We can win the fight against tropical diseases in our lifetime - if we make the right decisions now

Just over five years ago, I left the private sector to join the Bill & Melinda Gates Foundation. One of the first events I attended in my new role was the signing of the London Declaration on Neglected Tropical Diseases, or NTDs.

I was astonished by what I witnessed: one by one, leaders from the World Health Organization, pharmaceutical companies, governments and civil society committed to bring an end to these terrible diseases. It was the largest global health effort I had ever been a part of – and still is to this day.

With names like onchocerciasis and lymphatic filariasis, NTDs are old and painful diseases that collectively affect nearly 1.5 billion of the poorest people around the world. Some NTDs have been around for thousands of years, and many cause blindness and disfiguration. All NTDs keep people from working and economies from thriving.

Thanks to drug donations – and the efforts of governments, donors and health workers – we’re now getting treatments to those who need them most. Since 2012, pharmaceutical companies have donated a total of 7.9 billion tablets, enough for 5 billion NTD treatments. In 2015 alone, we reached nearly 1 billion people with critical treatments.

NTD programmes use these donations to multiply the impact of every dollar invested. Today, it costs less than $0.50 per person per year to reach and treat someone with NTD medicines, producing a huge return on investment. A new study estimates that every dollar invested in NTD control and elimination could produce between $27 to $42 in economic benefits; another estimates that tackling NTDs could restore around $600 billion in lost economic productivity by 2030.

But while we are turning the tide against these ancient foes, we also need to stay focused on measuring progress toward elimination and investing in innovation where it is needed to accelerate progress. While many NTDs can be treated with inexpensive pills, others – like sleeping sickness – currently require specialized medical care with toxic and invasive drugs. And while existing drugs against onchocerciasis and lymphatic filariasis successfully kill the juvenile worms, they don’t affect adult worms, which keep releasing thousands of new larvae every day. That means we have to treat those infected every year until the adult worm dies.

Public-private partnerships are essential to driving the development of innovative tools. Product development partnerships – like the Drugs for Neglected Disease initiative (DNDi) and PATH – have worked to develop new diagnostics for NTDs like lymphatic filariasis and onchocerciasis, and will be key to identifying new treatments and approaches moving forward.

Several of these new tools are coming together for sleeping sickness. In the past few years, countries have introduced a new rapid diagnostic test that relies on only a finger-prick blood sample, as well as cheap but highly effective fabric targets that have been shown to quickly crash fly populations of the fly that carries the disease. We’re also hopeful that a revolutionary new oral treatment will be introduced that is capable of curing patients with a short course of pills rather than the existing treatment, which requires the administration of highly toxic intravenous drugs and a long hospital stay. Sleeping sickness is now at its lowest level in decades – fewer than 3,000 cases last year – and the new oral treatment might be the final piece of the puzzle that ends this ancient disease for good.

Beyond the development of better tools to detect, treat and prevent NTDs, we can help countries build their capacity to measure progress toward elimination by supporting the launch of state-of-the-art disease surveillance networks under the newly created African Centers for Disease Control.

When it comes to NTDs, our investments are beginning to pay off. Eight countries certified elimination of at least one NTD in 2016 – by far the most certified in any year – and the future looks bright for more eliminations in the years ahead. With more investment in innovation and in R&D systems, I am confident we can bring an end to NTDs in our lifetime – and pave the way for more success.