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Introduction: This study aimed to assess the occurrence of gonotrophic discordance in females of Culex quinquefasciatus in São Paulo, Brazil., Methods: Resting females were collected monthly for 8 months. Females of Cx. quinquefasciatus were identified, and their midgut and ovaries were dissected., Results: Two hundred females were dissected, out of which, 27.5% were nulliparous and 57% were parous. Most females had no blood in the midgut, but gonotrophic discordance was found in 21% females., Conclusions: Females of Cx. quinquefasciatus showed a high parity rate and gonotrophic discordance, which could favor the vector capacity of this species.

Background: The objective of the Global Program to Eliminate Lymphatic Filariasis (GPELF) is to phase out this endemic disease as a public health problem by 2020. Validation of elimination is obtained from the World Health Organization through evidence of non-transmission in countries that have already been subjected to mass drug administration (MDA) and in places adjoining these endemic areas. While three municipalities in Brazil have completed MDA, the epidemiological situation remains uncertain in nine adjoining municipalities. To determine the epidemiological status, this study was to perform a review of the literature and a school-based survey to describe the past and recent endemicity of lymphatic filariasis (LF) theses nine municipalities in Brazil., Methodology/principle Findings: For review of the literature, both formal and informal literature sources were accessed since the first reports of filariasis in the Metropolitan Region of Recife, Brazil. We conducted a school-based survey in 2016 using immunochromatographic card tests (ICTs) among schoolchildren aged 6-10 years living in nine municipalities contiguous with the endemic areas in which MDA was conducted. Our review of the literature identified eight studies involving surveys demonstrating that microfilariae had been circulating in eight of the municipalities since 1967, with a low prevalence of microfilaremia, isolated autochthonous cases, and treatment of individual cases. The school-based survey included 17,222 children in 185 urban schools in the nine areas of Brazil with uncertain endemicity. One child affected by allochthonous transmission was antigen positive based on ICT and lived in a municipality adjacent to Recife; this child's family came from Recife, but no other case was diagnosed within the family., Conclusions/significance: The study results suggest that there is no transmission of LF in the municipalities investigated. However, these areas have population migration and socioenvironmental conditions favorable to mosquito breeding grounds; therefore, surveillance is strongly recommended in these areas., Competing Interests: The authors have declared that no competing interests exist.

Introduction: The aim of this work was to identify possible lymphatic filariasis foci in the western Brazilian Amazonian that could be established from the reports of Rachou in the 1950s. The study was conducted in three cities of the western Brazilian Amazon region - Porto Velho and Guajará-Mirim (State of Rondônia) and Humaitá (State of Amazonas)., Methods: For human infection evaluation thick blood smear stained with Giemsa was used to analyze samples collected from 10pm to 1am. Polymerase chain reaction (PCR) was used to examine mosquito vectors for the presence of Wuchereria bancrofti DNA. Humans were randomly sampled from night schools students and from inhabitants in neighborhoods lacking sanitation. Mosquitoes were collected from residences only., Results: A total 2,709 night students enrolled in the Program for Education of Young Adults (EJA), and 935 people registered in the residences near the schools were examined, being 641 from Porto Velho, 214 from Guajará-Mirim and 80 from Humaitá. No individual examined was positive for the presence of microfilariae in the blood stream. A total of 7,860 female Culex quinquefasciatus specimens examined were negative by PCR., Conclusions: This survey including human and mosquito examinations indicates that the western Amazon region of Brazil is not a focus of Bancroftian filariasis infection or transmission. Therefore, there is no need to be included in the Brazilian lymphatic filariasis control program.

A parasitological survey was conducted among children and adolescents in the municipality of Jaboatão dos Guararapes, Brazil to describe the occurrence and spatial distribution of lymphatic filariasis. Microfilaraemia was investigated through the thick smear technique, using 50 μl of capillary blood that was collected at night. The spatial analysis used a digital base map of the municipality, divided into districts, which were classified as hypoendemic, mesoendemic or hyperendemic. 8670 children were examined and 96 cases of microfilaraemia were identified (1.1%). The prevalence rate did not differ significantly between the sexes. Occurrences of filarial infection increased with increasing age: the greatest prevalence was recorded between 15 and 18 years of age (P<0.05). There were 49 reports of clinical manifestations. The spatial distribution of microfilaraemia according to residential district showed that 13 (54.2%) of the 24 districts investigated were positive. Approximately 33% of the districts were hyperendemic. The results demonstrated that the pediatric population had intense early exposure to the parasite, thus characterizing filariasis as endemic in the municipality. The spatial analysis allowed identification of areas with greater occurrence of infection among children, and showed localities where the populations most exposed to transmission were concentrated. Epidemiological surveillance of microfilaraemia among children and spatial analysis are important local transmission indicators and form instruments for planning actions within the Global Program to Eliminate Lymphatic Filariasis, since they make it possible to identify priority areas., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Objective: 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 Jaboatão 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., (© 2011 Blackwell Publishing Ltd.)

Objective: To describe the spatial distribution of lymphatic filariasis and its relationship with the socioenvironmental risk indicator, thus identifying priority localities for interventions in endemic urban areas., Methods: The study area was the municipality of Jaboatão dos Guararapes, State of Pernambuco, Brazil. The data sources were a parasitological survey and the 2000 demographic census. From these data, a socioenvironmental composite risk indicator was constructed using the 484 census tracts (CT) as the analysis units, based on the score-formation technique. Census tracts with higher indicator values presented higher risk of occurrences of filariasis., Results: Six thousand five hundred and seven households were surveyed and 23 673 individuals were examined, among whom 323 cases of microfilaremia were identified. The mean prevalence rate for the municipality was 1.4%. The indicator showed that 73% (237/323) of the cases of microfilaremia were in high-risk areas (third and fourth quartiles) with worse socioenvironmental conditions (RR = 4.86, CI = 3.09-7.73, P < 0.05)., Conclusions: The socioenvironmental composite risk indicator demonstrated sensitivity, since it was able to identify the localities with greater occurrence of infection. Because it can stratify spaces by using official and available data, it constitutes an important tool for use in the worldwide program for eliminating lymphatic filariasis.

The concept of a "socially organized space" supported by new analytical techniques and mapping of health events has guided innovative methodological developments in public health interventions. This study aimed to evaluate a social/environmental indicator constructed with a scoring methodology to stratify areas in the city of Olinda by different levels of risk for Bancroftian filariasis transmission. The study mapped areas and the location of sample households and identified all residents ages 5 to 65 years as part of the parasitological survey. Among the 3,232 individuals who had blood samples taken, 42 were microfilaremic (1.3% prevalence). Global statistical analysis of filarial case distribution has suggested spatial clustering. Some 85.7% of positive individuals resided in the two strata with the highest transmission risk. The high sensitivity of the proposed indicator for predicting the places where the vast majority of filariasis cases occurred justifies its use in planning and implementing interventions.

The occurrence of circulating Wuchereria bancrofti microfilariae was investigated in 304 pregnant women from the "Unidade Mista Pof. Barros Lima" and "Hospital das Clínicas/UFPE". The filtration technique was employed to detect microfilaraemia during pregnancy, and 13 women were found to be positive (4.2%). The investigation of microfilariae in the cord blood of their children was negative (6/13), and also in venous blood samples collected up to 72 hours after birth and with 6 months of life. Milk samples from these mothers also had no microfilariae. The authors suggest that the occurrence of placentary lesions may be a possible factor involved in the transplacental transfer of microfilariae, and that in utero exposure to microfilariae and/or filarial antigens may influence the response to a filarial infection acquired later, thus being important a clinical and laboratorial follow-up of children exposed previously to filarial antigens during early periods of human development.