Lymphatic filariasis: Surveillance action among immigrants from endemic areas, Acre State, Brazilian Amazon

ObjectiveTo investigate the positivity of Wuchereria bancrofti (W. bancrofti) in immigrants who entered the country through Rio Branco, reducing the risk of introduction of parasites into new areas and endemic areas of the past.MethodsIt was realized a descriptive study. The AD12-ICT card test was applied on all immigrants living temporarily in the Chacara Alliance shelter, located in the metropolitan area of Rio Branco-AC, Brazil. For the positive patients, 10 mL of venous blood was collected between 11:00 pm and 1:00 am. About 4 mL of venous blood was collected to detect the presence of microfilariae in circulation in the tube using ethylene diamine tetraacetic acid and 6 mL of venous blood was collected to obtain blood serum for the Og4C3-ELISA, antibody Bm-14 and DNA-W. bancrofti tests.ResultsThe present study evaluated 415 individuals in September 2014 by circulating filarial antigen for W. bancrofti using the AD12-ICT card test. A total of 15/415 (3.61%) positive cases were found, all from Haiti. Night blood collection and serum were performed on 1/14 for confirmation the infection of W. bancrofti, which presented 34 microfilariae/mL, antigen, antibodies and PCR positives.ConclusionsThis surveillance action reveals, in a pioneering and unequivocal manner, that Brazil is an influx of immigrants carrying lymphatic filariasis and there is an urgent need to step up surveillance at the main entry point for immigrants. Active surveillance may prevent the reintroduction of lymphatic filariasis in areas under control, or prevent its introduction into other states of Brazil.