Monday 7 September 2020

The many strands of malaria elimination

The WHO Collaborating Centre on Global Health Histories supported by the Wellcome Trust has produced a series of seminars and webinars which look at different aspects of malaria control, and at how this can only be achieved through a combination of approaches.

 

The two seminars can be viewed here:

Can malaria be eradicated? The future of malaria control

(GHH seminar 148, 21 July 2020)

Speakers: Dr Ian Graham, Director of BioYork and Weston Chair of Biochemical Genetics at the University of York), Dr Karen Barnes (Professor of Clinical Pharmacology at the University of Cape Town and Co-Chair of the South African Malaria Elimination Committee), Dr Rajitha Wickremasinghe (Professor of Public Health and former Dean of the Faculty of Medicine at the University of Kelaniya in Sri Lanka)

 

Health Diplomacy: The bases for international and global health

(GHH seminar 164, 6 March 2020)

Speaker(s): Professor Sanjoy Bhattacharya (Professor in the History of Medicine, University of York, UK and Director, WHO Collaborating Centre for Global Health Histories), Dr Lakshmi C. Somatunga Deputy Director General (Medical Services(I)), Ministry of Health, Nutrition and Indigenous Medicine, Sri Lanka)

 

This briefing draws upon the presentations at these seminars, as well as additional conversations with Professor Sanjoy Bhattacharya.

 

“We need to recover the huge amount of information on what makes it possible to implement public health programmes,” says Professor Sanjoy Bhattacharya, director of the Centre for Global Health Histories at the University of York and of the WHO Collaborating Centre for Global Health Histories. “Countries need to recognise the importance of their own implementation histories and experiences and fund the recording of that because they are disempowering themselves by not doing so and falling victim to the idea that the only important ideas were at global rather than the national level. This is a critical history that engages with policy but tries to record all sides of the argument to see which of those ideas made a difference on the ground.”

 

To date, the world has eradicated one human disease [Smallpox]. It is becoming increasingly possible that malaria may follow suit. With a new vaccine showing some signs of success in reducing malaria in young children [https://www.who.int/malaria/media/malaria-vaccine-implementation-qa/en/], and an increasing number of countries being declared malaria-free, along with advances in treatment, the discussions about malaria have moved from control to elimination to the possibility of global eradication.

 

However, the disease is still responsible for hundreds of thousands of deaths every year, almost all of them in Africa and especially among young children. And as Bhattacharya points out, when malaria is finally eradicated, this will be the result of what has (and has not) happened in different countries, specific to those cultures and needs.

 

Effective public health: Sri Lanka


Dr Rajitha Wickremasinghe, who is Professor of Public Health and former Dean of the Faculty of Medicine at the University of Kelaniya in Sri Lanka, describes the reason why the country was certified malaria-free on 6 September 2016 as “nothing but good public health practice”. Along the way, there were definite peaks and troughs: by 1963 the disease had almost vanished from Sri Lanka but then returned (and during this period Sri Lanka also experienced civil war and a huge amount of violence and unrest).  However, in 2009 the country moved from a ‘control’ programme to an ‘elimination’ one, led by the Ministry of Health and two local NGOs and targeting different malaria species in succession. “The interventions were basically universal access to diagnosis and treatment, and vector control” (the use of insecticide-treated nets and/or residual indoor spraying, to get rid of the mosquitoes which transmit the malaria parasite).

 

Much of this good practice, Wickremasinghe explains, involved comprehensive access to control measures (which includes access to education that means people adopt those control measures). “We have an excellent public health system; we have good road connectivity and transport network; we have a literate population, and also there were no counterfeit medicines in the market. Even during the separatist war malaria commodities were provided to rebel-held areas.”

 

 It also involved coordination and a degree of flexibility over how health bodies spend donated funds. And, significantly, the period when a greater proportion of funding was spent on ‘management and other costs’ – in other words, human resources and technical support – rather than insecticides and spraying materials is when the rate of malaria decreased. This is an important counter to the widespread objection to ‘spending on administration rather than frontline costs’ that many potential donors raise.

 

In reality, Wickremasinghe says, “flexible funding which enabled them to do things that government regulations did not otherwise provide was more effective. A programme must be agile and able to respond to the on-the-ground realities.”  An integrated approach is essential, everyone agrees. And that approach has to focus on the people and communities who are at risk of the disease.

 

Experts in their own realities


“Communities are not all the same and of course, because of that, you can't have the same engagement strategy for all communities. There's no ‘one-size-fits-all’,” says Professor Karen Barnes of the University of Cape Town, who is also the Co-Chair of the South African Malaria Elimination Committee. “We've got some good tools that have advanced the control of malaria and aided its elimination in some countries, Sri Lanka included. But each of these tools really depends on community buy-in and community acceptance of what needs to happen. And community engagement must be bidirectional, it's not just a case of the government or the technical experts telling communities what to do; you have to find a way of hearing what the communities think – what they like, what they understand and what they need more of.” 

 

These are the people, she points out, who are “experts in their own realities”. “These are communities that know how bad malaria is. Most people know someone who's died from malaria and they've often had malaria themselves.” (Conversely, areas where malaria rates are low, community buy-in requires a lot more work: communities have, after all, plenty of other concerns that they worry more about than malaria.)

 

Barnes was involved in the Lubombo Spatial Development Initiative (LSDI), a government initiative between Mozambique, South Africa and Eswatini (Swaziland) aimed at enhancing economic development in the area, a key component of which was malaria control. It used a combination of approaches – indoor spraying (the malarial mosquitoes in the area rest predominantly indoors) and/or the use of bed nets to prevent the disease, rapid diagnosis if someone is suspected to have malaria and combination therapies including the drug artemisinin for treatment. All of these require people at risk, or who contract malaria, to take their own action – not least because they need to finish a full course of treatment, rather than stop as soon as they feel better and save the remaining medication for later. “We also needed community engagement to support the very important surveillance necessary to understand how people respond to treatment. Are they cured? Are there factors around a homestead that might put them at more risk of malaria? Have the number of malaria-transmitting mosquitoes been reduced?” 

 

Those experts in their own realities are the people who can bring about real change: for instance,  138 community members in the LSDI volunteered to have window traps on their homes to monitor the number of mosquitoes in their area. However, that only happens if they believe that it’s worth doing and they trust the people doing it; indoor spraying, in particular, involves taking the risk of letting a stranger into the home and in other areas people may refuse this. 

 

In Mozambique, local communities have selected people to be trained as community health workers – either unpaid or with minimal pay. These health workers are trained in carrying out malaria tests, in the correct use of drug treatments, and in recognising when sick people in their community need to make the long journey to the hospital. As a result, many people do not need to leave the local area to travel to a clinic or health centre; the programme is being brought directly to them.   

 

The limitations of treatment


There is also a major concern that the major treatment on offer may become less effective. Dr Ian Graham, Director of BioYork and Weston Chair of Biochemical Genetics at the University of York, has worked on producing hybrid variants of the Artemisia annua plant which can be grown by small-scale farmers. The plant itself has been used as a fever treatment for over 400 years, but it is the specific artemisinin molecule (identified by Chinese pharmaceutical chemist Tu Youyou, who was awarded the Nobel Prize in 2016 as a result) that is usually highly effective, and needs to be produced in larger quantities. It is also most effective as part of combination therapy, and it is very important to keep it as such. 

 

“Artemisinin derived drugs are the most effective treatment for malaria but we already know that the parasite causing the disease can mutate and develop resistance to these drugs, which represents a major public health threat,” Graham explains. “The main way to combat resistance developing is to use artemisinin in combination with partner drugs, as this prevents parasites that manage to mutate and develop resistance to one drug taking hold. Herbal treatments containing artemisinin, using the drug as monotherapy or not completing a full course of combination therapy treatment can all increase the risk of resistance developing. It is essential that we do everything we can to prevent resistance from becoming established, especially in sub-Saharan Africa where local emergence of resistance has recently been reported.”

 

“Artemisinin resistance is a global threat,” says Barnes. “If artemisinins don't work well then, it’s not just that they clear the parasites more slowly. There’s also an increase in the malaria parasites (called gametocytes)that transmit malaria. That means a potential increase in malaria transmission. There’s also more pressure on the other drugs that are being used in the combination treatment, so these partner drugs start to fail too. There are some places in Southeast Asia where there are quite frightening levels of treatment failure: over half the patients treated were not cured by the recommended artemisinin combinations. And we are now getting isolated reports from elsewhere in the world. The impact on malaria cases and deaths if such artemisinin resistance spreads to the Indian subcontinent or sub-Saharan Africa or South America are quite frightening to think about. We'll stop talking about elimination for a long time if that happens.” “It is important to keep looking for alternatives,” Graham agrees. “We are in an arms race with the malaria parasite, which given the opportunity will almost certainly develop resistance.”

 

 

No scope to stand still


Artemisinin resistance is not the only reason why malaria control or elimination programmes have to be, as Barnes says, “dynamic, not static”. In areas where control programmes lose funding and support, the rate of malaria goes up – and that is in areas where communities are very happy to play their part. 

 

In addition, malaria is by definition a very mobile disease. Mosquitoes do not observe regional or national borders. In any case, the borders in many places, like southern Africa, are extremely porous – they are lines drawn up by previous imperial rulers, rather than any division that local people themselves would recognise. This is why regional collaboration like the LSDI, and collaboration between malaria programmes, is essential. 

 

The global plan for elimination is a genuine, and a realistic, goal. However, it will only be achieved if those coordinated, integrated and dynamic programmes are continued – and if they involve the people who are at most risk of malaria themselves.

 

 

 

Radhika Holmström is a writer and communications specialist working with the Global Health Histories project at the University of York. 

 

 

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