Risk Factors for Podoconiosis: Kamwenge District, Western Uganda, September 2015

Abstract

Podoconiosis, a noninfectious elephantiasis, is a disabling neglected tropical disease. In August 2015, an elephantiasis case-cluster was reported in Kamwenge District, western Uganda. We investigated to identify the disease's nature and risk factors. We defined a suspected podoconiosis case as onset in a Kamwenge resident of bilateral asymmetrical lower limb swelling lasting ≥ 1 month, plus ≥ 1 of the following associated symptoms: skin itching, burning sensation, plantar edema, lymph ooze, prominent skin markings, rigid toes, or mossy papillomata. A probable case was a suspected case with negative microfilaria antigen immunochromatographic card test (ruling out filarial elephantiasis). We conducted active case-finding. In a case-control investigation, we tested the hypothesis that the disease was caused by prolonged foot skin exposure to irritant soils, using 40 probable case-persons and 80 asymptomatic village control-persons, individually matched by age and sex. We collected soil samples to characterize irritants. We identified 52 suspected (including 40 probable) cases with onset from 1980 to 2015. Prevalence rates increased with age; annual incidence (by reported onset of disease) was stable over time at 2.9/100,000. We found that 93% (37/40) of cases and 68% (54/80) of controls never wore shoes at work (Mantel-Haenszel odds ratio [OR] = 7.7; 95% [confidence interval] CI = 2.0-30); 80% (32/40) of cases and 49% (39/80) of controls never wore shoes at home (OR = 5.2; 95% CI = 1.8-15); and 70% (27/39) of cases and 44% (35/79) of controls washed feet at day end (versus immediately after work) (OR = 11; 95% CI = 2.1-56). Soil samples were characterized as rich black-red volcanic clays. In conclusion, this reported elephantiasis is podoconiosis associated with prolonged foot exposure to volcanic soil. We recommended foot hygiene and universal use of protective shoes.

Global epidemiology of podoconiosis: A systematic review

“…The remaining study was from three states in India: Manipur, Mizoram and Rajasthan. The prevalence of podoconiosis was recorded in 27 studies and ranged from 0.1% in Uganda [ 53 ] to 8.08% in Cameroon [ 49 ]. Of the 27 studies reporting prevalence, 13 were conducted in Ethiopia where prevalence ranged from 2.73% to 7.45% [ 4 , 20 , 21 , 29 , 30 , 32 , 33 , 35 , 37 , 38 , 40 , 41 , 48 ].…”

Podoconiosis in Rwanda: Knowledge, attitudes and practices among health professionals and environmental officers

“…Many respondents believed that women were more likely to contract podoconiosis than men, although there is no biological reason for differences in prevalence [4]. However, in Ethiopia, Uganda and Kenya, disparities in income and access to personal protective equipment are PLOS NEGLECTED TROPICAL DISEASES apparent between men and women, especially in rural, agricultural areas, providing an explanation for why women were more affected [5,21,22]. On one hand, most respondents had positive attitudes toward podoconiosis patients and the majority of health professionals were not afraid of treating podoconiosis or worried about receiving criticism for taking care of affected patients.…”

“…Many respondents believed that women were more likely to contract podoconiosis than men, although there is no biological reason for differences in prevalence [ 4 ]. However, in Ethiopia, Uganda and Kenya, disparities in income and access to personal protective equipment are apparent between men and women, especially in rural, agricultural areas, providing an explanation for why women were more affected [ 5 , 21 , 22 ].…”

Predicting the environmental suitability and population at risk of podoconiosis in Africa

“…Podoconiosis national programmes require a detailed understanding of the geographical distribution of the disease so that all endemic areas can be targeted. Previous attempts to map podoconiosis include a detailed literature review [12] and mapping at national [17,19,20] and subnational levels [24][25][26]. However, there are no maps outlining the potential distribution of podoconiosis at continental and global levels.…”