Expanding poliomyelitis and measles surveillance networks to establish surveillance for acute meningitis and encephalitis syndromes–Bangladesh, China, and India, 2006-2008

Quality surveillance is critical to the control and elimination of vaccine-preventable diseases (VPDs). A key strategy for enhancing VPD surveillance, outlined in the World Health Organization (WHO) Global Framework for Immunization Monitoring and Surveillance (GFIMS), is to expand and link existing VPD surveillance systems (particularly those developed for polio eradication and measles elimination) to include other priority VPDs. Since the launch of the Global Polio Eradication Initiative in 1988, the incidence of polio has decrease by 99% worldwide. A cornerstone of this success is a sensitive surveillance system based on the rapid and timely reporting of all acute flaccid paralysis (AFP) cases in children aged <15 years, with confirmatory diagnostic testing performed by laboratories that are part of a global network. As countries achieve polio-free status, many have expanded syndromic surveillance to include persons with rash and fever, and have built measles diagnostic capacity in existing polio reference laboratories. Acute meningitis/encephalitis syndrome (AMES) and acute encephalitis syndrome (AES) are candidates for expanded surveillance because they are most often caused by VPDs of public health importance for which confirmatory laboratory tests exist. Vaccine-preventable cases of encephalitis include approximately 68,000 Japanese encephalitis (JE) cases, resulting in 13,000-20,000 deaths each year in Asia. Moreover, although bacterial meningitis incidence in Asia is not as well-documented, pneumococcal and meningococcal meningitis outbreaks have been reported in Bangladesh and China, and the incidence of Haemophilus influenzae type b (Hib) meningitis in children aged <5 years in India has been estimated to be 7.1 per 100,000 population, similar to that in European countries before the introduction of vaccine. This report describes a prototype for expanding existing polio and measles surveillance networks in Bangladesh, China, and India to include surveillance for viral and bacterial vaccine-preventable causes of AMES and AES and presents data from 2006-2008.