How does a disease become neglected?

Following the accepted definition, neglect is seen largely in a monetary sense; a comparative lack of funding. However, diseases can also be neglected in terms of a lack of…

• Policy initiatives
• Prevention/Surveillance/Control
• Research
• Drug development/supply

In the case of neglected tropical diseases, the main reasons for their neglect tends to correlate strongly with the low socioeconomic status of the affected populations. Hotez et. al, describe these populations as not just the poorest in the world, but also having a low visibility and little political voice.

Alongside these compounding factors, the diseases associated with this group are often inextricably linked with social and behavioural patterns.

Becoming infected with an NTD, is not an unusual event or an anomalous experience, but rather a consequence of daily life. The normalization of NTD infection within the poorest communities, coupled with the lack of influence these communities have on decision-makers, often results in their plight falling out of consciousness.

In the case of schistosomiasis, transmission is mainly the result of human behavior and geographical location. As one of the most important water-based diseases, schistosomiasis has been found in continents including Africa, South America, and Southeast Asia as well as some countries in the Middle East. As it is co-associated with the presence of water-resource development, schistosomiasis is often widespread where access to clean water and basic sanitation is limited and health systems are near non-existent. All of these features help explain how schistosomiasis in particular has been typified as a disease of poverty. However, this poverty seems to be largely concentrated in the Africa, with 85% of sufferers residing in sub-saharan countries.

In countries such as Japan and Tunisia, the disease has been eliminated and it is near elimination in Brazil, China and Egypt, with reported prevalence rates at <1%. The reason for such disparity amongst geographically similar regions is due to the differing levels of “recognition of the public health implications of schistosomiasis, political will and commitment, and sustained implementation of national control programmes,” as described by Utzinger et.al.

In many countries in sub-saharan Africa, there has been a noticeable lack of specific policy initiatives and schistosomiasis control measures. One reason may be that schistosomiasis infection is often co-endemic with other NTDs and/or other, better known diseases such as tuberculosis, malaria and HIV. With this added complexity and also the insidious nature of the schistosomiasis infection, the cause of its neglect becomes increasingly obvious. This coupled with the poverty-promoting nature of schistosomiasis, once people realize that their symptoms can be attributed to the disease, they effects of such infection have often affected their own ability to work. Further silencing the affected populations by pushing them further into poverty.

As for a lack of research and development of drugs to treat schistosomiasis, the vast disengagement of pharmaceutical companies in the 1970s resulted in a stagnation in research efforts and drug discovery. In the wake of accelerated medical advances, schistosomiasis research and treatment has fallen further and further behind. A major contributing factor for this, which has been iterated time and time again, is that the “market forces are insufficient to drive the discovery and development of new drugs for [tropical] diseases.” These market forces are influenced by A) the population B) the geography C) the financial incentive. For a disease like schistosomiasis, the disease affects the poorest people, in distant locations, with little prospect of financial return. Because of this combination, research and development of drugs to treat schistosomiasis becomes increasingly unattractive to investors.

This is a pattern seen often in NTDs, hence their namesake. Neglect of a disease, and thus of an affected population, is active in its passivity. Diseases aren’t randomly assigned to be actively neglected, but rather a combination of factors related to these diseases contributes to a shift in focus. This gradual divergence, contrasted with the rate of medical advances and the scale of funding for other diseases, highlights the vast disparity of attention. To combat this, we must be pro-active in our approach to raise awareness of these diseases and reverse their neglect.

In an upcoming podcast, Challenging Neglect talked to Professor Alan Fenwick, the Director of the Schistosomiasis Control Initiative (SCI). As a public-private partnership, SCI receives funding from the Bill and Melinda Gates Foundation and assists Ministries of Health across Sub-Saharan Africa in a bid to control and eliminate schistosomiasis. We talked to him the role epidemiology plays in the fight to tackle NTDs.