Malaria status & challenges of the epidemic
Context - Malaria is one of the most common infectious diseases and a great public health problem worldwide. About one million people die each year from malaria, and half of the world's population lives in areas where there is a risk of getting the disease through the bites of infected mosquitoes.
What is being done to control the spread of malaria? Can the disease be
Anopheles mosquito, the vector for malaria
Malaria is one of the most common
infectious diseases and a great
public health problem worldwide, particularly in Africa and south Asia.
It is caused by a microscopic
parasite transmitted by mosquito
bites. Only certain species of mosquitoes of the
Anopheles genus – and only females
of those species – can transmit malaria.
About half of the world’s population lives in areas where people are
at risk of getting malaria through the bites of
Each year, about 250 million persons suffer from the disease and one
million of them die, mostly African children under five years of
There is growing agreement on the best available prevention and
treatment methods, and international organizations such as the
World Health Organization
(WHO) have set up ambitious
objectives for a large-scale fight against malaria.
2. Which strategies were adopted to prevent and treat malaria?
Mosquito nets are a major prevention measure.
To prevent malaria in areas where malaria cases are
reported, the WHO recommends two
First, people should sleep under mosquito nets treated with long
lasting insecticides. This prevents
bites from malaria-infected
mosquitoes and kills them. Such nets should be used as a priority by
pregnant women and children under five years of age,
who are most vulnerable.
Second, the inside walls of houses should be sprayed with
insecticide to kill large numbers
To be more effective, in high risk areas (i.e. with one or more
malaria cases per 1000 inhabitants per year), these two methods can be
combined or even be complemented by other methods when needed. It is
crucial to check whether mosquitoes transmitting the malaria
parasite are becoming resistant to
the insecticides used. Moreover,
pregnant women in high-risk areas should be given suitable preventive
malaria treatment at least twice during pregnancy, and three times if
they are also HIV positive.
Currently, the best way to treat malaria is to use a
combination of two or several anti-malarial drugs including
artemisinin. In order to prevent
the development of drug-resistant
parasites, the treatment of malaria infections should only be
administered to infected
individuals, based on preliminary detection of the
parasite in the blood. Children
under five years of age with malarial symptoms are the exception and
should be treated straight away.
For 2010, the WHO had set the
ambitious target of offering prevention and treatment services to over
80% of the people who need them. The objective
is to cut the proportion of people who get ill
or die from malaria by at least half by 2010 and by at least three
quarters by 2015.
3. How many people were affected by malaria in 2006?
Approximately half of the world’s population lives in countries where
there is some risk of being
infected with malaria and one
fifth in high-risk areas (i.e. with one or more malaria cases per 1000
inhabitants). Globally, malaria is a problem in 109 countries. Most of
the people at high risk of getting malaria live in Africa and South-East
In 2006, an estimated 247 million malaria cases occurred. Most cases
were reported in Africa and half of these in just five countries:
Nigeria, the Democratic Republic of the Congo, Ethiopia, Tanzania and
Kenya. India accounted for one third of the malaria cases occurring
WHO African Region.
In 2006, close to one million people died from malaria, the vast
majority of which were African children under five years of age.
It is very difficult to estimate with great accuracy the number of
malaria cases and deaths, and figures vary among different studies.
Estimates of the WHO World Malaria
Report 2008 are based, in part, on the number of cases reported by
national malaria control programmes. The reliability of these estimates
depends on how complete the national data are, on how many people use
public health facilities compared to private facilities, and on how many
suspected malaria cases are confirmed by laboratory analysis.
4. What is being done to prevent and treat malaria?
Child holding a mosquito net in Togo. There are still insufficient
numbers of nets in many countries.
Source: Leslie Hallman
The WHO developed policy
recommendations to prevent and treat malaria. Many of these policies
were adopted, but the extent to which they are implemented varies
between countries and WHO Regions.
Regarding malaria prevention, despite big increases
in recent years in the supply of mosquito nets, notably to pregnant
women and children, the number of nets available is still by far
insufficient in most countries. The other main prevention measure of
spraying the inside walls of houses with
insecticide is typically used in
specific areas where risk is the highest, and only in a few countries
does this method protect a significant proportion of the population.
Regarding malaria treatment, the distribution of
anti-malarial drugs through public health services increased sharply
between 2001 and 2006. However, most of these drugs were distributed in
a limited number of countries and access to treatment was inadequate.
Also, the distribution of rapid diagnostic tests remained insufficient
and very uneven.
In the WHO African Region,
despite some progress, most countries are still far from meeting the WHO
targets for prevention and treatment. For instance, in 2006, only one
fifth of the mosquito nets needed were distributed and less than one in
five pregnant women were given preventive malaria treatment. However, a
few African countries are performing well and there are some hopeful
signs that the numbers of malaria cases and deaths are decreasing in
these countries (see also
Outside the WHO African Region,
it is more difficult to estimate the coverage of prevention measures
because, among other things, they often only target areas with the
highest risk and the actual number of people covered remains unknown. In
terms of treatment, only a handful of countries were well supplied with
anti-malarial drugs. Some South-East Asian countries that implemented
strong malaria control campaigns reported decreasing numbers of malaria
cases and deaths.
5. How much funding is allocated to malaria control?
Although many countries have not provided information, funding for
malaria control in 2006 was reported to be greater than ever before.
However, it is currently impossible to tell which countries have enough
money to fight malaria or whether the money available was used
The sharpest increase in reported malaria funding occurred in the
WHO African Region, where the
amount of money allocated to the fight against malaria was three times
greater in 2006 than in 2004. Still, it remains insufficient to meet the
WHO targets for prevention and
The two major sources of funding for malaria control are the national
governments of the affected countries and the
Global Fund to Fight AIDS, Tuberculosis and Malaria.
The relative share of the funding from each source varies between
countries. African countries received support from the greatest number
of external agencies.
6. How effective is malaria control?
National records of malaria cases and deaths are not always reliable
but are nonetheless useful to identify trends and to estimate whether
changes from one year to the next are due to specific malaria control
measures or to other factors.
In the WHO African Region,
the number of reported malaria cases and deaths more than doubled
between 2001 and 2006; this reflects either an improvement in
surveillance or more complete records for recent years. Furthermore,
since control campaigns in most African countries had only reached a
small share of the population by 2006, an overall reduction in the
number of malaria cases and deaths in the region is not yet expected.
Nevertheless, in four African countries with relatively small
populations (Eritrea, Rwanda, Sao Tome and Principe, and Zanzibar)
nationwide effects of malaria control were particularly clear. Good
surveillance and high coverage of the prevention and treatment measures
reduced the number of malaria cases and deaths by half or more between
2000 and 2006-2007.
However, in other African countries where a large share of the
population has access to anti-malarial drugs and insecticidal nets,
malaria figures should have declined but did not, which seems to
indicate that either the data are incomplete or the control programmes
are not very effective.
Outside the WHO African Region,
the number of reported malaria cases declined in at least 25 countries
between 1997 and 2006, by more than half in most of them. In some
countries, this decline can be attributed to specific malaria control
policies but, in others, the cause is not so clear.
7. Can malaria be completely eradicated?
Approximately half of the world’s countries are affected by malaria
and each one is at a different stage of malaria elimination. The aim of
the WHO Global Malaria Programme is
not only to reduce the burden of the disease in areas where malaria is
present, but also to limit the geographical extent of malaria in the
world. By 2008, out of the 109 countries still affected by malaria:
- 11 reached the pre-elimination phase. In
those countries, laboratory tests showed that less than 5% of
suspected malaria cases are actually malaria.
- 10 reached the elimination phase. Those
countries have less than one malaria case per 1000 people at risk
- 6 were taking
prevention measures to avoid malaria reintroduction.
These countries have no local malaria transmission by mosquitoes. If
this is achieved for three or more consecutive years, countries are
certified malaria-free by the
The United Arab Emirates is the latest country to succeed in
eliminating malaria bringing the total number of malaria-free countries
or territories in the world to 92. It is not clear whether it is
possible to eliminate malaria completely and permanently in areas where
the rate of infection is currently
high (with one or more malaria cases per 1000 inhabitants per
Determining the impact of control measures on malaria is not easy.
There are hopeful signs from a few countries with small populations,
that widespread preventive measures and prompt treatment can have a
nationwide impact and significantly reduce the number of malaria cases
and deaths. However, the effects of malaria control measures are less
obvious in countries with larger populations.
When data on the number of malaria cases and deaths are gathered and
used properly, they are very useful to measure the trends in illness and
death and the effectiveness of control programmes at local, national and
international levels. This information is essential to improve
prevention and treatment programmes.