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M de la Rosa

Publications and source records attributed to M de la Rosa.

At least 19 recordsLinked to original sources
PubMed2000

Surgical site infections at the National Cancer Institute in Mexico: a case-control study.

OBJECTIVES: To quantify the surgical infection rate and to identify risk factors associated with surgical site infection. METHODS: We conducted a case-control study of all surgical patients between January 1, 1993, and June 30, 1994. The frequency of surgical site infection per 100 surgeries was calculated. The odds ratio (OR) was estimated by using logistic regression analysis. SETTING: A 130-bed tertiary-care teaching hospital for adult patients with cancer. RESULTS: The study followed 3372 surgeries. Three hundred thirteen patients had a surgical site infection (rate per 100 surgeries: 9. 30). The risk factors associated with surgical site infection were diabetes mellitus (OR = 2.5, 95% confidence interval [CI] = 1.27-4. 91), obesity (OR = 1.76, 95% CI = 1.14-2.7), presence of surgical drains for >5 and <16 days (OR = 1.84, 95% CI = 1.02-3.31), and presence of surgical drains for >/=16 days (OR = 2.14, 95% CI = 1. 0-4.6). The bacteria most frequently isolated were Escherichia coli 38 (21.8% of the total of microorganisms found), Pseudomonas sp 22 (12.6%), Staphylococcus aureus 16 (9.2%), and coagulase-negative Staphylococcus 25 (13.6%). The coexistence of other nosocomial infections was greater among the cases (OR = 1.8, 95% CI = 1.1-3.1) than in the control group. CONCLUSIONS: The surgical site infection rate in our hospital is slightly higher than the rates reported for general hospitals. The risk factors associated with surgical site infection are similar to those previously reported. Diabetes mellitus, obesity, and prolonged presence of a surgical drain increased the risk of infection.

Adult↗
PubMed2000

[Simplified method for the processing of sputum in the diagnosis of tuberculosis].

OBJECTIVE: We evaluated a simplified method for processing three serial sputum samples as a single sample, and compare the results with those obtained when processing three samples individually. MATERIAL AND METHODS: During a 32-week period, we studied 867 sputum samples from 289 patients with pulmonary tuberculosis suspicious. Samples from 148 patients (n = 444) were processed by simplified method, and samples from 141 patients (n = 423) were processed by individually method. All cultures were processed by ESP Culture System II (Difco Laboratories, USA). RESULTS: Seven mycobacterium's strains were isolated by individually method. Simplified method detected another seven strains. In both cases, four strains were identified as Mycobacterium tuberculosis. Mean time to detection mycobacteria were 21.5 and 24 days for simplified and individually method, respectively. Cultures from 21 patients were contaminated (11 patients by simplified method and 10 patients by individually method). Mean time to detection contaminated cultures were 8 days and 7.5 days for simplified and individually method, respectively. CONCLUSION: Simplified method may be a useful alternative in laboratories that must handle increasing numbers of samples, without decline in diagnostic performance.

Bacteriological Techniques↗
PubMed1999

[Surveillance of surgical wound infections. 18-month experience in the Instituto Nacional de Cancerología].

OBJECTIVE: To calculate the surgical site infection (SSI) rates with a surgical prospective surveillance program and postdischarge follow-up. MATERIAL AND METHODS: During a 18 months period (01/01/93 to 04/30/94), a surgical wound surveillance program followed on the surgeries practiced at the National Institute of Cancerology, a referral center situated in Mexico City. Rates per 100 surgeries were calculated for the surgical services and for each of the wound class strata. The SS's were classified according to the 1992 Center for Disease Control definitions for surgical infections. RESULTS: Three thousand, three hundred and severity-two surgeries were assessed; 313 were diagnosed as infected: 140 (44.7%) were superficial incisional, 137 (43.7%) were deep incisional and 36 (11.5%) were organ and space infections. The SSI rate for this period was 9.28%; for the clean, clean-contaminated, contaminated and dirty surgeries the rates were 7.35, 10.5, 17.3 and 21.5% respectively. The rates for each service were: gastroenterology, 14.13%; breast tumors, 11.08%; mixed tumors, 10.98%; gynecology, 9.06%; urology, 7.38%; head and neck, 7.13%, and thoracic surgery, 1.81%. On average SSI were detected at 11.6 +/- 6.23 days, eighty-five (27.16%) were diagnosed while the patient was in-hospital, the remaining 228 (72.84%) were detected after discharge. In 134 (42.8%) patients a culture was obtained. The bacteria most frequently found were: E. coli, 38 (22.5%); coagulase negative Staphylococci, 23 (13.6%); Pseudomonas sp., 22 (13%); S. aureus, 16 (9.4%); and Enterococcus, 13 (7.7%). CONCLUSIONS: The prospective surveillance program with a follow-up for 30 days increased by 400% the chance to identify a SSI. The SSI rate for clean and clean-contaminated surgeries are above the rates reported in the literature.

Bacteria↗
PubMed1999

[Toxoplasma gondii infection in Amerindians of Venezuelan Amazon].

We conducted a serological survey for Toxoplasma gondii in 121 Amerindians of the Guajibo ethnic group, 4 to 45 years of age, inhabiting Amazonas State, in the Venezuelan rain forest. The overall prevalence was 88%. Pattern of prevalence and antibody titres were compatible with constant transmission. Sex differences in antibody prevalence were not detected but antibody titres were significantly higher in females. The study is consistent with the presence of risk factors, which favour a frequent exposure of these Amerindians to T. gondii since childhood.

Adolescent↗
PubMed1998

Effect of the addition of vancomycin on the performance of an automated nonradioactive system for detection of mycobacteria.

A recently developed automated, nonradioactive system for the detection of mycobacteria (MB/BacT; Organon Teknika, Belgium) has provided good results, but the contamination rate was found to be higher than that obtained with the radiometric Bactec 460 system (Becton Dickinson, USA). In the present study, the effects of adding vancomycin (1 microg/ml) to the antibiotic mixture of the nonradioactive system were evaluated, and the performance of the system with versus without vancomycin was compared. Three hundred sputum samples were tested, using the radiometric system as the reference method. Mycobacteria were isolated from 47 (15.7%) samples. The nonradioactive system with and without vancomycin detected 42 and 43 strains, respectively; the time to detection was 1 day shorter with the medium without vancomycin (15.7 days vs. 14.3 days). The radiometric system detected 42 strains of mycobacteria in a mean detection time of 13.6 days. Contamination rates with the nonradioactive system were 6.7% in the medium without vancomycin and 2.7% in the medium with vancomycin. The latter figure was approximately the same as the contamination rate found with the radiometric system (2.3%). Our data suggest that the addition of vancomycin considerably reduces the number of contaminants in the MB/BacT medium without affecting the performance of the system.

Bacteriological Techniques↗
PubMed1995

Plasmodium vivax: detection of blood parasites using fluorochrome labelled monoclonal antibodies.

A monoclonal antibody (MoAb) 2C6111 specific for Plasmodium vivax erythrocytic stages was shown to detect parasitized erythrocytes in blood samples collected in the field. This MoAb binds to the mature trophozoite, schizont and gametes of P. vivax and upon examination of 43 wild isolates no evidence of polymorphism was found. To search for P. vivax parasites in human blood a MoAb immunofluorescent test (MoAb-IFT) was developed. The assay is based on the ability of fluorescein isothiocyanate labelled MoAb 2C6111 to combine with parasitized erythrocytes on thin blood smears. A preliminary field trial was carried out in Venezuela to determine the usefulness of MoAb-IFT for the specific diagnosis of P. vivax malaria. Blood samples collected from malarious and non-malarious individuals were examined both by standard microscopy of Giemsa stained thick blood smears (G-TS) and MoAb-IFT. The latter was specific and gave a 100% correlation with G-TS. Sensitivity was close to that usually achieved with Giemsa stained blood films.

Animals↗
PubMed1994

[Detection of Brucella with an automatic hemoculture system: Bact/Alert].

BACKGROUND: The ability of in vitro and in vivo detection of Brucella spp. with the Bact/Alert system was studied. METHODS: Three strains of Brucella melitensis and two of Brucella abortus were used. Different dilutions of the five strains were performed in trypticase soy broth (TSB), achieving concentrations of 1 cfu/ml, 5 cfu/ml, 10 cfu/ml and 100 cfu/ml. Ten ml of each dilution and strain were inoculated into 5 aerobic bottles Bact/Alert and 5 biphasic Hemóline bottles. Furthermore, over a 9 month period, 8,216 bottles of Bact/Alert bottles from hospitalized patients and from the emergency department were processed in the authors' laboratory. RESULTS: The mean detection time for Brucella growth was from 2 to 3 days with the Bact/Alert system, and 14 days in the biphasic bottles. Former bottles processed in the authors' laboratory, 11 aerobic bottles belonged to 5 patients in whom brucelosis was confirmed by bloodculture. The Bact/Alert system detected Brucella melitensis in only on bottle at 2.9 days of incubation. In 7 bottles Bact/Alert detected B. melitensis by a blind pass of these bottles at 10 to 20 days of incubation. CONCLUSIONS: These results suggest that the Bact/Alert system does not totally solve the diagnosis of brucellosis. Blind passes of the bloodcultures are required.

Bacteriological Techniques↗
PubMed1994

[Asymptomatic bacteriuria and pyuria during pregnancy].

BACKGROUND: The presence of pyuria and the role of mixed culture in the diagnosis of asymptomatic bacteriuria in pregnant women have been evaluated METHODS: One hundred and sixty four pregnant women without any symptomatology have been studied using two cultures of mid-stream urine samples and pyuria quantification. In addition culture of bladder urine has been carried out in 17 of these patients (12 with pure cultures and 5 with mixed cultures). RESULTS: 110 samples were culture negative without pyuria; 7 were pure cultures with pyuria; 19 pure culture without pyuria and the remaining 28 patients yielded mixed culture with or without pyuria in the first culture. Twenty of these 28 mixed cultures were negative in the second culture. A estimated frequency of asymptomatic bacteriuria in pregnancy was 16% and pyuria was only found in 27% of pregnant women with asymptomatic bacteriuria. CONCLUSION: The pyuria is not a useful marker for the diagnosis of asymptomatic bacteriuria in pregnancy.

Bacteria↗
PubMed1993

Posthysterectomy wound infection. A review.

We reviewed the microorganisms isolated from gynecologic surgery wounds showing signs of infection, from January to December 1990. A total of 88 samples of abdominal wall exudates from as many patients who had undergone abdominal hysterectomy were studied. In 54 women (61.3%), cultures were positive and, in 26 specimens (48.1%), mixed aerobic-anaerobic flora were isolated. In 28 cases (51.9%), a single microorganism was isolated, the most frequent being Staphylococcus aureus, followed by Mycoplasma hominis and Escherichia coli. Mycoplasma hominis was unexpectedly frequent, appearing in five women with wall abscess and fever.

Bacteria↗
PubMed1992

Evaluation of three rapid enzyme immunoassays and cell culture for detection of respiratory syncytial virus.

Three rapid enzyme immunoassay techniques for the detection of respiratory syncytial virus antigen (Becton Dickinson Directigen RSV, Abbott RSV Testpack and Abbott RSV EIA) and cell culture were evaluated in a total of 250 nasal washings. The sensitivity and specificity were 62% and 76% respectively for Directigen, 64% and 86% for RSV Testpack, and 76% and 81% for RSV EIA, taking cell culture as the reference method. Agreement between cell culture and EIA techniques was 79% (70 positive and 128 negative results). All three EIA techniques gave positive results in 69 samples (52 positive and 17 negative in the cell culture). In 121 samples all three EIA techniques gave negative results (103 negative and 18 positive in the cell culture). Using the cell culture technique 46 strains other than respiratory syncytial virus were isolated.

Animals↗
PubMed1992

New Granada Medium for detection and identification of group B streptococci.

A methotrexate-containing medium for the detection of beta-hemolytic group B streptococci from clinical specimens on the basis of detection of pigment is described. The medium contained peptone, starch, serum, MgSO4, glucose, pyruvate, methotrexate (as pigment enhancer), phosphate-morpholine-propanesulfonic acid buffer, and selective agents. The recovery of beta-hemolytic group B streptococci was comparable to that obtained with selective broth.

Bacteriological Techniques↗