NIGERIA is advising its sub-regions to limit public gatherings, close bars and nightclubs over the next five weeks amid a spike in new COVID-19 cases, according to the government coronavirus task force. Africa's most populous nation could be on the verge of a second wave of the novel coronavirus with the number of confirmed cases rising within communities over the last few weeks. Lagos, Nigeria's commercial capital, Abuja and northern state of Kaduna have emerged as new epicenters with over 70% of confirmed cases, said Boss Mustapha, chairman of the presidential task force for COVID-19, who is the country's most…