Abuja - More than 800 people have died in a meningitis outbreak in Nigeria but the disease is now spreading more slowly, says health minister Isaac Adewole."The death toll up to now is 813," he told reporters in Abuja after a cabinet meeting. "As of now, we are noticing a decline. "This is week 16. This is also expected because we are moving away from the active season. We are confident that in the next couple of weeks everything will be over."The outbreak of meningitis C is concentrated in northern Nigeria, where a mass vaccination programme has begun to limit its spread.On April 19 the government said 745 people had died - a spike of more than 50% from the previous week - and there had been more than 8 000 suspected cases.Five northern states accounted for the majority of cases.Nigeria lies on the so-called "meningitis belt" of sub-Saharan Africa that stretches from Senegal in the west to Ethiopia in the east, where outbreaks are a regular occurrence.