Malaria Control Program at PATH
Working Paper on Accelerating Program Progress toward Transmission
Elimination in Africa
This working paper summarizes findings, experience, and analysis resulting from the efforts of a wide
range of national, regional, and global malaria experts. It is intended to provide an updateable reference
point for discussion at a time of rapid change in our understanding of how to eliminate malaria in African
countries. The several African countries currently targeting elimination have mobilized actions relatively
recently; while scientific evidence and experience from previous and current efforts in countries outside
of Africa are informing program planning and implementation, much of what is being done today to
develop a robust evidence base on how to eliminate the disease in Africa is a result of consultation,
analysis, and guidance from a wide range of Roll Back Malaria partners. Technical guidance, practical
experience, and leadership from African governments, national ministries of health, their malaria
programs, and their partners at the country level are providing critical lessons to shape the path ahead.
Today is a time of rapid change and there is much to be learned about how to optimize efforts and
sustain commitment to eliminating malaria in Africa.
Introduction and background
The world has made remarkable progress in controlling malaria in that past half-century. The Global
Malaria Eradication Program (GMEP), launched by the World Health Organization (WHO) in 1955, was
the first concerted effort to stop the disease in the 143 malaria-endemic countries. By 1978 it was
successful in freeing 37 countries from malaria and reducing the disease burden in many others,
although African countries did not benefit from these efforts out of recognition by the WHO African
Regional Committee that the strategies and tools could not be effectively implemented in the region.
Challenges including drug and insecticide resistance eroded confidence in GMEP efforts and it was
abandoned in 1969. By the late 1990s, ten countries—most in the WHO Eastern Mediterranean region—
successfully eliminated malaria, while the malaria situation deteriorated in other parts of the world. This
period also was characterized by a re-energized commitment to developing new tools, including
insecticide-treated mosquito nets (ITNs), artemisinin-based combination therapies, and diagnostics.
Establishment of the Roll Back Malaria (RBM) Partnership in 1998 launched an era of concerted effort to
halt malaria in African nations. Progress toward elimination continued during the most recent decade; in
that time, four countries were certified by WHO as having eliminated the disease and every WHO region
of the world demonstrated improvements in reducing disease burden. Also during this era, the scale-up
for impact (SUFI) approach was tested and proven as a strategy to rapidly implement prevention
interventions that achieve health impact. The success of SUFI led to wide adoption of this approach
across the Africa region with strong support from the RBM Partnership; US President’s Malaria Initiative
(PMI); the Global Fund to Fight AIDS, Tuberculosis and Malaria; and the World Bank. During the last
decade SUFI has become the strategic approach implemented by more than 40 countries in the region.
With the early successes demonstrated by SUFI, Bill and Melinda Gates convened the Gates Malaria
Forum in 2007 and put malaria elimination and ultimate eradication back on the global stage. WHO
director general Margaret Chan strongly supported the endeavor, prompting considerable discussion
and debate in the global malaria community. In 2009, the RBM Partnership’s Global Malaria Action Plan
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was launched, describing the path from scale-up through elimination, one that is dependent on
sequential reduction of malaria transmission within each program step (from SUFI, through sustained
control, pre-elimination, and elimination). The Malaria Elimination Group (MEG) established a series of
meetings and publications on issues of malaria elimination and WHO published guidance and restated
the certification process for national malaria elimination.
Since 2007, several African countries have announced their intent to eliminate malaria, including
countries in the Southern Africa Development Community, which joined the sub-regional malaria
elimination initiative in Southern Africa known as the Elimination Eight. The WHO African Region
adopted a resolution in 2009 to accelerate control to achieve malaria elimination. In response to the
suggestion that new and better tools and strategies would be required to ultimately achieve global
malaria eradication, the Malaria Eradication Research Agenda (malERA) Group detailed the research
agenda to accomplish this. In 2010 the World Health Organization convened malaria experts from
diverse backgrounds to examine options for next steps in further controlling malaria transmission and
explore opportunities for eliminating the disease in African communities with existing tools. The group
detailed and endorsed the concept of strengthened information systems and community leadership and
responsibility to seek and contain malaria transmission.
A view today toward malaria transmission elimination
Today, nearly one third of all remaining malaria-affected countries are on course to eliminate the
disease in the next decade. We know that SUFI is not a comprehensive approach to malaria control but
represents a strategy to launch comprehensive malaria programming en route to elimination. Country
experience is demonstrating that success in rapidly scaling up malaria control intervention coverage,
while capable of dramatic impact on mortality and illness rates, does not constitute a sustainable
program strategy. Country progress in achieving low or very low transmission rates is laudable, but it is
not an endpoint. The persisting financial, development, and human cost of malaria, even when the
disease becomes very rare, is unacceptable. Only by eliminating malaria can countries end the burden
associated at all levels of transmission.
The RBM partners currently face several important challenges to continuing the expansion of program
scale-up to the entire Africa region—especially in large countries where large numbers of malaria deaths
continue to occur—and to implementing effective strategies to extend the gains of scale-up that will
progressively reduce malaria transmission to zero, thus eliminating the disease. The Malaria Control and
Evaluation Partnership in Africa (MACEPA), a program within PATH’s Malaria Control Program, is
partnering with several African countries to lead the development of effective program strategies to
guide progression along the spectrum from scale-up to elimination. Documenting strategies and lessons
from countries building on SUFI to move toward elimination is providing critical guidance on how
malaria transmission can be systematically reduced and eventually halted.
The pathway to malaria transmission elimination
The progression from high malaria transmission to elimination is a process that requires continual
adjustments to programming across the evolving epidemiological spectrum to ensure attention to
detecting and treating increasingly rare instances of infection (Figure 1). As these epidemiologic steps
are reached— presented here as ten-fold reductions—programmatic adjustments must be made based
on the extent to which the added or modified intervention or the intensified resource investment will
further reduce malaria transmission. Once a SUFI approach to programming has succeeded in reducing
infection transmission through vector control (killing or shortening the life of female mosquitoes so that
they are not able to transmit infection), the focus must incorporate the balance of clearing malaria
2
parasites from symptomatic and asymptomatic individuals so that they do not transmit parasites back to
mosquitoes. Success in moving toward infection elimination today is based on the assumption that
progress can be made by deploying existing interventions, tools, and systems; building on malaria
program infrastructure; and transitioning much of the orientation of a national program to incorporate
the spectrum from centralized leadership to community-based action where each level of the malaria
program and the health care system has critical responsibilities for the work.
Key concepts about malaria transmission
It is highly variable across Africa. While most countries are broadly considered “malariaendemic” and their populations are at high risk for malaria, there is a very wide range of
transmission intensity and it is important to assess where populations are on the spectrum
so that appropriate strategies can be applied.
It is measured by the frequency of infections in the human population. Historically, this
has been presented as the entomologic inoculation rate (EIR)—the number of infectious
mosquito bites per person per time interval (typically per year). This is translated into a
rate of infections per 1,000 population per year.
It is a circular process—from mosquitoes to humans and then back to mosquitoes—and
transmission reduction must attack both arms of the circle. To date, highly effective vector
control tools (long-lasting insecticide treated nets [LLINs] and indoor residual spraying of
insecticide [IRS]) have proven to have a dramatic impact on both processes, leading to
about a ten-fold reduction in transmission under current program implementation efforts.
Malaria parasites can be transmitted and harbored by someone who feels and appears
healthy. While prompt diagnosis and treatment of malaria cases is critical for the
individual who is sick with malaria, many infected people are not symptomatic and so do
not seek treatment. Frequently, this leaves a large population of asymptomatic, infected
people able to infect mosquitoes. For each step in transmission control the objective is to
achieve further reductions in the remaining reservoir of malaria parasites, and
consequently the source of further transmission in the population—either addressing the
mosquito-to-human process or the human-to-mosquito process.
Program actions must be able to respond to rapidly changing transmission. The rate at
which malaria transmission can change is dramatic and programs must be ready to
Malaria
transmission
and
impactprograms
on populations
and success
programming
respond
accordingly. For
example,
achieving rapid
in transmission
reductionfrom
through
population-based
community
and treatment
will need
to
Progression
scale-up
to elimination
can be screening
characterized
as a multi-step
process
(Figure 1). In
quickly
transition
to
a
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prioritizes
rapidly
identifying
and
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isolated
new
programmatic terms this has been characterized in the RBM Global Malaria Action Plan as beginning
and screening
in the
vicinity
who may
have effort
been exposed.
withinfections
SUFI, progressing
to aindividuals
consolidated
and
sustained
control
and then transitioning toward
elimination. Each step builds on the progress achieved from existing program action; and each step
must lead to progressive and substantial transmission reduction. Figure 1 illustrates the single path
from high to no malaria transmission. It highlights the probable population experience with malaria
infections and illness and summary program actions and evolving pattern of interventions required as
a community, district, or province transitions along the path toward decreasing transmission. To
progress along the malaria elimination spectrum, countries require accurate, real-time data on the
disease’s epidemiological profile. The intensity of malaria transmission has important implications for
timing and configuring the strategies required to bring about further reductions.
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Figure 1. Malaria transmission reduction: Population experience and intervention strategies
for progress
In settings where initial transmission is high there still may be much variability in transmission
intensity. For example, a country may have implemented an excellent SUFI program that reduces
transmission ten-fold, but still there persists an entomologic infection rate (EIR) of five to ten or
greater, parasite prevalence may remain high,1 and morbidity and mortality persist. Thus, the
progress in transmission reduction will require continued attention to the ongoing levels of infection
in the population and continued evolution of interventions to address the level and focus of that
transmission.
Programmatic components of malaria elimination
Strategic program design is critical to success regardless of where a program falls along the
elimination spectrum (Figure 2). Required actions can be organized into three general areas of focus.
The first is about leadership: addressing governance; resourcing; guidance on policy, procedure, and
strategy; and human resource needs. The second is about strengthening local program action with an
emphasis on optimizing existing intervention coverage and the required supply systems and a new
emphasis on finding and clearing parasites from all people, and the building of robust surveillance
systems and community action. The third is about documenting progress in transmission reduction
and finding or using new tools that will contribute specifically to that success.
1
Because parasite prevalence is determined by both incidence and duration of infection, long duration asymptomatic
infections (untreated) may contribute to persistent high parasite prevalence even when incidence has been markedly reduced.
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Figure 2. Programmatic components of malaria elimination
Mobilize
national
leadership
Engage
districts and
communities
Strengthen
surveillance
information
systems
Address key issues (including
governance; resourcing; guidance
on policy, procedure, strategy; and
HR needs)
Optimize
prevention
intervention
coverage
Identify and
test new
strategies
and tools
Track
transmission
Reduce
parasites in
human
populations
Strengthen
local
programs
Maximize impact and document
progress and factors contributing
to success
Mobilize national leadership
Durable national commitment at the highest levels is required for countries to succeed in eliminating
malaria. A sustained commitment to providing leadership and resourcing on policy, strategy, and
implementation are critical at each stage on the pathway to elimination.
Engage at the district and local levels
Country success also depends on sub-national capacity for and acceptance of the concept and specific
approaches to be undertaken for malaria transmission reduction leading to elimination. Engagement
efforts will need to focus on technical skills, program capacity, and supply chain systems that are critical
for scaling up the elimination effort.
Develop or strengthen a malaria infection-detection surveillance system
A key element of an effective transmission reduction effort is the development of a data collection
system to inform metrics for planning and measuring progress. This system requires diagnostic
confirmation with available methods (rapid diagnostic tests [RDTs] and microscopy) at the local level;
results comprise the core data for directing transmission reduction work and for tracking progress in
lowering transmission and so must be made readily available (it will also serve as the basis for fever
management).
Optimize prevention intervention coverage
There is limited experience and guidance on optimizing intervention mix and coverage for maximum
benefit and cost-effectiveness.2 There are no pre-defined coverage levels to achieve lowest possible
malaria transmission levels. While progressively reducing transmission might seem to suggest the
appropriateness of ever-increasing interventions used and coverage rates sought, growing evidence
2
RBM identifies the standard prevention interventions as long-lasting insecticide-treated nets (LLINs), indoor residual spraying
(IRS), intermittent preventive treatment (IPT) strategies in pregnant women, and possibly in infants, and seasonally in children.
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from both field experience and modeling suggest, for example, that 100 percent coverage with ITNs is
not necessarily required for maximal benefit. This optimization process needs to be based on systematic
assessment of existing transmission intensity and an iterative process of examining the benefit of an
added intervention versus the benefit of improving on coverage with an existing intervention. As
transmission is dramatically reduced and quality, timely surveillance, and response is improved in a
country, using surveillance as an intervention may replace or supplement existing strategies and
contribute importantly to final steps of transmission elimination.
Implement diagnosis and drug therapy strategies to locate and eliminate the human reservoir of
parasitemia
Strategies for accomplishing this may vary. In some instances, a campaign-style mass drug
administration effort may be appropriate to presumptively treat everyone in a community where cases
are known to be present. A screen and treat approach (also known as active infection detection) may be
used to screen entire populations or focal areas where cases are identified and to treat all infected
persons. Alternately, active investigation of transmission based on infection identification could be
implemented, in which those living in or near a household where an infection is found are tested and
treated when necessary. All strategies share in common the goal of reducing transmission, then driving
it to a very local level, and eventually eliminating transmission altogether.
Identify and test new tools and strategies
Several countries achieved strong impact with SUFI and are now testing strategies for malaria
elimination. These early efforts are already providing important lessons from which others can learn.
Similarly, while current tools are understood to be sufficient to achieve elimination, new ones will be
available soon that can be tested and implemented.
Assess progress toward transmission elimination
This is based on the strengthened surveillance system output to monitor transmission intensity with
occasional population surveys to monitor program inputs, coverage, and use. Attention must be given to
assessing service delivery feasibility, cost, and evolving benefits in morbidity, mortality, and
socioeconomic conditions.
Key program considerations for achieving malaria control
The proposed conceptual framework detailed here offers a definable and measurable strategic
orientation for malaria elimination that will lead to predictable and progressive reductions in malaria
transmission in Africa, building on the systems and gains already established with SUFI. There is much to
be learned and there are many challenges ahead.
Critical questions will need to be resolved in the relatively near term to leverage support for and guide
programming, including the following:
1. When is it appropriate for a country to embark on malaria elimination? Many countries have
already declared their intention to seek elimination. While some external experts may think this is
premature for certain countries (for example large countries with high parasite prevalence and
transmission rates and constraints on programmatic capacity), early encouragement to start and
learn may be important for the long path that they will need to take.
2. Where is it most logical to begin testing elimination strategies? It stands to reason that the first
steps should be taken both in areas where success is most likely (because the program will need
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early success to gain a sense that this can be done) and in areas where it will be most difficult
(because the program will need to be there eventually and need to strengthen weak systems that
make these areas problematic now).
3. What is the optimal size of malaria-free zones and the relevant border of the zone for protection
from reintroduction? The size is of local relevance—it should be big enough to be credible as a
replicable effort that could achieve national scale, but small enough to manage in the early days.
And, one should attend to both the lowest transmission settings and the settings that are most likely
to reintroduce malaria to the elimination area. Coalescing malaria-free zones into a national
elimination effort will begin the end-game of elimination.
4. How can programs move rapidly along the elimination spectrum while maintaining quality?
Building on progress attained through SUFI, the population will still have much immunity and be at
least partially protected from severe disease and death; this will have distinct advantages for rapid
continued efforts toward transmission elimination. The time required for programs to progress to
elimination has important cost implications; the desire to progress rapidly will need to be balanced
with the need to assemble solid, effective programs. Further, clear progress toward malaria
elimination needs to occur in a timely manner to build and sustain commitment.
5. How is progress measured and promoted when there is very little malaria? The measurement
metric (and its evolution under changing epidemiological conditions) needs to be established in
order to demonstrate the extent of progress in malaria elimination and to galvanize sustained
support for ongoing efforts among communities, thought leaders, donors, and global leaders in
malaria.
6. What are critical potential impediments that need to be addressed to support smooth progression
to elimination? Potential barriers include interrupted funding flows, quality control issues, or
waning top-level support for programming.
Challenges at the global and country level will be ongoing and accruing country action and experience
will help address some of the anticipated concerns:

Demonstrating that it can be done in one “large enough” setting in malaria-endemic Africa will
present an enormous challenge and debate among the global community.

Identifying and improving the critical health systems such as procurement and supply chain
management, information collection, and analysis for action will help the global community
prioritize its investment.

Clarifying the value-for-investment of malaria elimination. Cost-effectiveness studies of full
program actions are needed to generate data that can substantiate the financial case for investing in
malaria elimination. This will likely be critical to assure ongoing national and external financing of
the elimination agenda.
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