The number of refugees fleeing conflict to seek shelter in neighbouring countries peaked at 18.2 million in 1993. A further 24 million were estimated to be internally displaced. The risk of malaria is often high among refugees in tropical countries. What strategies should be used to protect them?

These questions are addressed through research by Health-Net International among Afghan refugees at the Pakistan-Afghanistan border and by the Shoklo Malaria Research Unit among Karen refugees at the Thailand-Myanmar border.

The main reasons why malaria flourishes in conditions of crisis and population displacement are:

• breakdown of health services
• displacement of non-immune refugees to malaria-risk areas
• malnutrition
• siting of camps on poor quality land able to support mosquito breeding
• problems in reaching or supplying medicines to displaced populations
• lack of protective shelter and other barriers to mosquitoes.

The challenges posed by the epidemiology of malaria in these two refugee populations demand different strategies. The Afghan refugees had little or no immunity when they arrived at camps sited on land prone to mosquito breeding. Nomadic refugees may transport malaria to unaffected areas, are hard to follow up, and cannot be protected by house spraying of insecticide. Different strategies were used to prevent and control malaria in the camps, depending on the situation:

• spraying tents with insecticide for new arrivals
• providing treated mosquito nets
• treating blankets with insecticide for emergency epidemic control
• spraying houses with insecticide for long-term refugees
• sponging domestic livestock to kill mosquitoes.

In Karen camps in Thailand in the late 1980s, malaria was the biggest cause of illness and mortality (15 percent of deaths). The burden was especially heavy in pregnancy. An estimated one percent of all pregnant women in the camps died of cerebral malaria each year. The malaria parasite, P. falciparum, is fully resistant to chloroquine and sulfadoxine-pyrimethamine in south-east Asia. In these camps:

• New artemesinin derivatives combined with high-dose mefloquine reduced malaria incidence by 90 percent.
• Insecticide-treated bednets only partially protected school children from local mosquitoes and were not widely adopted.
• Insect repellent mixed with a local cosmetic was effective against mosquito bites in a pilot study.

The authors recommend that:

• Tents should be treated with insecticide whenever they are distributed to refugees in malaria-endemic countries.
• Treated blankets are appropriate for short-term epidemic control but bednets are more suitable if refugees stay a long while and go on to build mud houses.
• Aid agencies should carefully consider the question of cost recovery and sustainability when distributing nets as communities seem to be unwilling to pay for nets or insecticide when nets are initially supplied for free during an emergency. Sustainable markets will not develop.
• Operational research, integrated into a regular malaria control programme, can provide the evidence base for appropriate interventions and sustainable reductions in malaria.
• Agencies should be encouraged to include simple studies in their malaria control projects rather than see research as the domain of outside specialists.

Source(s):
'Malaria epidemiology and control in refugee camps and complex emergencies', Annals of Tropical Medicine and Parasitology 95 (8): 741-754, by M.Rowland and F. Nosten, 2001

Funded by: European Commission; UNHCR; WHO/UNDP/World Bank Special Programme for Research and Training in Tropical Diseases; UK Department for International Development; Gates Foundation; Wellcome Trust

id21 Research Highlight: 08 May 2002

Further Information:
Mark Rowland
London School of Hygiene and Tropical Medicine
Keppel Street
London
WC1E 7HT
UK

Tel: +44 (0)20 7299 4708
Fax: +44 (0)20 7580 9075
Contact the contributor: mark.rowland@lshtm.ac.uk

London School of Hygiene and Tropical Medicine, UK

Francois Nosten
Shoklo Malaria Research Unit
736/2 Intrakiri Road
P.O Box 46
Mae Sod 63110
Tak
Thailand

Tel: +66 55 531531
Fax: +66 55 535440
Contact the contributor: shoklo@cscoms.com

Shoklo Malaria Research Unit, Thailand

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