Neglected tropical diseases

Dr. Lorenzo Savioli

Dr Lorenzo Savioli, Director, Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva

A letter from the Director

Control of neglected tropical diseases has taken on a new dimension.

Large scale drug distribution and preventive chemotherapy now provide an opportunity to simultaneously control and eliminate selected neglected tropical diseases that have afflicted humanity for centuries.

More than 1 billion people – a sixth of the world’s population – suffer from one or more neglected tropical diseases. Success in tackling the situation resides in our ability to create global awareness of these diseases, and the world is increasingly becoming responsive to the plight of the people who live with them.

In 2007 alone, a total of 546 million people around the globe were treated to prevent transmission of lymphatic filariasis, commonly known as elephantiasis. In August 2007, the People’s Republic of China became the first country declared to have successfully eliminated lymphatic filariasis as a public health problem, followed by the Republic of Korea in March 2008.

Treatment for schistosomiasis (bilharziasis) is ongoing for 27 million schoolchildren in Africa, with the distribution of praziquantel tablets over a period of 10 years. The disease has a serious impact on school attendance rates and can impair cognitive and growth development. Untreated in its early reversible stages, schistosomiasis can cause serious and permanent pathology, fatally reducing the life-span of an individual.

Dracunculiasis, commonly known as guinea-worm disease, which was prevalent in 20 nations in Africa and Asia two decades ago, is now endemic in only 6 sub-Saharan countries. If social and political conditions stay favourable, guinea worm disease will soon be the second disease to be eradicated.

The number of reported cases of human African trypanosomiasis, also known as sleeping sickness, decreased to 10 486 in 2008 from 16 378 in 2005 as a result of effective surveillance. Renewed efforts are being made to eliminate yaws, a chronic but easily treatable infection that affects the skin, bone and cartilage. Better coordination is also being made to lessen the burden of zoonotic viral diseases, particularly dog rabies; this preventable disease kills an estimated 55 000 people annually, almost 50% of whom are children under 15 years of age.

Parasitic and bacterial diseases, known to be neglected, are among some of the most common infections affecting an estimated 2.7 billion people who live on less than US$ 2 a day. Disparity between the haves and the have-nots has continued, and global climate change – besides unleashing natural calamities – is also creating conditions for diseases to thrive and for vectors to re-emerge in regions where they were previously thought to have been eliminated. The resurgence of dengue fever over the past few years is testimony to this phenomenon.

WHO initiatives on integrated vector management and the management of public health pesticides demonstrate the importance of, and need for, investment in vector control as an important component of controlling transmission of vector-borne diseases. These diseases represent about 17% of the global burden of parasitic and infectious diseases. Most neglected tropical diseases are endemic in rural areas of sub-Saharan Africa and in poor urban settings of low-income countries in Asia and Latin America. They lead to long-term disability, disfigurement, impaired childhood growth, adverse pregnancy outcomes and reduced economic productivity.

Neglected tropical diseases kill an estimated 534 000 people worldwide every year. Their impact on worker productivity adds up to billions of dollars lost annually and maintains low-income countries in poverty. A WHO report on Social Determinants of Health found that those living in poverty, even those inhabiting large affluent cities, remain the most vulnerable and die younger. How much more severe must be the plight of millions who live in deprived rural communities where basic facilities are non-existent.

During the last five years we have come a long way in convincing the world and particularly political leaders in endemic and non endemic countries to invest in the control of neglected tropical diseases as a means to boost human and economic development towards achieving the Millennium Development Goals. WHO, its international partners, donor agencies and NGOs have set up better channels to support endemic countries to distribute both donated and purchased drugs to needy areas. Convergence of technology is now providing better possibilities of communication and exchange of data with field staff in remote areas. Such collaborative efforts have made interventions against neglected diseases more viable and cost effective.

In addition to efforts made by endemic countries, funds have been pledged by the world community for the promotion of global health. Substantial contribution has come from the United States government, the United Kingdom Department for International Development (DFID), the Bill and Melinda Gates Foundation, The Carter Center, the United States Agency for International Development (USAID) and the private sector. Donation of drugs such as praziquantel and triclabendazole has added to an existing list of donated drugs for better distribution in endemic areas. Some of these drugs are being administered as part of an integrated campaign involving malaria and HIV/AIDS, helping us to create a broader awareness about neglected tropical diseases.

As the world slowly recovers from one of the worst financial crises, we intend to keep-up the momentum and further motivate the international community to support endemic countries to strengthen existing health infrastructure and service delivery. Investing in the human and social capital of poor people is essential as it enables them to develop the fundamentals they need to renew their own communities through prevention programmes.

For a very long time, neglected tropical diseases received little or no attention at all, despite their magnitude and their impact on both economic development and quality of life. Our actions are aimed to promote the common good of every individual and are based on a human rights approach, which requires that interventions and processes are guided by human rights principles of participation, non-discrimination and accountability.

Everyone aspires to live a life free of disease. Our task is to create the conditions to make this happen. Although the task ahead is arduous, we will persevere: this is the only way to go forward.

Dr Lorenzo Savioli
Director, Department of Control of Neglected Tropical Diseases
World Health Organization
Geneva, Switzerland