Abuja - More than 1 000 people have died in an outbreak of meningitis in Nigeria, the Centre for Disease Control said on Thursday, but added that the spread of the disease is slowing.The outbreak has mostly affected children in Africa's most populous country.As of May 9, a total of 13 420 suspected cases had been reported in 23 states with 1 069 deaths, giving a fatality ratio of eight per cent, the CDC said in a statement.The northern states of Zamfara, Sokoto, Katsina and Kebbi, which were the worst affected, have all seen a drop in the number of cases.Two others which were also badly hit - Kebbi and Niger - recorded no deaths, the CDC said.A new strain of meningitis C was first reported in Zamfara last November and spread to 22 other states in northern Nigeria. A mass vaccination programme was started to limit its spread. The CDC said a new batch of vaccines was expected to arrive in the next few days.Meningitis is caused by different types of bacteria, six of which can cause epidemics. It is transmitted between people through coughs and sneezes, close contact and cramped living conditions.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.