Spatial patterns of multidrug resistant tuberculosis and relationships to socio-economic, demographic and household factors in northwest Ethiopia. Kefyalew Addis Alene , Kerri Viney, Emma S. McBryde, Archie C. A. Clements.Published: February 9, doi.org/10.1371/journal.pone.0171800
Understanding the geographical distribution of multidrugresistant tuberculosis (MDRTB) in high TB burden countries such as Ethiopia is crucial for effective control of TB epidemics in these countries, and thus globally. We present the first spatial analysis of multidrug resistant tuberculosis, and its relationship to socioeconomic, demographic and household factors in northwest Ethiopia.
An ecological study was conducted using data on patients diagnosed with MDRTB at the University of Gondar Hospital MDRTB treatment centre, for the period 2010 to 2015. District level population data were extracted from the Ethiopia National and Regional Census Report. Spatial autocorrelation was explored using Moran’s I statistic, Local Indicators of Spatial Association (LISA), and the GetisOrd statistics. A multivariate Poisson regression model was developed with a conditional autoregressive (CAR) prior structure, and with posterior parameters estimated using a Bayesian Markov chain Monte Carlo (MCMC) simulation approach with Gibbs sampling, in WinBUGS.
A total of 264 MDRTB patients were included in the analysis. The overall crude incidence rate of MDRTB for the sixyear period was 3.0 cases per 100,000 population. The highest incidence rate was observed in Metema (21 cases per 100,000 population) and Humera (18 cases per 100,000 population) districts; whereas nine districts had zero cases. Spatial clustering of MDRTB was observed in districts located in the EthiopiaSudan and EthiopiaEritrea border regions, where large numbers of seasonal migrants live. Spatial clustering of MDRTB was positively associated with urbanization (RR: 1.02; 95%CI: 1.01, 1.04) and the percentage of men (RR: 1.58; 95% CI: 1.26, 1.99) in the districts; after accounting for these factors there was no residual spatial clustering.
Spatial clustering of MDRTB, fully explained by demographic factors (urbanization and percent male), was detected in the border regions of northwest Ethiopia, in locations where seasonal migrants live and work. Crossborder initiatives including options for mobile TB treatment and follow up are important for the effective control of MDRTB in the region.