title: Individual correlates of podoconiosis in areas of varying endemicity: a case-control study.
abstract: BACKGROUND
  Podoconiosis is a non-filarial form of elephantiasis resulting in lymphedema of the lower legs. Previous studies have suggested that podoconiosis arises from the interplay of individual and environmental factors. Here, our aim was to understand the individual-level correlates of podoconiosis by comparing 460 podoconiosis-affected individuals and 707 unaffected controls.
  
  
  RESULTS
  This was a case-control study carried out in six kebeles (the lowest governmental administrative unit) in northern Ethiopia. Each kebele was classified into one of three endemicity levels: 'low' (prevalence <1%), 'medium' (1-5%) and 'high' (>5%). A total of 142 (30.7%) households had two or more cases of podoconiosis. Compared to controls, the majority of the cases, especially women, were less educated (OR = 1.7, 95% CI = 1.3 to 2.2), were unmarried (OR = 3.4, 95% CI = 2.6-4.6) and had lower income (t = -4.4, p<0.0001). On average, cases started wearing shoes ten years later than controls. Among cases, age of first wearing shoes was positively correlated with age of onset of podoconiosis (r = 0.6, t = 12.5, p<0.0001). Among all study participants average duration of shoe wearing was less than 30 years. Between both cases and controls, people in 'high' and 'medium' endemicity kebeles were less likely than people in 'low' endemicity areas to 'ever' have owned shoes (OR = 0.5, 95% CI = 0.4-0.7).
  
  
  CONCLUSIONS
  Late use of shoes, usually after the onset of podoconiosis, and inequalities in education, income and marriage were found among cases, particularly among females. There were clustering of cases within households, thus interventions against podoconiosis will benefit from household-targeted case tracing. Most importantly, we identified a secular increase in shoe-wearing over recent years, which may give opportunities to promote shoe-wearing without increasing stigma among those at high risk of podoconiosis.
authors: Department of Earth Sciences, Addis Ababa University, Addis Ababa, Ethiopia ; Brighton and Sussex Medical School, Falmer, Brighton, United Kingdom.
authors: Yordanos B
authors: YB
authors: Molla
authors: Jennifer S
authors: JS
authors: Le Blond
authors: Nicola
authors: N
authors: Wardrop
authors: Peter
authors: P
authors: Baxter
authors: Peter M
authors: PM
authors: Atkinson
authors: Melanie J
authors: MJ
authors: Newport
authors: Gail
authors: G
authors: Davey
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002648:Child; D004604:Elephantiasis / Q000453:epidemiology*; D019353:Endemic Diseases; D005002:Ethiopia / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012309:Risk-Taking; D012775:Shoes; D055815:Young Adult