Tuberculosis multiresistente en un área rural de Angola.

Student thesis: Doctoral thesis


Multidrug-resistant TB (MDR TB) is caused by bacillus Mycobacterium tuberculosis (MTB) resistant to rifampin (RIF) and isoniazid (INH). In 2017, more than 160,000 cases of MDR TB were reported, and only 25% of them started treatment with second-line drugs. However, it’s estimated that about 558,000 cases developed RIF-resistant TB, of which 82% had MDR TB. There are numerous barriers that justify the differences between reported cases and estimated cases, such as the difficulty of access to health systems, the lack of diagnostic tools and the poor case notification. In Angola, the prevalence of MDR TB was unknown since there was no appropriate method for diagnosis. The realization of the projects related to this thesis revealed the first cases of the country. The papers that compose this thesis were inspired by the results of a first study carried out by our group in which a high proportion of failure was observed among patients diagnosed with TB who started treatment with first-line drugs. These data suggested that one of the causes of the high percentage of failures was the presence of MDR TB in the area. To corroborate this hypothesis, the first rapid molecular diagnosis equipment for detection of both MTB and resistance to RIF (Xpert MTB / RIF) was installed in the country, which allowed to know the prevalence of this disease, and to initiate the appropriate treatment with second-line drugs in patients infected with MDR TB strains. The first of the studies that compose this thesis describes the prevalence of MDR TB found in Cubal, which is much higher than the estimated by WHO for Angola (8% in patients not previously treated for TB and 71.1% in patients who had received treatment for TB previously), as well as factors related to the development of MDR TB. The second study describes the clinical characteristics and microbiological outcomes of patients diagnosed with MDR TB who were treated with a standardized second-line regimen, observing that more than 80% of the patients experienced adverse effects related to second-line drugs and that only 54% of cases achieved treatment success. The conclusions of this thesis have been enormously valuable to know that MDR TB is a very important problem in the country. Based on the results observed in the articles described in this thesis, Angola's national TB control program (PNLT) has installed new Xpert MTB / RIF devices in the country and the treatment guidelines have been modified, considering the regimen for MDR TB and starting the process for the performance of an epidemiological study to know the prevalence of MDR TB nationwide.
Date of Award6 Nov 2019
Original languageSpanish
Supervisor Molina Romero, Israel (Director), Vicenç Falco Ferrer (Tutor) & Maria Teresa Tortola Fernandez (Director)

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