If alert veterinarians and practicing physicians had not sought to identify the cause of the deaths of crows and of human encephalitis in New York City in 1999, health officials would probably have included the human cases in the large "cause undetermined" category of encephalitis.
This would explain the recently discovered association of the most severe form of human encephalitis with the SIB strains [17].
Using data from the same prospective study presented in this paper, our group previously identified fever, personality and behavioural change, headache and lethargy, as the main characteristics of human encephalitis [ 10, 11].
The main objective of this paper, therefore, is to perform exploratory cluster analysis using the England human encephalitis data set with the aim of achieving a better understanding of human encephalitis and generate hypotheses about etiology.
The dark red colour in the heatmap indicates that fever and abnormal white blood cell counts (WCC) are indicated as the two major characteristics of human encephalitis.
Before 2005, the only recorded outbreak of human encephalitis caused by flaviviruses in this region was in 1975 in Brazil, which was attributable to Rocío virus (10 ).
West Nile virus (WNV) has become a major public health concern in North America since 1999, when the first outbreak in the Western Hemisphere occurred in New York City, causing 62 cases of human encephalitis and 7 deaths [ Centers for Disease Control and Prevention CDCC) 1999].
West Nile virus (WNV) is an important agent of human encephalitis that has quickly become endemic across much of the United States since its identification in North America in 1999.
Approximately 130 species of wild and domesticated animals have been affected with B. procyonis neural larva migrans, and the parasite is increasingly recognized as a cause of human encephalitis (2 ; K. Kazacos, unpub. data).
Exploration of human encephalitis data using advanced multivariable statistical modelling approaches that can capture the inherent complexity in the data is, therefore, crucial for elucidating the causes of human encephalitis.
