title: Still mesoendemic onchocerciasis in two Cameroonian community-directed treatment with ivermectin projects despite more than 15 years of mass treatment.
abstract: After more than a decade of community-directed treatment with ivermectin (CDTI) in Centre and Littoral Regions of Cameroon, onchocerciasis endemicity was still high in some communities according to the 2011 epidemiological evaluations. Some corrective measures were undertaken to improve the CDTI process and therefore reduce the burden of the disease. The objective of the present study was to assess the progress made towards the elimination of onchocerciasis in the Centre 1 and Littoral 2 CDTI projects where the worst performances were found in 2011. To this end, a cross-sectional survey was conducted in April 2015 in eight communities in two health districts (HD), Bafia in Centre 1 and Yabassi in Littoral 2, chosen because assessed at baseline and in 2011. All volunteers living for at least five years in the community, aged five years or more, underwent clinical and parasitological examinations. Individual compliance to ivermectin treatment was also assessed. Analyses of data were weighted proportionally to age and gender distribution in the population.
  
  
  
  In the Bafia and Yabassi HD, 514 and 242 individuals were examined with a mean age of 35.1 (standard deviation, SD: 20.7) and 44.6 (SD: 16.3) years, respectively. In the Bafia HD, the weighted prevalences varied from 24.4 to 57.0 % for microfilaridermia and from 3.6 to 37.4 % for nodule presence across the surveyed communities. The community microfilarial load (CMFL), expressed in microfilariae/skin snip (mf/ss), significantly dropped from 20.84-114.50 mf/ss in 1991 to 0.31-1.62 mf/ss in 2015 in all the surveyed communities. In the Yabassi HD, the weighted prevalences varied from 12.3 to 59.3 % for microfilaridermia and from 1.5 to 3.7 % for nodule presence across the surveyed communities, while a significant drop was observed in CMFL, from 20.40-28.50 mf/ss in 1999 to 0.48-1.74 mf/ss in 2015. The 2014 weighted therapeutic coverage of participants varied from 65.8 % (95 % CI: 58.4-73.2) in Yabassi HD, to 68.0 % (95 % CI: 63.3-72.7) in Bafia HD, with important variations among communities.
  
  
  
  After more than 15 years of CDTI, onchocerciasis is still mesoendemic in the surveyed communities. Further studies targeting therapeutic coverage, socio-anthropological considerations of CDTI implementation and entomological studies would bring more insights to the persistence of the disease as observed in the present study.
authors.affiliation: Ministry of Public Health, N°8, Rue 3038 quartier du Lac, Yaoundé, Cameroon. guyrogerkgr@gmail.com.|Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), P.O. Box 5797, Yaoundé, Cameroon. guyrogerkgr@gmail.com.|Institut de Recherche Expérimentale et Clinique, Faculté de santé publique, Université catholique de Louvain, Clos Chapelle-aux-champs 30 bte B1.30.13 BE-1200, Brussels, Belgium. guyrogerkgr@gmail.com.
authors.forename: Guy-Roger
authors.initials: GR
authors.lastname: Kamga
authors.affiliation: Ministry of Public Health, N°8, Rue 3038 quartier du Lac, Yaoundé, Cameroon.|Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), P.O. Box 5797, Yaoundé, Cameroon.|Institute of Biology of Molecular Medicine, Université Libre de Bruxelles, Rue des professeurs Jeener et Brachet 12 BE-6041 Gosselies, Brussels, Belgium.
authors.forename: Fanny N
authors.initials: FN
authors.lastname: Dissak-Delon
authors.affiliation: Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), P.O. Box 5797, Yaoundé, Cameroon.|Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, P.O. Box 1364, Yaoundé, Cameroon.
authors.forename: Hugues C
authors.initials: HC
authors.lastname: Nana-Djeunga
authors.affiliation: Ministry of Public Health, N°8, Rue 3038 quartier du Lac, Yaoundé, Cameroon.
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Biholong
authors.affiliation: Molecular and Cell Biology Laboratory, Department of Biochemistry and Molecular Biology, University of Buea, P.O. Box 63, Buea, Cameroon.
authors.forename: Stephen
authors.initials: S
authors.lastname: Mbigha-Ghogomu
authors.affiliation: Institute of Biology of Molecular Medicine, Université Libre de Bruxelles, Rue des professeurs Jeener et Brachet 12 BE-6041 Gosselies, Brussels, Belgium.
authors.forename: Jacob
authors.initials: J
authors.lastname: Souopgui
authors.affiliation: World Health Organization, African Programme for Onchocerciasis Control (APOC), 01 P.O. Box 549, Ouagadougou 01, Burkina Faso.
authors.forename: Honorat G M
authors.initials: HG
authors.lastname: Zoure
authors.affiliation: Institut de Recherche pour le Développement (IRD), IRD UMI 233 TransVIHMI - Université Montpellier - INSERM U1175, 911 avenue Agropolis, P.O. Box 64501, 34394, Montpellier Cedex 5, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Boussinesq
authors.affiliation: Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), P.O. Box 5797, Yaoundé, Cameroon.|Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, P.O. Box 1364, Yaoundé, Cameroon.
authors.forename: Joseph
authors.initials: J
authors.lastname: Kamgno
authors.affiliation: Institut de Recherche Expérimentale et Clinique, Faculté de santé publique, Université catholique de Louvain, Clos Chapelle-aux-champs 30 bte B1.30.13 BE-1200, Brussels, Belgium.
authors.forename: Annie
authors.initials: A
authors.lastname: Robert
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000977:Antiparasitic Agents / Q000008:administration & dosage*; D002163:Cameroon / Q000453:epidemiology; D002648:Child; D003430:Cross-Sectional Studies; D019353:Endemic Diseases; D005260:Female; D006801:Humans; D007559:Ivermectin / Q000008:administration & dosage*; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D009854:Onchocerca / Q000302:isolation & purification; D009855:Onchocerciasis / Q000188:drug therapy* / Q000453:epidemiology*; D059208:Parasite Load; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000977:Antiparasitic Agents; D007559:Ivermectin
keywords: Bafia; Cameroon; Elimination; Ivermectin; Onchocerciasis; Persistence; Yabassi