Brote de tuberculosis multirresistente / Outbreak of Multiresistant Tuberculosis

Fundamento. Se estudian seis casos de tuberculosis multirresistente diagnosticados en el Hospital de Navarra durante el año 1996.Material y métodos. Las pruebas de sensibilidad se realizaron utilizando el sistema BACTEC 460TB frente a cuatro fármacos antituberculosos mayores: isoniacida, estreptomicina, rifampicina y etambutol. En el estudio epidemiológico se utilizaron técnicas de "fingerprinting" mediante RFLP con IS 6110.Resultados.Cuatro de los pacientes estaban coinfectados con el VIH. Todos ellos tuvieron un pronóstico fatal a corto plazo. Los cuatro presentaban resistencia a todos los fármacos estudiados; en tres la resistencia fue primaria, y en el cuarto secundaria. El estudio molecular puso de manifiesto que tres pacientes VIH+ tenían patrones idénticos de polimorfismo en la longitud de los fragmentos de restricción (RFLP). Dos eran hermanos y en el tercero se demostró la contaminación nosocomial. Por otra parte, el patrón de RPLF de estos pacientes, presentaba gran similitud con el de una de las pacientes VIH-, lo que sugiere un origen clonal de las cepas, no habiéndose encontrado otra relación epidemiológica. El patrón de RPLF del otro paciente VIH+ era idéntico al de otra cepa suya, aislada 14 meses antes, siendo la primera sensible. Las otras dos pacientes eran mujeres VIH-, y evolucionaron favorablemente, En una, que era diabética, se había diagnosticado una tuberculosis multirresistente hacía 7 años, habiendo permanecido asintomática hasta la actualidad. La otra, se trataba de una resistencia secundaria por un tratamiento deficiente. Conclusiones. La aparición de tuberculosis multirresistente se plantea como un problema muy grave entre los pacientes VIH+, especialmente en un momento en que su esperanza de vida se ha visto notablemente mejorada gracias a las nuevas terapias. En los pacientes VIH-, la tuberculosis multirresistente tiene mejor pronóstico. La tipificacion mediante polimorfismo en la longitud de los fragmentos de restricción es muy útil para poder esclarecer el origen de los casos (AU)

[Confirmation by molecular typing of cross-contamination in a mycobacteria laboratory]. / Confirmación mediante tipificación molecular de contaminaciones cruzadas en el laboratorio de micobacterias.

BACKGROUND: Detection of cross-contamination in the laboratory by restriction fragments length polymorphism (RFLP) analysis of Mycobacterium tuberculosis strains. MATERIAL AND METHODS: 224 strains isolated during a five years period were characterized by IS6110 fingerprinting performed (RFLP) by standardized protocols. RESULTS: Four groups of isolates with smear-negative specimens and low number of colony form its units were detected. They were processed in the same batch and day than other smear-positive specimens with identical RFLP patterns. Fifteen patients were involved and the review of four patients' charts showed that they did not have the typical manifestations of tuberculosis. CONCLUSIONS: When M. tuberculosis isolates were obtained from smear-negative specimens, the results of specimens processed in the same batch and the patients' charts should be reviewed. If with these data the possibility of cross-contamination is suspected, the isolates must be analyzed by molecular typing methods.

[Outbreak of multiresistant tuberculosis]. / Brote de tuberculosis multirresistente.

BASIS: Six cases of multiresistant tuberculosis diagnosed in the Hospital of Navarra in 1996 were studied. MATERIAL AND METHODS: Sensitivity tests were carried out using the BACTEC 460TB system against four main anti-tuberculosis medicines: Isoniazid, Streptomycin, Rifampizin and Ethambutol. "Fingerprinting" techniques by means of RFLP with IS 6110 were used in the epidemiological study. RESULTS: Four of the patients were also infected with HIV. All of them had a fatal short-term prognosis. These four showed resistance to the drugs under study; in three resistance was primary, and secondary in the fourth. The molecular study showed that three HIV+ patients had identical patterns of restriction fragment length polymorphism (RFLP). Two were brothers and nosocomial infection was demonstrated in the third. On the other hand, the RPLF pattern of these patients showed great similarity to that of one of the HIV- patients, which suggests a clone origin of the strains, no other epidemiological relationship being found. The RPLF pattern of the other HIV+ patient was identical to that of another of his strains, isolated 14 months before, with the first strain sensitive. The other two patients were HIV- women, and they evolved favourably. In one, who was diabetic, a multiresistant tuberculosis had been diagnosed 7 years before, remaining asymptomatic up until the present. The other involved a secondary resistance due to deficient treatment. CONCLUSIONS: The appearance of multiresistant tuberculosis is a very serious problem amongst HIV+ patients, especially at a time when their life expectancy has improved considerably due to the new therapies. In HIV- patients, multiresistant tuberculosis has a better prognosis. Typification by means of restriction fragment length polymorphism is very useful in clarifying the origin of the cases.

[Epidemiology of gastroenteritis by Salmonella (1983-1994)]. / Epidemiología de las gastroenteritis por Salmonella (1983-1994).

BACKGROUND: The incidence of Salmonella enteritidis infection has been study in order to determine their epidemic spread from 1983 to 1994, and the impact of the measures introduced to attempt its control. METHOD: Review of the stool cultures positives for enteric pathogens obtained in the Hospital de Navarra from 1983-1994. RESULTS: Looking at the isolation rates of the different enteric pathogens from 1983 to 1994, a sharp increase of S. enteritidis was recorded on 1985 as a consequence of several outbreaks associated with the consumption of mayonnaise elaborated with row eggs. From 409 strains of Salmonella isolated that year, 302 were serotype enteritidis, this means a 7.5 fold rise since the preceding year in which the prevailing serotype was S typhimurium. From 1985 through 1991 the incidence of S. enteritidis stand high, and pick again on 1990. Since then, a decline has been observed, and in 1994 the number of Salmonella cases recorded were about those on 1984, however, S. enteritidis is now the prevailing serotype. CONCLUSIONS: The egg-borne S. enteritidis epidemic emerged as a major public health problem in Navarra in 1995, associated to the consumption of home made mayonnaise. The measures introduced by local Public Health authorities to attempt control of non pasteurized mayonnaise were insufficient. Evidence from other places links human infections to vertical transmission from breeding flocks to layers. And makes of S. enteritidis infection an international challenge. The severity of the lived experience demands a time-temperature control of eggs in the interval from purchaser to consumer and a more generalized use of pasteurized egg products, no only in the industry but also in the household.

[Evaluation of blood cultures in anaerobiosis]. / Evaluación de los hemocultivos en anaerobiosis.

BACKGROUND: The rate of processed blood cultures from anaerobic bottles was checked and the number of isolates from anaerobic microorganisms and other non anaerobic ones from processed bottles was established. Next, we studied the relationship between bacteremia caused by anaerobic organisms and the clinical history. METHODS: A total of 3.540 blood cultures have been checked for a period of 21 months; all of them were processed using Bactec NR 730 system. Those patients suffering bacteremia caused by anaerobic microorganisms had their medical histories revised. There is neither Gynecology nor Pediatrics Services at our Medical Center. RESULTS: Eleven episodes of bacteremias caused by anaerobic microorganisms have been detected since we started our research 21 months ago. Three aerobic microorganisms grew only in the two processed bottles in anaerobiosis, being their respective aerobic cultures negative. In all cases of bacteremia caused by anaerobic bacteria, the clinical history was compatible with this infection. CONCLUSIONS: We consider it is worth keeping the anaerobic bottles, because the number of anaerobic microorganisms isolates is considerable and clinically significant. A 2.76% incidence, where there is not gynecologist hospitalization, seems to be a high and relevant one. An alternative approach is to perform them only under certain clinical circumstances, although the process of collecting samples would make it a difficult task.