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.
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).
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.
Podoconiosis is a neglected tropical disease that results in swelling of the lower legs and feet. It is common among barefoot individuals within defined areas due to the geochemical characteristics of the soil in these areas. Presence of podoconiosis and its huge burden among the affected people in north Ethiopia has previously been documented. Moreover, difference in the occurrence of the disease by area and among individuals had been observed. In the present study, we investigated individual factors for the occurrence of podoconiosis, by comparing individuals with podoconiosis and without podoconiosis that live in three areas with varying disease prevalence. We found that individuals with the disease, particularly women, were less educated, with lower income and less likely to be married, compared to healthy individuals. Moreover, more than one individual was found in most of the affected households. Podoconiosis-affected individuals started wearing shoes at later ages than healthy individuals, and their feet were observed to be more cracked and dirty. There is a recent increase in shoe-wearing among all study subjects. We concluded that intervention efforts should focus to address late age shoe-wearing and inequalities in education, income and marriage, between podoconiosis affected individuals, and particularly among female patients. In addition, the presence of more than one patient per household helps for targeted case identification for intervention.