LIVERPOOL – The developed world is familiar with the global threats of viral infections that incite fear in both rich populations and poor.

The pandemics of SARS, avian, and swine influenza have cost the global economy an estimated $200 billion. These threats emerge frequently and unpredictably from human contact with animals.

Rapid response is required of governments, United Nations agencies, regulatory authorities, and the pharmaceutical industry for coordination, surveillance, and vaccine production.

But the poorest people – those who live on less than $2 per day – are often not considered important when a pandemic threat emerges. They do not contribute significantly to the global economy, and their countries’ health systems function on a tiny fraction of what advanced economies devote to their populations’ health.

Conversely, the developed countries’ view of the diseases of the developing world is that only three are important: AIDS, tuberculosis, and malaria. This stems from the power of advocacy constituencies and the recognition that these diseases might threaten the developed world.

As a result, these diseases receive a disproportionate amount of funding for research and control, while other infections kill, blind, deform, and disable many more – the "bottom billion” – who have little access to health care.

These infections are known as the Neglected Tropical Diseases (NTDs). They are unfamiliar to the developed world, and their names are often difficult to pronounce: filariasis (elephantiasis), onchocerciasis (river blindness), schistosomiasis (bilharzia), and others, particularly intestinal worms.

These are not familiar diseases to people lucky enough to live in the world’s richest countries, but they are household names to hundreds of millions of poor people, who are often infected with more than one of them. They are long-lasting conditions, often contracted at an early age, and both the illnesses and their symptoms are progressive.

Indeed, whereas the misery that worm diseases cause is extensive and the burden excessive – as much as tuberculosis or malaria – they do not kill immediately. Instead, they gradually erode children’s development prospects.

And symptoms accumulate: sight is gradually lost, genital lesions appear around puberty (sometimes increasing risk of HIV), and skin condition declines as millions of microscopic worms become intolerably itchy. Blood loss, causing anemia, is the result of thousands of worms chewing at the wall of the gut.

Other diseases, such as sleeping sickness, transmitted by tsetse flies are fatal if untreated, as is leishmaniasis, if the parasites that cause it – transmitted by tiny sandflies – invade the liver and spleen. Again, the misery caused by these infections exceeds the burden of tuberculosis or malaria.

The good news is that NTDs can be treated, as quality drugs – donated by the major pharmaceutical companies – are made available. These drug donations for river blindness, trachoma (another blinding disease), leprosy, elephantiasis, worms, and bilharzia, as well as for sleeping sickness, give hope to millions.

Moreover, the cost of the annual treatment recommended by the World Health Organization is often less than $0.50, and much less in Asia, with delivery carried out by communities or through schools.

The increase in treatment has been spectacular – more than 500 million people in 51 countries treated for elephantiasis in 2007, and 60 million in 19 countries have been treated for river blindness. Guinea disease is now endemic in only four countries, and leprosy is a problem in only six.

These are impressive figures, and the expense is trivial compared to the anti-retroviral drugs needed to treat AIDS, which cost more than $200 annually and must be taken every day, not every year.

Given that roughly one billion people are infected with NTDs, compared to 40 million with HIV, and that the drugs targeting them are donated and actually prevent disease and stop transmission, treating NTDs is a major opportunity to lift populations out of poverty.

The main challenge is to convince policymakers that there is more to reducing poverty than focusing on just three diseases. In fact, NTDs are "low-hanging fruit.”

If the international community is serious about alleviating poverty and achieving development goals, tackling the diseases so directly associated with economic misery should be a fundamental objective.

We can easily meet that objective, because we have drugs that are effective, free (or very cheap), that have low delivery costs, and that provide add-on benefits.

Now is the time to rethink our public-health investments and messaging, and evaluate whether we are getting the best value for our donor dollars, or whether we should do much more to tackle diseases that we have so far largely ignored.     

David Molyneux is Professor Emeritus at the Liverpool School of Tropical Medicine.

Copyright: Project Syndicate, 2010.