PubMed Health⌕ Search

Biomedical subjects

E A Engels

Publications and source records attributed to E A Engels.

31 records · Page 2Linked to original sources
PubMed2000

Vaccines for preventing typhoid fever.

BACKGROUND: Whole cell vaccines, consisting of relatively crude preparations of Salmonella typhi administered parenterally, are effective but have a high incidence of adverse effects. Two vaccines have been developed more recently. Ty21a (an attenuated strain of S. typhi administered orally) and Vi (the purified bacterial capsule, given parenterally), have appeared less toxic than the older whole cell vaccines and are thought to be equally effective. OBJECTIVES: The objective of this review was to assess the effects of typhoid fever vaccines. SEARCH STRATEGY: We searched the Cochrane Library, Medline, Index Medicus, Embase and reference lists of articles. SELECTION CRITERIA: Randomised trials comparing typhoid vaccines to other types of vaccine or placebo. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial quality and extracted data. MAIN RESULTS: Seventeen studies, involving nearly two million people, were included. For the whole cell vaccines single dose regimens provided significant protection for the first two years. Two dose regimens provided significant protection for five years. For the Ty21a vaccine, both two and three dose regimens provided statistically significant protection for two years. The three dose regimen provided protection in the third and fourth years, but protection was not statistically significant in the fifth year. The Vi vaccine provided protection for two years, but the protection in the third year was not significant. The three year cumulative efficacy of two doses of whole cell vaccines was 73% (95% confidence interval 65-80), three doses of Ty21a was 51%, (95% confidence interval 35 to 63) and one dose of Vi was 55% (95% confidence interval 30 to 71). Data on adverse effects were limited, but indicate that whole cell vaccines are more toxic than the newer Ty21a and Vi vaccines. REVIEWER'S CONCLUSIONS: The whole cell vaccines provided more prolonged protection than either the Ty21a vaccine or the Vi vaccine. However whole cell vaccines are associated with higher toxicity.

Adolescent↗
PubMed2000

Meta-analysis of diagnostic tests for acute sinusitis.

To facilitate management of acute sinusitis, we conducted a meta-analysis of published studies comparing diagnostic tests for this disorder. Thirteen studies were identified through literature search. Based on sinus puncture/aspiration (considered most accurate), 49-83% of symptomatic patients had acute sinusitis. Compared with puncture/aspiration, radiography offered moderate ability to diagnose sinusitis (summary receiver operator curve [SROC] area, 0.83). Using sinus opacity or fluid as the criterion for sinusitis, radiography had sensitivity of 0.73 and specificity of 0.80. Studies evaluating ultrasonography revealed substantial variation in test performance. The clinical evaluation, particularly risk scores formally incorporating history and physical examination findings, had moderate ability to identify patients with positive radiographs (SROC area, 0.74). Many studies were of poor quality, with inadequately described test methods and unblinded test interpretation. In conclusion, acute sinusitis is common among symptomatic patients. Radiography and clinical evaluation (especially risk scores) appear to provide useful information for diagnosis of sinusitis.

Acute Disease↗
PubMed1999

Plasma HIV viral load in patients with hemophilia and late-stage HIV disease: a measure of current immune suppression. Multicenter Hemophilia Cohort Study.

BACKGROUND: For patients infected with HIV, plasma HIV viral load in early disease predicts long-term prognosis. However, the implications of viral load measurements late in HIV disease are uncertain. OBJECTIVE: To evaluate the relation between plasma HIV viral load and subsequent risk for disease progression in patients with late-stage HIV disease. DESIGN: Retrospective cohort study. SETTING: 16 treatment centers for patients with hemophilia. PATIENTS: 389 patients with hemophilia and late-stage HIV disease (CD4 count < 200 cells/mm3). MEASUREMENTS: Plasma HIV viral load was measured at baseline. Patients were followed for AIDS-related illnesses (primary outcome) and, specifically, Pneumocystis carinii pneumonia (secondary outcome). RESULTS: HIV viral load strongly predicted AIDS-related illness. For patients with viral loads less than 4.00 log10 copies/mL, the 1-year actuarial risk was 0% and the 5-year risk was 25%. For patients with viral loads of at least 6.00 log10 copies/mL, the 1-year actuarial risk was 42% and the 5-year risk was 78%. A linear relation existed between viral load and risk for AIDS-related illness (hazard ratio, 2.37 per 1og10 copies/mL; P < 0.001). In addition, viral load most strongly predicted risk for illness immediately after viral load testing; this predictive relation attenuated over time (P = 0.002). These findings changed little after adjustment for CD4 cell counts that were updated during follow-up. In the first year after viral load was measured, it predicted occurrence of P. carinii pneumonia (hazard ratio, 4.69 per 1og10 copies/mL; P < 0.001). CONCLUSIONS: In patients with hemophilia and late-stage HIV disease, viral load predicts disease progression independently of CD4 cell counts. Because viral load most strongly predicts progression immediately after load is measured, it seems to reflect the current level of immunosuppression.

AIDS-Related Opportunistic Infections↗
PubMed1999

Zoster incidence in human immunodeficiency virus-infected hemophiliacs and homosexual men, 1984-1997. District of Columbia Gay Cohort Study. Multicenter Hemophilia Cohort Study.

Zoster is an important clinical problem for human immunodeficiency virus type 1 (HIV)-infected patients. Risk factors for zoster and trends in incidence in HIV-infected hemophiliacs and homosexual men (n=1218) were examined. From 1984 to 1997, 174 zoster cases were identified (average yearly incidence, 2.5%). Prior zoster episodes were associated with increased risk for a subsequent episode (relative risk [RR], 4.30; 95% confidence interval [CI], 3.11-5.95). Among hemophiliacs, children and adolescents had the highest zoster risk, and zoster risk declined with age (RR, 0.80 per decade; 95% CI, 0.68-0.93). These findings suggest that HIV-infected persons do not produce or maintain adequate booster responses after varicella zoster virus exposure. Zoster risk was relatively constant when CD4 cell counts >200 cells/mm3 but increased steeply below this level. During the 14 years of follow-up, zoster incidence declined 9% per year. This trend occurred despite decreasing CD4 cell counts and was unexplained by zidovudine or acyclovir use.

Adolescent↗
PubMed1999

Early infection in bone marrow transplantation: quantitative study of clinical factors that affect risk.

Infections remain common life-threatening complications of bone marrow transplantation. To examine clinical factors that affect infection risk, we retrospectively studied patients who received bone marrow transplants (53 autologous and 51 allogeneic). Over a median of 27 hospital days, 44 patients developed documented infections. Both autologous transplantation and hematopoietic growth factor use were associated with less prolonged neutropenia and decreased occurrence of infection (P < or = .05). In a survival regression model, variables independently associated with infection risk were the log10 of the neutrophil count (hazard ratio [HR], 0.49; 95% confidence interval [CI], 0.32-0.75), ciprofloxacin prophylaxis (HR, 0.42; 95% CI, 0.19-0.95), empirical intravenous antibiotic use (HR, 0.09; 95% CI, 0.03-0.32), and an interaction between neutrophil count and intravenous antibiotic use (HR, 1.86; 95% CI, 1.06-3.29). In this model, infection risk increases steeply at low neutrophil counts for patients receiving no antibiotic therapy. Ciprofloxacin prophylaxis and particularly intravenous antibiotic therapy provide substantial protection at low neutrophil counts. These results can be used to model management strategies for transplant recipients.

Adult↗
PubMed1998

Typhoid fever vaccines: a meta-analysis of studies on efficacy and toxicity.

OBJECTIVE: To estimate the efficacy and toxicity of typhoid fever vaccines. DESIGN: Meta-analysis of randomised efficacy trials and both randomised and non-randomised toxicity studies of the parenteral whole cell, oral Ty21a, and parenteral Vi vaccines. SUBJECTS: 1,866,951 subjects in 17 efficacy trials; 11,204 subjects in 20 toxicity studies. MAIN OUTCOME MEASURES: Pooled estimates of three year cumulative efficacy, year specific efficacy, and incidence of adverse events. RESULTS: Three year cumulative efficacy was 73% (95% confidence interval 65% to 80%) for two doses of whole cell vaccines (based on seven trials); 51% (35% to 63%) for three doses of Ty21a vaccine (four trials); and 55% (30% to 71%) for one dose of Vi vaccine (one trial). For whole cell and Ty21a vaccines, regimens of fewer doses were less effective. Efficacy was shown to be significant for five years for whole cell vaccines, four years for Ty21a vaccine, and two years for Vi vaccine. Neither the age of vaccine recipient nor the incidence of typhoid fever in the control group (varying from 6 to 810 cases per 100,000 person years) affected the efficacy of the whole cell or Ty21a vaccines. After vaccination, fever occurred in 15.7% (11.5% to 21.2%) of whole cell vaccine recipients, 2.0% (0.7% to 5.3%) of Ty21a vaccine recipients, and 1.1% (0.1% to 12.3%) of Vi vaccine recipients. CONCLUSIONS: Whole cell vaccines are more effective than the Ty21a and Vi vaccines but are more frequently associated with adverse events. Whether the added efficacy of the whole cell vaccines outweighs their toxicity will depend on the setting in which vaccination is used.

Administration, Oral↗
PubMed1998

Efficacy of quinolone prophylaxis in neutropenic cancer patients: a meta-analysis.

PURPOSE: To perform a meta-analysis to estimate the efficacy of quinolone antibiotics in preventing infections, fevers, and deaths among cancer patients neutropenic following chemotherapy. METHODS: We searched MEDLINE to identify randomized trials of quinolone prophylaxis, controlled either with no prophylaxis or trimethoprim/sulfamethoxazole (TMS) prophylaxis. We pooled relative risks for outcomes using a random-effects model. RESULTS: Eighteen trials with 1,408 subjects were included. Compared with no prophylaxis, quinolones significantly reduced the incidence of gram-negative bacterial infections (relative risk, 0.21; 95% confidence interval [CI], 0.12 to 0.37), microbiologically documented infections (0.65; 0.50 to 0.85), total infections (0.54; 0.31 to 0.95), and fevers (0.85; 0.73 to 0.99). Quinolone prophylaxis did not alter the incidence of gram-positive bacterial, fungal, or clinically documented infections, or infection-related deaths. Results were similar for trials that used TMS as the control regimen. Among those who received quinolones, the incidence of infections due to quinolone-resistant organisms was 3.0% (95% CI, 1.7% to 5.2%) for gram-negative species and 9.4% (95% CI, 5.3% to 16.3%) for gram-positive species. Based on limited data, the incidence of quinolone-resistant infections was not higher among quinolone recipients than controls. With fever as outcome, blinded trials found quinolones less efficacious than did unblinded trials. CONCLUSION: Quinolone prophylaxis substantially reduces the incidence of various infection-related outcomes, but not deaths, in these patients. Although this reduction in infections may translate into a decrease in morbidity, the reduction in fevers (and by extension, use of empiric antibiotics) appears small, and blinded trials provided less evidence for benefit than unblinded trials. Quinolone-resistant infections are uncommon, but continued vigilance is warranted.

Anti-Infective Agents↗