (MarDx Diagnostics Inc, Scotch Plains, NJ), while 7% tested at less than or equal to 83% by the Access test kit (Access Medical Systems Inc, Branford, Conn) and the Cambridge BioScience test kit (Cambridge BioScience, Worcester, Mass). Overall specificity was 98.8%, with specificities greater than 99% for both solid-phase fluorescence immunoassay and enzyme immunoassay users and 92.9% for immunofluorescence assay users. Cross-reactivity with Treponema pallidum antibody was high for the Hillcrest (Hillcrest Biologicals, Cypress, Calif) (30%) and Wampole (Wampole Laboratories, Cranbury, NJ) (25%) immunofluorescence assay test kit users and for the MarDx (30%) and 3M (3M Diagnostics Systems Inc, Santa Clara, Calif) (24%) enzyme immunoassay test kit users. Laboratories that tested by the Wampole immunofluorescence assay test kit had also high cross-reactivity (25%) against heterophile antibody.

Assay of rubella antibody by passive hemagglutination and by a modified indirect immunofluorescence test.

The passive hemagglutination (PHA) test and a modified indirect immunofluorescence (IF) test were compared with the standard hemagglutination-inhibition (HI) test for the assay of rubella antibody. For sera from healthy individuals with or without detectable rubella antibody the agreement between the new and the standard procedure was 96.4% for the PHA and 98.1% for the IF test. In rubella patients with serologic confirmation by HI, the IF test detected significant rises in 219 (99.1%) of 221 patients and the PHA test detected antibody conversion in 68 (93%) of 73 patients. In some circumstances the PHA or the IF test may facilitate a presumptive or definitive diagnosis. Absence of PHA reactions in single sera from patients with HI antibody was often (41% of such cases) an early indication of current rubella infection. IF antibody increased more gradually than HI antibody in rubella patients, and diagnostic IF titer rises were observed in several cases when HI titers had reached a plateau.

Viral antibody in the cerebrospinal fluid of patients with acute central nervous system infections.

Cerebrospinal fluid (CSF) and sera from 129 patients of a study population of 139 were tested for antibody to herpes simplex, measles,and mumps viruses. Herpes simplex virus antibody was found in three of five patients with laboratory-confirmed herpes simplex infection and in eight patients without serological or virological evidence of current infection with this or other common neurotropic visuses. Eleven of the 139 patients were studied for antibody to lymphocytic choriomeningitis (LCM) virus. Eight of these had laboratory-confirmed LCM infection, and antibody was detected in the CSF of five of them. In one of these five, complement-fixing antibody appeared earlier in the CSF than in the blood. Assay of LCM virus antibody in the CSF may thus indicate infection with LCM virus more rapidly than serological and virological studies. The diagnostic and the possible prognostic significance of herpes simplex visus antibody in CSF remains to be ascertained.

Lymphocytic choriomeningitis virus in man. Serologic evidence of association with pet hamsters;.

Laboratory evidence of recent or current lymphocytic choriomeningitis (LCM) virus infection was obtained in 60 patients. Twelve had diagnosis of central nervous system (CNS) infection: four of meningoencephalitis and eight of meningitis. Thirty-four patients had a grippe-like syndrome. Fifty-nine had had contact with pet hamsters. All of the 24 patients whose pets were studied had been exposed to one or more hamsters with serologic evidence of past LCM virus infection. The data implicate pet hamsters as a source of LCM in man. A continuous effective control of LCM virus in pet hamsters appears impractical. At present, the only feasible way to prevent further cases is the physician's special attention to the possibility of rodent contacts of patients with CNS disease and early laboratory confirmation of suspected cases of human LCM virus infections.