NIAMEY (REUTERS) - Niger has shut all schools in the region around the capital Niamey and launched a campaign to vaccinate children aged two to 15 in an effort to halt a meningitis outbreak that has killed at least 85 since January.

Schools will be closed from Wednesday until Monday next week, the government said, adding that 905 cases of the disease had been recorded, most of them in Niamey and the west of the country.

"A vaccination campaign targeting children will start on Friday April 24," the statement said.

In 2010-2011, uranium and oil-producing Niger, one of the world's poorest nations, successfully carried out a campaign to eliminate the "A" strain of the disease.

Meningococcal meningitis infects the thin lining surrounding the brain and spinal cord.

It can cause severe brain damage, deafness, epilepsy or necrosis and if untreated is fatal in 50 per cent of cases.

Authorities said the current outbreak included the W135, "C" strain and pneumococcal kinds of meningitis.