Effective monitoring and evaluation is not only necessary during the mass drug administration (MDA) period but important throughout the lifespan of lymphatic filariasis (LF) programs, including after MDA has stopped. Current WHO recommendations for surveillance advise programs to implement activities to detect new foci of transmission through the assessment of microfilaremia, antigenemia or antibodies. There is a critical need for reliable diagnostic tools that can be used to guide programmatic decisions, especially decisions made in the final stages of the program and in areas where co-endemic filarial diseases complicate program activities. Although there are diagnostic tools available to detect microfilariae (Mf), Wuchereria bancrofti circulating filarial antigen (CFA), and antifilarial antibodies, antibody responses are detectable earlier than CFA or Mf (Gass et al) and provide the earliest indicator of filarial exposure. Furthermore, antibody responses decline after MDA (Steel et al), potentially offering opportunity to use antibody responses for surveillance.
The objectives of the meeting were:
- To review existing antibody data;
- To determine programmatic use cases using current antibody tools; and
- To determine potential programmatic use cases using modified/new antibody tools