Spatial patterns of multidrug resistant tuberculosis and relationships to socio-economic, demographic and household factors in northwest Ethiopia.
BACKGROUND
Understanding the geographical distribution of multidrug-resistant tuberculosis (MDR-TB) 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 socio-economic, demographic and household factors in northwest Ethiopia.


METHODS
An ecological study was conducted using data on patients diagnosed with MDR-TB at the University of Gondar Hospital MDR-TB 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 Getis-Ord 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.


RESULTS
A total of 264 MDR-TB patients were included in the analysis. The overall crude incidence rate of MDR-TB for the six-year 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 MDR-TB was observed in districts located in the Ethiopia-Sudan and Ethiopia-Eritrea border regions, where large numbers of seasonal migrants live. Spatial clustering of MDR-TB 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.


CONCLUSIONS
Spatial clustering of MDR-TB, 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. Cross-border initiatives including options for mobile TB treatment and follow up are important for the effective control of MDR-TB in the region.
Research School of Population Health, College of Medicine, Biology and Environment, The Australian National University, Canberra, Australian Capital Territory, Australia.|Institute of Public Health, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia.
Kefyalew Addis
http://orcid.org/0000-0002-1904-4682
KA
Alene
Research School of Population Health, College of Medicine, Biology and Environment, The Australian National University, Canberra, Australian Capital Territory, Australia.
Kerri
K
Viney
Centre for Population Health, Burnet Institute, Melbourne, Victoria, Australia.|Department of Medicine, The University of Melbourne, Parkville, Victoria, Australia.|Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, Queensland, Australia.
Emma S
ES
McBryde
Research School of Population Health, College of Medicine, Biology and Environment, The Australian National University, Canberra, Australian Capital Territory, Australia.
Archie C A
AC
Clements
D000328:Adult; D000995:Antitubercular Agents / Q000627:therapeutic use; D001499:Bayes Theorem; D003710:Demography; D005002:Ethiopia / Q000453:epidemiology; D005191:Family Characteristics; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D012959:Socioeconomic Factors; D018088:Tuberculosis, Multidrug-Resistant / Q000188:drug therapy / Q000453:epidemiology*; D014505:Urban Population / Q000706:statistics & numerical data
D000995:Antitubercular Agents