Hearing impairment is due to various causes including
ototoxicity from
aminoglycosides. The susceptibility to
aminoglycosides increases in the presence of certain mitochondria gene mutations. There is unrestrained use of
aminoglycosides in many developing nations which may worsen the burden of
hearing impairment in these countries but there is lack of data to drive required policy changes.
Streptomycin (an
aminoglycoside) is part of the drug regimen in re-treatment of
tuberculosis. Exploring the impact of
streptomycin ototoxicity in
tuberculosis patients provides a unique opportunity to study
aminoglycoside ototoxicity within the population thus providing data that can inform policy. Also, since
streptomycin ototoxicity could adversely affect treatment adherence in
tuberculosis patients this study could enable better pre-treatment counseling with subsequent better treatment adherence. Patients on
tuberculosis re-treatment will be recruited longitudinally from Direct Observation
Therapy-Short course centers. A baseline full audiologic assessment will be done before commencement of treatment and after completion of treatment. Early detection of
ototoxicity will be determined using the American Speech and Hearing Association criteria and genetic analysis to determine relevant mitochondria gene mutations will be done. The incidence of
ototoxicity in the cohort will be analyzed. Both Kaplan-Meier survival curve and Cox proportional hazards tests will be utilized to determine factors associated with development of
ototoxicity and to examine association between genotype status and
ototoxicity. This study will provide data on the burden and associated predictors of developing
aminoglycoside induced
ototoxicity. This will inform public health strategies to regulate
aminoglycoside usage and optimization of treatment adherence and the management of
drug-induced ototoxicity among TB patients. Furthermore the study will describe mitochondrial gene mutations associated with
ototoxicity in the African population.