Vaccine effectiveness in preventing laboratory-confirmed influenza in Navarre, Spain: 2013/14 mid-season analysis.

We estimate mid-2013/14 season vaccine effectiveness (VE) of the influenza trivalent vaccine in Navarre, Spain. Influenza-like illness cases attended in hospital (n=431) and primary healthcare (n=344) were included. The overall adjusted VE in preventing laboratory-confirmed influenza was 24% (95% CI: -14 to 50). The VE was 40% (95% CI: -12 to 68) against influenza A(H1)pdm09 and 13% (95% CI: -36 to 45) against influenza A(H3). These results suggest a moderate preventive effect against influenza A(H1)pdm09 and low protection against influenza A(H3).

Population-based contact investigation of a cluster of tuberculosis cases in a small village.

A cluster of five cases of tuberculosis (TB) in persons aged 19-23 years who were not close contacts was detected in a small village in Spain in 2006. All culture isolates had the same chromosomal-DNA restriction pattern. Contact investigations of family members, friends, workmates and schoolmates were complemented with tuberculin screening offered to the resident population born between 1976 and 1995. Expanded contact tracing detected two new cases of TB, 27 tuberculin conversions and an excess of latent tuberculosis infections (LTI) in persons born between 1978 and 1990. The contacts of two cases had a significantly elevated prevalence of LTI. Two secondary cases of TB, 33.3% of those diagnosed with LTI and 47.8% of the converters were unaware of any contact with the TB cases, but had frequented some of the same bars. This study suggests that a considerable percentage of the episodes of TB transmission in young people may escape detection in conventional contact studies.

[Clinical relevance of nontuberculous mycobacteria]. / Relevancia clínica de los aislamientos de micobacterias no tuberculosas.

BACKGROUND: The isolation of nontuberculous mycobacteria (NTM) has increased in recent years largely due to the use of liquid cultivation media. In many cases such isolations lack clinical relevance, which is why the evaluation of their meaning must be carried out on the basis of international clinical criteria. This article studies the impact of using the criteria that the American Thoracic Society (ATS) has established for differentiating an infection of NTM colonisation in respiratory samples. METHODS: Microbiological and clinical study of the patients with repeated isolations of NTM in respiratory samples registered in our laboratory between 2000 and 2004. RESULTS: One hundred and sixteen positive cultivations of NTM were obtained, repeatedly isolated in 46 episodes corresponding to 42 patients. Eleven different species were identified: M. xenopi (16 cases), M. avium (12), M. kansasii (7), M. fortuitum (5), M. malmoense (2) and, finally, 1 of each of the following: M. genavense, M. simiae, M. gordonae and M. lentiflavum. It was possible to study 36 patients, of whom 17 met the criteria of the ATS, and, out of these, only 12 received specific treatment. In those cases that did not meet the ATS criteria the isolations did not have any clinical repercussion. In both the treated and untreated groups a clearly differentiated evolution was not observed. CONCLUSIONS: Facing the difficulty of attributing an etiological role to an NTM of respiratory samples, it is necessary to follow international criteria such as those of the ATS before beginning a specific treatment in order to avoid the incorrect treatment of patients.

[Uncomplicated urinary tract infections. Antimicrobial susceptibility study in Navarre]. / Infecciones del tracto urinario. Estudio de sensibilidad antimicrobiana en Navarra.

BACKGROUND: Urinary tract infection (UTI) is a high prevalence infection at the community level. In order to improve the adequacy of the empirical therapy, we evaluated the etiology and the resistance pattern of the main uropathogens responsible for community acquired UTI in Navarre. METHODS: Retrospective study (2014-2016) in which we included microorganisms recovered with significant counts from samples of patients with community-acquired UTI. The global etiology and etiology according to age and sex was analyzed. Antimicrobial resistance was studied with urotopathogens isolated in 2016. RESULTS: Escherichia coli was the most frequently isolated microorganism both in the population (60.8%) and in each of the groups analyzed according to age and sex. The sensitivity of E. coli was: nitrofurantoin 97.4%, fosfomycin 96.5% amoxicillin-clavulanic acid 83.8%, trimethoprim-sulfamethoxazole 68.3%, quinolones 63.4% and amoxicillin 41.9%. Pooled sensitivity shows that the sensitivity to fosfomycin was 83.4% in men <15 years, 89.4% in women <15 years and 81.9% in women between 15-65 years; and to nitrofurantoin was 86.7% in women <15 years and 82.2% in women between 15-65 years. CONCLUSIONS: E. coli continues to be the most frequent microorganism in community-acquired UTI with a rate of sensitivity to fosfomycin and nitrofurantoin above 95%. The empirical treatment of UTI in our environment should not include amoxicillin, amoxicillin-clavulanic acid, trimethoprim-sulfamethoxazole or quinolones. Fosfomycin may be empirically used in the treatment of uncomplicated cystitis in men younger than 15 years and in women under 65 years, and nitrofurantoin may be used empirically in women under 65 years.

[Comparative study of HIV-1/2 antibody confirmatory assay: Geenius™ versus INNO-LIA™]. / Estudio comparativo de técnicas confirmatorias de anticuerpos frente VIH-1/2: Geenius™versus INNO-LIA™.

OBJECTIVE: The aim of the study is to compare two confirmatory tests for HIV-1/2 infection. METHODS: A prospective study was carried out between 01/01/2015 and 12/31/2015. Serum samples with repeatedly positive results in the Antibody-Antigen-HIV-1/2 (Architect, Abbott) screening assay were included. The serum samples corresponding to new diagnosed cases were selected and were used to compare the two confirmatory assays: Geenius™ HIV-1/2 (Bio-Rad) and INNO-LIA™ HIV-1/2 score line-immunoassay (Innogene-tics®). The HIV-1 viral load (Cobas® AmpliPrepHIV, Ro-che) was performed in discordant or indeterminate cases. RESULTS: Eight five samples were included. The results of both confirmatory assays were concordant in 80/85 samples: 53 HIV-1, 1 HIV-2, 25 negative and one indeterminate. Cohen's Kappa concordance coefficient between Geenius™ and INNO-LIA™ techniques was very high (0.878). CONCLUSIONS: The concordance between the two assays is high. The procedure for Geenius™ is simple and fast. Geenius™ is a good alternative to include in the HIV-1/2 diagnostic algorithm.

[Study of the resistance of Mycobacterium tuberculosis to the principal tuberculostatics (Hospital of Navarra 1996-2003)]. / Estudio de la resistencia de Mycobacterium tuberculosis a los principales tuberculostáticos (Hospital de Navarra 1996-2003).

INTRODUCTION: The aim of this study was to evaluate the sensitivity to the principal tuberculostatics of the M. tuberculosis stocks isolated in our laboratory and to study the factors related to resistance. METHODS: Study of 475 stocks of M. tuberculosis corresponding to all cases diagnosed in the eight year period between 1996 and 2003. We employed the BACTEC 460TB system, together with Lowenstein solid medium, in the cultivation of the samples. The sensitivity studies were carried out using the BACTEC 460TB system. RESULTS AND CONCLUSIONS: Both the incidence and the number of cases of resistant tuberculosis showed oscillations over the eight years of the study. The fact that there is no homogeneous tendency makes it necessary to maintain active surveillance of this process. Global resistance to isoniacide was 8%, making it is convenient to carry out sensitivity studies in all the diagnosed cases. The cases of multiresistant tuberculosis (resistant to at least isoniacide and rifampicin), did not exceed 3%. The prognosis of the patients with resistant tuberculosis was bleak in cases of coinfection with HIV; however, when the immunological defences were conserved, and guidelines for treatment with active drugs were provided, the recovery of the majority of the patients was achieved. At present, sensitive and rapid procedures are available to us, making it recommendable to study the sensitivity of all the stocks of M. tuberculosis that are isolated; this is essential in the case of HIV positive or immigrant patients.

[Evaluation of the MTD-2 test for the direct detection of Mycobacterium tuberculosis in specimens]. / Valoración de la prueba de amplificación MTD-2 para la detección directa de Mycobacterium tuberculosis en la muestra.

BACKGROUND: To evaluate the utility of the Amplified Mycobacterium Tuberculosis Direct Test (MTD-2, Gen-Probe) in the microbiological diagnosis of tuberculosis. METHODS: We evaluated the results obtained in 146 specimens with the MTD-2 test, together with those of the culture and smears. The MTD-2 test was performed on all the smear positives specimens (n=47), on the smear-negative specimens, when the test was demanded (n=19), and in other smear-negative specimens previously selected, according to the clinical history of the patient (n=80). We considered real cases of tuberculosis, those that were culture positive for Mycobacterium tuberculosis and those that were specifically treated. RESULTS: The overall sensitivity, specificity, positive and negative predictive values for the MTD test were: 95, 76, 71, and 96%, for the culture; and 84, 100, 100 and 90% and 75, 94, 89 and 86% for the smears, respectively. In smear positive specimens, the test showed a great specificity, and differentiated M. tuberculosis from other mycobacteria. In the smear negatives, the sensitivity of the test was low and so was the positive predictive value, especially in series performed with a high work load. CONCLUSIONS: Data from our study show that the MTD-2 test is a reliable method for rapid diagnosis of tuberculosis in smear positive specimens. However, due to its low sensitivity and positive predictive value, it is not recommended in the routine diagnosis of tuberculosis. Also, for this reason, whenever a positive result is obtained with a smear negative specimen, the result needs to be confirmed with another specimen.

[State of methicillin resistant Staphylococcus aureus in the Hospital of Navarre (2000-2002)]. / Situación de Staphylococcus aureus resistente a meticilina en el Hospital de Navarra (2002-2002).

BACKGROUND: The aim of the present paper was to determine the prevalence and characteristics shown by isolations of Methicillin Resistant Staphylococcus Aureus, isolated in our Microbiology Service. METHODS: Retrospective study, covering the years 2000, 2001 and 2002. Analysis was made of the origin of the infection (nosocomial or non-nosocomial), the unit of origin in the event of nosocomial origin, anatomical localisation of the sample, and pattern of antibiotic sensitivity. RESULTS: The isolations of Methicillin Resistant Staphylococcus aureus accounted for 7.88% of the Staphylococcus aureus isolated. Less than half of the strains (44.87%) had a nosocomial origin and were most often isolated in the exudates of wounds. With respect to the pattern of resistance, there was some 50% of resistance to erythromycin, some 43.60% to clindamycine and some 21.79% to mupirocin. CONCLUSIONS: The prevalence and resistance pattern in vitro of the isolations of Methicillin Resistant Staphylococcus Aureus in our hospital are lower than that published in other areas of Spain.

[Spontaneous bacterial peritonitis and bacteraemia due to Aeromonas hydrophila]. / Peritonitis bacteriana espontánea y bacteriemia por Aeromonas hydrophila.

Bacterial peritonitis is a frequent complication in cirrhotic patients. Amongst the aetiological germs, Aeromonas is very infrequent. We present the clinical case of a cirrhotic patient with peritonitis and bacteraemia due to Aeromonas hydrophila. This micro-organism is a Gram-negative bacillus of the Vibrionaceae family. It very frequently produces gastroenteritis in the human being. Exceptionally it can give rise to extraintestinal infections, especially in immunodepressed patients. Peritonitis due to Aeromonas has been described in association with spontaneous bacterial peritonitis in cirrhotic patients, in patients on peritoneal dialysis and in cases of peritonitis secondary to intestinal perforation.

[Resistance to penicillin and other antimicrobials in 103 clinical isolations of Streptococcus pneumoniae (2000-2001)]. / Resistencia a penicilina y otros antimicrobianos en 103 aislamientos clínicos de Streptococcus pneumoniae (2000-2001).

BACKGROUND: To determine in our hospital the sensitivity of isolations of Streptococcus pneumoniae to penicillin, as well as to analyse the association of resistance to penicillin and other antimicrobials and the activity of cefotaxime and cefepime in pencillin resistant strains of Streptococcus pneumoniae. METHODS: The sensitivity was determined on 103 isolations of Streptococcus pneumoniae, from clinical samples from the years 2000-2001, to penicillin, eritromycine, cloramfenicol, tetracycline, cotrimoxazol, cefotaxime, cefepime and levofloxacine. RESULTS: Sixty-eight percent of the isolations were sensitive to penicillin, while some 32% of the isolated strains of Streptococcus pneumoniae were penicillin resistant, with 7.7% showing a high degree of resistance. Resistance to eritromycine, cloramfenicol, tetracycline, cotrimoxazol and levofloxacine was 38.8%; 9.7%; 20.4%; 25.2% and 2.9% respectively, increasing to values of 66.6%; 30.3%; 48.5%; 72.7% and 9.1% in the 33 penicillin resistant strains. Resistance to cefotaxime and cefepime was 9.7% and 10.6% respectively. CONCLUSIONS. A high percentage of strains of Streptococcus pneumoniae show some degree of resistance to penicillin, but with lower figures than in other studies carried out at a national level. Similarly, it was demonstrated that resistance to penicillin is significantly associated (p < 0.001) with resistance to all the antimicrobials studied, except for levofloxacine. The resistances to cefotaxime and cefepime were comparable, with less activity being observed in these when facing penicillin resistant strains of Streptococcus pneumoniae.

[Bacteremia and hepatic abscess caused by Yersinia enterocolitica]. / Bacteriemia y absceso hepático causado por Yersinia enterocolitica.

Yersinia enterocolitica is a Gram-negative coccobacillus that is distributed world-wide and whose natural reservoir is found in a great variety of animals. Transmission to humans mainly occurs through the faecal-oral path although cases have been described of transmission through blood transfusions. It is isolated within a gastro-intestinal clinical picture and it rarely produces extra-intestinal disorders such as bacteraemia, abscesses, cutaneous signs, etc. The latter have been associated with different underlying diseases such as alterations of the iron metabolism, diabetes mellitus, alcoholism, malnutrition, tumours, immunosuppressant therapy and cirrhosis. We present the case of a diabetic patient who developed bacteraemia associated with hepatic abscess due to Yersinia enterocolitica.

Infecciones del tracto urinario. Estudio de sensibilidad antimicrobiana en Navarra / Uncomplicated urinary tract infections. Antimicrobial susceptibility study in Navarre

Fundamento: La infección del tracto urinario (ITU) tiene una elevada prevalencia en atención primaria. Con el fin de mejorar el tratamiento empírico se ha estudiado la etiología y el perfil de resistencia antibiótica de las bacterias más frecuentes productoras de ITU comunitaria en Navarra. Material y métodos: Estudio retrospectivo (2014-2016) en el que se incluyeron los microorganismos aislados con recuento significativo en muestras de orina de pacientes con ITU. Se analizó la etiología global y en función de la edad y sexo. El estudio de sensibilidad se realizó con los aislamientos del 2016. Resultados: Escherichia coli fue el microorganismo más aislado tanto en el conjunto de la población (60,8%) como en cada uno de los grupos analizados según edad y sexo. Su sensibilidad fue: nitrofurantoína 97,4%, fosfomicina 96,5%, amoxicilinaácido clavulánico 83,8%, trimetoprim-sulfametoxazol 68,3%, quinolonas 63,4% y amoxicilina 41,9%. Los datos de sensibilidad ponderada muestran que la sensibilidad a fosfomicina fue 83,4% en varones <15 años, 89,4% en mujeres <15 años y 81,9% en mujeres entre 15-65 años, y a nitrofurantorina 86,7% en mujeres <15 años y 82,2% en mujeres entre 15-65 años. Conclusiones: E. coli continua siendo el microorganismo más frecuente en ITU de origen comunitario con sensibilidad a fosfomicina y nitrofurantoína superior al 95%. El tratamiento empírico de ITU en nuestro medio debería excluir amoxicilina, amoxicilina-ácido clavulánico, trimetoprim-ulfametoxazol y quinolonas. Fosfomicina puede emplearse de forma empírica en el tratamiento de cistitis no complicada en varones menores de 15 años y en mujeres menores de 65 años y nitrofurantoína en mujeres menores de 65 años

Background: Urinary tract infection (UTI) is a high prevalence infection at the community level. In order to improve the adequacy of the empirical therapy, we evaluated the etiology and the resistance pattern of the main uropathogens responsible for community acquired UTI in Navarre. Methods: Retrospective study (2014-2016) in which we included microorganisms recovered with significant counts from samples of patients with community-acquired UTI. The global etiology and etiology according to age and sex was analyzed. Antimicrobial resistance was studied with urotopathogens isolated in 2016. Results: Escherichia coli was the most frequently isolated microorganism both in the population (60.8%) and in each of the groups analyzed according to age and sex. The sensitivity of E. coli was: nitrofurantoin 97.4%, fosfomycin 96.5% amoxicillin-clavulanic acid 83.8%, trimethoprim-sulfamethoxazole 68.3%, quinolones 63.4% and amoxicillin 41.9%. Pooled sensitivity shows that the sensitivity to fosfomycin was 83.4% in men <15 years, 89.4% in women <15 years and 81.9% in women between 15-65 years; and to nitrofurantoin was 86.7% in women <15 years and 82.2% in women between 15-65 years. Conclusions: E. coli continues to be the most frequent microorganism in community-acquired UTI with a rate of sensitivity to fosfomycin and nitrofurantoin above 95%. The empirical treatment of UTI in our environment should not include amoxicillin, amoxicillin-clavulanic acid, trimethoprim-sulfamethoxazole or quinolones. Fosfomycin may be empirically used in the treatment of uncomplicated cystitis in men younger than 15 years and in women under 65 years, and nitrofurantoin may be used empirically in women under 65 years

Comparación de las características clínicas y diagnósticas de los subgrupos A y B del virus respiratorio sincitial / Comparison of clinical features and diagnosis between the A and B subgroups of respiratory syncytial virus

Fundamento: La infección del tracto respiratorio inferior por virus respiratorio sincitial (VRS) es la causa más frecuente de ingreso en menores de 2 años. Los subgrupos de VRS A y B pueden circular indistintamente. Nuestro objetivo fue determinar si existían diferencias clínicas entre los VRS subgrupo A y B, y si la sensibilidad del test de detección rápida de antígeno del VRS por inmunocromatografía difiere de la técnica de referencia (RT-PCR). Material y métodos: Estudio retrospectivo, observacional realizado en el hospital terciario desde octubre de 2013 a marzo de 2014. Se consultó la historia clínica y las analíticas de los niños menores de 5 años ingresados en por infección respiratoria de vías bajas con RT-PCR positivo a VRS en una muestra de lavado nasal. De la misma muestra previamente se había realizado el test de detección rápida de antígeno de VRS. Resultados: Se confirmaron 198 niños menores de 5 años para VRS mediante RT-PCR: 55 (28%) fueron VRS-A, 132 (67%) VRS-B y 11 (5%) fueron positivos para ambos subgrupos. No encontramos diferencias entre subgrupos en antecedentes, clínica, radiología, analítica y gravedad. La sensibilidad del test de detección rápida fue 52%, mayor para VRS-A (69%) que para VRS-B (44%, p=0,001). Conclusiones: Los dos subgrupos de VRS fueron indistinguibles por su presentación clínica y pronóstico. La sensibilidad del test rápido en comparación con la RT-PCR fue baja, lo que limita su utilidad en la toma de decisiones clínicas (AU)

Background: Lower respiratory tract infection by respiratory syncytial virus (RSV) is the most frequent cause of admission in children under 2 years old. The RSV subgroups A and B may circulate simultaneously. We aimed to determine whether clinical differences exist between RSV subgroups A and B. Additionally, we tested the sensitivity of the rapid antigen detection test (RADT) based on immunochromatography in diagnosing subgroups A and B, taking the polymerase chain reaction assay (RT-PCR) as reference. Methods: A retrospective observational study was performed in a tertiary hospital from October 2013 to March 2014. Clinical records and analytical variables of all children under 5 admitted with lower respiratory tract infection and RT-PCR positive for RSV in nasal lavage were consulted. Previously, the RADT for RSV had been performed from the same sample. Results: A total of 198 children under 5 were diagnosed with RSV by RT-PCR: 55 (28%) were RSV-A, 132 (67%) RSVB and 11 (5%) were positive for both subgroups. No differences were observed between subgroups in medical history, symptoms, radiological and analytical findings, and severity. The sensitivity of RADT for RSV was 52%, higher for RSV-A (69%) than for RSV-B (44%, p=0.001). Conclusions: The two RSV subgroups were indistinguishable in symptoms and prognosis. The sensitivity of RADT compared to RT-PCR was low and limits its usefulness for clinical decision-making (AU)

[Loa Loa and Mansonella perstans coinfection in a patient from Guinea]. / Coinfección por dos filarias (Loa loa y Mansonella perstans) en una paciente proveniente de Guinea.

We present a case of mixed infection by two filariae (Loa loa and Mansonella perstans). It seems that the infection was suspected due to a pronounced eosinophilia in a routine analysis. Sheathed and unsheathed microfilariae were observed in the spread of peripheral blood, which enabled a diagnosis to be established of mixed infection by filariae. The definitive diagnosis of the species was carried out at the National Centre of Microbiolgy of Majadahonda. A treatment was initiated with dietilcarbamazina and mebendazole which resulted in the patient's being cured and in the elimination of the microfilariae in the patient's blood. Filariasis is still endemic in many countries. Due to the increase of travellers to such zones and the migratory movements from such areas it is not unusual for us to come across such a diagnosis. The implantation of massive treatments against filariae in endemic zones by the World Health Organisation is reducing their transmission and is managing to eliminate the disease in some areas.

Confección por dos filarias (Loa loa y Mansonella perstans) en una paciente proveniente de Guinea / Loa Loa and Mansonella perstans coinfection in a patient from Guinea

Presentamos un caso de una infección mixta por 2filarias (Loa loa y Mansonella perstans). La infección sesospechó, al aparecer, una marcada eosinofilia en unaanalítica de rutina. En la extensión de sangre periféricase observaban microfilarias envainadas y sin envainar,con lo que se estableció un diagnóstico de infecciónmixta por filarias. El diagnóstico definitivo de especiese realizó en el Centro Nacional de Microbiología deMajadahonda. Se instauró un tratamiento con dietilcarbamicinay mebendazol que conllevó la curación de lossíntomas de la paciente y la eliminación de las microfilariasen sangre.La filariasis es todavía endémica en muchos países.Debido al aumento de viajeros a dichas zonas y alos movimientos migratorios desde dichas áreas, no esinfrecuente enfrentarnos a su diagnóstico. La implantaciónde tratamientos masivos contra las filarias en zonasendémicas por parte de la Organización Mundial dela Salud está disminuyendo su transmisión, consiguiendola eliminación de la enfermedad en algunas áreas(AU)

We present a case of mixed infection by two filariae(Loa loa and Mansonella perstans). It seems that theinfection was suspected due to a pronounced eosinophiliain a routine analysis. Sheathed and unsheathedmicrofilariae were observed in the spread of peripheralblood, which enabled a diagnosis to be established ofmixed infection by filariae. The definitive diagnosis ofthe species was carried out at the National Centre ofMicrobiolgy of Majadahonda. A treatment was initiatedwith dietilcarbamazina and mebendazole which resultedin the patient’s being cured and in the elimination ofthe microfilariae in the patient’s blood.Filariasis is still endemic in many countries. Due tothe increase of travellers to such zones and the migratorymovements from such areas it is not unusual forus to come across such a diagnosis. The implantationof massive treatments against filariae in endemic zonesby the World Health Organisation is reducing theirtransmission and is managing to eliminate the diseasein some areas(AU)

Resistencias de M. tuberculosis complex en Navarra: diferencias entre población autóctona e inmigrante (2000-2007) / M. tuberculosis complex drug resistance in Navarre: differences between the local and immigrant populations

Fundamento. La tuberculosis es un importante problemade salud pública, cuya epidemiología ha cambiadoen los últimos años en nuestro país debido al aumentode población inmigrante. El objetivo de este trabajo hasido valorar la frecuencia de resistencias a los cuatroantituberculosos principales, tanto en población autóctonacomo inmigrante.Material y métodos. Se han estudiado los antibiogramasde 457 aislamientos de Mycobacterium tuberculosisrealizados en el Hospital de Navarra en el periodo 2000-2007. Los antibiogramas fueron procesados mediante elsistema BACTEC460TB.Resultados. El 26,3% de las cepas correspondieron a inmigrantes,produciéndose a lo largo del periodo un incrementosignificativo. Las frecuencias de resistenciasa los distintos fármacos antituberculosos en poblaciónautóctona e inmigrante, respectivamente fueron: a almenos uno 5,6% vs 20,8% (p <0,001), a isoniacida 4,5%vs 14,2% (p <0,001), a estreptomicina 2,4% vs 12,5% (p<0,001), a rifampicina 0,9% vs 5% (p <0,05), a etambutol0,3% vs 2,5% (p <0,05) y multirresistencia 0,3% vs 2,5%(p <0,05).Conclusión. Existen diferencias significativas entre lapoblación autóctona e inmigrante en el patrón de resistenciasde las cepas aisladas. Esta última, debidoa la alta frecuencia con que presenta resistencia a laisoniacida, debe tratarse inicialmente con una pautade cuatro fármacos hasta disponer del resultado del antibiograma(AU)

Background. Tuberculosis is an important publichealth problem, whose epidemiology in our countryhas changed in recent years due to the increase in theimmigrant population. The aim of this article is to evaluatethe frequency of resistance to the four principalantitubercular drugs in both the local and immigrantpopulations.Methods. A study was made of the antibiograms of 457isolations of Mycobacterium tuberculosis carried out inthe Hospital of Navarre in 2000-2007. The antibiogramswere processed using the BACTEC460TB system.Results. Twenty six point three percent of the strainscorresponded to immigrants, with a significant increaseoccurring over the period. The frequencies of resistancesto the different antitubercular drugs in the local andimmigrant populations respectively were: to at leastone 5.6% vs 20.8% (p <0.001); to isoniazid 4.5% vs 14.2%(p <0.001); to streptomycin 2.4% vs 12.5% (p <0.001);to rifampicin 0.9% vs 5% (p <0.05); to ethambutol 0.3%vs 2.5% (p <0.05); and multiresistance 0.3% vs 2.5% (p<0.05).Conclusion. There are significant differences betweenlocal and immigrant populations in the pattern of resistancesof the strains isolated. The immigrant population,due to the high frequency with which resistanceis shown to isoniazid, must be treated initially with apattern of four drugs until the result of the biogram is available(AU)

Relevancia clínica de los aislamientos de micobacterias no tuberculosas / Clinical relevance of nontuberculous Mycobacteria

Fundamento: El aislamiento de micobacterias no tuberculosas (MNT) se ha incrementado en los últimos años debido en gran parte a la utilización de medios de cultivo líquidos. Estos aislamientos carecen en muchos casos de relevancia clínica, por lo que la valoración de su significado debe realizarse en base a unos criterios clínicos internacionales. En el presente trabajo hemos estudiado el impacto que supondría la aplicación de los criterios que la American Thoracic Society (ATS) ha establecido para diferenciar en muestras respiratorias una infección de una colonización por MNT. Métodos: Estudio microbiológico y clínico de los pacientes con aislamientos repetidos de MNT en muestras respiratorias registrados en nuestro laboratorio entre los años 2000-2004. Resultados: Se obtuvieron 116 cultivos positivos de MNT aisladas repetidamente en 46 episodios correspondientes a 42 pacientes. Se identificaron 11especies distintas: M. xenopi (16 casos), M. avium (12), M. kansasii (7), M. fortuitum (5), M. malmoense (2) y finalmente 1 de cada una de las siguientes: M. genavense, M. simiae, M. gordonae y M. lentiflavum. Se pudieron estudiar 36 pacientes, de los que 17 cumplían los criterios de la ATS y, de estos, sólo 12 recibieron tratamiento específico. En los casos que no se cumplían los criterios de la ATS los aislamientos no tuvieron ninguna repercusión clínica. En ambos grupos, tratados y no tratados, no se observó una evolución claramente diferenciada. Conclusiones: Ante la dificultad de atribuir a una MNT de muestras respiratorias un papel etiológico, es necesario atenerse a criterios internacionales como los de la ATS antes de iniciar un tratamiento específico para evitar tratamientos incorrectos a los pacientes (AU)

Background: The isolation of non tuberculous mycobacterias (NTM) has increased in recent years largely due to the use of liquid cultivation media. In many cases such isolations lack clinical relevance, which is why the evaluation of their meaning must be carried out on the basis of international clinical criteria. This article studies the impact of using the criteria that the American Thoracic Society (ATS) has established for differentiating an infection of NTM colonization in respiratory samples. Methods: Microbiological and clinical study of the patients with repeated isolations of NTM in respiratory samples registered in our laboratory between 2000and 2004.Results. One hundred and sixteen positive cultivations of NTM were obtained, repeatedly isolated in 46episodes corresponding to 42 patients. Eleven different species were identified: M. xenopi (16 cases), M.avium (12), M. kansasii (7), M. fortuitum (5), M. malmoense (2) and, finally, 1 of each of the following: M. genavense, M. simiae, M. gordonae and M. lentiflavum. It was possible to study 36 patients, of whom 17 met the criteria of the ATS, and, out of these, only 12 received specific treatment. In those cases that did not meet the ATS criteria the isolations did not have any clinical repercussion. In both the treated and untreated groups a clearly differentiated evolution was not observed. Conclusions: Facing the difficulty of attributing an etiological role to an NTM of respiratory samples, it is necessary to follow international criteria such as those of the ATS before beginning a specific treatment in order to avoid the incorrect treatment of patients (AU)

Valoración de la prueba de amplificación MTD-2 para la detección directa de Mycobacterium tuberculosis en la muestra / Evaluation of the MTD-2 test for the direct detection of Mycobacterium tuberculosis in specimens

Fundamento. Valorar la rentabilidad de la prueba Amplified Mycobacterium Tuberculosis DirecVt Test (MTD-2, Gen-Probe) en el diagnóstico microbiológico de la tuberculosis.Métodos. Se valoraron los resultados obtenidos con la prueba MTD-2 realizada en 146 muestras, junto con los del cultivo y baciloscopia. MTD-2 se realizó en todas las muestras con baciloscopia positiva (n=47) y en muestras con baciloscopia negativa, si había sido solicitada por el clínico (n=19); además, se testaron una serie de muestras seleccionadas en el laboratorio en base a los datos clínicos y a la calidad de la muestra (n=80). Se consideraron casos de tuberculosis aquellos en los que se aisló Mycobacterium tuberculosis y los que fueron tratados como tales.Resultados. Los resultados de sensibilidad, especificidad, valor predictivo positivo y negativo de la MTD-2 fueron: 95, 76, 71 y 96%. Para el cultivo: 84, 100, 100, y 90% y para la baciloscopia: 75, 94, 89 y 86% respectivamente. En las muestras con baciloscopia positiva, MTD-2 mostró una alta especificidad, diferenciando las que correspondían a M. tuberculosis de las debidas a otras micobacterias. En las muestras con baciloscopia negativa, la sensibilidad no alcanzó los niveles deseados y se obtuvo un bajo valor predictivo positivo. Conclusiones. MTD-2 ha demostrado ser de gran utilidad en muestras con baciloscopia positiva pues en pocas horas permite diagnosticar una tuberculosis o excluirla. Sin embargo, no nos parece recomendable su empleo en el diagnóstico rutinario de la tuberculosis, debido a su bajo valor predictivo positivo. Por esto, siempre que sea positiva en una muestra con baciloscopia negativa, éste resultado debe ser confirmado con otra muestra

Background. To evaluate the utility of the Amplified Mycobacterium Tuberculosis Direct Test (MTD-2, Gen-Probe) in the microbiological diagnosis of tuberculosis.Methods. We evaluated the results obtained in 146 specimens with the MTD-2 test, together with those of the culture and smears. The MTD-2 test was performed on all the smear positives specimens (n=47), on the smear-negative specimens, when the test was demanded (n=19), and in other smear-negative specimens previously selected, according to the clinical history of the patient (n=80). We considered real cases of tuberculosis, those that were culture positive for Mycobacterium tuberculosis and those that were specifically treated.Results. The overall sensitivity, specificity, positive and negative predictive values for the MTD test were: 95, 76, 71, and 96%, for the culture; and 84, 100, 100 and 90% and 75, 94, 89 and 86% for the smears, respectively. In smear positive specimens, the test showed a great specificity, and differentiated M. tuberculosis from other mycobacteria. In the smear negatives, the sensitivity of the test was low and so was the positive predictive value, especially in series performed with a high work load.Conclusions. Data from our study show that the MTD-2 test is a reliable method for rapid diagnosis of tuberculosis in smear positive specimens. However, due to its low sensitivity and positive predictive value, it is not recommended in the routine diagnosis of tuberculosis. Also, for this reason, whenever a positive result is obtained with a smear negative specimen, the result needs to be confirmed with another specimen

Estudio de la resistencia de Mycobacterium tuberculosis a los principales tuberculostáticos (Hospital de Navarra 1996-2003) / Study of the resistance of Mycobacterium tuberculosis to the principal tuberculostatics (Hospital of Navarra 1996-2003)

Introducción. El objeto de este trabajo ha sidovalorar la sensibilidad a los principales tuberculostáticosde las cepas de M. tuberculosis aisladas en nuestrolaboratorio y estudiar los factores relacionados con laresistencia.Material y métodos. Se han estudiado 475 cepasde M. tuberculosis correspondientes a la totalidad delos casos diagnosticados entre los años 1996-2003ambos inclusive.En el cultivo de las muestras, se utilizó el sistemaBACTEC 460TB, junto con el medio sólido de Lowenstein.Los estudios de sensibilidad se realizaron medianteel sistema BACTEC 460TB.Resultados y conclusiones. Tanto la incidencia,como el número de casos de tuberculosis resistentes,se presentaron con oscilaciones a lo largo de los 8 añosdel estudio. El hecho de que no exista una tendenciahomogénea, obliga a mantener una vigilancia activafrente a este proceso.La resistencia global a isoniacida fue del 8%, por loque es conveniente realizar estudios de sensibilidad entodos los casos diagnosticados.Los casos de tuberculosis multirresistentes (resistentesal menos a isoniacida y rifampicina), no superaronel 3%.El pronóstico de los pacientes con tuberculosisresistente fue sombrío en los casos de coinfección conel VIH, sin embargo, cuando las defensas inmunológicasestaban conservadas, y se pautó un tratamientocon drogas activas, se consiguió la recuperación de lamayoría de los pacientes.En la actualidad, disponemos de procedimientossensibles y rápidos que hacen recomendable el estudiode sensibilidad en todas las cepas de M. tuberculosisaisladas, y en el caso de pacientes VIH+ o inmigrantes,resulta imprescindible

Introduction. The aim of this study was toevaluate the sensitivity to the principaltuberculostatics of the M. tuberculosis stocks isolatedin our laboratory and to study the factors related toresistance.Methods. Study of 475 stocks of M. tuberculosiscorresponding to all cases diagnosed in the eight yearperiod between 1996 and 2003.We employed the BACTEC 460TB system, togetherwith Lowenstein solid medium, in the cultivation of thesamples. The sensitivity studies were carried out usingthe BACTEC 460TB system.Results and conclusions. Both the incidence andthe number of cases of resistant tuberculosis showedoscillations over the eight years of the study. The factthat there is no homogeneous tendency makes itnecessary to maintain active surveillance of thisprocess.Global resistance to isoniacide was 8%, making itis convenient to carry out sensitivity studies in all thediagnosed cases.The cases of multiresistant tuberculosis (resistantto at least isoniacide and rifampicin), did not exceed3%.The prognosis of the patients with resistanttuberculosis was bleak in cases of coinfection with HIV;however, when the immunological defences wereconserved, and guidelines for treatment with activedrugs were provided, the recovery of the majority ofthe patients was achieved.At present, sensitive and rapid procedures areavailable to us, making it recommendable to study thesensitivity of all the stocks of M. tuberculosis that areisolated; this is essential in the case of HIV positive orimmigrant patients