WHO releases new guidance on insecticide-treated mosquito nets

The World Health Organization (WHO) today issued new global guidance for the use of insecticide-treated mosquito nets to protect people from malaria. For the first time, WHO recommends that insecticidal nets be long-lasting, and distributed either free or highly subsidized and used by all community members.


Impressive results in Kenya, achieved by means of the new WHO-recommended strategy, show that free mass distribution of long-lasting insecticidal nets is a powerful way to quickly and dramatically increase coverage, particularly among the poorest people.

Previously, WHO’s guidelines focused primarily on providing insecticide-treated mosquito nets for use by children under five years old and pregnant women. However, recent studies have shown that by expanding the use of these nets to all people in targeted areas, increased coverage and enhanced protection of vulnerable groups can be achieved, while protecting all community members. In areas of high transmission of malaria, where young children and pregnant women are the most vulnerable, the WHO now recommends making their protection the immediate priority while progressively achieving full coverage.

In Kenya, from 2004 to 2006, a near ten-fold increase in the number of young children sleeping under insecticide-treated mosquito nets was observed in targeted districts, resulting in 44% fewer deaths than among children not protected by nets, according to preliminary data from the Government of Kenya. This is the first demonstration of the impact of large-scale distribution of insecticide treated mosquito nets under programme conditions, rather than in research settings, where, in different parts of Africa, reduction observed in overall mortality has ranged from 14 % up to 60 %.

These achievements can be attributed to three principal ingredients, which all need to be present for malaria control efforts to succeed - high political commitment from the government, strong technical assistance from WHO, and adequate funding from bilateral and multilateral donors.

“WHO’s new evidence-based guidance provides a road map for ensuring that life-saving long- lasting insecticidal nets are more widely available and used by communities, and are more effective in protecting poor women and children,” said Dr Margaret Chan, the Director-General of the World Health Organization. “The collaboration between the Government of Kenya, WHO, and donors serves as a model that should be replicated throughout malarious countries in Africa.”

In 2001, the Ministry of Health of Kenya developed the new national strategy for malaria control targeting increased coverage of insecticide treated mosquito nets. In 2006, President Mwai Kibaki launched an effort, funded by a US$ 17 million grant from the Global Fund to Fight AIDS, Tuberculosis and Malaria, to distribute 3.4 million long-lasting insecticidal nets free of charge to children in 45 of Kenya’s 70 districts through two campaigns. The Division of Malaria Control of Kenya, working with an international research team, has been monitoring the coverage and impact of this intervention.

Between 2002 and 2006, with a GBP 6 million grant from the United Kingdom Department for International Development, WHO has advocated for and supported the Kenyan Government to undertake free mass distribution, provided technical support for the preparation of two Global Fund proposals, and provided a full-time logistician to support planning and implementation of free net distribution. WHO’s contribution also included helping to outline delivery mechanisms and pricing strategies to reach coverage targets, sharing knowledge and lessons learnt related to net distribution, and strengthening partnerships. Two WHO staff work full-time on supporting the Kenyan Government’s malaria control programme.

“The Government of Kenya is strongly committed to achieving improved and equitable health outcomes for all Kenyans, particularly women and children. The incredible gains in Kenya have been made possible with donor funds, which enabled us to buy these nets, and WHO’s technical support, which helped ensure that they reached those who most need them,” said Charity Ngilu, Minister of Health of Kenya.

Insecticide-treated nets are mosquito nets treated with insecticides which repel, disable or kill the vector mosquitoes which transmit malaria. Conventional insecticide treated mosquito nets need to be re-treated regularly, while long-lasting insecticidal nets (LLINs) are designed to be effective without re-treatment for the life of the net.

The new WHO guidance on nets recommends that campaign-like mass distribution strategies be complemented by delivery through routine health services to achieve and maintain high levels of coverage.

At around US$ 5 per net, LLINs are a simple and cost-effective intervention against malaria. Until recently, progress in scaling up insecticide treated mosquito nets has been slow in many countries, due in part to the inability of the international community to reach a consensus on how to deliver them to achieve and sustain high coverage. Approaches have included commercial channels, social marketing, and free or subsidized distribution through routine public health services or campaigns.

In some cases, a small co-payment may motivate health workers to distribute long-lasting insecticidal nets, thus boosting coverage, but the new WHO guidance stresses that cost should not be a barrier to access. Thus far, only free distribution has enabled rapid achievement of high population coverage and elimination of inequities in net use, as has been demonstrated in Kenya.

“This data from Kenya ends the debate about how to deliver long-lasting insecticidal (or just mosquito nets) nets,” said Arata Kochi, head of the WHO’s Global Malaria Programme. “No longer should the safety and well-being of your family be based upon whether you are rich or poor. When insecticide treated mosquito nets are easily available for every person, young or old, malaria is reduced.”

Malaria, which is preventable and treatable, still kills more than one million people each year, mainly African children under five years of age.