A Covid-19 antibodies survey in Nigeria suggests that four million people in Lagos state alone have had the virus – more than has been officially recorded for the whole of Africa.

The official figure for Nigeria is 153,000 cases with 1,862 deaths.

The study was done on 10,000 people from four Nigerian states to estimate the extent of coronavirus in Africa’s most populous nation.

It was conducted before a second wave began in early December.

The findings of the seroprevalence survey, carried out in September and October by Nigeria’s Centre for Disease Control (NCDC) and the Institute for Medical Research (IMR), are staggering, reports the BBC’s Mayeni Jones from Lagos.

Rates of infection were initially thought to be low during the first wave of the pandemic, our reporter says.

The country recorded its highest daily infection rate in January, when it logged 1,600 new cases, suggesting many more people were infected in the second wave.