Interruption of lymphatic filariasis transmission in Manaus, a former focus of Wuchereria bancrofti in the Western Brazilian Amazon

OBJECTIVE. To confirm the absence of Wuchereria bancrofti autochthonous cases in Manaus, a former focus of lymphatic filariasis in the Western Brazilian Amazon. METHODS. A field survey was carried out in 2016 using immunochromatographic rapid tests (ICT card) for the detection of circulating filarial antigens in blood. The sample included a group of 3 000 schoolchildren aged 6 to 10 years enrolled in schools from different urban areas of Manaus (including the former lymphatic filariasis focus in the city) and a group of 709 adolescents and adults, between the ages of 11 and 85 years, born and raised in different areas of Manaus. RESULTS. All of the individuals tested negative for W. bancrofti antigen. CONCLUSIONS. Although Manaus was once considered endemic, this focus no longer seems to be active for lymphatic filariasis transmission. The results of this study could support the certification by the World Health Organization of the lymphatic filariasis transmission elimination exercise in Brazil.