title: Using kernel density estimates to investigate lymphatic filariasis in northeast Brazil.
abstract: After more than 10 years of the Global Program to Eliminate Lymphatic Filariasis (GPELF) in Brazil, advances have been seen, but the endemic disease persists as a public health problem. The aim of this study was to describe the spatial distribution of lymphatic filariasis in the municipality  of Jaboatão dos Guararapes, Pernambuco, Brazil. An epidemiological survey was conducted in the municipality, and positive filariasis cases identified in this survey were georeferenced in point form, using the GPS. A kernel intensity estimator was applied to identify clusters with greater  intensity of cases. We examined 23 673 individuals and 323 individuals with microfilaremia were identified, representing a mean prevalence rate of 1·4%. Around 88% of the districts surveyed presented cases of filarial infection, with prevalences of 0-5·6%. The male  population was more affected by the infection, with 63·8% of the cases (P<0·005). Positive cases were found in all age groups examined. The kernel intensity estimator identified the areas of greatest intensity and least intensity of filarial infection cases. The case  distribution was heterogeneous across the municipality. The kernel estimator identified spatial clusters of cases, thus indicating locations with greater intensity of transmission. The main advantage of this type of analysis lies in its ability to rapidly and easily show areas with the highest  concentration of cases, thereby contributing towards planning, monitoring, and surveillance of filariasis elimination actions. Incorporation of geoprocessing and spatial analysis techniques constitutes an important tool for use within the GPELF.
authors.affiliation: Oswaldo Cruz Foundation - FIOCRUZ, Rio de Janeiro, Brazil. medeiros@cpqam.fiocruz.br
authors.forename: Zulma
authors.initials: Z
authors.lastname: Medeiros
authors.forename: Cristine
authors.initials: C
authors.lastname: Bonfim
authors.forename: Eduardo
authors.initials: E
authors.lastname: Brandão
authors.forename: Maria José Evangelista
authors.initials: MJ
authors.lastname: Netto
authors.forename: Lucia
authors.initials: L
authors.lastname: Vasconcellos
authors.forename: Liany
authors.initials: L
authors.lastname: Ribeiro
authors.forename: Joséluiz
authors.initials: J
authors.lastname: Portugal
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D004605:Elephantiasis, Filarial / Q000453:epidemiology*; D019353:Endemic Diseases; D005260:Female; D040362:Geographic Information Systems; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D017678:Sex Distribution; D019371:Topography, Medical; D055815:Young Adult