For want of a shoe…
Podoconiosis is a poorly understood tropical disease. In this post Dr Gail Davey, from Brighton & Sussex Medical School, explains more about it, and looks at what is being done to treat it.
There are still many places round the world where people cannot afford a pair of shoes. For some, this means cold, cut or bruised feet but for others it can lead to a disfiguring and disabling leg swelling called podoconiosis. ‘Podo’, as it is often called, is a type of elephantiasis (leg swelling) you rarely hear about, found in subsistence farming communities in the tropics. It’s an unusual disease, triggered not by a bacterium, virus or parasite, but by an abnormal reaction to irritant mineral particles found in soils of volcanic origins. Many years of walking, ploughing or playing barefoot on these soils appears to trigger inflammatory changes within the lymph system in the legs, which in time can lead to foot swelling and ultimately elephantiasis.
Not everyone who lives and works without shoes in these areas develops podo – studies have shown strong ‘heritability’ of the disease. Currently, research funded by the Wellcome Trust is looking to identify where the susceptibility genes might lie in the genome. The study is also trying to discover which mineral or minerals in the soil trigger the disease. Other groups are investigating the stigma associated with the disease (affected people are often barred from school or have difficulty finding marriage partners), studying immunological changes associated with podo, exploring overlaps with other common tropical diseases and establishing the most ethical ways of working in the remote communities in which podo patients are usually found.
You might think the obvious solution is just to distribute shoes, but even that isn’t simple. Behavioural scientists at the US National Institutes of Health are working with Ethiopian colleagues to explore why children who receive shoes to prevent podo don’t always wear them. There are many misunderstandings about the cause of the disease, and people don’t always understand the need to protect their feet.
While all this research is going on, what is happening to help people with podo? As Fasil Tekola, an Ethiopian scientist whose PhD focused on podoconiosis genetics explains, “This is an ignored public health problem; research has a role in bringing podoconiosis to a wider audience”. Research has been vital in providing the evidence on which to base recent advocacy, which in February this year resulted in podo being included in the WHO list of Neglected Tropical Diseases. The momentum around this highly eradicable disease continues – on November 12th, in Addis Ababa, the first meeting of the Ethiopian National Podoconiosis Action Network was held, attended by representatives from government ministries, WHO, universities and patient care organizations. On December 5th, a new International Podoconiosis Initiative, ‘Footwork’ is being launched in Philadelphia, to bring together public and private partners to prevent and treat podoconiosis. Footwork aims to integrate podo control with that of other NTDs wherever possible, and to partner with organizations working in foot-related conditions to advocate for shoes as ‘the new bed-nets’ – so there is no reason in future that any person’s life is destroyed for the want of a shoe.
Gail Davey is a Reader in Global Health and is supported by the Wellcome Trust to research podoconiosis.