Drug-resistance of Mycobacterium tuberculosis in Patras, Greece

The global distribution of drug resistant tuberculosis reflects the quality of tuberculosis control worldwide and is still a major public health-problem. To our knowledge, no data exists in literature about resistance to anti-tuberculosis drugs in Greece.

The aim of this study was to determine the prevalence of resistance to the main anti-tuberculosis drugs in newly and previously treated tuberculosis patients, in the region of Patras, in Greece and to evaluate the contribution of foreign-born and human immunodeficiency virus (HIV) positive cases to drug resistance.

A total of 207 initial isolates of Mycobacterium tuberculosis were analysed. All clinical specimens submitted for cultural diagnosis were collected before chemotherapy commenced. The age of the patients varied from 16 to 78 years old. Sex distribution was 144 males (69.56%) and 63 females (30.43%). Nineteen patients (9.17%) were recent immigrants in Greece. All the patients were HIV-negative. One hundred-one initial isolates of Mycobacterium tuberculosis (48.79%) were susceptible to all first-line anti-tuberculosis drugs, isoniazid, streptomycin, ethambutol and rifampicin. The prevalence of primary mono- and poly-drug resistance was lower (isoniazid 5.79%, streptomycin 4.34%, ethambutol 1.93%, isoniazid + streptomycin 3.38%, isoniazid + ethambutol 0.9%, isoniazid + streptomycin + ethambutol 1.44%) when compared with the prevalence of secondary (acquired) mono- and poly-drug resistance (isoniazid 8.69%, streptomycin 10.14%, ethambutol 3.86%, isoniazid + streptomycin 3.86%, isoniazid + rifampicin 1.44%, isoniazid + streptomycin + ethambutol 4.83%, isoniazid + streptomycin + rifampicin 1.44%). No primary mono - resistance to rifampicin, or primary multi - drug resistance (defined here as Mycobacterium tuberculosis resistant to at least isoniazid and rifampicin) were observed.

According to our data, overall drug resistance was high. Fortunately, multi-drug resistance tuberculosis was not common but special efforts are needed to monitor the prevalence of drug resistance and to ensure adequate treatment in all the population.