The implementation of social distancing measures and hand-washing campaigns in the world's poorest communities is a "herculean task", Christian aid agency Tearfund has warned.
It has launched an appeal as it seeks to expand support for hygiene and education work in developing countries at risk of being overwhelmed by coronavirus.
"We are very concerned about some of the poorest countries, where life is already difficult and there is little infrastructure to deal with coronavirus," said Jane Pleace, Tearfund's Global Fundraising Director.
"Living in a crowded household in a densely populated community, such as a refugee camp, and having to walk a long way for water, makes it much harder for people to take apparently simple measures such as social distancing and increased handwashing. These become incredibly hard asks, piled on top of an already challenging daily life."
An area of particular concern is Cox's Bazar in Bangladesh, which is home to nearly a million Rohingya refugees.
Sudarshan Kodooru, Tearfund's Country Director in Bangladesh, said that overcrowding and a lack of hygiene facilities are huge challenges in the refugee camp.
"Sanitation and hygiene facilities in the camp are already inadequate and the streets are narrow and crowded, so social distancing is extremely difficult, and currently there aren't enough hand-washing facilities," said Kodooru.
"Tearfund is working both in the camps and in the host communities around, distributing leaflets about handwashing, distancing and recognising symptoms, and giving out hygiene kits containing soap, sanitiser and detergent powder, as well as installing 200 community washing facilities and giving food to those in quarantine."
Day labourers have also been badly affected. Rita Rani Bala's family is dependent on what little her husband earns as a street trader near Cox's Bazar, but with Bangladesh in lockdown until May 5, he has no way of working until then.
Although she really wanted hygiene items to keep the family safe, Rita told Tearfund she had been unable to purchase them.
Tearfund's local partner has started distributing hygiene kits in Rita's community to help meet the need.
Pleace said it would be important to work with faith leaders in the response to Covid-19.
'We know from our experience working in the Ebola crisis in West Africa that faith leaders play a vital role in conveying public health messages to communities, so where possible, we're working with church partners to promote the right messages to prevent the spread of coronavirus and to correct any lies and misinformation about the disease," she said.
"Faith leaders are trusted and known members of their communities to whom people naturally turn for advice, support and information."