Nigeria Center for Disease Control (NCDC) statistics show that reported cases of the hemorrhagic disease -- both confirmed and suspected -- stood at 175 with a total of 101 deaths since August.
"As of today, 19 (including Abuja) states are currently following up contacts, or have suspected cases with laboratory results pending or laboratory confirmed cases," the NCDC said in a statement.
Deaths from the virus were recorded in the nation's political capital, Abuja, Lagos, and 14 other states, the NCDC said.
While health authorities assure Africa's most populous country of more than 170 million they have the virus under control, there are fears the actual scale of the outbreak is under-reported.
The outbreak of Lassa fever was only announced in January -- months after the first case of the disease happened in August -- with subsequent deaths reported in 10 states, including Abuja, AFP reported.
Last year, 12 people died in Nigeria out of 375 infected, while in 2012 there were 1,723 cases and 112 deaths, according to the NCDC.
In neighboring Benin at least nine people have died in a Lassa outbreak, with a total of 20 suspected cases, health authorities said Tuesday.
Benin was last hit by a Lassa fever outbreak in October 2014, when nine people suspected of having the virus died.