Elimination within reach: A cross-sectional study highlighting the factors that contribute to persistent lymphatic filariasis in eight communities in rural Ghana

Abstract

BackgroundDespite the progress achieved in scaling-up mass drug administration (MDA) for lymphatic filariasis (LF) in Ghana, communities with persistent LF still exist even after 10 years of community treatment. To understand the reasons for persistence, we conducted a study to assess the status of disease elimination and understand the adherence to interventions including MDA and insecticide treated nets.Methodology and principal findingsWe conducted a parasitological and epidemiological cross-sectional study in adults from eight villages still under MDA in the Northern Region savannah and the coastal Western Region of the country. Prevalence of filarial antigen ranged 0 to 32.4% and in five villages the prevalence of night blood microfilaria (mf) was above 1%, ranging from 0 to 5.7%. Median mf density was 67 mf/ml (range: 10–3,560). LF antigen positivity was positively associated with male sex but negatively associated with participating in MDA the previous year. Male sex was also associated with a decreased probability of participating in MDA. A stochastic model (TRANSFIL) was used to assess the expected microfilaria prevalence under different MDA coverage scenarios using historical data on one community in the Western Region. In this example, the model simulations suggested that the slow decline in mf prevalence is what we would expect given high baseline prevalence and a high correlation between MDA adherence from year to year, despite high MDA coverage.ConclusionsThere is a need for an integrated quantitative and qualitative research approach to identify the variations in prevalence, associated risk factors and intervention coverage and use levels between and within regions and districts. Such knowledge will help target resources and enhance surveillance to the communities most at risk and to reach the 2020 LF elimination goals in Ghana.

Demographic, socioeconomic and disease knowledge factors, but not population mobility, associated with lymphatic filariasis infection in adult workers in American Samoa in 2014

“…The approach of testing adults, although not at work sites, has also been reported by Rao et al [30] in Sri Lanka. The present study demonstrates the value of targeted surveys of working adults for efficiently providing representative information about LF prevalence and risk factors without the necessity of costly and time-consuming household cluster surveys, as have been done in many other LF endemic countries to monitor progress [31][32][33].…”

Low transmission of Wuchereria bancrofti in cross-border districts of Côte d’Ivoire: A great step towards lymphatic filariasis elimination in West Africa

“…This could thus require the continuation of MDA efforts until the prevalence of worm antigenemia drops below 1%. Similarly, Minetti et al [37] observed a persistence of LF infection among communities after 10 years of community treatment in rural Ghana. They reported that the prevalence of filarial antigen ranged 0 to 32.4%, and the prevalence of night blood microfilaria (Mf) in five villages was above 1%, while median Mf density was 67 Mf/mL [37].…”

“…Similarly, Minetti et al [37] observed a persistence of LF infection among communities after 10 years of community treatment in rural Ghana. They reported that the prevalence of filarial antigen ranged 0 to 32.4%, and the prevalence of night blood microfilaria (Mf) in five villages was above 1%, while median Mf density was 67 Mf/mL [37]. In the same line, Rao et al [38] recorded persistent W. Bancrofti infection in Sri Lanka that has low-level persistence of LF following multiple rounds of MDA in American Samoa.…”

Field evaluation of DNA detection of human filarial and malaria parasites using mosquito excreta/feces

“…We tested this tool in two villages of rural Ghana and we have shown for the first time that the method is fully field-applicable, including for pathogens which are not transmitted by mosquitoes. Our primary goal was to verify the presence of W. bancrofti in these communities, using lymphatic filariasis as an example of the capacity of our approach to detect an infection at a very low prevalence and approaching elimination [29]. W. bancrofti DNA was successfully recovered from both insect E/F and carcasses, with the low DNA positivity rates comparable to the prevalence of microfilaria in people.…”

“…We conducted the study in the communities of Sekyerekura and Dugli, located in the Bole District, in the Savannah Region of Ghana. We previously surveyed all the households (24 in Sekyerekura and 47 in Dugli) in March 2017 as part of a study on the status of elimination and determinants of LF persistence in Ghana [29]. At the time of the survey, estimated W. bancrofti microfilaria community prevalences were 7.4% and 5.5% for Sekyerekura and Dugli, respectively.…”