Progress and Impact of 13 Years of the Global Programme to Eliminate Lymphatic Filariasis on Reducing the Burden of Filarial Disease

Abstract

A Global Programme to Eliminate Lymphatic Filariasis was launched in 2000, with mass drug administration (MDA) as the core strategy of the programme. After completing 13 years of operations through 2012 and with MDA in place in 55 of 73 endemic countries, the impact of the MDA programme on microfilaraemia, hydrocele and lymphedema is in need of being assessed. During 2000–2012, the MDA programme made remarkable achievements – a total of 6.37 billion treatments were offered and an estimated 4.45 billion treatments were consumed by the population living in endemic areas. Using a model based on empirical observations of the effects of treatment on clinical manifestations, it is estimated that 96.71 million LF cases, including 79.20 million microfilaria carriers, 18.73 million hydrocele cases and a minimum of 5.49 million lymphedema cases have been prevented or cured during this period. Consequently, the global prevalence of LF is calculated to have fallen by 59%, from 3.55% to 1.47%. The fall was highest for microfilaraemia prevalence (68%), followed by 49% in hydrocele prevalence and 25% in lymphedema prevalence. It is estimated that, currently, i.e. after 13 years of the MDA programme, there are still an estimated 67.88 million LF cases that include 36.45 million microfilaria carriers, 19.43 million hydrocele cases and 16.68 million lymphedema cases. The MDA programme has resulted in significant reduction of the LF burden. Extension of MDA to all at-risk countries and to all regions within those countries where MDA has not yet reached 100% geographic coverage is imperative to further reduce the number of microfilaraemia and chronic disease cases and to reach the global target of interrupting transmission of LF by 2020. The mass drug administration (MDA) programme to eliminate lymphatic filariasis (LF) was initiated in 2000. By the end of 2012, the programme was in place in 55 endemic countries. During these first 13 years (2000–2012) of programme implementation, 6.37 billion annual single dose anti-filarial treatments were offered and 4.45 billion doses were consumed by the target populations. This massive programme is estimated to have prevented or cured 96.71 million LF cases that include 79.20 million microfilaria carriers, 18.73 million hydrocele cases and a minimum of 5.49 million lymphedema cases, a 59% reduction of initial LF levels. It is further estimated that, currently, i.e. after 13 years of the MDA programme, 67.88 million LF cases remain, including 36.45 million microfilaria carriers, 19.43 million hydrocele cases and 16.68 million lymphedema cases. Progressive reduction in this burden is possible as the programme extends to the endemic countries and regions within endemic countries that have not yet been covered by the MDA programme, and if the morbidity management component of the programme can be effectively implemented.