Effects of antigen dose and immunization regimens on antibody responses to a cytomegalovirus glycoprotein B subunit vaccine.

The purpose of this phase I study was to evaluate the safety and immunogenicity of 2 doses of cytomegalovirus glycoprotein B (CMV gB)/MF59 vaccine at 3 different immunization schedules. Ninety-five volunteers were randomized to 6 groups. Antibodies to gB represent the majority of the CMV-specific neutralizing response. Three groups received 5 microgram of gB antigen combined with MF59 (a proprietary adjuvant) and 3 groups received a 30-microgram dose at 0, 1, and 2 months; 0, 1, and 4 months; or 0, 1, and 6 months. The vaccine was well tolerated, and there was no significant difference in antibody production between the 2 doses. The vaccine induced highest antibody titers when given at 0, 1, and 6 months. A low dose of CMV gB/MF59 may be the preferred dose for future studies.

Rhodesian trypanosomiasis in a splenectomized patient.

We report the first apparent case of a splenectomized individual who developed severe trypanosomiasis with central nervous system involvement. The patient was a 41-year-old man who participated in an east African safari. Upon his return to the United States, the patient presented with an infection with Trypanosoma brucei rhodesiense that was treated successfully with suramin and melarsoprol. The onset of symptoms, laboratory studies, and disease progression did not differ from previously reported cases in the literature. The role of the spleen in trypanosomiasis is not well understood and the few reports available describe only animal models. This report suggests that asplenia had no apparent effect on the onset of symptoms and overall severity of illness. Further studies are necessary to ultimately define the role of the spleen in trypanosomiasis.

Colonization with penicillin-nonsusceptible Streptococcus pneumoniae in urban and rural child-care centers.

OBJECTIVES: To determine the prevalence of penicillin-nonsusceptible Streptococcus pneumoniae (NS-SP) at 12 child-care centers (CCC) in urban and rural Nebraska and to evaluate the genetic diversity of pneumococcal strains present in the CCC environment. METHODS: Nasopharyngeal cultures for S. pneumoniae were obtained from children 2 to 24 months old. Capsular serotyping, pulsed field gel electrophoresis (PFGE) and microbroth dilution MICs were performed for all S. pneumoniae. Antibiotic exposure was also evaluated as a potential risk factor for colonization with NS-SP. RESULTS: Nasopharyngeal colonization with S. pneumoniae was present in 121 (56%) of 215 children. The MICs of penicillin were 0.12 to 1.0 microgram/ml for 57 (47%) and > 1.0 microgram/ml for 10 (8%) isolates. Clindamycin MICs of > 0.5 microgram/ml were found in 6 isolates (5%). MICs of ceftriaxone were 0.5 microgram/ml in 28% of S. pneumoniae and 1.0 microgram/ml in 7%. PFGE and capsular serotyping demonstrated multiple strains that were penicillin-nonsusceptible in both the urban and rural CCC. PFGE and capsular serotype defined shared strains within each CCC, but some PFGE "types" could be found in multiple serotypes. Antibiotic exposure during the 2 months before nasopharyngeal culture was not a statistically significant risk factor for nasopharyngeal colonization with NS-SP. CONCLUSIONS: NS-SP are highly prevalent in urban and rural Nebraska. PFGE similarities between serotypes may reflect "serotype switching" but may also reflect genetic similarity between S. pneumoniae strains.

Colonization with penicillin-resistant Streptococcus pneumoniae in a child-care center.

We obtained nasopharyngeal cultures for Streptococcus pneumoniae from 54 children ages 2 to 24 months attending an Omaha child-care center (CCC) in April 1994. Thirty-two (59%) of the 54 children were colonized with S. pneumoniae belonging to serotypes 23, 19, 6 and 11. Seventeen (53%) of the pneumococcal isolates were highly resistant to penicillin (minimal inhibitory concentration > or = 2.0 micrograms/ml; HR-SP) and 7 (22%) were intermediately resistant to penicillin (0.12 < or = minimal inhibitory concentration < or = 1.0 microgram/ml; IR-SP). Within each pneumococcal capsular serotype, there were 1 to 3 DNA subtypes based on pulsed field gel electrophoresis analysis. A single pulsed field gel electrophoresis strain predominated in most CCC rooms, suggesting horizontal transmission among cohorted children. Nasopharyngeal cultures obtained 4 months later revealed similar S. pneumoniae colonization rates (28 of 52, 54%); however, only 2 (7%) of 28 isolates were HR-SP and 11 (39%) were IR-SP. Colonization with resistant pneumococci persisted after 4 months in 4 (12%) of 34 children cultured on both occasions. Antibiotic use by attendees had decreased notably between the two sampling periods, suggesting that selective pressure within the CCC might contribute to seasonal variation in colonization rates with HR-SP and IR-SP. We conclude that multiple genetic clones of penicillin-resistant pneumococci can occur simultaneously in a single CCC, especially during periods of heavy antibiotic selection pressure. However, individual clones of penicillin-resistant S. pneumoniae may be spread from child to child, suggesting that colonization with penicillin-resistant S. pneumoniae should now be considered a CCC-associated phenomenon.

Fluconazole-resistant Candida albicans.

Mucocutaneous candidiasis caused by Candida albicans is a common complication of human immunodeficiency virus (HIV) infection. Recent reports of isolation of resistant strains of C. albicans raise the specter of more widespread resistance, but limited series are available to analyze situations in which the likelihood of resistance is greatest. We present our experience with fluconazole-resistant candidiasis in patients with HIV infection obtained from retrospective chart review and by testing strains of C. albicans isolated during relapse for susceptibility to antifungal agents. The possible reasons for failure of antifungal therapy are discussed, as well the correlation between in vivo and in vitro data. Resistant candidiasis in patients with HIV disease is an emerging problem of considerable concern that merits further study.

Treatment of Strongyloides stercoralis hyperinfection syndrome with thiabendazole administered per rectum.

There is a rising interest in Strongyloides stercoralis infection due to the expanding population of immunosuppressed patients. Currently the drug of choice for both enteric and tissue forms of infection with this organism is oral thiabendazole. We report a patient with a small bowel obstruction due to S. stercoralis hyperinfection who was unable to take thiabendazole orally. Thiabendazole was administered rectally, and the hyperinfection syndrome resolved. Peak serum concentrations of thiabendazole were achieved 4 hours after rectal administration, and drug levels were sustained longer than previously reported with oral dosing. In addition, elevated levels of thiabendazole metabolites in the patient's urine further confirmed significant absorption. Rectal administration of thiabendazole should be considered for patients unable to take the medication orally.