Survey of Bancroftian filariasis infection in humans and Culex mosquitoes in the western Brazilian Amazon region: implications for transmission and control

Abstract

Revista da Sociedade Brasileira de Medicina Tropical 46(2):214-220, Mar-Apr, 2013http://dx.doi. org/10.1590/0037-8682-1708-2013 Major Article INTRODUCTION Survey of Bancroftian filariasis infection in humans and ABSTRACT 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.

Perceived threat and benefit toward community compliance of filariasis’ mass drug administration in Pekalongan district, Indonesia

“…Risk of LF transmission increases in individual who lived in endemic area for 10 years. 27 Having a household member with lymphedema, or being a patient him/herself, might affect the awareness of LF risk. 28 These factors will influence them to comply with the MDA.…”

Temporal abundance of Aedes aegypti in Manaus, Brazil, measured by two trap types for adult mosquitoes

“…Aspirators have been usually used in Brazil to detect Wuchereria bancrofti infections in Cx. quinquefasciatus ( Medeiros et al 1992 , Fontes et al 2012 , Korte et al 2013) . To catch the filariasis vectors through aspiration, it is necessary to have access to households during the nocturnal period.…”

Evaluation of Actin-1 Expression in Wild Caught Wuchereria bancrofti-Infected Mosquito Vectors

“…Primers ( Table 1 ) were used to amplify the 188 bp SspI repeats of Wuchereria bancrofti [ 23 ]. PCR was performed in a thermocycler (Applied Biosystems) with conditions set at 96°C for 15 seconds followed by 25 cycles of 94°C for 3 seconds, 56°C for 3 seconds, and 72°C for 5 seconds [ 24 , 25 ]. A total reaction volume of 25 μ l containing 2 μ l of DNA sample, 10 mM Tris-HCl, pH 9.2, 2 mM MgCl 2 , 75 mM KCl, 1.2 mM of each deoxynucleotide triphosphate, 10 pmol each of SspI forward and reverse oligonucleotide primers ( Table 1 ), and 2 unit of Taq polymerase was used.…”