CouNTDown integrated control strategies to eliminate lymphatic filariasis in Ghana
Scaling-up access to preventive chemotherapy for LF to achieve effective treatment coverage remains key. This alone is not enough to achieve the 2020 NTD targets. In addition to preventive chemotherapy, the WHO recommends complementary strategies to accelerate transmission interruption, including improved vector control, the provision of sanitation and hygiene, health awareness and capacity building. As elimination becomes a target for more NTDs, it is necessary to address the underlying causes that allowed such diseases to persist despite long periods of intervention.
In Ghana, MDA has been on-going in some endemic communities for over 15years, with treatment coverage of more than 65%, leading to tremendous progress and local elimination of LF in over 80 districts, which are still under surveillance (GHS,2014/2015). However, the disease is still present in about 16 districts with persistent infections and microfilaria prevalence rates, ranging from 1% to 18.2% after 8 rounds of MDA. These persistent low microfilaremia that sustain transmission despite successful repeated rounds of MDAs have been described as hotspots. These hotspots constitute a major bottleneck to the elimination agenda. It has therefore become vital to identify the characteristics of these hotspots and devise integrated approaches to speed up the elimination of LF.
This work is carried out by the CSIR team led by Dr Mike Osei Atweneboana in Ghana and Dr Lisa Reimer at LSTM.
STUDY GOALS AND OBJECTIVES
The main aim of this implementation research is to provide evidence to support rapid and sustainable scale-up of complementary intervention strategies to eliminate LF in Ghana. This will be achieved through the following specific objectives:
1. Evaluate the impacts of vector control on LF transmission in hotspots
a. Evaluate the social, entomological and epidemiological characteristics of hotspots
b. Evaluate the impacts of an integrated MDA & vector control programme on service delivery, community participation and LF transmission
2. Identify opportunities for planning and co-implementation of MDA and LLINs (Long Lasting Insecticidal Nets) at the district and community level
3. Develop tools and methods to inform scale-down of interventions
a. Apply transmission models to predict impacts of interventions on LF and to set locally relevant targets for elimination
b. Evaluate and optimise available and emerging xeno-monitoring tools for post-MDA surveillance
STUDY DESIGN
Existing LF programme data has shown that many regions of Ghana are still endemic for LF despite 15 years or more of MDA and three of these regions; Upper East, Upper West and Western regions were selected for the study.
COUNTDOWN will identify the social, entomological and epidemiological factors responsible for LF persistence in three endemic districts within the three selected regions in Ghana.
The epidemiological study will involve a cross-sectional study followed by a longitudinal study to assess micro-filarial dynamics before and after ivermectin and albendazole treatment. Also, a parallel mosquito collection will be carried out using different methods to assess vectoral capacity and vector infectivity. The multiple entomological methods will be compared to optimisexeno-monitoring protocols for post-MDA surveillance in Ghana.