Tropical Health Matters

The Asia Pacific Malaria Elimination Network (APMEN) is starting a workshop entitled ‘Building Competence in Connnunity Engagement for Malaria Elimination,’ tomorrow (22 November) in Chiang Mai, Thailand. APMEN includes 11 countries that are making clear progress to malaria elimination in the region.

The meeting will feature discussions on topics such as …

• Lessons from 60 years of community participation in communicable disease control and elimination
• Going to scale with community engagement for malaria elimination (models for equitable access and sustainability)
• Experiences and challenges in achieving synchronous cross‐border community engagement for malaria elimination
• Embedding community engagement for malaria elimination in comprehensive Primary Health Care delivery: A systems strengthening approach

Country case studies will be shared by Bhutan, China, Indonesia, Malaysia, Philippines, Republic of Korea, Solomon Islands, Sri Lanka, Thailand and Vanuatu. Discussions will focus on identifying intervention, training and research strategies to support elimination efforts.  Reports on the meeting will begin tomorrow.

If target dates were realistic, there would have been no more guinea worm in the world as of 1995. As it stands today …

“Ghana appears to have broken Guinea worm transmission! With 7 consecutive months of zero cases reported since May 2010, and 14 months after reporting its last known uncontained case in October 2009, Ghana might have conquered Guinea worm disease! Surveillance continues while the Guinea Worm Eradication Program waits and watches. Currently, only four countries continue to report cases of Guinea worm disease: Southern Sudan, Mali, Ethiopia, and Chad.”

Sixteen years after the supposed eradication date approximatelt 376 cases were documented in the first four months of 2011.

Even the famous smallpox eradication effort could not achieve its targets until a paradigm shift occurred that changed intervention approaches from from maintaining high vaccine coverage to case containment that focused on outbreaks – vaccinating in a radius around cases until the disease disappeared.

Another set of goals – 80% coverage with key malaria interventions by the end of 2010 – has come and gone. The country with the largest burden of disease, Nigeria, was able to achieve around 67% of its insecticide treated bednet distribution target by 31 December 2011, let alone actual use by 80% of the population.  Nigeria is not alone in this situation.

The website, Global Atlanta, headlines that “U.S. Works to End Malaria by 2015”. While not technically true, the headline is followed by the actual goal – “The U.S. government is leading the way in ending malaria-related deaths by 2015, the head of the President’s Malaria Initiative said at a youth leadership conference organized by Usher’s New Look Foundation.”

The 2015 date refers to the Millennium Development Goals. Many countries find themselves lagging in in the interrelated MDGs (see picture). Our ability to reduce malaria mortality (if not morbidity) depends so much on health systems issues – procurement, supply, distribution, access, and use.

We have to be careful with public goal statements lest we create and then deflate expectations, with the unwanted side-effect of scaring away donors and national financial commitment.  Goals are a public relations tool – just be careful that they are realistic and don’t backfire.

We are unlikely to eliminate mosquitoes, according to Tanya Russell and colleagues, but she notes that this should not stop us from implementing all available interventions. Specifically their study of malaria vectors in Tanzania found that the at reduced densities of mosquito populations, they try to reproduce more, meaning we may never get below 10% mosquito elimination.

Instead, a member of the National Malaria Control Program in Tanzania says our goal “should be to reduce, and eventually halt, transmission of the parasite, rather than eliminating the vector.” If we can achieve no more than 90% elimination of mosquitoes, what is a realistic coverage figure for malaria interventions?

Applications of net and case management strategies in Rwanda and Ethiopia have definitely shown that major drops in malaria incidence are possible.  But the RBM targets of 80% coverage (85% for the US President’s Malaria Initiative) are elusive.  Demographic and malaria surveys from Senegal, Liberia and Nigeria show that even in homes that own nets, net use among people at most risk, does not reach this target.

Are we really sure that 80% is the right target?

Fred Binka was one of the first to demonstrate that people living in homes without nets can be protected by their neighbors’ nets, which kill mosquitoes in the community. ITNs “provided very good personal protection to children using them, and also protected nonusers in nearby compounds. Among nonusers, the mortality risk increased by 6.7% with each additional shift of 100 m away from the nearest compound” with nets. This led the researchers to speculate on the need to study whether the “mass effect from a small number of highly dispersed nets would provide equivalent protection to complete coverage.”

A few years later William Hawley and co-researchers reported that, “protective effect of ITNs on compounds lacking ITNs located within 300 meters of compounds with ITNs for child mortality, moderate anemia, high-density parasitemia, and hemoglobin levels.”

As part of the move toward universal coverage, Killeen and colleagues examined the importance of considering all household members, not just the ‘vulnerable.’ The group condluded that …

Using field-parameterized malaria transmission models, we show that high (80% use) but exclusively targeted coverage of young children and pregnant women (20% of the population) will deliver limited protection and equity for these vulnerable groups. In contrast, relatively modest coverage (35%–65% use, with this threshold depending on ecological scenario and net quality) of all adults and children, rather than just vulnerable groups, can achieve equitable community-wide benefits equivalent to or greater than personal protection.

Barat has called for ‘data driven decision making‘ in the effort to eliminate malaria. Using data in models as done by Killeen is a further important step. The onchocerciasis control community has been working with such models for over 15 years now. New data are fed into the Onchosim model based on program progress such that it is possible to forecast that onchocerciasis could be eliminated from areas with high initial prevalence if 65% coverage of ivermectin treatment were maintained for at least 25 years.

Unlike onchocerciasis control, malaria elimination rests on multiple interventions.  This makes modeling much more urgent, as outlined by malERA’s research agenda for eradication. Since universal coverage unfortunately does not mean universal usage, we need to seek valid data and models to help us plan for distribution of malaria interventions more strategically in ways that are affordable and can be maintained and at the same time can achieve maximum reductions in morbidity and mortality.

Sarah Boseley of the Guardian has opined that, “not to say that elimination should no longer be contemplated. It’s just more possible in some countries than in others.” Some comments we added to her blog follow:

When Melinda Gates used the ‘E’ word, she did add the caveat that eradication would not be in the immediate future, and as we have learned, the Gates Foundation has invested a lot in vaccine research.  Even with the addition of a vaccine, malaria elimination will continue to require multiple tools adapted and adopted according to the epidemiological situation of the area. Surveillance will continue to be the foundation tool for any effort to eliminate a disease.

The overall question of when can we start seriously talking about elimination requires a quick look back in history. Medical News Today in reviewing Feachem’s recent Lancet article, notes that, “Up to 1945, about 178 nations had endemic malaria. Since then 79 countries have eradicated the disease.” (Technically they have eliminated malaria since eradication only occurs when elimination country-by-country has occurred worldwide).  So 44% achievement in elimination over 65 years means _____ (your guess – fill in the blank).
There has been massive scale-up of malaria control activities over the past 5 years, but even with this, ensuring that an insecticide treated nets are inside a household does not guarantee that people will use them according to recent Demographic and Health Surveys and Malaria Indicator Surveys.

The danger of targeting a specific year is that once that year passes, donors and the public lose interest.  This is why it might be logical in the near term to ensure that appropriate malaria control and elimination activities are integrated into basic and universal primary health care services – which hopefully will not go out of style.

Spain has reported a case of indigenously transmitted malaria – P. vivax. Although there are up to 500 ‘imported’ cases annually, it is believed that the local vector, Anopheles atroparvus, was responsible.

The last such case in Spain occurred in 1961. “Malaria was officially declared eradicated in Spain in 1964,” according to the Examiner. Technically the term for removing malaria from one country is elimination, while eradication is reserved for worldwide cessation of transmission, but whatever one calls it, the situation in Spain shows that we cannot be complacent once we think malaria might be gone from a country.

A similar experience occurred in Virginia in the USA in 2002. “Two cases of Plasmodium vivax malaria near the US capital seem to have been acquired locally from indigenous malaria carrying mosquitoes breeding in the area, not from malaria carrying mosquitoes escaping from Dulles international airport.”

Malaria shows a penchant for moving with its human hosts. In observance of the 400th anniversary of the settlement of Jamestown in the USA, National Geographic Magazine (2007) made the claim that, “Colonists carried the plasmodium (vivax) parasite to Virginia in their blood. Mosquitoes along the Chesapeake were ‘infected’ by the settlers and spread the parasite to other humans.”

Many countries on the frontline of malaria elimination such as Botswana and Namibia should be concerned. First more attention is being paid to high burden countries than those close to elimination. Secondly, opportunities to learn how to achieve elimination are not receiving donor attention. This attention needs to include strategies for keeping malaria out once elimination has been declared.

For example, in its Roadmap to universal coverage Botswana documents …

• No specific govt allocation towards LLINS
• National requirement for universal coverage is 400,000
• Need to re-orient the program towards pre-elimination
• Inadequate resources for malaria focal persons

Malaria is a moving target. Are we ready to keep up the chase?

Humans and monkeys have shared and competed in the same environments, though not always to the benefit of monkeys.  In an interesting form of retribution for killing and eating monkeys, humans may have acquired the simian immunodeficiency virus (SIV) which mutated into HIV.

Although the earliest evidence of HIV was traced to about 60 years ago, a new study in Science as reported by the New York Times, suggests that monkeys may have harbored SIV for over 30,000 years. The Times notes that scientists have questioned …

What happened in Africa in the early 20th century that let a mild monkey disease move into humans, mutate to become highly transmissible and then explode into one of history’s great killers, one that has claimed 25 million lives so far? Among the theories different researchers have put forward are the growth of African cities and the proliferation of cheap syringes.

HIV is not the only health problem humans and monkeys share. Erma Sulistyaningsih and colleagues are among the most recent to address the problem of Plasmodium knowlesi, acquired from monkeys when tourists among others visit forests as a possible fifth form of human malaria in southeastern Asia including Indonesia, Malaysia, Vietnam,  the Philippines and recently in Myanmar.

There is also … “the theory of P. vivax originating in macaques in Southeast Asia and the close relationship to other primate malaria parasites.” Studies in Brazil also show that monkeys could serve as reservoirs for P vivax.

Researchers have also been exploring the “co-speciation hypothesis” in the relationship between P. reichenowi in chimpanzees and P. falciparum in humans. Hughes and Verra concluded that, “The available data are thus most consistent with the hypothesis that P. reichenowi (in the strict sense) and P. falciparum co-speciated with their hosts about 5–7 million years ago.”

Then last year Medical News Today reported that, “Researchers based in Gabon and France report the discovery of a new malaria agent infecting chimpanzees in Central Africa. This new species, named Plasmodium gaboni, is a close relative of the most virulent human agent P. falciparum.”

The authors of the Gabon study warn that, “The risk of transfer and emergence of this new species in humans must be now seriously considered given that it was found in two chimpanzees living in contact with humans and its close relatedness to the most virulent agent of malaria.” Similarly other researchers have expressed concern that, “Finally, our data and that of others indicated that chimpanzees and bonobos maintain malaria parasites, to which humans are susceptible, a factor of some relevance to the renewed efforts to eradicate malaria.”

Hence we see the lesson. In all our efforts to eliminate malaria, we do not want to monkey around with other possible reservoirs of infection.  Capacity to monitor our simian cousins is a key element in eventually ridding humans of the malaria parasite.

First the good news. Roll Back Malaria’s “Saving Lives with Malaria Control: Counting Down to the Millennium Development Goals” report provides encouragement when one reads that, “it is estimated that in the past 10 years, scaling up malaria prevention has saved the lives of nearly three quarters of a million children in 34 malaria-endemic African countries, 85% of these in the past 5 years alone.”

This is the latest report in RBM’s Progress Series and indicates that, “the results suggest that if current scale-up trends are maintained until 2015, another 1.14 million African children’s lives will be saved between 2011 and 2015.”

On the other hand, RBM warns that, “if funding were to cease in 2010 and prevention efforts were to fall, an estimated 476 000 additional children would die in that same period.” Is it possible that a greater focus on future eradication of malaria could distract from saving lives now and reaching the 2015 Millennium Development Goals?

The New York Times reported three years ago that, “challenging global health orthodoxy, Bill and Melinda Gates called for the eradication of malaria.” According to the Times, the Gateses labeled this call to action ‘audacious,’ while some partners called it ‘inspirational,’ ‘noble but quixotic’ and even ‘harmful.’

Now the Seattle Times reports that Bill and Melinda Gates are, “revamping the scientific agenda with their eyes on the controversial goal they set three years ago: driving malaria to extinction”

Justifying the focus, the Seattle Times indicated that, “Although total eradication of the disease may be as much as forty years away, it’s important to start work on drugs and vaccines that could take a decade or more to bring to the field, David Brandling-Bennett, leader of the Gates Foundation’s malaria programs.”

The implications of “The increased focus on the future means the Gates Foundation is ending its support for some efforts to lessen the disease’s current toll. Those include research to improve treatment of the severe infections that strike children and pregnant women, and that are responsible for most of the estimated 850,000 annual deaths from malaria,” according to the Seattle Times. Fears have arisen that this change by Gates, due to its financial influence, may pull resources away from other malaria research and program implementation efforts.

On the programming side, Gates has pledged 3% of the total Global Fund pledges as of August 2009, which is three-quarters of the funds pledged by all non-governmental organizations (foundations, corporations, etc.). While this is important, it is unlikely that even if Gates does not continue its support for programming, the bigger threat to major malaria funding sources – i.e. governments – is the current weak global economic environment.

We can all agree that Bill and Melinda Gates have influence. Currently they are using it to advocate to other wealthy individuals, corporations and foundations to contribute more toward charitable pursuits. In the area of malaria, they can also advocate with governments – both donor and endemic – to maintain and increase their financial support for malaria control and elimination. By then the new malaria tools deriving from Gates-supported research may be ready to carry elimination into eradication world-wide.

The World Health Organization reminds us that …

2010 marks the 30th anniversary of the eradication of smallpox. Smallpox was officially declared eradicated in 1980 and is the first disease to have been fought on a global scale. This extraordinary achievement was accomplished through the collaboration of countries around the world.

A key point to keep in mind is that the final battle was fought in Africa and Asia where health systems were often weak.  The organizers adapted to this reality and in the end adopted a case containment strategy.  This entailed a move away from the resource intensive mass vaccination campaigns to focused vaccination within a radius of a detected case. Containment required a good surveillance system, but was helped by the easy recognition of the distinctive signs of a ‘case.’

Two other diseases are now on the verge of eradication, guinea worm and polio. WHO reports on guinea worm that, “There were only 3190 confirmed cases in 2009 compared with 25217 cases in 2006 and almost 3.5 million cases in 1986.”

So far in 2010 there are less than 600 reported cases. Guinea-worm disease is now endemic in only four countries in Africa: Ethiopia, Ghana, Mali and Sudan. The guinea worm effort also drew valuable lessons from the case containment strategy of smallpox.

At WHO’s Media Center, Veronica Riemer reports that …

Polio eradication is at a critical juncture. Only four countries in the world remain polio-endemic: Afghanistan, India, Nigeria and Pakistan. In Nigeria, case numbers have collapsed by more than 99% in the past year, from 312 cases to just three in 2010. In India, for the first time, the remaining endemic states of Uttar Pradesh and Bihar have not reported any wild poliovirus type 1 cases concurrently for more than six months. That’s the good news. The bad news is that Tajikistan, which had been polio-free since 1996, was reinfected with poliovirus from northern India in 2010. By mid June more than 200 children were paralysed.

So far this year there have been 456 cases of wild polio virus detected; 1604 were counted in 2009. There still are a few cases being reported this year in Chad, Nigeria, Mauritania, Niger and Mali among 15 affected countries.

What can malaria elimination proponents learn from these experiences? At present malaria programs are generally at a mass intervention scale-up phase, though some places, notably in southern Africa, are getting close to elimination.

It is in these pre-elimination countries that we will begin to learn whether surveillance and containment activities used in other eradication efforts can be successful. Malaria does not have the relatively unmistakable signs of the smallpox rash, the emergent guinea worm or acute flaccid paralysis that makes surveillance and detection relatively easier for the other three diseases. Malaria is known to be confused by both community members and clinical staff for other febrile illnesses.

What we do share is that conflict or post-conflict countries are among the hot spots of the remaining cases of polio and guinea worm – as is also the case of malaria, and these areas have health systems challenges that make both mass intervention and focused surveillance systems difficult to operate.

We also worry as the number of cases wind down for polio and guinea worm that attention may wane and new cases spring up.  Guinea worm for example, has been lumped under the rubric of ‘neglected tropical diseases,’ which hopefully will not be a recipe for further neglect.

Unexpected outbreaks gave occurred with both guinea worm and polio because of human movement alone (the pond-bound cyclops that serve as intermediate host of guinea worm can be dealt with using temephos). With malaria both humans and vectors/mosquitoes are on the move.

This leads to another major difference. smallpox and polio have been attacked with one major tool – vaccines. Guinea worm could be solved with provision of safe water supplies or at least by filtering pond water through a piece of cloth. Malaria requires medicines and nets and sprays.

We have our work cut out for us. we can draw hope from the successes of other eradication campaigns, but also take lessons that the job requires perseverance until the last case is detected and controlled.

The New York Times points out that “17 African countries, including Nigeria, gained independence in 1960.” Apparently there are few major commemorations. The Times quotes Ibrahima Thioub, a Senegalese historian, who said, “It’s tough to mobilize people for celebrations, because the flowers of independence have faded. The last 50 years have not at all met the people’s hopes and expectations.”

Have these 50 years brought Africa any closer to independence from malaria? It was during those years in the late 1950s and early 1960s when most countries were gaining independence that the first effort to eradicate malaria failed. We have had twelve years of rolling back malaria now – are the critical factors in place to ensure that eliminating the disease is feasible now?

The New York Times article addresses critical factors – ranging from weakness of institutions like parliaments to gaps in civil society engagement – that would impede  public health and social welfare programs including malaria control. African intellectuals quoted in the article bemoan that “democracy is held hostage by elites,” and the public accepts that “power is a matter of essences, a heritage, something in the blood, that what is normal for a state is unlimited monarchy.”  While both power and malaria may be ‘in the blood’, the former does not appear to be as easily transmissible or shareable, making the latter all the less easy to control.

The Times notes that, “… there is the reliance on heavy inflows of foreign aid, which equaled a quarter to nearly a third of government spending in countries like Burkina Faso, Cameroon and Mali in 2008.” Clearly this includes inputs from the Global Fund, The World Bank Booster Program and the US President’s Malaria Initiative (PMI). What aspects of health programming are not covered by aid is often paid out of pocket by the public, which is already impoverished by diseases like malaria.

Although there have been recent worries about both the level of donor funding moving forward and the willingness of countries to sustain programs should donor funding collapse, there are some positive signs from the donor side.  The US Government is increasing its malaria focus beyond the 15 PMI countries to include at least Burkina Faso, Burundi, Nigeria, Democratic Republic of the Congo and Sudan, and the Global Fund is embarking on a new ‘grant architecture.’

Known as ‘single stream funding’ the new Global Fund grant architecture “will shift the Global Fund towards a more program-based approach, with significantly improved harmonization and alignment, improving its support of holistic health planning and implementation,” to each principle recipients. This should simplify management, provide continuity, and reduce transaction costs – so even if funding does not increase as desired, there still may be savings and efficiencies for the allocated resources.

There are signs that we may get closer to independence from malaria this year as strides are being made to achieve universal coverage of malaria interventions. It may take another 50 years to see whether malaria can truly be eradicated. Hopefully when many endemic African countries will be observing their 100th year of independence, malaria will have become a thing of the past.

We encourage the malaria community to learn lessons from other disease elimination and eradication programs. Guinea worm appears to be on its last ‘legs’, and we need to consider how it dropped from over 3 million global cases annually in the 1980s to around 3,000 now.

Nicholas Kristof of the New York Times has encouraged people to take heart in efforts to eliminate the disease from Sudan, one of the apparent four remaining strongholds of the disease. He has written a ‘good news column’ from Sudan and stresses that, “This district (where he is visiting) is, in fact, one of the last places on earth with Guinea worms. If all goes well, Guinea worms will be eradicated worldwide in the next couple of years — only the second disease ever to be eliminated, after smallpox.”

The additional ‘couple years’ should be seen in the context of initial efforts that set the target date for global eradication at 1995.  No one says eradication – the total elimination of a disease from the world – is an easy task, but preventing people from drinking guinea worm infested pond water is a little easier than preventing malaria.  If guinea worm eradication is overdue, what can we say about hopes expressed in recent years to eradicate malaria?

Yes, we too like to look for good news. Donald Hopkins of the Carter Center (see photo) told the New York Times recently that, “After 20 years, the Carter Center is ready to declare a major victory in its war on guinea worm: Nigeria, once the worst-afflicted country in the world, appears to be free of the worms. It will take two more years for the World Health Organization to make it official, but not a single worm has been found in Nigeria for 12 consecutive months.”

Why more years? Certifying that a disease is no longer in a country requires continued surveillance after the last known case. Specifically, those countries that had active transmission when the eradication efforts started around 1986 “need to continue surveillance for three years after reporting zero cases and should then be visited by an International Certification Team (ICT) to ascertain that the country is disease-free. The country report and ICT report are presented to the Commission.”

Tayeh and Cairncross drawing lessons from the guinea worm eradication certification process for other diseases explain that, “It is important to reduce the cost of certification and at the same time to ensure that interruption of the disease transmission has really taken place. It is also important not to overload a country’s health system with work when the disease is no longer a public health problem and interest in it has waned.”

IRIN reports that, “Some 80 percent of cases worldwide are in Southern Sudan, a region left in ruins by a 22-year long civil war,” where a settlement was reached only in 2005.  This is another lesson for malaria elimination since the disease actually thrives in war torn areas with diminished amenities, housing and health care.

Kristof ends his column thus: “My favorite moment came when we were bouncing along with Anyak (a local child) toward the Carter Center compound. I asked him what he wants to be when he grows up, and he answered with the most prestigious and altruistic position he could imagine: ‘I’d like to be a Guinea worm volunteer.'”

Hopefully guinea worm will truly be eradicated before Anyak grows up. Maybe he can then focus his career goals on malaria instead. We will need such people of dedication to maintain the long years of surveillance needed to certify the end of malaria when it comes.