Harold Russell

Evaluation of sera from patients with Lyme disease in the fluorescent treponemal antibody-absorption test for syphilis

To determine whether the cross-reactivity between Treponema pallidum and Borrelia burgdorferi affects the specificity of the fluorescent treponemal antibody-absorption (FTA-Abs) test for syphilis, sera from patients with Lyme disease or syphilis were examined in a quantitative FTA-Abs test. Sera were diluted serially in phosphate-buffered saline, then in sorbent, and were tested with T. pallidum and B. burgdorferi antigens. Nine of 40 sera from patients with known Lyme disease were reactive at the 1:5 dilution with antigen from T. pallidum; only one serum was reactive at the 1:10 dilution. When both antigens were tested, the titer against B. burgdorferi was always higher than that against T. pallidum. Similarly, sera from patients with syphilis showed cross-reactivity with B. burgdorferi. Although reactivity could be absorbed with Treponemal phagedenis (Reiter strain), simultaneous titration with both antigens was easily performed and designated the etiologic agent.

The Geographic Distribution of Lyme Disease in the United States

In 1982, national surveillance for Lyme disease was established by the Centers for Disease Control to monitor trends and determine endemic geographic areas. Initially, the endemic areas corresponded to the known distribution of Ixodes dammini, a five-state area of the northeastern seaboard (New York, New Jersey, Connecticut, Rhode Island, and Massachusetts) and Wisconsin and Minnesota. Increasing numbers of cases have been reported outside these areas, however, 86% of the provisional 5731 cases reported to CDC were acquired in these seven states. The number of reported cases increased from 491 in 1982 to approximately 1500 per year in 1984-1986, making Lyme disease the most commonly reported tick-borne illness in the United States. The apparently widening distribution of Lyme disease indicates that physicians in all regions of the country should be familiar with its signs and symptoms. Investigations of the vector in areas endemic for Lyme disease where Ixodes ticks are not found are warranted.

Distinguishing Chlamydia species by restriction analysis of the major outer membrane protein gene

Clinical isolates of Chlamydia pneumoniae from diverse geographic locations and strains of other Chlamydia species were typed by polymerase chain reaction (PCR) amplification of the major outer membrane protein (MOMP) gene followed by restriction fragment length polymorphism analysis of the product. Use of synthetic primers corresponding to highly conserved regions of the MOMP gene resulted in amplification of a 1070 bp product in laboratory strains and clinical isolates of C. pneumoniae, C. trachomatis and C. psittaci. PCR products were digested with restriction enzymes Alu I and Mbo I and separated by polyacrylamide gel electrophoresis. Restriction fragment patterns varied in length from 8-12 bands of 30-400 bp in size in Alu I digests, and 6-7 bands of 50-400 bp in size in Mbo I digests. Strains representing different chlamydia species were easily distinguishable by this method, as were different serovars of C. trachomatis. Strains of C. pneumoniae tested include laboratory strain TW-183 and recent clinical isolates from Atlanta, Brooklyn, Wisconsin and Norway. One combination of primers reacted with C. psittaci strains and C. pneumoniae strain TW-183, but not with other strains of C. pneumoniae tested regardless of the concentration of DNA in the sample. With use of a pan-reactive primer combination, however, restriction patterns were similar in all strains of C. pneumoniae tested. This gene typing technique can be valuable for distinguishing the three chlamydial species and potentially strains of C. pneumoniae in clinical and epidemiologic studies.

Comparison of a Pneumococcal Common Protein (PsaA) Antibody ELISA and a PsaA Immune Complex ELISA for Detection of Pneumococcal Serum Antibody

We examined and compared results from three assays, an enzyme-linked immunosorbent assay (ELISA) and two immune complex ELISAs for analysis of the serum antibody response to a native pneumococcal 37-kD common cell-wall protein by using acute- and convalescent-phase sera from 56 patients with community-acquired pneumonia. The sensitivities of the ELISA, the undissociated and dissociated immune complex assays were 85% (23 of 27), 78% (21 of 27) and 67% (18 of 27), respectively. To determine specificity, paired sera from patients with pneumonia of other bacterial etiologies were tested. The specificities were 83, 83 and 72% for the ELISA, undissociated immune complex, and dissociated immune complex, respectively. Based on this study, the sensitivities of the three assays were not statistically different. These tests could be used retrospectively to confirm invasive pneumococcal disease.

Tetanus immunity in emergency department patients

Demographic data and blood samples were collected from 278 patients seen at two District of Columbia emergency departments, and tetanus antitoxin assays by hemagglutination were performed at the Centers for Disease Control. Twenty-seven patients (10%) had antibody levels below the 0.01 U/mL considered protective. Four demographic characteristics were different in the patients with inadequate immunity (in decreasing order of significance): advanced age, fewer years of education, female sex, and non-US origin. Fourteen of the inadequately immunized patients were over 70 years of age. Of the 84 patients who reported their immunization histories, five reported no complete series of tetanus shots but had adequate antibody levels, while three reported a complete series but had inadequate levels. Twenty-two patients with inadequate immunity were not offered immunization in the emergency department because they did not have wounds. Patient recall of immunization history is not a reliable guide to tetanus immunization in the emergency department, but patients in certain demographic groups, such as older women, are more likely to have inadequate immunity.

Epidemiology of Lyme Disease in Virginia

Prior to January 1986, only one case of Lyme disease was reported from Virginia. In 1986-87, however, the Virginia Department of Health observed an increase in reports of suspected Lyme disease by physicians, despite the fact that Ixodes dammini is not highly prevalent in the Virginia tick population. Twenty-eight cases of Lyme disease were identified in Virginia, of which eight cases occurred in 1986 and 20 in 1987. Lyme disease appears to be increasing in frequency in Virginia and moving southward along the Eastern Atlantic Seaboard.