WHO-coordinated IB-VPD sentinel hospital surveillancefor meningitis is established at large (usually pediatric) referral hospitals. A limitation of sentinel surveillance has been the inability to calculate meningitis incidence rates because of the absence of a known denominator of children at-risk for meningitis. In 2012, WHO, under the guidance of a technical advisory group, developed a method for estimating the denominator of at-risk children to calculate hospitalization rates for meningitis among children in the catchment area of a sentinel hospital (4). The method was finalized based on results of pilot tests conducted in IB-VPD surveillance network countries and is similar to a method recently developed
for influenza sentinel hospital surveillance (Anthony Mounts, MD, Global Influenza Programme, WHO, personal communication, March 1, 2013)