Lagos state's health commissioner for has warned residents to be ready to answer questions from health workers who are going house-to-house asking about coronavirus symptoms.

The health workers will "make inquiries about symptoms of cough, cold and fever", Prof Akin Abayomi is quoted as saying in a tweet by Lagos state government.

Coronavirus infects the lungs. The two main symptoms are a fever and a dry continuous cough, which can sometimes lead to breathing problems.

Prof Abayomi is quoted as saying the survey "is in a bid to intensify our search for possible cases of Covid-19".

The survey is meant as a way of screening people to identify suspected cases of coronavirus who will be prioritised for testing, explains the BBC's senior Africa correspondent Anne Soy.

A similar survey was carried out in Cameroon’s biggest city Douala. There they identified 2,000 people to be tested out of 180,000 who were screened.

The Nigeria Centre for Disease Control (NCDC) says that laboratories in the country have a capacity to process 1,500 tests a day whereas the city of Lagos has at least 14 million residents.

Nigeria has so far confirmed seven deaths and 288 cases of coronavirus, 158 of which are in Lagos state.