SUMMARYA cross-sectional population-based survey on the occurrence of lymphatic filariasis was carried out in the municipality of Cabo de Santo Agostinho, Pernambuco, Northeast Brazil. 7,650 individuals of both sexes were examined (from 1,416 households) of whom six tested positive for microfilaria according to the thick blood diagnostic test. The age of the individuals examined varied from 0 to 98 (averaging 26.6 years), whilst the age of the microfilaria-positive individuals varied from 11 to 29, averaging 22.5 years. Five of the six positive cases were male. These cases were residents of the following areas: Pista Preta (one case); Ponte dos Carvalhos (four cases); and Pontezinha (one case). This last case from Pontezinha was autochthonous. Of the individuals examined, 109 (1.4%) cited complaints relating to filariasis. These results suggest that filariasis is being transmitted in the municipality of Cabo de Santo Agostinho, a finding that establishes the need to carry out disease control activities, and to collaborate with the planning of the national programme for the elimination of filariasis.

Summaryobjective To evaluate composite living conditions as indicators of urban areas with a higher risk of filariasis transmission.methods This was an ecological study in the municipality of Jaboatã o dos Guararapes, in Brazil. The analysis units were census tracts. The study was divided into three phases. First, data gathered during an epidemiological investigation were analysed. Secondly, living condition indicators were drawn up and the relationship between these indicators and microfilaremia prevalence rates was analysed. Thirdly, positive cases were georeferenced with a view to identifying spatial concentration using kernel intensity estimates. Two composite living condition indicators were calculated: a socio-environmental risk index (in the form of scores) and a social deprivation index (through principal-component factor analysis).results Of 23 673 individuals examined, 1.4% had microfilaremia. According to the two indicators, greater prevalence was found in the high-risk strata, and this association was confirmed by the kernel intensity estimates.conclusions Classification of census tracts into risk strata showed the relevance of socio-economic factors and environmental conditions in identifying priority areas in urban spaces for interventions by the surveillance services and in planning filariasis control. Spatial analysis also proved to be an important tool for building up a territorially based surveillance system. These indicators, used in association with spatial analysis, are an instrument to be used by the Global Programme to Eliminate Lymphatic Filariasis.keywords lymphatic filariasis, spatial analysis, socio-economic factors, risk index, control programs

In 2002, the status of lymphatic filariasis (LF) in the district of Jaboatão, in north-eastern Brazil, was reviewed, 41 years after the first case of the disease was recorded in the area. Current data from Jaboatão were compared with older information from the district that had been published, as official reports on filariasis cases and mosquitoes and as the result of population surveys, between 1948 and 1997. Although the first microfilaria-positive cases were detected in the district in 1959, it was not until 1993 that the national Ministry of Health categorized Jaboatão as an endemic area. In 2002, fingerprick samples of blood, each of about 50 microl, were collected at night (23.00-01.00 hours) from 4365 individuals in the district and used to make thick smears. Microfilariae were detected in the smears of blood from 33 (0.8%) of the subjects, 12 of whom were considered autochthonous cases of LF. The male subjects were significantly more likely to be microfilaraemic than the female (1.1% v. 0.4%; P<0.05) but there was no direct relationship between prevalence and age, the microfilaraemics varying in age from 6-64 years. The Socorro sub-district had the highest prevalence, of 2.9%. It is recommended that the National Programme to Eliminate Filariasis uses mass drug administrations and vector control throughout the district, regardless of the prevalences recorded in the latest survey.

The indicator used is a promising tool that enables the precise measurement of the relationship between social deprivation and the prevalence of filarial infection among children. Thus, it can be used to plan control and elimination actions.