Christian Aid has warned the risk of hunger and malnutrition in the Ebola-hit communities of West Africa is threatening to undermine the effectiveness of quarantine measures and the wider Ebola response.

The charity is calling on the international community to address food insecurity for over a million people in quarantine in Sierra Leone. While the global response has focused largely on medical treatment, the threat of widespread hunger could destabilise efforts to curb the outbreak, Christian Aid warns.

Adrian Ouvry, Christian Aid's humanitarian programmes manager, said: "Households, neighbourhoods and entire districts have been isolated in Sierra Leone. To break the chain of transmission, you have to limit people's movements, but it is counter-productive to restrict their movement without addressing their basic needs. Endemic poverty, increased food prices and limited support to affected communities are forcing people to leave quarantined homes to fend for their families.

"Governments and aid agencies must recognise that quarantine will only be effective if those who are isolated are guaranteed a sufficient and constant supply of nutritious food and clean water. Otherwise, the issue of hunger and food security will undermine the success of quarantine measures."

The World Food Programme has begun providing emergency food assistance to over a million people across Guinea, Sierra Leone and Liberia, but much more is needed.

Former nurse Theresa Bagrey, Christian Aid's senior programme officer for community health, based in Freetown, said: "Many people here in Freetown still need to go out every day to find their daily bread. Markets are still crowded and busy, as people move about and try desperately to buy, sell and scrape together a living."

Adrian Ouvry added: "In Sierra Leone farmers are unable to plant or harvest and there are widespread restrictions on the transportation of foodstuffs and weekly local markets are being closed. The cost of food is rising sharply and families cannot afford to eat. For example, the price of a 50kg bag of rice –Sierra Leone's staple food –has risen by over £5.

"These disruptions can cause immense hardship, particularly for the many people living a hand-to-mouth existence."

Ebola has claimed the lives of almost 4,500 people according to the World Health Organisation (WHO). Liberia, Guinea, Sierra Leone, Nigeria and Senegal have all been affected and the virus is still spreading.

The immediate impact of Ebola is severe but economic growth in these poor countries will also be hit in a major way for years to come, due to travel and trade restrictions and excessive inflation.

Alliance member Tearfund's partners in countries affected by the Ebola outbreak are working with at-risk communities to heighten awareness of the deadly virus. Sierra Leone has declared a state of emergency, with President Koroma warning that Ebola is "beyond the scope of any one country, or community to defeat."

"So many lives have been severely affected," says Francis Wahome, head of Tearfund's work in Sierra Leone. "Programmes that were addressing pressing needs such as maternal and child health, malaria, water and food security have come to a halt. Please pray."

Tearfund partners, the Association of Evangelicals of Liberia, the Evangelical Fellowship of Sierra Leone and New Harvest Development Organisation are working with churches to improve awareness and understanding of Ebola among their communities and to help prevent the spread of the disease.

The Salvation Army has also joined the fight against the deadly Ebola virus in Liberia and forty volunteer workers have been recruited to bolster The Salvation Army's mobile medical clinic team in the country.  With prevention key to the response, they are distributing sanitiser, gloves and mouth guards in 17 communities where Ebola is prevalent.

Residents in these areas are particularly susceptible to the disease due to poverty and hygienic living conditions. Food packages, including rice, beans and cooking oil, have also been distributed to families in need.