[Resistance of Mycobacterium tuberculosis in the province of Castellón]

Impacto de la inmigración en las resistencias de Mycobacterium tuberculosis en la provincia de Castellón: 1995-2003

BACKGROUND AND OBJECTIVE

The aim of this study was to know the frequency of resistant Mycobacterium tuberculosis in the province of Castellon (Spain) and to determine whether immigration is associated with resistance.

MATERIAL AND METHOD

All culture-positive cases diagnosed in Castellon from January 1995 to December 2003 were included in this retrospective study. Susceptibility tests were performed using the Canetti's proportion method and the MB/BacT system. Risk factors associated with tuberculosis were investigated in every case.

RESULTS

Six hundred and forty-four cases of tuberculosis were studied: 560 were Spaniards and 84 foreigners. The overall frequency of resistant strains was 5%. The total rate of resistance in Spaniards was 3.7% and in foreigners 13.1%. In Spanish new cases, drug resistance was 3.2% and in foreigners new cases it was 13.9%. In previously treated cases, drug resistance was 6.7% in Spaniards and 0% in immigrants. No acquired drug resistance was detected in immigrants. Of those strains with resistance, 71.9% had resistance to only one drug, 18.7% to two drugs and 9.4% to more than two drugs. Multidrug-resistance was found in 9.4% of the resistant cases, and in 0.5% of all the studied population. The presence of resistant Mycobacterium tuberculosis was associated with the fact of having a foreign nationality (OR = 3.87; p < 0.001).

CONCLUSIONS

Tuberculosis has been diminishing in Spanish patients in Castellon. Nevertheless, there is an important increase in the number of cases in foreigners, which is associated with a major percentage of resistances. Epidemiological vigilance efforts should especially concentrate on this group in order to support the progressive declivity of the disease.

[Resistance of Mycobacterium tuberculosis in Zaragoza, Spain (1993-1997) and related factors]

BACKGROUND

To know the frequency of resistance of Mycobacterium tuberculosis in a general hospital and the related factors.

PATIENTS AND METHOD

Transversal study of the sensitivity of Mycobacterium tuberculosis in the Hospital Miguel Servet (Zaragoza, Spain) between 1993-1997; the proportions method was used to study the susceptibility. Statistical analysis of conventional tests and significance level at p < 0.05 were performed.

RESULTS

Four hundred and twenty height patients with culture-positive to Mycobacterium tuberculosis were studied; 136 (31.8%) were HIV+, 121 (28.3%) were HIV and in 171 (39.9%) this situation was unknown. In 47 patients (10.9%) the strains isolated were resistant at least to one drug. Primary resistance was 5.9% (22 patients) and acquired resistance was 42.4% (25 patients). Primary resistance in HIV+ patients was 9. 2% and in HIV patients was 7.5%; acquired resistance in HIV+ patients was greater than in HIV patients (51.8% vs 42.8%). When we compared the resistances between both HIV+ and HIV patients we did not find significant differences. Twenty isolates (4.7%) were resistant to more than one drug and 10 (2.3%) were resistant to at least isoniazid and rifampin. The risk factors for acquired resistance were alcohol (odds ratio [OR] = 2.65; 95% CI, 1.24-5.65), drugs users (OR = 2.33; 95% CI, 1.05-5.17), previous episodes of tuberculosis (OR = 109.40; 95% CI, 15.02-796.43) and homeless (OR = 3.75; 95% CI, 1.26-11.17); we did not find significant differences between the different risk factors according to primary resistance.

CONCLUSIONS

On one study, the resistance of M. tuberculosis is similar to other described in Spain. We haven't found significant differences between both seropositive and seronegative patients. The risk factors for acquired resistance were alcoholism, drug users, previous episodes of tuberculosis and homeless.

[Drug resistance in Mycobacterium tuberculosis. A multicenter study of the Barcelona area. Grupo de Trabajo sobre Resistencias en Tuberculosis]

BACKGROUND

The aims of this multicenter study was to establish the level of primary and acquired drug resistance of M. Tuberculosis strains isolated in Barcelona and to identify possible risk groups using clinical data.

PATIENTS AND METHODS

All tuberculosis patients with isolation and identification of M. tuberculosis strains from October 1995 to September 1997 were included. Susceptibility tests isoniazid, rifampin, ethambutol, streptomycin and pyrazinamide were performed using the Bactec 460 system and the proportions method on solid medium. Logistic progression was used for statistical analysis.

RESULTS

The total number of patients included was 1,749 (1,535 non-treated and 214 previously treated). Primary drug resistance was 5.7% (isoniazid 3.8%; rifampin 1.0%, streptomycin 2.1%, ethambutol 0.3% and pyrazinamide 1.0%). Acquired drug resistance was 20.5% (isoniazid 17.3%, rifampin 9.8%, ethambutol 1.9%, streptomycin 4.7% and pyrazinamide 6.5%). Primary drug resistance was associated with people over 60 years old and women.

CONCLUSIONS

The low level of drug resistance enables antituberculosis treatment of non-treated patients to start with the standardised three-drug regimes except in the case of foreign people from countries with a high level of drug resistance. Susceptibility tests are recommended on all M. tuberculosis strains isolated, together with controlled studies of drug resistance surveillance.

[Characteristics of tuberculosis in a tertiary hospital during the years 1993-1996. Influence of the coinfection with HIV]

To assess and compare epidemiological factors, clinical and radiological signs, laboratory results and drug resistance in patients with tuberculosis (TB) with and without AIDS. Retrospective study of TB diagnosed bacteriologically between January 1993 and December 1996 at Hospital Universitario La Fe. Annual rates were 41.7, 47.1, 34.6 and 43.8 per 100,000 inhabitants in 1993 to 1996, respectively. AIDS was present in 22.4%. TB was pulmonary in 87% and 49.4% in patients without and with AIDS, respectively. Incidence was higher in the 25 to 34 age range. Prior contact with TB patients was established in 19.2% of cases. Pulmonary TB in patients with AIDS presented with normal lung X-rays in 30.1%; 16.2% of these had positive sputum cultures. Pulmonary cavitation was evident in 32.6% of TB patients without AIDS and 6.8% of those with AIDS. Pulmonary TB was diagnosed by culture of sputum taken at the time of admission in 25.9% of non AIDS patients and in 12.4% of patients with AIDS. Extrapulmonary TB was diagnosed by culture in most cases. Such forms predominated among TB plus AIDS patients, with most cases being ganglial and urogenital. Overall drug resistance was 8.3% (7.4% non-AIDS/11.5% AIDS). Primary resistance (PR) was 6.3% and 7.1%, PR to hydrazides was 5% and 5.4%, and secondary resistance was 32.4% and 33.3%. Drug resistance in non-AIDS and AIDS patients, was associated with a history of TB and past treatment (p < 0.009), prior contact with TB patients (p < 0.004) and pulmonary cavitatin (p < 0.02). TB with AIDS tends to occur in a younger population, is often extrapulmonary or with atypical lung involvement. Drug resistance is similar in patients with and without AIDS.