When the Nigeria Centre for Disease Control (NCDC) announced 91 new cases on Sunday, four new states recorded their index cases.

The only four Nigerian states that remain unaffected by COVID-19 are Kogi, Cross River, Nasarawa, and Yobe.

The country's index case was a 44-year-old Italian businessman who arrived the country through Lagos and travelled to Ogun State.

The second case, announced on March 8 was also recorded in Ogun, a contact of the Italian businessman.

The third case was announced in Lagos on March 16 - a 30-year old Nigerian woman who returned from the United Kingdom on March 13.

Ekiti was the third state to record an index case on March 18, followed by the FCT on March 21, Oyo on March 22, and Edo on March 23.

Bauchi recorded its index case on March 24, just a day before Osun and Rivers recorded index cases on March 25, followed by Enugu on March 27, and Benue and Kaduna on March 28.

The coronavirus disease, which has infected over 3 million people across the world, spread to 21 Nigerian states in April alone.

Akwa Ibom recorded its own index case on April 1, before Ondo on April 3, Kwara on April 6, and Delta and Katsina on April 7.

Niger and Anambra both recorded index cases on April 10, followed by Kano on April 11, after which no new state recorded an index case for an entire week until Jigawa on April 19.

Abia, Sokoto, and Gombe recorded index cases on April 20, followed by Borno on April 21, Adamawa on April 22, Plateau on April 23, Zamfara on April 24, and Imo on April 25.

The latest states to have recorded index cases are Taraba, Ebonyi, Kebbi, and Bayelsa who all announced on April 26.

The NCDC disclosed on Monday, April 27 that it has tested a total of 11,462 samples since the outbreak started in February, but Nigerians have relentlessly insisted that more tests be done.

The agency's director general, Chikwe Ihekweazu, announced on Sunday that it was in desperate need of more testing kits.

Since the outbreak started, a total of 239 people have recovered and been discharged in 16 states.

128 of them have been released in Lagos which is the epicentre of the coronavirus outbreak in Nigeria with 731 cases recorded - 57.4% of the country's total.

The state has also recorded 19 deaths, 47.5% of Nigeria's total death toll - 40.

Other deaths have been recorded in the FCT (3), Edo (3), and two each in Osun, Katsina, Borno, Oyo, and Rivers.

Kano, Ogun, Akwa-Ibom, Ekiti, and Delta have recorded one death each.

Iheaweazu said earlier in April that all 36 states in Nigeria are likely to record coronavirus cases.

"It (coronavirus) will grow to every state in Nigeria. There is no reason why it won't - it is a respiratory virus," he said.

The outbreak has led to the crippling of social and economic activities across Nigeria with many states imposing a partial or complete lockdown in a desperate bid to contain the spread.

Total confirmed cases - 1273

Active cases - 994

Recovered - 239

Dead - 40