[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.

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.

[Biochemical characterization of Campylobacter using the "Micro Campy" method]. / Perfiles bioquímicos de Campylobacter por el método "Micro Campy".

Three species of Campylobacter are recognized as enteropathogens in children under five years of age and in immunocompromised patients. Several groups have tried to classify them using biochemical profiles and have found six different patterns which comprise 12 individual tests. We have designed a "Micro Campy" method which identifies C. jejuni, C. coli and C. lari classifying them into several biotypes. Fifty two Campylobacter strains isolated from humans were studied and classified in 24 different patterns. Strains isolated from diarrhea episodes were seen in two specific patterns. We propose the use of this easy to perform method which has a reproducibility higher than 92% in biotyping Campylobacter strains.