Spatiotemporal patterns of successful TB treatment outcomes among HIV co-infected patients in Kenya
Date
2019
Authors
Otiende, Verrah A.
Achia, Thomas N. O.
Mwambi, Henry G
Journal Title
Journal ISSN
Volume Title
Publisher
Strathmore University
Abstract
Convergence of the Tuberculosis (TB) and HIV epidemics threatens the
management of TB treatment. These has been evidenced by various studies
describing how HIV cc-infection propagates unsuccessful TB treatment outcomes.
Information on the spatiotemporal patterns of successful TB treatment outcomes
remain less understood despite the multi-organizational TB treatment efforts. This
study uses case notification data to evaluate the spatiotemporal patterns of
successful TB treatment outcomes for HIV co-infected patients in Kenya. This
study used the case notification data from the Kenya National TB control program
to investigate successful TB treatment outcomes in forty-seven counties in the
period 2012 - 2017. The population of study was HIV co-infected cases with
known TB treatment outcome. Achi-squre test was performed to determine the
association between treatment outcomes and risk factors; TB- type, age, gender,
ART therapy and patient type. The study also assessed the geographic patterns and
temporal trends by mapping the TB treatment success rate in each county for the
six-year period. Using the Integrated Nested Laplace Approach (INLA), the TB
treatment success of HIV co-infected patients was modeled. The spatial parameters
assumed the BesagYork-Mollie (BYM) specification. The temporally structured
effect was represented through a neighboring structure and the temporally
unstructured effects using a Gaussian exchangeable prior. Among the 172233 HIV
co-infected cases included in the analysis, 135973 (78.9%) achieved successful TB
treatment outcomes. Female cases registered higher treatment success rates
(80.1%) compared to the male cases (77.8%). The cases on Anti-Retroviral Therapy
(ART) recorded a success rate of 79.9% against 69.1% for their counterpart not on ART.
The spatial trend depicted increased treatment success in some parts of the country with
a relatively high level of associated certainty, characterized by a spatial relative success
above 1 and posterior probabilities above 0.8. The temporal trend of treatment success
showed an increase in the treatment success of TB in HIV coinfected cases. Overall, the
success rate was still below 85% particularly for Homabay, Siaya, Kisumu, Migori and
Busia counties in western Kenya. The successful TB treatment outcomes for HIV coinfected
cases in Kenya were slightly below the 85% standard threshold set by the World
Health Organization. Our study showed that even though co-infected cases have an
increased risk of unsuccessful treatment outcomes, enhanced treatment monitoring
improved the treatment outcome in most counties for the six-year period.
Description
Paper presented at the 5th Strathmore International Mathematics Conference (SIMC 2019), 12 - 16 August 2019, Strathmore University, Nairobi, Kenya
Keywords
TB-HIV co-infection, Spatiotemporal patterns