Contents
Main Page
Foreword
Introduction
Managing Water Resources
Food Security for the Poor
Health Problems of the Poor
 Rolling back Malaria
 Saving a Mother´s Life
 Benefits of Fortification
 Making Thai Food Safe
Environmental Management
Strengthening Nuclear Safety
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Rolling Back Malaria: New Tools for Fighting a Leading Killer

Bamako, Mali. It was the autumn of 1999, and Dr. Abdoulaye Djimde, a pharmacist at the Malaria Research and Training Center in this capital city, had just learned of a major malaria outbreak in the northern region of Kidal. Oddly, the epidemic was spreading in an arid area not known for malaria, probably due to recent, heavy rains. Nonetheless, several thousand adults and children had fallen ill, and some were dying because they lacked any natural immunity.

“We needed a strategy to work with the local health authorities in finding the fastest and most efficient means to curb the epidemic,” explains Dr. Djimde. “If mortality was to be effectively reduced, it would be critical to determine the population’s level of susceptibility to anti-malarial drugs.”

The situation was compounded by a rebellion in the Kidal area. Thus, the government arranged for transportation of a medical team to Kidal on board a military plane. Numerous blood samples and mosquitoes were collected to measure the magnitude and specific nature of the epidemic. Once back in their laboratory, the team employed molecular methods to analyze samples for the prevalence of mutations, which ultimately provide information on drug resistance in the malaria parasites. The whole process took a few days.

“We were happy that molecular methods could be applied in a real-life situation,” says Dr. Djimde. “Without them, we would not have been able to determine that these parasites were resistant to chloroquine, but not to Fansidar. Molecular methods helped us to bring the epidemic under control within a month, rather than in several months using conventional means.”

Molecular methods helped Malian health authorities to act quickly, and also to develop a tailored response, based on scientific evidence, targeting the core of the problem and directing efforts effectively. The lives of many poor villagers were spared.

Malaria’s Wide Reach

Malaria is one of the leading killers of humans worldwide. It does not halt at political borders, but invades wherever the Anopheles mosquito is present. It thrives especially in the tropics of numerous countries in Asia, Africa, and South and Central America.

According to the WHO, malaria:

• Kills more than one million people per year, approximately 3,000 deaths each day;

• Causes about 300—500 million clinical cases each year;

• Leads to the death of over 700,000 children per year under the age of five; and

• Impairs the learning of as much as 60 per cent of schoolchildren in endemic areas.

Some 40 per cent of the world’s population live in high-risk areas, and 90 per cent of the infections occur in sub-Saharan Africa. The African situation is compounded by deteriorating health systems, growing drug and insecticide resistance, periodic changes in weather patterns, civil unrest, human migration, and population displacement.

Malaria-endemic countries are among the poorest nations. The disease slows down economic growth in Africa by an estimated 1.3 per cent each year. If malaria had been eliminated some 35 years ago, Sub-Saharan Africa’s GDP would be 32 per cent greater today, according to economists. Households spend between US$ .39 and 3.84 per person in Sub-Saharan Africa to prevent and treat malaria. Most importantly, malaria is preventing the improvement of living standards of future generations and the economic development of the world.

Malaria’s Long Legacy

Malaria is believed to have originated in Africa, and spread through human migration to the Mediterranean shores, India, and South East Asia. Lurking in the marshy swamps around ancient Rome, it derived its name from the Italian “mal aria” or “bad air”. It is also known as the “Roman fever”.

Scientists discovered the cause of malaria in 1880: the Plasmodium parasite. Some 18 years later they traced its transmission to the Anopheles mosquito. Once the cause was identified, a targeted battle was initiated and public measures introduced to ensure its elimination. In particular, during World War II the application of the insecticide DDT and the drug chloroquine were highly effective in combating the disease. A far-reaching WHO programme, which combined insecticide and drug treatment, resulted either in complete eradication in many regions, or a sizeable decrease of infections.

But malaria made a resurgence in the 1960s, mainly due to the resistance of mosquito strains to insecticides and the parasite’s resistance to chloroquine. In recent decades, the expansion of irrigated agriculture in developing countries provided new breeding sites for Anopheles mosquitoes and aggravated the malaria problem.

What Causes Malaria?

Malaria is caused by a parasite transmitted to humans through the bite of the female Anopheles mosquito. Four strains have been identified, and the one responsible for the most serious illness is Plasmodium falciparum.

When a mosquito takes a blood meal from an infected person, it can ingest the parasites. These parasites reproduce in the insect before moving to the salivary glands, where they are transmitted to another person when the mosquito feeds again. Once inside an individual, Plasmodium first infects the liver and then invades the red blood cells. Some parasites mature and are ingested by mosquitoes, thereby continuing the infection cycle.

What are the Symptoms?

Malaria is characterised by recurrent attacks of chills, followed by fevers and sweating. Its most common symptoms are headaches, nausea and vomiting, pain, anemia, and convulsions. If untreated, it can lead to coma and severe anemia, which often results in death. Drug treatments are available, but drug resistance is a major concern in endemic areas.

How Do We Fight Malaria?

Numerous strategies have been applied to combat malaria: traditional drugs such as quinine; insect repellents and insecticides; more advanced drugs; vaccine research and development; and improved mosquito control. But all have come up short of success.

Quinine, extracted from the bark of the cinchona tree, has been available since 1600. Chloroquine, the most popular drug until the mid-1990s, was particularly effective, cheap to produce, and easy to administer with few side effects. But, parasite resistance has emerged to chloroquine, and other new drugs have proven only partially effective due to parasite mutation and resistance. Thus, research continues to explore new drugs and control alternatives—including the nuclear-based Sterile Insect Technique (see here for more info)

DDT was an effective for mosquito control during and after World War II. But due to environmental concerns, its application was banned widely. More recent insecticides never matched DDT’s effectiveness. Pyrethroid-treated bednets—used to prevent contact between humans and female mosquitoes—have significantly reduced disease transmission. Research is being conducted to develop genetically manipulated mosquitoes that are unable to transmit disease. And development of a vaccine is on-going, although much new research is still required.

How Are Molecular Methods Used to Fight Malaria?

Since 1997, IAEA TC has been working to enhance Member States’ capabilities in controlling malaria through the application of molecular and radioisotope-based techniques in detecting drug-resistant malaria. Already, Kenya, Mali, Sudan, Tanzania, Zambia and Uganda have used these techniques to identify parasite mutations for detecting resistance to chloroquine and Fansidar.

Monitoring of chloroquine and Fansidar resistance on a large scale—previously impossible because of lengthy, manpower-intensive and costly in vivo trials—is now feasible. Sampling and screening of larger population groups will provide more reliable and timely information to national disease control authorities, and enable them to devise sound control measures and surveillance strategies.

In a new phase of activities, more African countries have joined in the effort on an expanded scope. This includes:

• ensuring that the more advanced and experienced institutes support the less experienced ones in the region;

• supporting expanded surveillance activities; and

• providing reliable information on resistance levels, essential in identifying the type of drug required for treatment.

International Collaboration

Malaria will only be eradicated through joint efforts. The IAEA has established numerous co-operative activities with international and regional programmes. These include the WHO Roll Back Malaria campaign, the Multilateral Initiative in Malaria and the East African Network for Monitoring Anti-Malarial Treatment. Clearly, accurate and rapid surveillance for drug resistance is one key to success in these efforts.

“Malaria cripples people, rendering them unable to work,” says biomedical scientist Baldip Khan of the IAEA. “It impacts the cognitive development of children, hindering their regular attendance at school. It even frightens away tourist dollars. Thus, it is essential to strengthen global and regional partnerships and to elicit contributions from the private sector and NGOs to garner both the technology and financial resources to effectively fight this killer.”

Alliance Against AIDS:
IAEA and WHO-UNAIDS

In late 2001, the IAEA began to identify areas where nuclear medicine could make a unique contribution to addressing the tragedy of the tragedy of AIDS (Acquired Immune Deficiency Syndrome). The nuclear potential was reviewed by the WHO-UNAIDS AIDS Vaccine Advisory Committee, which agreed that molecular biology techniques and radionuclide tracers could add special value if used to monitor HIV/AIDS, and could make a vital contribution to the development and trials for a new HIV (Human Immunodeficiency Virus)/AIDS vaccine.

The IAEA and WHO-UNAIDS will collaborate on field trials for an HIV-1 vaccine—the best long-term hope to control the AIDS pandemic, especially in poor countries. Both research and clinical trials are necessary, particularly on the HIV subtypes that are prevalent in developing countries. This is critical because vaccines under development for HIV strains prevalent in Africa and Asia have not received nearly as much attention as those strains prevalent in North America and Europe.

The new five-year joint endeavour will concentrate efforts in Africa through:

• Strengthening the capacity of selected laboratories, and funding the necessary equipment and reagents;

• Training local scientists and technicians in the relevant methodologies, including safe handling of radioisotopes; and

• Participating in multi-centre collaborative projects with application in care, epidemiology, public health, and vaccine development.

The objectives of the five-year initiative are three-fold:

• Monitoring the changing distribution of HIV-1 genetic subtypes and their recombinants;

• Monitoring the emergence of HIV-1 strains resistant to therapy; and

• Transferring and validating the technology to assess immune responses to new interventions/vaccines.

  Focusing Science on the Health Problems of the Poor
  Introduction...

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Malaria will be eradicated only through joint efforts. The IAEA has established numerous co-operative links with international and regional programmes.
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