Epidemiology of infectious meningitis in the State of Amazonas, Brazil.

Introduction: In the State of Amazonas, particularly in the capital Manaus, meningitis has affected populations of different cultures and social strata over the years. Bacterial meningitis is caused by several different species and represents a major issue of public health importance. The present study reports the meningitis case numbers with different etiologies in Amazonas from January 1976 to December 2012.

Methods: Since the 1970s, the (currently named) Tropical Medicine Foundation of Doutor Heitor Vieira Dourado [Fundação de Medicina Tropical Doutor Heitor Vieira Dourado (FMT-HVD)] has remained a reference center in Amazonas for the treatment of meningitis through the diagnosis and notification of cases and the confirmation of such cases using specific laboratory tests.

Results: The foundation has achieved coverage of over 90% of the state medical records for many years. Between 1990 and 2012, meningitis cases caused by Haemophilus influenzae decreased with the introduction of the H. influenzae vaccine. Meningococcal disease previously had a higher frequency of serogroup B disease, but starting in 2008, the detection of serogroup C increased gradually and has outpaced the detection of serogroup B. Recently, surveillance has improved the etiological definition of viral meningitis at FMT-HVD, with enteroviruses, Epstein-Barr virus (EBV) and varicella zoster virus (VZV) prevailing in this group of pathogens. With the advent of acquired immunodeficiency syndrome (AIDS), cryptococcal meningitis has become an important disease in Amazonas. Additionally, infectious meningitis is an important burden in the State of Amazonas.

Conclusions: Changes in the epidemiological profile for the different etiology-defined cases are the result of continuous epidemiological surveillance and laboratory capacity improvements and control measures, such as Haemophilus influenzae vaccination.