Predictors of vaccination rates during a mass meningococcal vaccination program on a college campus.

Factors contributing to students' compliance with mass vaccination programs during meningococcal outbreaks have not been well described. A 1997 mass vaccination campaign at Michigan State University provided an opportunity to study such factors. Of 34,024 students in the target population, 17,538 (51.5%) were vaccinated in 5 days. Vaccination rates were higher for women (47.9%) than for men (43.1%) and higher for on-campus residents (65.3%) than for off-campus residents (35.6%). For each year of students' age beyond 19, the adjusted odds of vaccination were reduced by 0.82. Adjusted odds ratios for vaccination, with White students as the reference group at 1.0, were 1.33 for Asian American students, 0.97 (not significant) for Hispanic students, 0.82 for African American students, and 0.80 for Native American students. Students from the Colleges of Business, Engineering, Communication, and Natural Science had the highest vaccination rates; those from the College of Arts and Letters had the lowest rates.

Newer oral antimicrobials for resistant respiratory tract pathogens. Which show the most promise?

As antimicrobial resistance to tried-and-true drugs continues to build, an arsenal of new drugs aimed at resistant respiratory tract pathogens is needed. Penicillin is now ineffective against several common pathogens, including many pneumococcal organisms. Newer antimicrobials, including macrolides, cephalosporins, and fluoroquinolones, have been developed to take its place. The authors of this article present a progress report of the fight against respiratory tract infection and an assessment of the most promising newer agents for use against multidrug-resistant pathogens.

Sparfloxacin: potential clinical and economic impact in the treatment of respiratory infections.

Sparfloxacin is a new oral fluoroquinolone antimicrobial that is highly active against common respiratory pathogens, including multiresistant strains. It is well absorbed and has excellent penetration into upper and lower respiratory tissues. Sparfloxacin is administered once a day and does not interfere with the metabolism of other drugs. The agent is highly effective and safe in the treatment of acute sinusitis, exacerbations of chronic bronchitis, and community-acquired pneumonia. Due to its activity against multidrug-resistant respiratory pathogens, it has the potential to prevent hospitalization as well as decrease parenteral antibiotic therapy. Consequently, it may generate significant pharmacoeconomic benefits to patients and payers of medical care.

Age-related hepatitis B seroconversion rates in health care workers.

BACKGROUND: Protective hepatitis titers are reported for more than 90% of healthy adults who received three intradeltoid injections of vaccine. Some factors that influence seroconversion rates include age, sex, and presence of chronic diseases. METHODS: Because of work-related factors that placed them at risk of acquiring hepatitis B, 112 employees, who ranged in age from 20 to 70 years with a mean age of 39.2 years, completed the hepatitis B vaccination series between 1986 and 1993. All participants received three vaccinations. RESULTS: Hepatitis B surface antibody did not develop in 16 of 112 recipients (14.2%, 95% CI, 7.6% to 20.8%). Race, sex, and duration to antibody titer did not affect rates of seroconversion. Age greater than 50 years was associated with significantly decreased seroconversion rates (64.7%, 95% CI, 42.0% to 87.4%) compared with seroconversion rates of those younger than 50 years of age (89.5%, 95% CI 83.3% to 95.7%, p = 0.02). CONCLUSIONS: Our results indicate that when a hepatitis B immunization program is implemented, seroconversion rates are lower than published rates for healthy adults and adolescents. We recommend that seroconversion data from immunization programs for employees at risk for hepatitis B be reviewed and that postimmunization testing be considered to ensure adequate protection for those employees at highest risk for nonconversion.

Disseminated histoplasmosis in a patient with sarcoidosis: a controversial relationship and a diagnostic dilemma.

The diagnosis of sarcoidosis in patients with disseminated histoplasmosis remains controversial. It has been suggested that the immune abnormalities in sarcoidosis predispose one to disseminated histoplasmosis. Two cases have been reported that indicate a possible relationship between the two diseases. This is a case of sarcoidosis complicated with disseminated histoplasmosis in which the controversial relationship between the two diseases is emphasized and the available medical literature is reviewed.

A preliminary study of clarithromycin versus doxycycline in the treatment of nongonococcal urethritis and mucopurulent cervicitis.

In a comparison of drug safety and efficacy, 40 adult outpatients with clinical signs and symptoms of nongonococcal urethritis or mucopurulent cervicitis were treated with either clarithromycin 250 mg or doxycycline 100 mg twice/day for 7 days. Clinical and laboratory evaluations were repeated during, at the end, and 3 weeks after the completion of therapy. Isolation and susceptibility tests of Chlamydia and Mycoplasma isolates were performed at each visit. All but one patient who received doxycycline were clinically cured or improved at the end of treatment. Two (10%) patients who received clarithromycin and three (15%) who received doxycycline had clinical relapses of the infection. All isolates of Chlamydia trachomatis were eradicated and did not recur in both groups. Doxycycline was more effective than clarithromycin in eradicating Ureaplasma urealyticum (p < 0.01). Both groups reported a high frequency of minor adverse effects, but no patient discontinued therapy. Overall, clarithromycin was clinically safe and effective treatment in patients with nongonococcal urethritis and mucopurulent cervicitis.

Legionella lansingensis sp. nov. isolated from a patient with pneumonia and underlying chronic lymphocytic leukemia.

A Legionella-like organism, strain 1677-MI-H, was isolated from the bronchoscopy washings of a patient with pneumonia who had a 2-year history of progressive, chronic lymphocytic leukemia. The growth characteristics, cellular fatty acids, and ubiquinone content of the isolate were consistent with those for Legionella spp. The isolate was serologically distinct in the slide agglutination test with absorbed antisera. DNA hybridization studies showed that strain 1677-MI-H (ATCC 49751) represents a new Legionella species which is named Legionella lansingensis.

The new macrolide antibiotics. Azithromycin and clarithromycin.

Azithromycin (Zithromax) and clarithromycin (Biaxin Filmtabs) are new macrolide antibiotics with several advantages over erythromycin. Azithromycin has an expanded spectrum against gram-negative bacilli. Clarithromycin is more active than erythromycin against gram-positive cocci; combination with its 14-hydroxy metabolite enhances its antimicrobial activity. These new agents penetrate well into tissues and concentrate in macrophages and polymorphonuclear leukocytes. They offer improved bioavailability and an extended half-life. The high tissue-to-serum level and extended elimination half-life of azithromycin allow for once-daily dosing and short-course therapy. Clarithromycin and 14-hydroxyclarithromycin maintain high serum levels and tissue-to-serum concentrations. Both of these new agents have been effective in streptococcal pharyngitis, acute sinusitis, acute lower respiratory tract infections, skin and soft-tissue infections, and sexually transmitted diseases. A single dose of azithromycin is effective for genital chlamydial infections. Adverse reactions to these agents have usually been mild and have not included serious organ toxicity. In clinical trials, the rate of premature discontinuation of therapy has been less than observed with erythromycin. Azithromycin and clarithromycin should be used according to the current guidelines of the Food and Drug Administration; their future role will be determined by ongoing laboratory and clinical evaluations.

High prevalence of historical risk factors for blood-borne infections among inpatients at three community hospitals.

To determine the prevalence of risk factors for blood-borne infections in a city with a low prevalence of human immunodeficiency virus (HIV), we confidentially surveyed 397 adult inpatients in three community hospitals. Twenty-one percent of inpatients reported one or more risk factors, 56% denied risks, 15% were unable to respond, and 8% declined to respond. Inpatients reporting a blood-borne infection risk factor, those declining response, and those denying risk were of comparable age, sex, race, and marital status. On medical floors, 28% of patients reported risk; on surgical floors, 23%; in intensive care units, 11%; and on obstetric floors, 5%. A recent blood transfusion (59%) and history of hepatitis (40%) were reported most often. Only 2.4% of persons with risks reported being positive for HIV antibody; however, 24% of reported risks were those frequently associated with HIV infection. By using history alone to determine isolation categories and by classifying patients unable to respond and those declining response as potentially infectious, more than 40% of our community's inpatients would require blood and body fluid precautions. This high historical risk supports use of a type of body substance isolation for all patients.

Comparison of chlamydial culture with Chlamydiazyme assay during erythromycin PCE treatment of Chlamydia genital infections.

We compared chlamydial culture with the chlamydial antigen detection enzyme immunoassay system (Chlamydiazyme, Abbott Diagnostic Products; Abbott Park, IL) during treatment of Chlamydia genital infections. Participants received 333 mg of erythromycin PCE (Abbott Laboratories; Abbott Park, IL) 3 times per day for 7 days. On days 0, 3, 7, and 14, chlamydial cultures were positive in 30/30 (100%), 5/29 (17.2%), 0/27, and 0/25 participants, respectively. Concurrent Chlamydiazyme assays were positive in 30/30 (100%), 11/30 (37%), 1/28 (4%), and 0/25 participants. Twenty-eight of 28 persons who received erythromycin PCE for at least 3 days had negative test results for both chlamydial culture and Chlamydiazyme at their last clinic visit. Chlamydiazyme assay tended to remain positive longer than chlamydial culture during treatment, but 7 days after therapy was completed, no Chlamydia trachomatis antigens were detectable by this assay. Erythromycin PCE was well tolerated and rapidly eliminated Chlamydia genital infections in 83% of persons showing negative cultures by the third day of therapy.

Comparison of ciprofloxacin and rifampicin in experimental Legionella pneumophila pneumonia.

We evaluated intraperitoneal ciprofloxacin and rifampicin alone and as combination therapy in experimentally induced Legionella pneumophila pneumonia in guinea pigs. Intraperitoneal treatment began 48 h after intratracheal inoculation of 3 X 10(6) L. pneumophila and consisted of sterile saline (0.3 ml bid), ciprofloxacin (30 mg/kg bid), rifampicin (10 mg/kg/bid), or ciprofloxacin plus rifampicin (same doses). Animals were treated for five days and survivors killed after 11 days. Quantitative lung cultures were done post mortem. Respective mean and median days of animal survival were increased by treatment with ciprofloxacin plus rifampicin (8.4 and 9.5 days), ciprofloxacin (8.2 and 7.5 days), or rifampicin (8.3 and 7.5 days), compared with controls (5.5 and 5.0 days). Compared with control animals (log rank test) survival was improved by treatment with ciprofloxacin plus rifampicin (P less than or equal to 0.047) ciprofloxacin (P less than or equal to 0.047) or rifampicin (P less than or equal to 0.047). Quantitative lung cultures (cfu/g) were also decreased by treatment with ciprofloxacin plus rifampicin (2.0 X 10(4)), ciprofloxacin (5.4 X 10(4)), or rifampicin (1.7 X 10(4)) compared with controls (3.2 X 10(8)). No differences in survival, quantitative lung cultures, or animal weights were noted between treatment groups. This study demonstrates that ciprofloxacin is as effective as rifampicin in the treatment of experimentally induced L. pneumophila pneumonia and that the combination of ciprofloxacin plus rifampicin has no advantages over single agent therapy in this model.

Effect of quinolones and other antimicrobial agents on cell-associated Legionella pneumophila.

We evaluated the in vitro susceptibility of Legionella pneumophila ATCC 33152 (serogroup I) to 13 antibiotics alone and in combination with rifampin (0.1 mg/liter) by three methods. Extracellular susceptibility was determined by MIC determinations and time kill curves in buffered yeast extract broth, while intracellular susceptibility was determined by peripheral human monocytes in RPMI 1640 culture medium. Antibiotic concentrations equal to or greater than the broth dilution MIC inhibited or killed L. pneumophila by the time kill method, except this was not the case for trimethoprim-sulfamethoxazole. Antibiotic concentrations below the broth dilution MIC did not inhibit Legionella growth. The only antibiotic-rifampin combinations which produced improved killing of L. pneumophila by the time kill method were those in which the logarithmic growth of L. pneumophila occurred during the experiment (rosoxacin, amifloxacin, cinoxacin, trimethoprim-sulfamethoxazole, clindamycin, and doxycycline). Neither direct MICs nor time kill curve assays accurately predicted intracellular L. pneumophila susceptibility. Rifampin, erythromycin, ciprofloxacin, rosoxacin, enoxacin, amifloxacin, gentamicin, clindamycin, and doxycycline all inhibited intracellular L. pneumophila growth at readily achievable concentrations in serum. Cefoxitin and thienamycin showed no inhibition of growth, although they were present extracellularly at concentrations that were 20 to 1,000 times their broth dilution MICs. Clindamycin was the only antibiotic that was able to inhibit intracellular L. pneumophila growth at an extracellular concentration below its MIC. The gentamicin (5 mg/liter)-rifampin combination was the only antibiotic-rifampin combination which demonstrated decreased cell-associated Legionella survival in this model of in vitro susceptibility.