Serogroup W135 meningococcal meningitis, Northern Cameroon, 2007-2008.

We analyzed results of recent microbiologic surveillance of meningitis in northern Cameroon. During the 2007 and 2008 meningitis seasons, all 57 identified meningococcal isolates were serogroup W135. This situation might indicate that the area is experiencing a period between epidemic waves due to 2 different clones of serogroup A meningococci.