TRANSACTIONS OF THE ROYAL SOCIETY OF TROPICAL MEDICINE AND HYGIENE (2001) 95,125-126

Refugee health in the tropics

Malaria control in Afghan refugee camps: novel solutions

Mark Rowland HealthNet International, I? 0. Box 889, University Town, Peshawar, Pakistan; and London School of Hygiene and Tropical Medicine, London WClE 7HT, UK

Abstract Malaria is one of the major communicable diseases to occur in refugee camps. Prevention of mortality by establishing good case management is always the priority. Various types of personal protection or vector control measures may be applied depending on local transmission conditions and stage of the emergency. The range of interventions applied in Afghan refugee camps, the factors influencing choice and the relevance to emergencies in other parts of the world are described.

Keywords: malaria, refugees, vector control, mosquitoes, Pakistan, Afghanistan

Malaria is a disease that flourishes in conditions of war and population displacement. Exposure to transmission is often several times greater among refugees than among local people (NAJERA, 1996). Several factors can give rise to a high malaria burden, including breakdown of health services, concentration of non-immune refugees in ma- laria risk areas, malnourishment, siting of refugee camps on marginal land prone to flooding and vector breeding, and problems in gaining access or supplying medicine to the displaced population (WHO, 2000). Conventional malaria control strategies need to be adapted to refugee situations accordingly.

Complex emergencies usually evolve from acute- emergency to post-emergency phases. The acute phase is characterized by sudden population displacement and high mortality, and may last only a few months. During the post-emergency phase the health situation is brought under control and basic needs are met. Chronic emer- gencies are characterized by political deadlock; some areas of the country stay locked in an acute phase while other areas may progress towards post-conflict stability.

Afghanistan provides examples of all 3 phases. The country has been at war for over 20 years. Refugees first came to Pakistan in the early 198Os, and over a million remain settled there. The war continues in the north of Afghanistan, but most of the country is at peace.

In refugee camps case management may not be sufficient response to contain malaria. If incidence or mortality continues to rise personal protection and vector control interventions need to be applied. Some methods are more suitable for the acute phase, others for the post-emergency phase. The choice of intervention will depend on local factors such as the type of shelter available, human habits, and vector behaviour.

Indoor residual spraying (IRS) is the method most often used in acute and chronic emergencies if displaced populations inhabit regular housing and vectors are indoor resting. It can work well when there is good organization. If coordination between agencies is lack- ing, or insecticide consignments are delayed, spray campaigns are often completed too late to be effective against seasonal malaria (ROWLAND, 1999).

It is not clear whether insecticide-treated nets (ITNs) are an effective intervention during acute emergencies. ITNs are beguilingly attractive to agencies and donors because they are technically simple, proven to be effec- tive in peaceful settings, and because of much recent good publicity. This may be deceptive. In acute emer- gencies free distribution of nets may lead to re-selling or black marketing if the refugee population has no previous experience of using nets. Experience shows that if ITNs

Address for correspondence: Dr Mark Rowland, Disease Con- trol and Vector Biology Unit, London School of Hygiene and Tropical Medicine, Keppel street, London WClE 7HT, UK; phone +44 (0)20 7927 2333, fax +44 (0)7580 9075, e-mail m.rowland@lshtm.ac.uk

are distributed like any other relief item (as they may have to be), with little or no health education, they may not be used properly or looked after. Also there is presently no international stockpiling for emergency use, the number of mass producers is limited, and consignments often arrive too late for the acute phase. The initial investment required may seem too much if the future of the camp is uncertain.

There are other, possibly better, alternatives to ITNs in the acute phase. Where canvas tents are issued, spraying of inner surfaces with a residual pyrethroid will give year-long protection against malaria vectors (HEWITT et al., 1995). Recurrent outbreaks of malaria among nomadic Afghan refugees were finally controlled by spraying tents with permethrin (BOUMA et al., 1996).

Treatment ofblankets or outer sheets with permethrin is a promising option for refugees sleeping under plastic sheeting or other makeshift materials. A recent study in an Afghan refugee camp showed over 60% protection against falciparum infection for 3 months, and no side- effects (ROWLAND et al., 1999). This new approach is ideal in short, acute emergencies because blankets are always distributed and treatment with permethrin will give protection in all types of shelter. The cost is only a fraction of that required for ITNs. A recent study has shown that treated blankets are equally effective against cutaneous leishmaniasis (Leishmania tropica) in Afghani- stan (RBYBURN et al., 2000).

In the post-emergency phase refugees will construct houses, allowing increased use of IRS or ITNs. Annual IRS campaigns can become an expensive drain on the refugee health budget. This is a good moment to change tack and introduce cost recovery. As refugees become more self-sufficient some are able and willing to pay for ITNs (ROWLAND et al., 1997). However, most may still require assistance.

Are there cheaper alternatives to ITNs and IRS that can be applied in chronic refugee settings? In the Afghan refugee camps HealthNet International is pioneering a new method involving the treatment of domestic live- stock with pyrethroid insecticide (HEWITT & ROWLAND, 1999). This approach would not be applicable when the vectors are highly anthropophilic, e.g., AnopheZesgambiae S.S. in Africa or An. dirus in South-East Asia. However, vectors in South Asia are highly zoophilic and domestic cattle can therefore act as bait to attract mosquitoes to a toxic surface. A recent study of treated cattle demon- strated a level of control better than that shown by ITNs or IRS, and at a fraction of the cost. The project was popular with refugees because cattle ectoparasites were visibly controlled.

Finally we must consider the conditions facing refu- gees when they return home after the conflict. The government health system may be in no state to provide malaria control. This is the stage where ITNs have greatest potential.

A lead agency may coordinate an ITN programme and

126 M. ROWLAND

provide training and commodities to non-specialized non-governmental organizations (NGOs) working at community level. ITNs and re-treatments may be sold through NGO clinics or by teams of community health workers. The NGO network may be the best way to achieve good coverage if government or private sector distribution systems are absent in the immediate post- conflict phase. Revenue from sales may serve as a revolving fund for purchase of further nets and insecti- cide.

Although no method of malaria prevention is perfect, appropriate methods do now exist which can ameliorate the situation at different stages of the emergency. Con- certed application of these over several years can have a marked effect on transmission rates. Guidelines are being produced by ‘Roll Back Malaria’ and these will enable agencies to select and apply the appropriate method according to the situation.

Acknowledgements This work was supported by WHO/UNDP/World Bank

Special Programme for Research and Training in Tropical Diseases (Project ID: 960662), the Department for Intema- tional Development of the UK, and HealthNet International.

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Hewitt, S. & Rowland, M. (1999). Control of zoophilic malaria vectors by applying pyrethroid insecticides to cattle. Tropical Medicine and International Health, 4,48 l-486.

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Reybum, H., Ashford, R., Mohsen, M., Hewitt, S. & Rowland, M. (2000). A randomized controlled trial of insecticide- treated bednets and chaddars or top sheets, and residual spraying of interior rooms for the prevention of cutaneous leishmaniasis in Kabul, Afghanistan. Transactions ofthe Royal Society of Tropical Medicine and Hygiene, 94, 361-366.

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Rowland, M., Hewitt, S., Durrani, N., Saleh, P., Bouma, M. & Sondo&, B. (1997). Sustainability ofpyrethroid impregnated bed nets for malaria control in Afghan communities. Bulletin of the World Health Organizatabn,75,23-29.

Rowland, M., Durrani, N., Hewitt, S., Mohammed, N., Bouma, M., Cameiro, I, Rozendaal, J. & Schapira, A. (1999). Permethrin-treated chaddars and top-sheets: appro- priate technology for protection against malaria in Afghani- stan and other complex emergencies. Transactions of the Royal Society of Tropical Medicine and Hygiene, 93, 465-472.

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Received 1 March 2000; revised31 March 2000; acceptedfor publication 16 August 2000

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