Monique Ameyo Dorkenoo1,2,3, Martin Kouame Tchankoni4, Degninou Yehadji5, Kossi Yakpa6, Mawèké Tchalim7, Efoe Sossou5, Rachel Bronzan8, Didier Koumavi Ekouevi9,4. 1. Université de Lomé, Faculté des Sciences de la Santé, BP 1515, Lomé, Togo. monicadork@yahoo.fr. 2. Programme National d'Elimination de la Filariose Lymphatique, Ministère de la Santé et de l'Hygiène Publique, BP 336, Lomé, Togo. monicadork@yahoo.fr. 3. Division des Laboratoires, Ministère de la Santé et de l'Hygiène Publique, 374 avenue Georges Pompidou, BP 1161, Lomé, Togo. monicadork@yahoo.fr. 4. Centre Africain de Recherche en Epidémiologie et en Santé Publique (CARESP), Lomé, Togo. 5. Division des Laboratoires, Ministère de la Santé et de l'Hygiène Publique, 374 avenue Georges Pompidou, BP 1161, Lomé, Togo. 6. Laboratoire de Parasitologie, Programme National de Lutte contre le Paludisme, Ministère de la Santé et de l'Hygiène Publique, Rue Adamé, Quartier administratif BP 518, Lomé, Togo. 7. Programme National d'Elimination de la Filariose Lymphatique, Ministère de la Santé et de l'Hygiène Publique, BP 336, Lomé, Togo. 8. Health and Development International (HDI), Newburyport, MA, USA. 9. Université de Lomé, Faculté des Sciences de la Santé, BP 1515, Lomé, Togo.
Abstract
BACKGROUND: In March 2017, Togo was declared the first country in sub-Saharan Africa to eliminate lymphatic filariasis as a public health problem, but post-validation surveillance has been lacking. In some areas of the country, migrant groups from neighboring countries that are still endemic for LF pose a risk of reintroduction of LF to Togo. The objective of this study was to identify the risk posed by migrant groups by measuring their prevalence of LF infection and investigating any positive case using Togo's case investigation algorithm to prevent resurgence of LF and sustain Togo's elimination success. METHOD: A cross-sectional study was conducted in 2018 in the northernmost region of the country. Three migrant populations were identified: (i) nomadic Peuhls, (ii) Togolese members of local communities who migrate annually to neighboring countries for seasonal labor, and (iii) refugees from Ghana who came to Togo because of a communal conflict in Ghana. A questionnaire was designed to collect data on demographics and history of LF and MDA; all participants were tested for circulating filariasis antigen (CFA) using the filariasis test strip (FTS). Any CFA-positive case was confirmed with nocturnal microfilaremia. RESULTS: Refugees, seasonal economic migrants and nomadic Peuhls represented 42.1%, 31.4% and 26.5% of the study participants, respectively. The overall prevalence of CFA was 4.2% (58/1391) with the highest prevalence in the nomadic Peuhl group (11.9%), but only one of them (0.07%) was confirmed positive with nocturnal microfilaremia. Using the case investigation algorithm, no other positive case was identified in the positive case's surroundings. CONCLUSION: This study demonstrates that nomadic Peuhls, with a CFA prevalence of 11.9%, pose a potential risk for reintroduction of LF into Togo while Ghanaian refugees and seasonal economic migrants do not appear to pose a significant risk. Periodic monitoring of migrants, especially the nomadic Peuhl population, is a potential post-validation surveillance approach that could be used to promptly detect any LF cluster that may arise.
BACKGROUND: In March 2017, Togo was declared the first country in sub-Saharan Africa to eliminate lymphatic filariasis as a public health problem, but post-validation surveillance has been lacking. In some areas of the country, migrant groups from neighboring countries that are still endemic for LF pose a risk of reintroduction of LF to Togo. The objective of this study was to identify the risk posed by migrant groups by measuring their prevalence of LF infection and investigating any positive case using Togo's case investigation algorithm to prevent resurgence of LF and sustain Togo's elimination success. METHOD: A cross-sectional study was conducted in 2018 in the northernmost region of the country. Three migrant populations were identified: (i) nomadic Peuhls, (ii) Togolese members of local communities who migrate annually to neighboring countries for seasonal labor, and (iii) refugees from Ghana who came to Togo because of a communal conflict in Ghana. A questionnaire was designed to collect data on demographics and history of LF and MDA; all participants were tested for circulating filariasis antigen (CFA) using the filariasis test strip (FTS). Any CFA-positive case was confirmed with nocturnal microfilaremia. RESULTS: Refugees, seasonal economic migrants and nomadic Peuhls represented 42.1%, 31.4% and 26.5% of the study participants, respectively. The overall prevalence of CFA was 4.2% (58/1391) with the highest prevalence in the nomadic Peuhl group (11.9%), but only one of them (0.07%) was confirmed positive with nocturnal microfilaremia. Using the case investigation algorithm, no other positive case was identified in the positive case's surroundings. CONCLUSION: This study demonstrates that nomadic Peuhls, with a CFA prevalence of 11.9%, pose a potential risk for reintroduction of LF into Togo while Ghanaian refugees and seasonal economic migrants do not appear to pose a significant risk. Periodic monitoring of migrants, especially the nomadic Peuhl population, is a potential post-validation surveillance approach that could be used to promptly detect any LF cluster that may arise.
Authors: Molly W Adams; Elizabeth G Sutherland; Erin L Eckert; Khalida Saalim; Richard Reithinger Journal: BMC Med Date: 2022-05-09 Impact factor: 11.150