Archive for Neglected Tropical Diseases

What are the long-term consequences of deworming programmes?

Dr Francisca Mutapi, University of Edinburgh

What happens afterwards? This apocalyptic question is one that is integral to all forms of intervention in human and animal diseases. This is particularly important in cases where the intervention occurs at a national scale. My research group has been asking this question in relation to the current global efforts to control worm (helminth) infections which significantly impact on the health and development of children. Specifically, we work on bilharzia (urinary schistosomiasis) an important, but neglected infectious disease caused by the blood fluke Schistosoma haematobium. Although we hear occasional reports of tourists infected during visits to resorts in endemic areas, bilharzia is typically a disease of poverty due its association with poor sanitation and unsafe water. People become infected when they come into contact with the infective stage in freshwater after it has been released by freshwater snail- hence the other name of the disease- snail fever. The disease affects over 100 million people, mainly in Africa.  Children carry the heaviest burden of infection; as a result, they experience bladder and kidney disorders, stunted growth and poor development.

Current global initiatives from Partners of Parasite Control including the World Health Organization (WHO), Bill and Melinda Gates Foundation, UNICEF, Schistosome Control Initiative and the World Bank are advocating regular school-based de-worming interventions to reduce the development of morbidity, promote school-child health and improve cognitive potential of the children. Children are treated with the antihelminthic drug praziquantel. Over the past decade, there has been a concerted global effort to control bilharzia, galvanised initially by the Millennium Development Goal (MDG) 6 to combat HIV/AIDS, malaria and other diseases by 2015 and the World Health Assembly resolution 54.19 to treat at least 75% of all school-age children at risk of schistosomiasis by 2010. The most recent schistosomiasis resolution, World Health Assembly resolution WHA65.21 passed in 2012 is advocating for the elimination of schistosome transmission and the WHO Schistosomiasis Strategic Plan 2012-–2020 sets out its vision of for a world free from schistosomiasis. This represents a real drive at the global scale not previously seen, to control this important disease of childhood.

Millions of school children in Africa are currently being treated with this drug resulting in significant health improvements. In several countries where the control programmes are currently being implemented, they are typically running for 5 years. The questions we are asking is what will happen to 1) the children who have been treated, 2) the rest of the population that has not been treated and 3) the parasites? The overall, long-term outcome of these treatment programmes for human health is believed to be good- but what evidence do we have for this? In my research group, we are interested in the long-term consequences of praziquantel treatment. Our studies and those of others have shown that the effects of praziquantel treatment go beyond the transient reduction of infection intensity and morbidity. Treatment with the antihelminthic also reduces future pathology and induces immune responses protective against re-infection by the parasites. What will be the effect of the 5-year treatment programmes on the host immune system and overall health?  Experimental studies of the regulation of the immune system suggest that treatment of helminth infection results in susceptibility/worsening of immune disorders (explained through the hygiene hypothesis). What is the relevance of these studies to human helminth infection? What are the long-term health implications in children treated through these national treatment programmes? Similar to malaria, people exposed to schistosome parasites develop natural acquired immunity to the parasites following repeated infection with the parasites. What is the consequence of praziquantel treatment on schistosome immunity and disease, decades after cessation of the control programmes? Providing answers to these questions is critical for informing strategic planning for ministries of health and prioritisation of resources as well as formulating /directing global health policy.

These really interesting scientific questions and the potential impact of the findings for human health are the drivers of research for Dr Francisca Mutapi and her group, the Parasite Immuno-epidemiology Group, at the University of Edinburgh.



Zoonotic diseases neglected for decades.

As part of a study to analyse changes in global health priorities at the global level of the resolutions adopted at the World Health Assembly – the decision making body of the WHO – the relative neglect of endemic zoonotic diseases has been highlighted. This work has recently been published in PLOS NTDs, and has received widespread media attention.

The eight diseases of interest (anthrax, bovine tuberculosis, brucellosis, cysticercosis, echinococcosis, human African trypanosomiasis (HAT), leishmaniasis, rabies) are part of the group termed Neglected Zoonotic Diseases (NZDs) at an international meeting in 2005, so called as they are “not adequately addressed” at national and international levels. Zoonotic diseases are defined as diseases that are transmissible between humans and animals.

In the last decade, the Neglected Tropical Diseases (NTDs) have received increased global attention, and recent events celebrated the increased advocacy and control that has occurred. The research highlighted that these diseases have received relatively little attention at the global policy level, living up to their neglected title. In developing countries where these diseases remain endemic and resources are limited, the control of these diseases is limited as other high profile diseases are prioritised.

Some of the diseases have high fatality and cause a high number of deaths globally each year. For example, rabies causes an estimated 60,000 deaths worldwide, yet this disease remains neglected despite evidence that the disease can be effectively controlled through dog vaccination.

Neurocysticercosis is the greatest cause of preventable epilepsy worldwide, causing an estimated 30% of the 17 million cases of epilepsy in areas where the causative parasite is endemic. This disease can be controlled through sanitation and improved pig husbandry, and improved diagnosis of human infection, requiring a multi-sector approach.

Following the London Declaration on NTDs, there has been increased focus on NTD control. Of the NZDs, only leishmaniasis and HAT are included in the ten diseases which are the focus of the declaration, meaning that the other diseases are not benefitting from the increased Research and Development and drug donations that the other NTDs are experiencing as a result of the declaration. This study highlighted three diseases in particular that are not included in the WHO NTDs. Anthrax, brucellosis and bovine tuberculosis have therefore not received the increased attention that the other NTDs have seen. Upon the inception of the WHO in 1948, around twenty zoonotic diseases were determined to be diseases of priority in the WHO, including bovine tuberculosis and brucellosis. Despite this, there have not been any resolutions adopted for these diseases since 1950.  For these diseases, effective and simple control methods exist, meaning that they are no longer endemic in many developed countries. It is therefore astonishing to many that they remain neglected.

It seems that these diseases are particularly neglected due to the complexities of controlling diseases that affect both humans and animals, and the required communication and collaboration between human and animal health sectors, both at community and ministerial levels, that is sometimes lacking. This despite the dual benefits that would be received by both human and animal health sectors upon increased effective control methods.

The international attention that has been received following the publication of this research may be indicative that the neglect of these diseases – some of which are well known and well controlled in some countries – may be something which is surprising, but that there is desire to reduce this neglect and therefore the deaths that occur as a result. In order to reduce this neglect, we must see increased cooperation and communication between human and animal sectors at all levels, and efforts to increase the advocacy for the control of these diseases.








Ms Hayley Mableson is in the final stages of completing a PhD from the University of Edinburgh.  Her research to date has focussed on global health advocacy and its application, with particular emphasis on the neglected tropical and zoonotic diseases. 

Shining a light on neglected tropical diseases

The publication of the second report on Uniting to Combat Neglected Tropical Diseases entitled “delivering on promised and driving progress” marks remarkable progress that has been achieved in the last two years in this field.  In January 2012, the London Declaration on Neglected Tropical Diseases marked commitment from a wide range of organisations and industry to achieving the goals of the WHO roadmap to control, eliminate or eradicate ten of the NTDs.

To mark the launch of the report, on the 2nd April 2014 global leaders convened in Paris to discuss the progress that has been achieved so far.  In this “conversation on progress”, Director-General of the WHO Margaret Chan thanked endemic countries, organisations and industries for their commitment to this cause, and commented that these diseases are no longer neglected as they are “shining a light” on these diseases which shackle over 1.6 billion people worldwide.  Control of NTDs must be a priority in order to achieve the targets of the Millennium Development Goals as they affect the world’s poorest populations.  Since the establishment of the NTD department in the WHO in 2005, effective advocacy has increased the profile of these ancient diseases, and they have been described as a “rags to riches story”.

In the two years following the London Declaration, which was endorsed by thirteen pharmaceutical companies, the drug donation pledges made by these companies have been fulfilled and in some cases surpassed.  These donations allow countries to fulfil and increase the demand for treatment, and have resulted in the scaling up of control interventions as drug supply has been removed as a barrier to the control of a number of the NTDs.  Seventy four countries, representing around two thirds of all NTD endemic countries have now developed national plans for the control of NTDs.  This country ownership is an important factor in the increased commitment to control, eliminating and eradicating these diseases.  Coupled with capacity building and political commitment NTD control can be a success.  The adoption of a World Health Assembly resolution on all seventeen NTDs in May 2013 has been described as a “landmark” in NTD control.  Not only does this resolution confirm country commitment to NTDs, but it marks a change in the way the world is approaching NTD control.  Throughout the history of the WHO, there have been many resolutions adopted which focus on one or more of the NTDs, but the adoption of the 2013 resolution highlights the change to integrated approaches to NTD control.  When we consider the NTDs collectively, they represent an enormous burden on human health, and many opportunities exist to control several of these diseases in combination.

New funding was also announced in conjunction with the report representing increased commitment from a range of partners representing a new collaboration to control soil-transmitted helminths.  This collaboration and funding highlights how multi-partner and multi-sector collaboration is becoming increasingly important in NTD control.

The report highlights that commitment to NTDs has gained momentum since the London Declaration.  In addition, the 2013 resolution on NTDs marks a global pledge by Member States to the control of these diseases that in turn can leverage even more commitment.  In the last two years, the light has begun to shine brightly on these diseases that afflict the world’s poorest and most vulnerable populations.  The control and elimination of NTDs is now recognised as one of the best investments in development.  As the report states “much has been achieved, but much more work lies ahead”.  We must continue to increase commitments and activities to control NTDs.  The report highlights the success and fulfilment of commitments to the ten NTDs included in the London Declaration, but there remain seven of the defined NTDs without such multi-partner pledges of drug donations and increased funding.

World Health Day on the 7th April this year focusses on Vector Borne Diseases. This includes a number the NTDs such as leishmaniasis and sleeping sickness.  We must build on these recent success and increased momentum and continue to combat these ancient diseases while the light continues to shine.








Ms Hayley Mableson is in the final stages of completing a PhD from the University of Edinburgh.  Her research to date has focussed on global health advocacy and its application, with particular emphasis on the neglected tropical and zoonotic diseases. 

Thinking about the post-MDG era

In 2015, the current eight Millennium Development Goals (MDGs) will expire. Results will be mixed, some will be met and some will not. What is clear, however, is that the MDGs have shaped the way we think about development, and our priorities and approaches to alleviating poverty.

The MDGs gave new prominence to the health issues affecting the poor; although their focus was restricted and derived from a top-down process of deliberation, rather than informed by inclusive analysis and a thorough prioritisation of development needs. Subsequently, the narrowly focused and largely sector-specific MDGs left gaps in coverage and failed to realise synergies between the foci covered by the goals (education, health, poverty, and gender). MDG 6 in particular—“combat HIV/AIDS, malaria and other diseases”—sidelined many of the communicable and non-communicable diseases that perpetuate the cycle of poverty in developing countries. And yet, the very act of naming HIV/AIDS and malaria raised the profile of these diseases immeasurably, stimulating increased funding, focused policy and dedicated institutions and programmes.

In response to the narrowness and specificity of the MDGs networks, alliances and lobby groups have emerged to argue for other priorities, perspectives and approaches. One of the most vocal examples – and the focus of the article – is the alliance arguing for Neglected Tropical Diseases (NTDs), a cluster of diseases of the bottom billion that are underserved with regards to research, treatment and control, to be included in the set of Goals that will replace the MDGs after 2015. At the moment it is looking increasingly likely that NTDs will be name-checked and specifically included in the “new” MDGs. This will be no mean feat.

The case for including NTDs in the post-2015 agenda has been building since their omission from MDG 6, which served as a call to arms for a group of concerned stakeholders, who have since contributed to a series of landmark initiatives that have placed NTDs firmly on the international agenda.

One “advantage” that the NTDs may have in a more enlightened and nuanced post-MDG era (with regards to development as well as to health), is that, by their very nature, they “undermine healthy lives” and cut across and threaten to undermine multiple silos of MDGs. This suggests a potentially fruitful bifurcated approach where focusing on NTDs can help make concrete inroads into reaffirmed or tweaked post-2015 MDGs, or NTDs can be used to articulate a set of goals that do not represent silos as targets to be met, but rather represent the strengthening of the institutions we need to manage the complex social, economic, environmental, and health systems that interact to shape future development.

Controlling NTDs in a post MDG era

MDGs and NTDs: Reshaping the Global Health Agenda

INZI Project (Investigating Networks of Zoonosis Innovation)


James Smith

Professor James Smith, Director, Global Development Academy, University of Edinburgh

Emma Michelle Taylor

Dr Emma Michelle Taylor, Research Fellow, INZI Project, Centre for African Studies, University of Edinburgh