Over 8,000 suspected cases of the disease have been reported across the country over the past five months, some 93% of which occurred in five northern states, a statement said.
The toll last week stood at 489.
The mass outbreak has mostly affected children, prompting a large-scale vaccination programme.
Meningitis is caused by different types of bacteria, six of which can cause epidemics.
It is transmitted between people through coughs and sneezes and facilitated by cramped living conditions and close contact.
The illness causes acute inflammation of the outer layers of the brain and spinal cord, with the most common symptoms being fever, headache and neck stiffness.
Nigeria lies in the so-called "meningitis belt" of sub-Saharan Africa, stretching from Senegal in the west to Ethiopia in the east, where outbreaks of the disease are a regular occurrence.
The five northern states hit are Zamfara, Sokoto, Katsina, Kebbi and Niger.