Double-blind placebo-controlled randomized clinical trial evaluating doxycycline effects on chemotherapy-induced oral mucositis.

WHAT IS KNOWN AND OBJECTIVE: Chemotherapy (CT)-associated oral mucositis (OM) is one of the most debilitating and painful side effects in oncology patients, with limited effective management options. During CT, matrix metalloproteinases (MMPs) are upregulated, causing damage in mucosal and submucosal tissues, and playing a key role in OM; therefore, the use of subantimicrobial doxycycline as a MMP inhibitor may represent a potential approach for OM management. The aim of this clinical trial was to evaluate the efficacy and safety of low doses of doxycycline in OM development in individuals with acute leukaemia (AL) during CT. METHODS: Randomized controlled clinical trial (Registration No. NCT01087476) performed in adult AL patients scheduled to receive CT (September 2010-October 2014). Individuals were stratified by leukaemia type and assigned randomly to receive doxycycline hyclate (50 mg/d) (doxycycline group: DG) or placebo (placebo group: PG) before and during CT. Included subjects had a baseline oral examination and thereafter 3 times a week during 21 days. The primary outcome was OM development. RESULTS AND DISCUSSION: One hundred and forty-seven AL subjects were enrolled: 74 in DG and 73 in PG; baseline characteristics between groups were comparable. During follow-up, 15 (10.2%) individuals developed OM; no differences between treatment groups were found (DG:8.1%, PG:12.3%; P = .59). The mean OM Assessment Scale score was 2.51, without differences between groups (DG:2.7, PG:2.4; P = .65). Low baseline blood albumin levels in the OM-affected individuals were identified, revealing the effect of systemic deterioration as a predisposing factor for OM development. No adverse effects were observed. WHAT IS NEW AND CONCLUSION: Subantimicrobial doses of doxycycline did not reduce the incidence, onset, duration or severity of OM.

TNF as marker of oral candidiasis, HSV infection, and mucositis onset during chemotherapy in leukemia patients.

OBJECTIVE: To assess changes in the salivary expression of IL-1α, IL-1ß, IL-2, IL-6, IL-10, IL-17, and TNF in acute leukemia (AL) patients before and during chemotherapy, and its association with HSV infection, oral candidiasis (OC), and oral mucositis (OM) onset. METHODS: Cohort study in AL patients >15 years starting induction chemotherapy at a Mexican oncological center (2013-2014). Onset of oral lesions (OLs) was assessed during follow-up, and saliva was obtained at baseline, at visit 2 (days 4-12), and at visit 3 (days 13-21) after chemotherapy, treated with a protease inhibitor and stored at -70°C. An enzyme-linked immunosorbent assay was performed. Cox proportional hazards regression models were constructed to estimate hazard ratios and its 95% CI (HR, 95% CI) for OL development. RESULTS: Forty-one patients were followed up, and 17 (41.5%) developed OLs. OL patients had higher baseline salivary IL-1α than those without lesions (p = 0.040). During visit 2, OL patients had higher levels of IL-1α (p = 0.033), IL-1ß (p = 0.016), IL-6 (p = 0.035), and TNF (p = 0.019) than those who did not develop OLs. Patients with HSV infection, OC, and OM showed higher salivary TNF levels during follow-up (HR: 3.52, 95% CI: 1.35-9.14, p = 0.010). CONCLUSION: AL patients undergoing chemotherapy with high salivary TNF levels were more likely to develop HSV infection, OC, and OM.

Validity of height and weight self-report in Mexican adults: results from the national health and aging study.

BACKGROUND: An adequate nutritional status is essential for maintaining the independence in the elderly. The height and weight self-report is considered a useful alternative for the estimation of body mass index (BMI). The validity of the self-report is an issue that has not been dealt with in developing countries. AIM: To assess the validity of the height and weight self-report in adults Mexican citizens. DESIGN: Transversal study. STUDY POPULATION: 1707 persons (836 males, 871 females) were asked for their height and weight and were measured. RESULTS: Mean (+/- standard deviation) age was 59.09 +/- 9.86 SD; mean years of education was 5.51 +/-4.67 years. We found a high correlation between self-reported and measured weight (R2= 0.837); the difference between both values rose along with the age (from 0.4 kg to 1.74 kg). A systematic difference between self-reported and measured height was found. Self-reported height was over-estimated, and the bias increased along with the age of the subjects (from 1.57 cm to 2.57 cm); further, over-estimation was larger in female individuals (+2.22 cm in female vs. +1.21 cm in male subjects). We calculated a linear model that predicts real height from self-reported height with moderate, although statistically significant results (R2= 0.39 y 0.50, for female and male, respectively, p < 0.0001). Knee height was also used to estimate "adulthood height" and thus, BMI. This method showed age-related dissimilarities, and the linear regression model yielded an unacceptably low correlation (R2= <0.10). The best method to estimate real BMI was to consider self-reported parameters. DISCUSSION: Height and weight estimation using self-reported parameters is an acceptable method. Its precision is not so high in subjects > 75 years. Height over-estimation is an expected finding congruent with age-related corporal changes. The estimation of height using knee height is not a useful method. CONCLUSION: Height and weight self-report is a valid method that may be used to accurately estimate height and weight in Mexican people.

Tuberculosis and tuberculin quality: best intentions, misleading results.

OBJECTIVE: To compare the performance of three purified protein derivative (PPD) formulations: Tubersol (Connaught); RT23, Statens Serum Institut (SSI); and RT23, Mexico, tested in Mexican populations at low and high risk for tuberculosis (TB). DESIGN: A double-blinded clinical trial. SETTING: A university hospital in Mexico City. PARTICIPANTS: The low-risk population was first or second-year medical students with no patient contact; the high-risk population was healthcare workers at a university hospital. METHODS: Each of the study subjects received the three different PPD preparations. Risk factors for TB, including age, gender, occupation, bacille Calmette-Guérin (BCG) status, and TB exposure, were recorded. A 0.1-mL aliquot of each preparation was injected in the left and right forearms of volunteers using the Mantoux technique. Blind readings were done 48 to 72 hours later. Sensitivity and specificity were calculated at 10 mm of induration using Tubersol as the reference standard. The SSI tested the potency of the different PPD preparations in previously sensitized guinea pigs. RESULTS: The low-risk population had a prevalence of positive PPD of 26%. In the low-risk population, RT23 prepared in Mexico, compared to the 5 TU of Tubersol, had a sensitivity of 51%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 86%. The RT23 prepared at the SSI had a sensitivity of 69%, a specificity of 99%, a positive predictive value of 95%, and a negative predictive value of 90%. In the high-risk population, the prevalence of positive PPD was 57%. The RT23 prepared in Mexico had a sensitivity of 33%, a specificity of 100%, and a positive predictive value of 53%; the RT23 prepared at the SSI had a sensitivity of 91%, a specificity of 98%, a positive predictive value of 98%, and a negative predictive value of 89%. RT23 used in Mexico had a potency of only 23% of that of the control. There was no statistical association among those with a positive PPD, irrespective of previous BCG vaccination (relative risk, 0.97; 95% confidence interval, 0.76-1.3;P=.78). CONCLUSIONS: Healthcare workers had twice the prevalence of positive PPD compared to medical students. RT23 prepared in Mexico had a low sensitivity in both populations compared to 5 TU of Tubersol and RT23 prepared at the SSI. Previous BCG vaccination did not correlate with a positive PPD. Low potency of the RT23 preparation in Mexico was confirmed in guinea pigs. Best intentions in a TB program are not enough if they are not followed by high-quality control.

[An outbreak of Salmonella gastroenteritis among hospital workers]. / Brote por Salmonella enteritidis en trabajadores de un hospital.

OBJECTIVE: To describe and identify the causes of an outbreak of Salmonella enteritidis gastroenteritis that took place in June 1998, among tertiary care hospital workers, in Mexico City. MATERIAL AND METHODS: Cases were hospital workers who developed diarrhea or fever associated with gastrointestinal symptoms, after a meal at the hospital's dining room on June eight; controls were asymptomatic employees who also ate at the hospital's dining room on the same day. A food questionnaire was applied, and stool samples were obtained from all study subjects, including kitchen personnel. Blood cultures were practiced for febrile patients. Odds ratios with 95% confidence intervals (95% CI) and the chi-squared were used for statistical analysis. Statistical significance was set at p < 0.05. RESULTS: One-hundred-fifty-five workers developed symptoms, but only 129 (83.2%) answered the questionnaire; 150 controls were also studied. The most common symptoms were diarrhea (85%), abdominal pain (84%), cephalea (81.4%), nausea (78.3%), and chills (74.4%). Eight blood cultures were negative; 59 stool cultures (46%) from cases and six (4%) from controls, were positive for Salmonella enteritidis. Egg-covered meat was the suspected source of infection (OR 19.39, 95% CI 9.09-41.4); some other foodstuffs like fruit dessert and yogurt, were significantly more frequent in cases than in controls. Food cultures were all negative. CONCLUSION: This outbreak was probably caused by Salmonella-contaminated foodstuffs (egg-covered meat with potatoes) due to deficient cooking. This report shows the importance of food-quality programs for hospital meals.

Comparative trial of stent-like balloon angioplasty versus coronary stenting for acute myocardial infarction.

Primary PTCA has been shown to be superior to any thrombolytic regimen and offers higher reperfusion rates and better coronary flow grades. Its limitations include recurrent ischemia (10%-15%), infarct-related artery reocclusion (5%-10%), angiographic restenosis (35%-50%), and need to perform repeat PTCA or CABG at 6-month follow-up (20%). Thus, the current role of coronary stenting for acute myocardial infarction (AMI) is very promising. From December 1995 through January 1997, 335 patients underwent primary angioplasty during the first 12 hr from symptom onset at our institution. We performed a retrospective study comparing the in-hospital and 6-month follow-up outcome of 61 patients who underwent coronary stenting (stent group) against 61 patients with optimal (residual lesion stenosis < 30%) balloon-only primary angioplasty (stent-like group). Patients were routinely treated with aspirin, and ticlopidine was given only to the stent group. In-hospital major adverse cardiac events (MACE) rate was 11.5% without statistical differences between the groups. Cardiac death rate was similar in both groups (4.9 vs. 6.6%; P = 1.0) and only two (3.3%) patients from the stent group and none from the PTCA group had nonfatal myocardial reinfarction. At 6-month follow-up, the rate of recurrent angina was higher in the stent-like group (30.9 vs. 7.1%; P < 0.001). Multivariate analysis showed that only stenting of the infarct-related artery was a borderline independent predictor for MACE (OR = 0; 95% CI = 0-1; P = 0.057). Primary stenting for AMI reduces the rate of recurrent angina or symptoms and MACE at 6-month follow-up.

Clinical manifestations and survival trends during the first 12 years of the AIDS epidemic in Mexico.

BACKGROUND: Our objective was to evaluate survival trends (1984-1995), the prevalence of AIDS-defining conditions, and the role of treatment with zidovudine and/or prophylaxis with trimethoprim-sulfamethoxazole (TMP-SMX) in survival following AIDS diagnosis. METHODS: We reviewed the clinical charts and postmortem studies of all patients admitted to the HIV Clinic from 1984-1995. Three groups were identified according to the following dates of HIV diagnosis: 1) 1984-1988; 2) 1989-1992, and 3) 1993-1995. RESULTS: We studied 909 charts. During the study period, 744 (81.6%) patients developed AIDS. Median survival increased from 11.7 months in group 1 to 15.4 and 17.5 months in groups 2 and 3, respectively (p <0.05). We observed the following important changes in the frequency of AIDS-defining conditions over the study period: Pneumocystis carinii pneumonia (PCP) decreased from 24.8 to 17 and 14% in groups 1, 2, and 3, respectively, (p = 0.008), and Kaposi's sarcoma (KS), from 31.1 to 10.5 and 13.5% (p <0.001). On the other hand, there was an increase in cytomegalovirus disease with 12.4, 20.4, and 18.6% (p = 0.04) and wasting syndrome with 36, 45, and 57% (p <0.001). In the proportional hazard model for death, zidovudine or TMP-SMX use was associated with a protective effect. CONCLUSIONS: Survival is improving among patients with HIV infection at our institution. The prevalence of AIDS-defining conditions has changed over the last 12 years. There has been a diminution of PCP and KS, whereas cases of CMV disease and wasting syndrome increased.

[Bioterrorism: notes for an agenda in case of the unexpected]. / Bioterrorismo: apuntes para una agenda de lo inesperado.

UNLABELLED: The vulnerability of human populations to chemical, biological, radiological, and nuclear terrorism has been widely discussed but insufficiently studied. Current public health policies are not guided by solid and relevant information to design cost-effective programs for preventing or controlling this kind of incidents in the future. Governmental budgets are insufficient to respond to bioterrorist attacks. To face these threats, developing countries like Mexico should frame strategies and devise specific preventive actions that consider the transmission dynamics of potential infectious agents likely to be used in a bioterrorist attack. PROPOSALS: The international reaction to a biological attack must be supported by international agreements that ban the use of biological agents for warfare and/or defense purposes, as well as on academic and technological exchange for the prevention of bioterrorist attacks. At the national level, the recommendations in the event of a biological attack are: a) establishing a legal defense strategy against bioterrorism; b) implementing education programs as a key strategy for defense against bioterrorism; c) devising a national program of interinstitutional anti-bioterrorist coordination that includes medical emergency assistance and collection of medical forensic evidence; d) including a biological weapon registry in epidemiological surveillance systems; e) implementing a laboratory for biological material analysis related to terrorist incidents; f) devising public health information campaigns, g) assuring the supply of diagnostic testing, special protection, and emergency treatment materials; h) decentralizing alert systems for the timely detection of bioterrorist attacks; i) responding to bioterrorist actions addressed against animals and plants, and j) organizing Ethics Committees in case of urgent events derived from a biological attack. CONCLUSIONS: The proper response to sudden and unexpected events of emergent or unusual infectious diseases involved in a bioterrorist attack requires an adequate public health infrastructure. Modern technology allows the timely identification of multiple infectious agents by nucleic acid analyses and should be widely available in reference laboratories. All these measures require sufficient funding to respond to this potential threat. Resource allocation to respond to bioterrorist attacks must be consonant with their potential public health consequences.

Prevalence of infections in intensive care units in Mexico: a multicenter study.

OBJECTIVE: To determine the 1-day prevalence of community-acquired, hospital-acquired, or intensive care unit (ICU)-acquired infections in Mexican ICUs. To identify associated risk factors, predominant infecting organisms, and mortality rates. DESIGN: A 1-day point-prevalence study. SETTING: A total of 254 adult ICUs in Mexico. PATIENTS: Adult patients hospitalized in the participating ICUs. RESULTS: A total of 895 patients were studied, of whom 521 patients (58.2%) were infected. Community-acquired infection occurred in 214 patients (23.9%), non-ICU nosocomial infection occurred in 99 patients (11.1%), and 208 patients had at least one ICU-acquired infection (23.2%; 1.45 episodes/patient). The most frequently reported ICU-acquired infections were pneumonia (39.7%), urinary tract infections (20.5%), wound infection (13.3%), and bacteremia (7.3%). The mortality rate for the ICU-acquired infections after 6 wks of follow-up was 25.5%. Multivariate regression analysis showed the following risk factors for ICU-acquired infections: neurologic failure as a primary cause of admission (odds ratio [OR], 1.697; 95% confidence interval [CI], 1.001-2.839); length of stay in ICU (OR, 1.119; 95% CI, 1.091-1.151); number of therapeutic and/or diagnostic interventions during the preceding week (OR, 1.118; 95% CI, 1.016-1.231); peripherally administered infusion of hyperosmolar solutions (OR, 6.93; 95% CI, 2.452-21.661); sedative usage in the preceding week (OR, 1.751; 95% CI, 1.183-2.602); history of an emergency surgery in the preceding month (OR, 1.875; 95% CI, 1.251-2.813). The administration of antimicrobial treatment if there was an infection decreased the risk of death (OR, 0.406; 95% CI, 0.204-0.755). CONCLUSIONS: Evidence of a high frequency of nosocomial infections was found, and potential risk factors for acquiring infections and mortality were identified. Mortality rates according to the hierarchy of the systemic inflammatory response syndrome in Latin American ICUs are reported.

[Tuberculosis in health personnel: importance of surveillance and control programs]. / Tuberculosis en trabajadores de la salud: importancia de los programas de vigilancia y control.

OBJECTIVE: To describe tuberculosis surveillance results among healthcare workers of a tertiary care center. MATERIAL AND METHODS: All medical records of workers from 1992-1998 were reviewed. Demographics, labor, medical history, previous testing, PPD, booster shots and follow-up were analyzed. Statistical analysis was performed with odds ratios, p-values, and 95% confidence intervals. Subgroup analysis were done with chi 2. Kaplan-Meier estimates were used to analyze times to conversion. RESULTS: Surveillance was done in 1617 workers (68% female and 32% male). Mean age was 26.9 +/- 7.6 (15-68) years. Job positions were 30.5% nurses, 14.6% residents and 14.1% interns. Place of origin was Mexico City in 65.8%. BCG vaccination was present in 71.6% and 15.1% had previous PPD. Admission PPD was positive in 39.6%, negative in 48.3% and 12.1% were lost to follow-up. On negatives, 483 booster shots were applied, and 49 additional positives were found. Follow-up was done in 231 workers, of which 100 (43.3%) converted. The mean time for conversion was 22.8 +/- 12.4 months. The conversion rate at twelve months was 20%. Fifty workers received/accepted isoniazid prophylaxis. CONCLUSIONS: A high percentage of workers were PPD-positive; booster shots allowed the detection of an additional 10%. A high conversion rate underscores the need to organize tuberculosis control programs in Mexico.

[Evaluation of a nosocomial infection surveillance program]. / Validación de un programa de vigilancia de infecciones nosocomiales.

OBJECTIVE: To validate the nosocomial infections surveillance system, establish its impact in morbi-mortality. MATERIAL AND METHODS: Surveillance of every single patient admitted during a one month period was done by one of us (DMG). Each possible case was discussed with two other hospital epidemiologists (SPLR, MSRF). This intensive surveillance was compared against the routinely surveillance performed by the nurses. We included all hospitalized patients between 11th July and 12th of August according to CDC (Atlanta, GA) nosocomial infections definitions. Patients were followed everyday and information about age, gender, underlying diagnosis, microorganisms responsible for nosocomial infections, hospital length of stay and mortality. RESULTS: During the study period 429 were admitted, 45 developed a nosocomial infection (cases) and 384 did not (controls). The incidence of nosocomial infections was 10.48 cases/100 discharges. The sensitivity and specificity of the surveillance system was 95.3 and 98.7%, respectively. Mortality in infected was 11.11% and in non infected was 2.4%. The average length of stay was 20 and 11 days for cases and non infected respectively (p < 0.01). Urinary tract infections were the most common NI (42%), secondary bacteremia (14 < or = %), pneumonia (11.11%) and deep surgical site infection (9.25%). The surgical wound infection rates were: 1.3%, 1.9% and 1.9% for clean, clean-contaminated and contaminated wounds. Patients with rapidly fatal diseases had an increased frequency of infections. The microorganisms most commonly isolated were Escherichia coli (28%), Staphylococcus aureus (11.11%), and Pseudomonas aeruginosa (8.6%). The level of antibiotic resistance was in average of 43% for those antibiotics tested. CONCLUSIONS: The sensitivity and specificity of the surveillance system was excellent. Patients with nosocomial infections had an increased length of stay and a higher mortality compared to those without NI. The validation of the surveillance system allows the production of trustable conclusions about nosocomial infections.

Mycobacterium tuberculosis infection in patients with systemic rheumatic diseases. A case-series.

OBJECTIVE: To describe the clinical characteristics of patients with systemic rheumatic diseases and tuberculosis. A retrospective case series from 1987 to 1994, drawn from a tertiary-care hospital in Mexico City, was studied. RESULTS: Thirty patients were included (20 women, 10 men), with mean age of 39.8 years (range 14-66), and a mean duration of the systemic rheumatic disease of 44 months (1-372). The rheumatic diseases included systemic lupus erythematosus (SLE) (n = 13), rheumatoid arthritis (7), polymyositis or dermatomyositis (5), and other diseases (5). During the six months previous to the diagnosis of tuberculosis, 22 patients had received corticosteroids, and 13 others immunosuppressants. Mycobacterium tuberculosis was isolated from 18 patients. Pulmonary tuberculosis was found in 10 patients, and extrapulmonary tuberculosis in 20, seven of these with miliary disease. SLE was seen in 6 of the patients with miliary tuberculosis. The clinical manifestations were: fever (67%), weight loss (67%), diaphoresis (60%), cough and sputum (53%), lymph node enlargement (43%), and dyspnea (33%). Sixteen patients had an abnormal chest film. Of 18 patients tested by PPD RT-2, 8 had an induration > 10 mm. Patients were initially treated with 3 or 4 anti-tuberculosis drugs for 15 days to 6 months, followed by 6 to 10 months of isoniazid plus rifampicin. Three relapsed, and 2 died of respiratory failure. CONCLUSIONS: This case series showed a particular pattern of tuberculosis in patients with systemic rheumatic diseases.

Tuberculosis prophylaxis in patients with steroid treatment and systemic rheumatic diseases. A case-control study.

OBJECTIVE: The aim of this study was to assess the impact of isoniazid prophylaxis in patients with systemic rheumatic diseases who attended a teaching hospital in Mexico City between 1987 and 1992. METHODS: In this case-control study, patients with systemic rheumatic diseases and tuberculosis (cases) were compared with patients with systemic rheumatic diseases without tuberculosis (controls). The groups were matched by year of hospital admission and rheumatic disease. Clinical charts were reviewed for: 1) isoniazid prophylaxis, defined as the administration of isoniazid 300 mg/day for 6 or more months in patients with exposure to steroids (prophylaxis with isoniazid was defined as complete, incomplete or any prophylaxis); 2) exposure to steroids: defined as the administration of prednisone > 15 mg/day (or its equivalent of another steroid) for 3 or more months before tuberculosis or recruitment into the study; 3) exposure to immunosuppressants, defined as the administration of any dose of azathioprine, methotrexate, cyclophosphamide, and/or 6-mercaptopurine, before tuberculosis in the cases or recruitment date in the controls; 4) reactivity to PPD; and 5) other relevant variables. RESULTS: Twenty cases and 66 controls were studied. A 70% decrease in the risk of developing tuberculosis was found among patients who received any prophylaxis with isoniazid as compared to controls: OR 0.31, 95% CI 0.09-0.98, p = 0.03. A 97% decrease was seen in those patients who received complete prophylaxis: OR 0.034, 95% CI 0.0001-0.216, p < 0.0001. The protective effect of complete prophylaxis persisted even after controlling for other potential confounders, such as age, gender, rheumatic disease, duration of rheumatic symptoms, and exposure to steroids and/or immunosuppressants. CONCLUSION: The results of this study suggest that in countries with a high prevalence of tuberculosis the use of isoniazid (300 mg/day for 6 months) in rheumatic patients with exposure to prednisone (> 15 mg/day for three or more months) may be useful to prevent tuberculosis, independently of the results of the PPD reactivity test. However, a controlled clinical trial will be required to confirm these results.

Salmonella gastroenteritis outbreak among workers from a tertiary care hospital in Mexico City.

OBJECTIVE: To describe an outbreak of Salmonella gastroenteritis among employees of the National Institute of Nutrition (INNSZ) of Mexico City during July, 1994. METHODS: Employees who developed diarrhea or fever associated with gastrointestinal symptoms starting on July 14th were included for study as well as 50 healthy controls. A questionnaire was applied to all, and they also provided a stool sample, along with other 80 asymptomatic people (included the kitchen workers) in whom only stool culture was done. RESULTS: Ninety-seven employees that ate regularly at the Hospital's cafeteria were affected by the outbreak, and 67 of them (69%) could be evaluated. Most of them were nurses (34%), and handymen (27%). Most common symptoms were abdominal pain (97%), diarrhea (95%), nausea (91%), and fever (89%). Cultures from suspicious food items were all negative, but stool cultures from 10/70 cases were positive for Salmonella enteritidis vs. 0/133 in the controls. The ten S. enteritidis isolates resulted identical either by serotyping and by rapid amplified polymorphic DNA (RAPD) analysis. Cultures from all kitchen employees were negative for S. enteritidis. Breakfast meal on July 14th was associated with the development of gastroenteritis (61/67 cases vs 26/50 controls, p < 0.001), and particularly with an egg-covered meat plate (61/62 vs 13/26 controls, p < 0.0001). CONCLUSIONS: This outbreak was probably caused by eggs contaminated with Salmonella, since no one of the kitchen personnel was found to be an asymptomatic carrier, and the implicated recipe allows for inappropriate cooking. Recommendations to improve cooking procedures must be added to the usual regulations to diminish the frequency of foodborne disease outbreaks in hospitals.

[Measuring the impact of medical interventions at the individual level]. / Medición del impacto de intervenciones médicas a nivel individual.

Medical interventions have a variable response among individuals. It is desirable to detect patients who are getting a therapeutic benefit. Any medical intervention has to show a favorable effect in survival and/or control of symptoms in order to be considered useful. In many clinical scenarios, laboratory test results are not enough to be confident of the effectiveness of a treatment. In order to do a clinical evaluation focused on patients' interests, we suggest the use of instruments to measure quality of life. Currently there are quality of life scales that have undergone a rigorous process of validation and reliability. Sub-group analysis is frequently used to predict an individual benefit of medical interventions. In the interpretation of sub-group analysis, it is important to be aware of the risk of misinterpretation, making false positive or false negative conclusions about the effect of the treatment. The N-of-1 trial is a valid scientific alternative to define individual effectiveness of therapy. Defining the degree of therapeutic benefit timely we avoid useless therapies, unnecessary side effects, and sequelae secondary to the lack of opportune treatment.

Pediatric primary gram-negative nosocomial bacteremia: a possible relationship with infusate contamination.

OBJECTIVE: To evaluate the potential contribution of "extrinsic" contamination of intravenous fluids in hospital bacteremia and infection. DESIGN: Prospective cross-sectional survey of infusate contamination, December 1992 to December 1993. SETTING: A pediatric department (1,500 admissions per year) in a general, urban teaching hospital, serving low-income patients. SAMPLES AND PATIENTS: Infusate samples (0.5 to 1.0 mL) from the injection port used by the staff were taken for cultures from all febrile or septic patients in hospital wards. At least four samples were taken each day; if no febrile or septic patients were available, other patients were sampled at convenience. RESULTS: A 6.8% positive culture rate (87 contaminates in 1,277 infusates) was obtained, without significant differences among the wards. Gram-negative organisms were recovered from 56 samples (62.9%), mainly of the tribe Klebsielleae (56.1%). Coagulase-negative staphylococci were isolated in 30 samples (33.7%). There was no significant difference between the febrile-septic group and the asymptomatic group in the rate of infusate contamination (P = .59). In eight patients, the same organisms were recovered from infusate and blood culture. The overall bacteremia rate was 2.5 per 100 discharges. CONCLUSIONS: Compared to previous reports, higher infusate contamination rates and different organisms (mainly gram-negative) were observed. In hospitals of underdeveloped countries, nosocomial infection control frequently is disregarded. Infusate contamination may be common and could lead to gram-negative bacteremia. In such settings, it seems advisable to perform surveillance studies to identify infusate contamination, because a single infusate contamination could be a signal for an epidemic.