Analysis of drug susceptibility patterns in tuberculosis diagnosed cases from Ecuador during 2012-2017

Mycobacterium tuberculosis is the principal causative agent of pulmonary tuberculosis. It constitutes a serious public health problem worldwide, especially in developing countries (e.g., Ecuador) where control strategies are scarce or inefficient. Some strains of this pathogen have high virulence and have acquired multiple drug resistance to standard first- and second-line drugs. In Ecuador, the National Institute for Research in Public Health (INSPI) collects national data from tuberculosis cases and performs drug susceptibility tests to assess the different resistant profiles. In the present work, national surveillance data from INSPI was used to evaluate the prevalence and evolution of the drug susceptibility patterns and multidrug-resistant tuberculosis (MDR-TB) in the cases diagnosed from 2012 to 2017. Data were analyzed using different statistical methods, and a variety of risk factors were considered to observe their influence in the development of any drug resistance and MDR-TB. A decrease from 2012 to 2014, followed by an increasing trend during the last years (2015-2017), were observed in the emergence of any resistance, as well as higher MDR-TB prevalence than the estimates by WHO. In Ecuador, the most important factor associated with the emergence of resistant TB is the previous treatment. These analyses are crucial to allow the implementation of efficient treatments and control strategies adapted to Ecuador. This study is one of the most recent studies performed in the region to take into account the epidemiology of different resistance patterns in tuberculosis.