About This Project

Mortality rate is significantly higher among clinically diagnosed Tuberculosis (TB) patients than the ones bacteriologically confirmed. Epidemiological studies have shown the emergence of Non-Tuberculous Mycobacteria (NTMs) causing lung damage and disease. This study aims to determine the proportion of NTM infections among TB patients. We hypothesize that the proportion of clinically diagnosed TB patients did not actually have TB but other serious lung conditions masquerading as TB.

Ask the Scientists

What is the context of this research?

Diagnosis remains the biggest gap in the Tuberculosis (TB) care cascade; early and accurate diagnosis is key in attaining global TB targets of eliminating TB as a public health concern. A considerable proportion of patients with presumed TB are found not to have Mycobacterium tuberculosis (MTB) following clinical and subsequent bacteriological investigation. Even though, clinical presentation of Non-Tuberculous Mycobacteria (NTMs) infection is quite similar to MTB, NTMs often go undetected or considered clinically irrelevant. Several NTM species cause lung damage and diseases contributing to substantial morbidity and mortality. Clinical diagnosis of TB is very common in high TB burden settings and remains a cause of high mortality rates among TB patients. Poor TB treatment outcomes especially death is strongly associated with clinically diagnosed TB patients.

What is the significance of this project?

The similarity of MTB and NTMs in clinical presentation and initial laboratory diagnosis confers a possibility of an unintended treatment. Treatment of NTMs is complicated and associated with higher liver toxicity compared to MTB treatment. It has been reported that there is a two- to five- fold higher mortality risk in clinically diagnosed TB cases compared to the bacteriologically confirmed cases in Kilifi County, Kenya. The high mortality raises concerns of misdiagnosis, where some patients treated for MTB may have had NTM infections. Results from this study shall demonstrate that TB diagnosis based solely on signs and symptoms, without bacteriological confirmation, is associated with poor treatment outcomes. Therefore, a clear understanding of the clinical presentation of MTB infection and a well-defined, systematic diagnostic approach are essential for effective TB control strategies.

What are the goals of the project?

In this ongoing study, we're recruiting TB patients from TB clinics around the county of Kilifi, Kenya. This is a prospective cohort study where the target is 383 participants (both clinically diagnosed and bacteriologically confirmed TB patients). The study participant shall produce sputum sample (thick mucus coughed up from the lower airways in the lungs) that is dedicated for molecular detection of NTMs and then advised to come to the clinic for monitoring after two (2) months where another sputum sample shall be taken. The treatment outcome shall be noted at the end of the full treatment course. Epidemiological, microbiological and transcriptomic data will be collected. For transcriptome sequence analysis, RNA from immune cells shall be extracted from three (3) categories of TB patients together with healthy controls. The objective is to establish if there is differential expression of specific immune related genes in MTB / NTM disease versus healthy controls.