Developing the Multi-disciplinarity of Parasitology, by taking three-steps at a time

COUNTDOWN at the British Society for Parasitology Autumn Symposium, 28th September 2017, with Lucas Cunningham, Louise Hamill, Zikmund Bartoníček, Lisa Reimer, Louis-Albert Tchuem-Tchuenté, David Molyneux, Mark Taylor, Russ Stothard

Parasitology BSP2017

The British Society for Parasitology Autumn Symposium is an annual event which this year took place on the 28th September 2017 in London at The Linnean Society, Burlington House. It was organised by Prof Russ Stothard and Dr Bonnie Webster, entitled “The Multidisciplinarity of Parasitology: Host-parasite evolution and control in an ever-changing world”.

The programme attempted to draw together and develop a multi-facet appraisal of the biology and control of parasites. The symposium has subsequently stimulated a meeting report and a blog on Bug Bitten on  why it is all interconnected in parasitology. Moreover, it was a convenient opportunity to feature some of COUNTDOWN’s stepwise progress in reporting our implementation research as set within the meeting’s three themes.  With just over 25 speakers and with an audience of just over one hundred, The Linnean’s auditorium was at maximum capacity; a clear evidence of the general interest in multi-disciplinarity.

Prof Stothard warmly welcomed everyone present with the simple message that ‘all living species are involved in parasitism, either as parasites or as hosts’. Indeed, this is a universal truth, for parasitism is not just a successful evolutionary strategy but is also part of a broader picture of symbiosis and part of the classification of how organisms, big or small, interact. As a metaphor, parasitism is tremendously powerful, and is regularly used in today’s language to describe significant socio-political events and processes as societies and sometimes nations negatively exploit others.

The modern agenda of parasitological research is therefore exciting, challenging and globally relevant as illustrated by Sir Roy Anderson. In the context of human disease, those parasites that typically play a detrimental role in global health are notorious, for example, malaria and the neglected tropical disease (NTD) collective are very well-known. To help guide the discussions and for convenience sake, the Autumn Symposium was split into three themes to help develop discussions in a stepwise manner.

The ‘ever changing world’ theme placed ongoing parasitological research within the new terminology of the Anthropocene and how mankind is altering global environments which may or may not favour parasitic diseases of medical, veterinary or wildlife importance. Both Prof David Molyneux and Prof Louis-Albert Tchuem-Tchuenté highlighted the challenge of NTD control against the background of planetary health, national control programmes and sustainable development goals. Both schistosomiasis and soil-transmitted helminthiasis are two of the most sensitive NTDs to human modifications of the environment and WASH infrastructures. For example, the building of water impoundment dams and expansion of freshwater irrigation schemes each has the potential to increase the parasite transmission, especially where urbanisation creates local water stress. Control of schistosomiasis is typically a long-haul endeavour and in recognition of his pioneering work on the epidemiology and control of schistosomiasis, David Rollinson was awarded a career medal by the International Federation for Tropical Medicine (IFTM) President, Santiago Mas-Coma.

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The ‘Multidisciplinarity of Parasitology’ encouraged synergies between molecular, ecological and social science components that link parasites and hosts into a more holistic appraisal of parasitism. COUNTDOWN molecular diagnostic work was presented by Lucas Cunningham and Zikmund Bartoníček on soil-transmitted helminthiasis and schistosomiasis as speed posters alongside surveillance and control studies on onchocerciasis control in Cameroon by Louise Hammill together with community engagement activities meshed with locally appropriate vector control strategies.

The ‘host-parasite evolution and control’ recognised that parasites are not simple self-replicating automata and are very able to respond rapidly to interventions waged against them. Lisa Reimer discussed opportunities for xenomonitoring of mosquito populations for surveillance of lymphatic filariasis.  The control of many parasitic diseases is a moving target as it is a dynamic and reactive system. It has been shown in previous control campaigns that a static strategy typically founder, therefore it is important to have in place an ability to monitor the success of any particular intervention and to ensure it is best tailored to the needs of the local populace for which it serves.

During the day, topics of discussion within the three themes often blurred, and they should, as cross-talk grew. Mark Taylor, President of the BSP closed the meeting and indicated that for a successful academic career in parasitology, a portfolio of skills and approaches is needed.  To end symposium, it was very fitting to discuss many aspects of parasite evolution in The Linnean Society where Darwin and Wallace once read their papers, nearly 160 years ago. Over this time much has changed and we hope an important milestone from this meeting will be the production of a special issue of Parasitology which will leave a longer lasting footprint of how parasitism and human health are most intimately intertwined.

Find here a link to the Storify on our participation at the meeting.

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Let’s Move the Agenda from Control to Elimination of NTDs

By Prof Louis Albert Tchuem Tchuenté, Pamela Bongkiyung & Prof Russell Stothard

Who has the perfect answer to controlling or eliminating a disease? It gets more difficult when simply using medication does not guarantee no re-infection. In the case of Schistosomiasis and Soil-transmitted Helminthiasis, in the agenda of elimination one wonders if what we need are more parasitologists in the affected areas or getting the current ones to be more publicly engaged in educating the population?

Prof. Louis-Albert Tchuem Tchuenté who has been working on schisto control for over three decades emphasises the control of Schisto as many other NTDs is a long-term combat. That means a lot of investment and capacity building at all levels. It also needs to have the involvement of many actors and stakeholders. It is difficult for a single organisation or a single group to interrupt the transmission of this disease. That is why intersectoral cooperation, partnership and involvement of stakeholders at all levels is very important. Policy makers, scientists, community health workers, health personnel staff, teachers and all category of the population need to be involved in this fight.

Training of parasitologists is very important because in the African setting more needs to be done. It is vital to optimise and adapt the strategy according to the different transmission setting. The same strategy cannot be deployed as it will not have the same impact. That is why for example in Cameroon, when you compare the current distribution of Schistosomiasis to what was done 25 – 30 years ago; there is a significant decrease in some areas. We have examples where transmission has been interrupted, we have many examples where prevalence has been lowered to more than 80 – 90 percent in some of the localities.

But we still have some challenges where the dynamics vary.  The disease prevalence is reducing but variances remain due to the existence of conditions that allow for the transmission cycle to continue. That is why moving from control to elimination requires integration is intensified. Part of this requires increasing capacity building by training more students, investment, health education, change in behaviour and increase awareness of the population. It is a huge challenge.

The Sustainable Development Goals (SDG) has as one of its key point a call for countries to invest more for the control and elimination of Neglected Tropical Diseases (NTDs). Therefore, for the transmission of schistosomiasis to be interrupted there is a need for countries to invest more for the elimination of this disease. When more is invested, this means that we also should invest in equipment, in sanitation, in access to water and change of the environment or that you improve the hygiene.

Prof. Tchuem Tchuenté said: “Granted, the control of schistosomiasis is very challenging, it is a long-term commitment which is feasible. At this stage, there are tools and strategies in place to interrupt the transmission of schistosomiasis; what we need now mainly in Africa is that we must change our approach to become more ambitious. We must move completely from control to elimination. This shift in paradigm should be clearly effective and endorsed by all African countries.”

He believes that when we keep the word ‘control’, we can be satisfied with morbidity control and therefore control morbidity forever. If the agenda shifts to elimination, then the momentum and the target aligns with that shift. Lymphatic Filariasis (LF) programmes have used this approach. The LF programme’s target for years has been elimination and this makes us put a lot of effort into its elimination.

There is a tendency to become complacent when you reduce a disease to the level where it no longer constitutes a health problem. This is when we need to be most careful as you could miss when the disease makes a come-back again. But if you have a target for elimination, this means additional or further efforts to interrupt the transmission and then to move to the surveillance phase. Japan is one of the good examples. In the 1960s, there were some areas in Japan where the prevalence of schistosomiasis was higher than in most parts of Africa. But they decided and launched a ‘zero parasite’ campaign. From the beginning, it was not about control but zero parasites; meaning elimination. In less than 20 years Japan has eliminated schistosomiasis. China started with control but then rapidly moved to the elimination phase. Now their objective is to eliminate everywhere in China.

The COUNTDOWN project is in a key position to contribute to this agenda. Our research aims to increase acceptability, affordability, accessibility and availability of Neglected Tropical Diseases solutions. Our multidisciplinary approach is investigating efficient methods to cost-effectively upscale mass drug administration programmes, thereby moving the agenda closer to elimination.

With this word elimination, you must put the necessary efforts and investment to interrupt transmission. In Africa, the time is right to think about this and to shift completely from control to elimination. It is not easy as this will require a lot of investment. We need to raise momentum and commitment from the government, including investment. That is what the SDG is about; as espoused in one of its goals –  for countries to invest more for the elimination of NTDs!

To find out more about our research visit our websites:

http://www.countdownonntds.org

http://countdowncameroon.org/

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@NTDCOUNTDOWN  @NTDGHCOUNTDOWN  @COUNTDOWNNTDCAM  @COUNTDOWNLR  @COUNTDOWNNG

 

 

China and Africa Join Forces in fight to Eliminate Schistosomiasis

by Prof Louis-Albert Tchuem Tchuenté, Pamela Bongkiyung, Prof Russell Stothard

In the fight against Neglected Tropical Diseases (NTDs), it has become obvious that learning from other countries’ successes will help many others to control and eliminate these diseases. This is how the China-Africa meeting and collaboration came about in 2012.

Whilst on a visit to the Liverpool School of Tropical Medicine, we caught up with Prof. Louis-Albert Tchuem Tchuenté regarding the China-Africa Meeting on Schistosomiasis Elimination and Training Course on Malacology, organised in Cameroon from the 24 – 28 October 2016.

Prof. Louis-Albert Tchuem-Tchuenté is an NTD Ambassador for Liverpool School of Tropical Medicine. He also heads the Centre for Schistosomiasis & Parasitology in Cameroon and is a professor of parasitology. He lectures at the University of Yaoundé I and is Country Director for the COUNTDOWN project in Cameroon. His expertise in Schistosomiasis and Soil-Transmitted Helminthiasis spans over 30 years. He is Cameroon’s National Coordinator for the control of Schistosomiasis and Intestinal Worms.

Discussions with Prof. Louis-Albert revealed that this China-Africa meeting started a long time ago. Given that China has a vast amount of experience in Schisto control and has successfully eliminated Schisto in many of their provinces; many African countries still struggling with schisto can learn from the Chinese experience. Very few areas have Schisto in China and Schisto has been eliminated as a public health problem there. The highest prevalence is probably 1-2 percent and the plan now is to interrupt the transmission everywhere.

According to Prof. Louis-Albert, China invested a lot on their elimination agenda including treatment, environmental modification and snail control. Most of the schistosomiasis cases in China are zoonotic because they have a lot of animals who act as reservoir hosts. That is why they have invested a lot of money to modify the environment so that the animals do not maintain the parasite life-cycle.

One of the highest components of this is the snail control. Schistosomiasis has two main hosts: vertebrate hosts (including human beings and animals) and the snails. In the transmission, you have both factors that make this happen. The snails are in the water and if you don’t change the environment, the snails remain present. Even if you reduce the transmission, then at some stage it just needs one person who is infected to defecate or urinate into the environment, to rebuild the transmission cycle. That is why it is very important to control the snails. The Chinese have done so successfully and have vast experience in snail control.

Based on this, it became important for African countries to benefit from the Chinese experience. That is why the World Health Organisation(WHO), together with the Chinese government, decided to have this China-Africa cooperation, for the elimination of schistosomiasis in Africa.

This began at the governmental level between China, WHO and the governments in Africa. The agenda was further discussed at the China-Health Ministerial Forum that reviews valuable health development issues. During the 2013 Minister’s Forum held in Beijing, an agreement was reached on this partnership and the initiative approved. This move was necessary to progress granted things take time at the government level. That is why the China team, WHO and African governments decided to start an institutional-based cooperation. This initiative was developed to sustain a China – Africa Cooperation for Schistosomiasis Elimination.

China has several provinces that are endemic for schistosomiasis and it was important to link these provinces to different African countries depending on the relationship they have. That is why in the first phase, ten countries were selected in Africa and were linked with different provinces in China.

The first meeting to set-up the institution-based cooperation was launched in 2015, in Malawi. The meeting launched the initiative and the memorandum of understanding between the partners. The memorandum was signed between different African institutions and Chinese institutions for research. The meeting in Cameroon was the second meeting and it was focused on snail and malacology training. Another component of the training was using mollusciciding to control the snails. The Chinese team and ten countries participated in the meeting in Cameroon.

The rationale for collaboration is clear as it fosters relationships between various actors and allows in-depth knowledge of what works in practice. This knowledge gets refined for better use through creating more cost-effective solutions which are sustainable in the long term for NTD control and elimination.

To continue this cross-sharing of knowledge, COUNTDOWN will be at the upcoming British Society of Parasitology Autumn Symposium taking place on 28th September 2017 taking place at The Linnean Society in London. This session will focus on ‘The Multidisciplinarity of Parasitology: Host-Parasite Evolution and Control in an Ever-Changing World’.

 

 

Onchocerciasis in Three Decades: Through the Lens of Prof. Samuel Wanji

By Prof Samuel Wanji & Pamela Bongkiyung

Prof. Samuel Wanji is Head of Department for Microbiology and Parasitology at the University of Buea, Cameroon. He is also Executive Director of the Research Foundation in Tropical Diseases and Environment, Buea. He heads the COUNTDOWN programme’s partnership with the University of Buea. He has worked extensively on Onchocerciasis control and been instrumental in its control. We caught up with him while he was on a visit to the Liverpool School of Tropical Medicine.

Pamela: Hello Prof. Wanji. Thank you for taking the time to talk to us. How long have you worked on Onchocerciasis?

Prof. Wanji:  My journey with onchocerciasis started as far back as 1988. We could be talking of almost 30 years of research in onchocerciasis. Everything started with an experimental model when I was doing my postgraduate studies in Paris, France. And later on, I remained within Filariasis/Onchocerciasis for my research and university career. So actually, it has been a very faithful relationship with research and onchocerciasis throughout my life as a student and a worker both for teaching and research.

P: In the almost three decades that you have worked on various projects in relation to onchocerciasis, what changes have you observed?

PW: Yes, there have been changes. I started almost when Ivermectin was introduced as a new tool for the control of Onchocerciasis. And we witnessed the huge impact Ivermectin has made in the control of Onchocerciasis through the African Programme for Onchocerciasis Control – APOC. We were among the researchers involved in mapping the disease across Africa for the implementation of the control. We also witnessed the decline of the disease in many of foci where the endemicity was really high.

But what has been my major contribution for the control of onchocerciasis came from another filarial parasite Loa Loa. Originally, nobody knew that Loa Loa could cause a problem for the onchocerciasis control. So, when it was established that some people taking Ivermectin could develop severe adverse events and could even die, the link was established with Loa Loa and it became a priority to know those places where the endemicity of Loa Loa that is dangerous for the intake of Ivermectin was.

We participated in those early days around 2000 to develop the rapid assessment procedure for Loa Loa which was later on extended to 15 African countries, where we coordinated the mapping exercises in those countries, to generate the first map for Loa Loa in Africa. This map was operationally very useful in saying this place is very dangerous, this place is safe. And that is how we contributed heavily to the control of onchocerciasis in those areas where there was co-endemicity with Loa Loa.

Besides that, at the level of the laboratory we developed an experimental model in baboons to understand the mechanisms of encephalopathy due to Loa Loa with the treatment we have with Ivermectin. Today we know that the microfilaria are massively killed and they block the micro capillary of the brain and that is how people almost get killed. People become withdrawn and they go into coma because of such. We know that mechanism and we even have an idea of how such things could be prevented with ivermectin and aspirin. We have worked a lot through Loa Loa to see how the control of onchocerciasis could be safe in the forested areas of Africa.

P: What are the major impediments to controlling Onchocerciasis not just in Cameroon as you seem to have worked extensively across Africa, but also how does Loa Loa add to these impediments that you might have encountered in your work?

PW: As we know Onchocerciasis is a Neglected Tropical Disease. So just by that fact, it is already an impediment in controlling such disease. Less attention was paid to it. Fortunately for the past ten years there has been a lot of momentum around Neglected Tropical Diseases and Onchocerciasis has also benefitted from that.

As you can imagine that for almost 30years, the only drug that has been used for the control of Onchocerciasis has been Ivermectin. Ivermectin does not kill adult Onchocerciasis besides of the fact that it creates problems with Loa Loa in areas where the two diseases co-exist, Ivermectin kills only Microfilaria, the children of filarial of Onchocerca Volvulus (O. Volvulus).

So you need to take the drug for longer than 15years, to expect getting rid of the disease. And that is a very long time because people can easily go into fatigue. If the resources are not properly mobilised people may not have resources to sustain such long term control.

One probable consequence of such impediment has been the suspicion (and I will call it suspicion because there has been a lot of controversy around it) of sub-optimal response of the worms to Ivermectin. That means when you have a long term pressure of the same one medication on a parasite, the parasite may develop a strategy to not be sensitive to that drug anymore. And that has been a very shortcoming of onchocerciasis control to know that instead of having two or three drugs to play with, only one drug exists.

It is only of recent that there is a lot of work going on to develop microfilaria drug that will kill the adult worm. That is why in many areas we are really doubting how the elimination will be feasible. Those areas where the transmission was very high or is very high, we are almost sure that Ivermectin alone cannot do the job. We need alternative strategies. That is why you have been hearing about Doxycycline which was developed recently. Doxycycline can kill adult Onchocerca Volvulus but it needs at least 4weeks to do that job. The four weeks treatment is far better than 15years yearly treatments because with 15yrs yearly treatment you may have fatigue effect more than 4wks continuous treatment. At the level of the public health people think it is not suitable to have a regimen of 4wks, they insist on shorter regimens.

Here at the Liverpool School of Tropical Medicine, we have the AWOL consortium which is developing a shorter regimen of Anti-Wolbachia. Doxycycline is an anti-wolbachia. It is a drug that kills the bacteria that lives in a worm. Because that bacteria is starkly associated to the worm, they exchange some functions. So if you kill the bacteria, the worm also dies. It is an indirect effect. So the AWOL consortium is developing a shorter regimen of antibiotics that can do the same job like doxycycline. We hope that doxycycline will play its own role in the elimination of onchocerciasis or anti-wolbachia drugs globally. But we are expecting contributions from other drugs like Flubendazole which is in the pipeline.

Globally to answer your question, the impediment has come from the fact that we are dealing with only one tool, for the control of onchocerciasis.

To be continued…