More than a decade of Boko Haram militant attacks have displaced over two million Nigerians in the north, with hundreds of thousands living in internally displaced people's camps.
Medical experts worry the camps lack the spacing and sanitary conditions to prevent an outbreak of coronavirus, which has so far infected more than 370 people in Nigeria and killed 10.
In an orphanage for displaced children, Samuel Adamu, 16, holds a weekly Bible study class at the House of Recab.
Adamu himself has been an internally displaced person (IDP) since 2014, when Boko Haram militants invaded his hometown of Gwoza.
"I have lost many things, Adamu said. "They have killed my loved ones and many other people that I know."
Doctors say the crowded camps are at high risk from infections like coronavirus and the disease it causes – COVID-19.
"Conditions such as cholera, tuberculosis, pneumonia, and if you put that in the context of the current pandemic in the world right now, that is the COVID-19, that will be the perfect breeding ground for this illness," said Enwongo Ime Campbell, a family physician at Mtha Mtha Regional Hospital
Aid workers said improving sanitation in the camps is a challenge.
"For us to ensure that people practice the regular hand washing, we need to have hand washing stations and soap installed and distributed at every strategic location, including camps," said Maxwell Samaila of Mercy Corps. "But with the current funding, we may not be able to achieve that because the funds have already been earmarked for some other interventions."
Nigeria's restrictions on movement and business to curb the coronavirus has increased demand for food aid in the camps, while the coronavirus pandemic has raised fears among IDPs on how they will cope.
"We need hand sanitizers; we need buckets for us to be able to wash our hands; and also face masks so that we would be able to prevent ourselves from this COVID-19," Adamu said.
Meanwhile, Nigerian authorities say they are working with the United Nations and other partners on emergency coronavirus prevention plans for IDPs and other vulnerable communities.