A Success Story: Togo Is Moving toward Becoming the First Sub-Saharan African Nation to Eliminate Lymphatic Filariasis through Mass Drug Administration and Countrywide Morbidity Alleviation

doi:10.1371/journal.pntd.0002080.t002 A Success Story: Togo Is Moving toward Becoming the First Sub-Saharan African Nation to Eliminate Lymphatic Filariasis through Mass Drug Administration and Countrywide Morbidity Alleviation Yao K. Sodahlon 0 Ameyo Monique Dorkenoo 0 Kodjo Morgah 0 Komlan Nabiliou 0 Kossivi Agbo 0 Rebecca Miller 0 Michel Datagni 0 Anders Seim 0 Els Mathieu 0 Patrick J. Lammie, Centers for Disease Control and Prevention, United States of America 0 1 Mectizan Donation Program, Decatur, Georgia, United States of America , 2 Ministe`re de la Sante, Lome , Togo , 3 Faculte Mixte de Me decine et de Pharmacie, Universite de Lome , Lome , Togo, 4 Department of Global Health, Rollins School of Public Health, Emory University , Atlanta , Georgia , United States of America, 5 HDI (Health & Development International) , Fjellstrand , Norway , 6 Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention , Atlanta, Georgia , United States of America - Lymphatic filariasis (LF) is a debilitating vector-borne disease predominantly caused by the helminths Wuchereria bancrofti and Brugia malayi [1,2]. Endemic in 72 countries, LF is responsible for 5.9 million DALYs lost and is implicated as the second leading cause of disability worldwide by the World Health Organization (WHO) [35]. Although 70% of those infected do not exhibit symptoms, almost all persons infected have subclinical damage to the lymphatic vessels [6,7]. An estimated 40 million people are symptomatic with the predominant morbidities associated with LF: lymphedema and/or hydrocele [8]. In recognition of the worldwide burden of LF, in 1997, the World Health Assembly passed the resolution WHA 50.29 calling for collaborative efforts by member states to eliminate the disease as a public health problem [9]. In 2000, the Global Programme to Eliminate Lymphatic Filariasis (GPELF) was formed in response to the WHA resolution and aimed to eliminate the disease by 2020. The program adopted a two-pronged strategy: (1) to interrupt transmission of the causal parasite and (2) to alleviate morbidities associated with the disease [10]. The two pillars of the GPELFs strategy form the basic framework for any successful LF program. Togo is one of the 34 African countries endemic for lymphatic filariasis and is surrounded by the endemic countries of Benin, Ghana, and Burkina Faso [11]. The National Program to Eliminate Lymphatic Filariasis (NPELF) was founded in 2000 and is one of the few LF programs that address the dual goals of the global elimination program on a national scale. Togo is the first sub-Saharan country to achieve probable interruption of transmission and to move to the post-MDA surveillance phase as defined by the WHO [12]. Here we describe the elements that proved successful in the national strategy to address LF in Togo. Assessing the Burden Infection The Togolese Ministry of Health (MoH) used the Rapid Assessment of Geographical Distribution of Filariasis (RAGFIL) methodology, developed by the Special Programme for Research and Training in Tropical Diseases (TDR), to assess countrywide infection [11,13]. National mapping was performed in two stages [11]. Thirty-seven villages representing 17 of Togos 35 health districts (with 5 in Lome, the capital city) participated in the initial mapping in 1998. In 2000, an additional 24 villages were selected using the WHOs Health Mapper software version 3.0 to ensure that the whole country was covered [11]. The distance between two mapped villages in the final map was never more than 50 km; each selected village represents the state of the transmission in a radius of 25 km. The tests for both stages entailed collection of 100 ml of capillary blood from a persons fingertip and subsequent testing using rapid immunochromatographic tests (ICT) (AMRAD, Townsville, Queensland, Australia). The ICT used is specific for W. bancrofti and detects the presence of circulating filarial antigen (CFA) [14]. From the 2009 samples collected in 61 villages, 89 persons (1.8%) were ICT positive. Seven districts were classified as endemic because the prevalence of ICT positivity exceeded the 1% threshold [15,16] (Figure 1). Several districts along the TogoBenin border in the south were unexpectedly classified as nonendemic although they were endemic in the past and currently have a high prevalence of LF morbidity [17]. Possibly, LF transmission was interrupted by intensive vector-control methods implemented in the area by the malaria program in the 1970s. Morbidity As accurate estimates of the national burden of LF morbidity are difficult to obtain, Mathieu and others described different methods to obtain LF morbidity prevalence in Togo [18]. Prevalence estimates for lymphedema and hydrocele were calculated based on information collected during LF mapping and from sentinel sites. Morbidity questions were also added onto three 30-cluster drug Figure 1. Districts endemic for lymphatic filariasis during the initial mapping. doi:10.1371/journal.pntd.0002080.g001 coverage surveys that were conducted in six of Togos endemic districts and onto a nationwide malaria bed net coverage survey. Sentinel site data, cluster survey data, and the malaria bed net coverage survey data detected a hydrocele prevalence of 0.61% (95% CI 0.001.41), 0.63% (95% CI 0.201.06), and 2.6% (95% CI 1.8 3.4), respectively [19]. These same sources revealed a lymphedema prevalence of 0.80% (95% CI 0.001.98), 0.17% (95% CI 0.000.34), and 0.6% (95% CI 0.3 0.9). Program Implementation Mass Drug Administration Shortly after the mapping, mass drug administration (MDA) campaigns were launched. All of Togos LF districts are coendemic for onchocerciasis, and the communities with less than 2,000 inhabitants have been undergoing an annual or biannual MDA with ivermectin since the late 1980s [20,21]. The NPELF modified the distribution system established by the onchocerciasis program through the coadministration of albendazole with ivermectin. The timings of the campaigns were synchronized since LF elimination distributions are required to be organized at the same time in all endemic areas. The geographic coverage in the districts was also expanded to treat villages that were not endemic for onchocerciasis or that had a population above 2,000 inhabitants. The processes of drug distribution and reporting were facilitated by utilizing Togos decentralized pyramidal health structure. A single community health worker (CHW) was selected to represent every 300 people in the endemic districts. As the first step toward calculating drug needs, the CHWs visited their respective households prior to each MDA in order to count all inhabitants. The results of the CHWs annual census were used by the national coordinator to calculate drug needs. The NPELF requested ivermectin (Merck & Co., Inc., White House Station, New Jersey, United States) and albendazole (GlaxoSmithKl (...truncated)