The influence of hospital antimicrobial use on carbapenem-non-susceptible Enterobacterales incidence rates according to their mechanism of resistance: a time-series analysis.

BACKGROUND: Carbapenem non-susceptible Enterobacterales (CNSE) can be broadly divided into those that produce carbapenemases (carbapenemase-producing Enterobacterales (CPE)), and those that harbour other mechanisms of resistance (non-carbapenemase-producing CNSE (NCP-CNSE)). AIM: To determine the predictors of CNSE nosocomial incidence rates according to their mechanism of resistance. METHODS: A time-series analysis was conducted (July 2013 to December 2018) to evaluate the relationship in time between hospital antibiotic use and the percentage of adherence to hand hygiene with the CNSE rates. FINDINGS: In all, 20,641 non-duplicated Enterobacterales isolates were identified; 2.2% were CNSE. Of these, 48.1% and 51.9% were CPE and NCP-CNSE, respectively. Of the CPE, 78.3% possessed a blaOXA-232 gene. A transfer function model was identified for CNSE, CPE, and OXA-232 CPE that explained 20.8%, 19.3%, and 24.2% of their variation, respectively. According to the CNSE and CPE models, an increase in piperacillin-tazobactam (TZP) use of 1 defined daily dose (DDD) per 100 hospital patient-days (HPD) would lead to an increase of 0.69 and 0.49 CNSE and CPE cases per 10,000 HPD, respectively. The OXA-232 CPE model estimates that an increase of 1 DDD per 100 HPD of TZP use would lead to an increase of 0.43 OXA-232 CPE cases per 10,000 HPD. A transfer function model was not identified for NCP-CNSE, nor was there an association between the adherence to handhygiene and the CNSE rates. CONCLUSION: The use of TZP is related in time with the CPE nosocomial rates, mostly explained by its effect on OXA-232 CPE.

Consensus on the prevention, diagnosis, and treatment of Clostridium difficile infection. / Consenso sobre prevención, diagnóstico y tratamiento de la infección por Clostridium difficile.

In recent decades, Clostridium difficile infection (CDI) has become a worldwide health problem. Mexico is no exception, and therefore the Asociación Mexicana de Gastroenterología brought together a multidisciplinary group (gastroenterologists, endoscopists, internists, infectious disease specialists, and microbiologists) to carry out the "Consensus on the prevention, diagnosis, and treatment of Clostridium difficile infection", establishing useful recommendations (in relation to the adult population) for the medical community. Said recommendations are presented herein. Among them, it was recognized that CDI should be suspected in subjects with diarrhea that have a history of antibiotic and/or immunosuppressant use, but that it can also be a community-acquired infection. A 2-step diagnostic algorithm was proposed, in which a highly sensitive test, such as glutamate dehydrogenase (GDH), is first utilized, and if positive, confirmed by the detection of toxins through immunoassay or nucleic acid detection tests. Another recommendation was that CDI based on clinical evaluation be categorized as mild-moderate, severe, and complicated severe, given that such a classification enables better therapeutic decisions to be made. In mild-moderate CDI, oral vancomycin is the medication of choice, and metronidazole is recommended as an alternative treatment. In addition, fecal microbiota transplantation was recognized as an efficacious option in patients with recurrence or in the more severe cases of infection, and surgery should be reserved for patients with severe colitis (toxic megacolon), in whom all medical treatment has failed.

Pneumonia in patients with systemic lupus erythematosus: Epidemiology, microbiology and outcomes.

Background and objective Pneumonia remains the main cause of mortality in patients with systemic lupus erythematosus (SLE). The aim of the study was to establish the clinical characteristics, microbiology and risk factors for poor prognosis in patients with SLE and pneumonia. Methods We reviewed medical records of patients with SLE (American College of Rheumatology criteria) and pneumonia who attended the emergency room in a single tertiary care center (January 2010-March 2015). We collected demographics, treatment and disease activity (SLEDAI-2K) data. Severity scales of pneumonia (CURB-65 (acronym for risk factors measured: confusion, urea nitrogen, respiratory rate, blood pressure, 65 years of age and older) and Pneumonia Severity Index (PSI)) were obtained. A negative composite outcome was defined as need for mechanical ventilation, septic shock or death secondary to pneumonia up to 30 days after discharge. We conducted a univariate and multivariable analysis. Results We studied 158 patients (76% women) with 187 episodes of pneumonia. There were no differences in age, SLE duration, SLE activity, treatment or comorbidities between patients with negative composite outcome vs the other group. In 53 episodes, patients presented with a negative composite outcome. Of these, 46 (24.6%) required intubation, 13 (7%) developed shock and 12 (6.4%) died. The most common bacteria isolated was S. aureus, and we observed a high percentage of nonhabitual microorganisms. Fifteen percent of patients who presented with a negative outcome had low values on CURB-65 and PSI scales. Conclusion Patients with SLE and pneumonia have a high risk of complications and present with a high percentage of nonhabitual microorganisms. Severity scales for pneumonia can misclassify as low risk SLE patients with poor prognosis.

First case of Nocardia amamiensis pulmonary infection in Mexico.

We report a case of Nocardia amamiensis pulmonary infection in a 43-year-old immunocompromised woman. The patient was treated with imipenem/cilastatin and trimethoprim/sulfamethoxazole and had a favourable outcome. It is important that laboratories perform species identification to understand the epidemiology and susceptibility patterns of the different Nocardia spp.

High prevalence of infections in patients with systemic lupus erythematosus and pulmonary haemorrhage.

The main objective of this study is to describe the presence of infections in patients with pulmonary haemorrhage and systemic lupus erythematosus. Patients with systemic lupus erythematosus and pulmonary haemorrhage were thoroughly evaluated in the first 48 hours with imaging plus bronchoscopy and bronchoalveolar fluid analysis. If needed, videoassisted thoracoscopy and lung biopsy were performed too. In all, search for bacterial, mycobacterial and fungal infections proceeded. Appropriate blood, bronchoalveolar fluid and tissue cultures were taken. Patients were treated with antibiotics and corticosteroids in case of infection. Otherwise, they received initial intravenous methylprednsiolone pulses for 3 days as standard therapy for pulmonary haemorrhage in systemic lupus erythematosus. Additional treatment with immunosuppressives was further decided by the treating physicians. Fourteen events in 13 patients were evaluated. In eight events (57%), an infection was demonstrated. Aetiological agents included Pseudomonas sp. and Aspergillus fumigatus. Four patients died, three of them because of the pulmonary infection and one because of cerebral haemorrhage secondary to severe systemic hypertension, 48 hours after methylprednisolone treatment. Patients with systemic lupus erythematosus and pulmonary haemorrhage have a high prevalence of infections. The influence of pulmonary haemorrhage in the setting of systemic lupus erythematosus needs further study to establish adequate treatment and to reduce the high mortality of this complication.

A novel identification scheme for genus Mycobacterium, M. tuberculosis complex, and seven mycobacteria species of human clinical impact.

Recently, the incidence of human mycobacterial infections due to species other than M. tuberculosis has increased worldwide. Since disease control depends on appropriate antimicrobial therapy, the precise identification of these species of clinical importance has become a major public health concern. Identification of mycobacteria has been hampered because of the lack of specific, rapid, and inexpensive methods. Therefore, we aimed at designing and validating a bacterial lysate-based polymerase chain reaction identification scheme. This scheme can classify clinical isolates into: (1) the genus Mycobacterium, (2) the M. tuberculosis complex, (3) the nontuberculous mycobacteria, and (4) the species M. avium, M. intracellulare, M. abscessus, M. chelonae, M. fortuitum and M. bovis of clinical importance, and M. gordonae, the most commonly encountered nonpathogenic species in clinical laboratories. By using M. fortuitum and M. avium lysates as models, the method sensitivity was determined to be 372 pg of DNA. In a blind parallel comparison between our approach and conventional biochemical tests, both assays correctly categorized 75 patient's mycobacterial isolates. However, our approach only required 4-9 h for categorization compared with at least 15 days by conventional tests. Furthermore, our methodology could also detect M. fortuitum and M. avium from liquid cultures, after only 2 and 6 days, respectively, of incubation. Our new identification scheme is therefore sensitive, specific, rapid, and economic. Additionally, it can help to provide proper treatment to patients, to control these diseases, and to improve our knowledge of the epidemiology of mycobacteriosis, all urgently needed, particularly in developing countries.

Gender differentials of pulmonary tuberculosis transmission and reactivation in an endemic area.

BACKGROUND: In most low income countries there are twice as many cases of tuberculosis (TB) reported among men than among women, a difference commonly attributed to biological and epidemiological characteristics as well as socioeconomic and cultural barriers in access to health care. The World Health Organization has encouraged gender specific comparisons in TB rates to determine whether women with TB are less likely than men with TB to be diagnosed, reported, and treated. A study was undertaken to identify gender based differences in patients with pulmonary TB and to use this information to improve TB control efforts. METHODS: Individuals with a cough for more than 2 weeks in southern Mexico were screened from March 1995 to April 2003. Clinical and mycobacteriological information (isolation, identification, drug susceptibility testing and IS6110 based genotyping, and spoligotyping) was collected from those with bacteriologically confirmed pulmonary TB. Patients were treated in accordance with official norms and followed to ascertain treatment outcome, retreatment, and vital status. RESULTS: 623 patients with pulmonary TB were enrolled. The male:female incidence rate ratio for overall, reactivated, and recently transmitted disease was 1.58 (95% CI 1.34 to 1.86), 1.64 (95% CI 1.36 to 1.98), and 1.41 (95% CI 1.01 to 1.96), respectively. Men were more likely than women to default from treatment (adjusted OR 3.30, 95% CI 1.46 to 7.43), to be retreated (hazard ratio (HR) 3.15, 95% CI 1.38 to 7.22), and to die from TB (HR 2.23, 95% CI 1.25 to 3.99). CONCLUSIONS: Higher rates of transmitted and reactivated disease and poorer treatment outcomes among men are indicators of gender differentials in the diagnosis and treatment of pulmonary TB, and suggest specific strategies in endemic settings.

Antibacterial resistance of community-acquired respiratory tract pathogens recovered from patients in Latin America: results from the PROTEKT surveillance study (1999-2000).

PROTEKT (Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin) is a global surveillance study established in 1999 to monitor antibacterial resistance of respiratory tract organisms. Thirteen centers from Argentina, Brazil and Mexico participated during 1999-2000; they collected 1806 isolates (Streptococcus pneumoniae 518, Haemophilus influenzae 520, Moraxella catarrhalis 140, Staphylococcus aureus 351, S. pyogenes 277). Overall, 218 (42.1%) of the S. pneumoniae isolates had reduced susceptibility to penicillin, 79 (15.3%) were penicillin-resistant and 79 (15.3%) were erythromycin-resistant. Mexico had the highest prevalence of penicillin (76.5%) and erythromycin (31.2%) resistance. Of 77 erythromycin-resistant S. pneumoniae tested for resistance genotype, 43 possessed mef(A), 33 possessed erm(B) and 1 possessed both erm(B) and mef(A) mechanism. All S. pneumoniae isolates were fully susceptible to telithromycin, linezolid, teicoplanin and vancomycin. Among H. influenzae isolates, 88 (16.9%) produced beta-lactamase, ranging from 11% (Brazil) to 24.5% (Mexico). Among M. catarrhalis isolates, 138 (98.6%) produced beta-lactamase. Twenty-four (8.7%) of the S. pyogenes isolates were erythromycin-resistant; resistance being attributable to mefA (n=18), ermTR (n=5) and ermB (n=1). All H. influenzae, M. catarrhalis and S. pyogenes were fully susceptible to telithromycin. Methicillin resistance was found in 26.5% of the S. aureus isolates (Argentina 15%; Mexico 20%; Brazil 31.3%). Telithromycin was effective against 97.7% of methicillin-susceptible isolates. PROTEKT confirms that antibacterial resistance is an emerging problem in Latin America. The previously reported high levels of pneumococcal resistance to the beta-lactam and macrolides were exceeded. New agents that do not induce resistance or that exert low selective pressure, e.g. telithromycin, are essential to safeguard future antibacterial efficacy.

Antibacterial resistance of community-acquired respiratory tract pathogens recovered from patients in Latin America: results from the PROTEKT surveillance study (1999-2000)

PROTEKT (Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin) is a global surveillance study established in 1999 to monitor antibacterial resistance of respiratory tract organisms. Thirteen centers from Argentina, Brazil and Mexico participat ed during 1999-2000; they collected 1,806 isolates (Streptococcus pneumoniae 518, Haemophilus influenzae 520, Moraxella catarrhalis 140, Staphylococcus aureus 351, S. pyogenes 277). Overall, 218 (42.1 percent) of the S. pneumoniae isolates had reduced susceptibility to penicillin, 79 (15.3 percent) were penicillin-resistant and 79 (15.3 percent) were erythromycin-resistant. Mexico had the highest prevalence of penicillin (76.5 percent) and erythromycin (31.2 percent) resistance. Of 77 erythromycin-resistant S. pneumoniae tested for resistance genotype, 43 possessed mef(A), 33 possessed erm(B) and 1 possessed both erm(B) and mef(A) mechanism. All S. pneumoniae isolates were fully susceptible to telithromycin, linezolid, teicoplanin and vancomycin. Among H. influenzae isolates, 88 (16.9 percent) produced b-lactamase, ranging from 11 percent (Brazil) to 24.5 percent (Mexico). Among M. catarrhalis isolates, 138 (98.6 percent) produced b-lactamase. Twenty-four (8.7 percent) of the S. pyogenes isolates were erythromycin-resistant; resistance being attributable to mefA (n=18), ermTR (n=5) and ermB (n=1). All H. influenzae, M. catarrhalis and S. pyogenes were fully susceptible to telithromycin. Methicillin resistance was found in 26.5 percent of the S. aureus isolates (Argentina 15 percent; Mexico 20 percent; Brazil 31.3 percent). Telithromycin was effective against 97.7 percent of methicillin-susceptible isolates. PROTEKT confirms that antibacterial resistance is an emerging problem in Latin America. The previously reported high levels of pneumococcal resistance to the b-lactam and macrolides were exceeded. New agents that do not induce resistance or that exert low selective pressure, e.g. telithromycin, are essential to safeguard future antibacterial efficacy

Purified protein derivative reaction in systemic lupus erythematosus patients. Indirect study of cellular immunity.

Cutaneous anergy in SLE patients results from disease activity and/or immunosuppressive treatment (IT). The aim of this study was to evaluate purified protein derivative (PPD) reaction in SLE patients. A total of 145 patients and 20 controls were studied. Five units of PPD were applied on day 0, and skin reaction was measured after 3 (PPD1) and 6 (PPD2) days. A booster was applied (day 14), and the reaction was measured after 3 (PPD3) and 6 (PPD4) days. Non-parametric ANOVA test and unpaired Student's t-test were performed. Forty patients (group I) were inactive (MexSLEDAI < 3), receiving no IT (at least 3 months previous to the PPD test); 39 (group II) were inactive receiving IT; 24 (group III) were active without IT, and 42 (group IV) were active with IT. Active patients had lower PPD1 (group III, 1.4 +/- 0.9; group IV, 0.6 +/- 0.5) than inactive patients (group I, 8.4 +/- 2.3; group II, 5.1 +/- 1.9) and than controls (9.4 +/- 3; P < or = 0.001). Group IV had lower delayed response (PPD2 = 0.3 +/- 0.3) than inactive groups (group I, 2.6 +/- 0.9; group II, 3.1 +/- 0.8) and than controls (7.9 +/- 2.5; P < or = 0.001). Group III had lower delayed reaction (PPD2 = 1.2 +/- 0.8) than controls (P < or = 0.001). Active SLE patients, receiving or not receiving IT, had lower skin response to PPD than inactive patients and controls.

rpoB Gene mutations in rifampin-resistant Mycobacterium tuberculosis identified by polymerase chain reaction single-stranded conformational polymorphism.

The use of polymerase chain reaction-single-stranded conformational polymorphism (PCR-SSCP) to study rpoB gene mutations in rifampin-resistant (RIFr) Mycobacterium tuberculosis has yielded contradictory results. To determine the sensitivity of this method, we analyzed 35 RIFr strains and 11 rifampin-susceptible (RIFs) strains, using the DNA sequencing of the core region of rpoB for comparison. Of the RIFr, 24 had a PCR-SSCP pattern identical to that of H37Rv; the other 11 had four different patterns. The 11 RIFs had PCR-SSCP patterns identical to that of H37Rv. The sensitivity of the assay was 31.4%; its specificity was 100%. We observed a strong correlation between the degree of resistance and the type of mutation.

Luciferase reporter mycobacteriophages for detection, identification, and antibiotic susceptibility testing of Mycobacterium tuberculosis in Mexico.

The utility of luciferase reporter mycobacteriophages (LRPs) for detection, identification, and antibiotic susceptibility testing of Mycobacterium tuberculosis was prospectively evaluated in a clinical microbiology laboratory in Mexico City, Mexico. Five hundred twenty-three consecutive sputum samples submitted to the laboratory during a 5-month period were included in this study. These specimens were cultivated in Middlebrook 7H9 (MADC), MGIT, and Löwenstein-Jensen (LJ) media. Of the 71 mycobacterial isolates recovered with any of the three media, 76% were detected with the LRPs, 97% were detected with the MGIT 960 method, and 90% were detected with LJ medium. When contaminated specimens were excluded from the analysis, the LRPs detected 92% (54 of 59) of the cultures. The median time to detection of bacteria was 7 days with both the LRPs and the MGIT 960 method. LRP detection of growth in the presence of p-nitro-alpha-acetylamino-beta-hydroxypropiophenone (NAP) was used for selective identification of M. tuberculosis complex (MTC) and compared to identification with BACTEC 460. Using the LRP NAP test, 47 (94%) out of 50 isolates were correctly identified as tuberculosis complex. The accuracy and speed of LRP antibiotic susceptibility testing with rifampin, streptomycin, isoniazid, and ethambutol were compared to those of the BACTEC 460 method, and discrepant results were checked by the conventional proportion method. In total, 50 MTC isolates were tested. The overall agreement between the LRP and BACTEC 460 results was 98.5%. The median LRP-based susceptibility turnaround time was 2 days (range, 2 to 4 days) compared to 10.5 days (range, 7 to 16 days) by the BACTEC 460 method. Phage resistance was not detected in any of the 243 MTC isolates tested. Mycobacteriophage-based approaches to tuberculosis diagnostics can be implemented in clinical laboratories with sensitivity, specificity, and rapidity that compare favorably with those of the MGIT 960 and BACTEC 460 methods. The phages currently provide the fastest phenotypic assay for susceptibility testing.

[Drug resistance of Mycobacterium tuberculosis in Orizaba, Veracruz. Implications for the tuberculosis prevention and control program]. / Resistencia de Mycobacterium tuberculosis a los antimicrobianos en Orizaba, Veracruz. Implicaciones para el Programa de Prevención y Control de la Tuberculosis.

BACKGROUND: Tuberculosis, declared a global emergency by the World Health Organization, continues to be an important public health problem in Mexico, included in the first twenty causes of death. OBJECTIVE: To know the impact of drug resistance of Mycobacterium tuberculosis on treatment outcome, need of re-treatment and mortality in a cohort of patients with pulmonary tuberculosis receiving directly observed therapy, short course (DOTS). METHODS: We conducted a population-based study in a suburban region in Southern Mexico. People who had been coughing for more than two weeks underwent sputum acid-fast bacilli smear. Patients with a positive smear were recruited and underwent clinical exam, chest X-ray, HIV testing, and sputum cultures. Identification, drug susceptibility testing and restriction fragment length polymorphism analysis (RFLP) were performed in all isolates. Patients were followed every 12 months for new episodes of tuberculosis and vital status. Patients were referred for clinical care to the local program of tuberculosis. Deaths were corroborated with death certificates. Informed consent was obtained from participants. RESULTS: Between March 1995 and February 1999, tuberculosis was diagnosed in 371 patients who were followed for an average of 32 months. M. tuberculosis was cultured from 316 patients; resistance to any drug occurred in 25.0% of isolates (primary 18.8%, acquired 49.2%); only to isoniazid in 6.8% (primary 7.3%, acquired 4.8%); to isoniazid and rifampin in 6.2% (primary 1.6%, acquired 23.8%). Patients with drug resistance had a higher probability of treatment failure (OR = 16.9, CI 95% 4.5-63.0) and patients with MDR strains had a higher probability of need of re-treatment (RR = 24.4, CI 95% 8.8-67.6), and of death (RR = 4.0, CI 95% 1.5-10.7). Additional variables were found to be associated with subsequent episodes of disease and mortality: Cocaine use, chronic disease, type of radiological lesions, HIV co-infection, non-compliance and treatment delay, as well as RFLP clustering. CONCLUSIONS: In this study, we observed that drug resistance showed a severe impact on the outcome and survival; drug-resistance was the most significant factor for these negative outcomes; DOTS may not be sufficient in areas where drug resistance is considerable, and patient follow-up for longer periods of time, as compared to evaluation at the end of treatment, provides additional information which is useful for prevention and control programs.

[Trends for bacteremia and risk factors for death in a tertiary hospital in Mexico City. 1981-1992]. / Tendencia de las bacteremias y factores de riesgo de muerte en un hospital de tercer nivel de la Ciudad de México. 1981 a 1992.

OBJECTIVE: To describe the trends and risk factors of death for bacteremia in adult from a tertiary-care center from 1981 to 1992. MATERIAL AND METHODS: We randomly included 20% of bacteremic episodes per year. RESULTS: 47,618 blood-cultures from 19,530 patients, 3428 patients (17.6%) had bacteremia (285/y). From 600 episodes (50/y), 307 were from men, 368 were hospital-acquired (HA), and 88% were monomicrobial. Diabetes mellitus was seen in 103 cases, cirrhosis of the liver in 98, and AIDS in 33, among others. The main microorganisms were: Escherichia coli (177), Klebsiella pneumoniae (53), Enterobacter (50), Salmonella (45) and Pseudomonas aeruginosa (35); coagulase-negative staphylococci (CNS) (116), Staphylococcus aureus (56), and enterococci (22), and Candida (20). CNS decreased during the study (p < 0.01), but Candida spp., Stenotrophomonas maltophilia and enterococci increased (p < 0.01). The crude mortality of the HA bacteremia was 70.8%, and 29.2% in the case of community-acquired, the mortality attributable to HA bacteremia was 41.6%. The main risk factors were: cardiac valvular disease (p < 0.001), stay at the intensive-care unit (p < 0.001), sepsis (p < 0.001), and pneumonia (p < 0.001). DISCUSSION: Bacteremia had a significant impact on mortality during the study period that has not change despite opportune therapy, Enterococci and candida have emerged as significant pathogens.

Bloodborne viral infections in patients attending an emergency room in Mexico City: estimate of seroconversion probability in healthcare workers after an occupational exposure.

The frequency of hepatitis C (HCV), hepatitis B (HBV), human immunodeficiency virus (HIV), and human T-cell lymphotropic virus (HTLV) I/II was determined in the emergency room of a teaching hospital. Of 909 patients, 19% had at least one infection; 7.8% had HCV, 6.9% HBV, 3.3% HIV, and 2.8% HTLV I/II. The probability that a healthcare worker would have an accident with an infected patient and seroconvert was 4.99 to 24.9 per 100,000 venipunctures for HBV, 5.6 to 8.4 for HCV, and 0.12-0.16 for HIV in our emergency room.

Clinical consequences and transmissibility of drug-resistant tuberculosis in southern Mexico.

BACKGROUND: Consequences of drug-resistant tuberculosis (TB) in developing countries using directly observed treatment, short-course (DOTS), are not well defined. OBJECTIVE: To determine the impact of drug resistance on clinical outcome and transmission of TB under programmatic conditions. PATIENTS AND METHODS: A prospective cohort and molecular epidemiologic study was conducted in southern Mexico. Between March 1995 and February 1998 all patients with persistent cough whose sputa had acid-fast bacilli (AFB) underwent clinical and mycobacteriologic evaluation (species identification, drug susceptibility testing, and IS6110-based genotyping). Treatment was provided in accordance with Mexico's National Tuberculosis Program. Clinical and microbiologic outcomes and molecular epidemiologically defined transmission were measured. RESULTS: Mycobacterium tuberculosis was isolated from 238 of the 284 AFB smear-positive persons. The overall rate of resistance was 28.4% (new, 20.7%; retreated, 54.7%), and 10.8% (new, 3.3%; retreated, 35.8%) had multi-drug-resistant TB (ie, resistance to isoniazid and rifampin). After treatment, 75% (new, 81.0%; retreated, 52.8%) were cured, 8% (new, 7.8%; retreated, 7.5%) abandoned therapy, 9% (new, 3.9%; retreated, 28.3%) had treatment failure, and 4% (new, 3.3%; retreated, 7.5%) died. Another 2% of patients relapsed, and 9% died during a median of 24.4 months of follow-up. Drug-resistance was a strong independent risk factor for treatment failure. Being infected with multi-drug-resistant TB was the only factor associated with a decreased likelihood of being in a restriction fragment length polymorphism cluster. CONCLUSIONS: Despite the use of DOTS, patients with drug-resistant TB had a dramatically increased probability of treatment failure and death. Although multi-drug-resistant TB may have a decreased propensity to spread and cause disease, it has a profoundly negative impact on TB control.

Mycobacterium tuberculosis drug resistance in a suburban community in southern Mexico.

OBJECTIVE: To determine the impact of drug resistance (DR) on the clinical outcome and transmission of tuberculosis under programmatic conditions. METHODS: Prospective cohort and molecular epidemiologic study in the Orizaba Health Jurisdiction of Mexico. Between March 1995 and July 1999, chronic coughers with positive acid-fast bacilli (AFB) detected in sputum smear underwent clinical and mycobacteriologic evaluation (species identification, drug susceptibility testing and IS6110-based genotyping). Treatment was provided in accordance with official norms. RESULTS: Mycobacterium tuberculosis was isolated from 326/387 AFB-positive cases. The rate of DR was 24.2% and that of multidrug resistance (MDR, defined as resistance to both isoniazid and rifampin at least) was 7.7%; 78% were cured, 8% abandoned treatment, 6% failed treatment, and 5% died. An additional 13.5% received retreatment and 8.9% died during a median 28.6 months of follow up. Factors associated with DR by multivariate analysis were chronicity of tuberculosis (OR 4.8, 95%CI 2.7-8.4, P < 0.001), age >40 years (OR 1.9, 95%CI 1.1-3.2, P = 0.02) and indigenous origin (OR 0.3, 95%CI 0.13-0.75, P = 0.01). Cox-adjusted relative risks showed that MDR (RR 2.5, 95%CI 1.02-6.16, P = 0.04), HIV infection (RR 31.3, 95%CI 11.6-84.8, P < 0.001), and chronicity of tuberculosis (RR 2.1, 95%CI 1.0-4.4, P = 0.06) were associated with mortality, controlling for age. Predictors of retreatment were DR (not including MDR) (RR 2.2 95%CI 0.89-5.31, P < 0.087), MDR (RR 12.6, 95%CI 5.46-28.88, P < 0.001), and living in a household with an earthen floor (RR 2.8, 95%CI 1.27-6.13, P = 0.011). Being infected with MDR-TB was the only factor associated with a decreased likelihood of being in an RFLP cluster (OR 0.31, 95%CI 0.12-0.81, P = 0.02). CONCLUSIONS: Although MDR-TB may have a decreased propensity to spread and cause disease, it has a profoundly negative impact on tuberculosis control.

[Fulminant sepsis caused by Vibrio vulnificus. A case series]. / Sepsis fulminante por Vibrio vulnificus. Serie de casos.

BACKGROUND: Vibrio vulnificus is a marine bacteria associated with the ingestion of raw shellfish or contact with seawater. It can produce wound infection, diarrhea and sepsis. The main risk factor for infection is the presence of chronic liver disease. Prior studies have shown mortality from 40% to 63%. OBJECTIVE: Report of 8 cases of disseminated infection with V. vulnificus causing fulminant sepsis. DESIGN: Series of cases. METHODS: We reviewed the database of the laboratory of clinical microbiology from 1990 to 1999. A computer-based review of the worldwide medical literature was also accomplished. RESULTS: There were 8 cases of V. vulnificus infection. All patients had chronic liver disease, 3 also had diabetes mellitus and 1 received immunosuppressive agents. Five patients were known to have ingested raw shellfish. The mean duration of illness before death was 4 days. All patients presented with sepsis, seven had cutaneous lesions. Five patients received early antimicrobial treatment during the first 24 hours and all of them in the first 48 hours. Regardless of susceptibility to the antimicrobial agents used, the mortality was of 87.5%. Disk-diffusion test showed 100% susceptibility to imipenem, ceftazidime and tetracycline; 83% to cefepime, ticarcillin and cotrimoxazole and 50% to quinolones. CONCLUSION: The V. vulnificus infection appears in patients with chronic liver disease and it is associated with high mortality. This infection has to be suspected in high-risk patients who have eaten raw shellfish and therapy must be initiated as soon as possible.