Forecasting assumptions

To build up the forecasting tables (general projections accounting for disease coendemicity and disease-specific projections) some assumptions have been made about expected outcomes of impact assessment surveys and the coverage achieved in the to-be-implemented PC interventions.

Population based estimates: we have used official census data that countries are submitting through the JAP reports. When this was not available, we used the demographic data that a cohort of data consultants managed to compile during a suite of “data consultancy missions” conducted by ESPEN in 2018 and 2019. These country missions were intended to complete the ESPEN data repository, validating the historical data gathered by ESPEN and its partners, and conducting a series of training on NTD databases and data management. We have used the estimated population growth rate also provided by country programs and Ministries of Health (MoH) to generate demographic projections until 2030. This indicator is provided at country level and applied equally to the implementation level demographics. 

Annual MDA projections: MDA projections are based on the current endemicity status (based on 2020 JAP reports), the number of rounds conducted up until 2019 and the results of recent surveys: impact assessments, mapping, re-evaluations. We are assuming that the forecasted MDA rounds will be effective, and the results of future surveys will be satisfactory. The current projections will be updated when new information on MDA/PC rounds and impact surveys are entered in the ESPEN data system.

Annual impact assessment plans: for lymphatic filariasis, Pre-TAS after 5 effective rounds of MDA1, MDA2, MDA4 or after 2 rounds MDA5 for IDA, and re-preTAS following 2 more rounds of MDA after failures of Pre-TAS. TAS1 is scheduled after success in pre-TAS and TAS2 two years after TAS1 and TAS3 three years after TAS2. For schistosomiasis, impact survey every 5 years (i.e. after 2 rounds for low prevalence, 3 rounds for moderate and 5 rounds for high prevalence). For soil-transmitted helminthiases (STH), first impact survey after 5 years of MDA rounds and impact survey every 3 years. In addition to this, the STH evaluation survey was systematically integrated into the SCH and LF TAS surveys. For the mapping gaps and the implementation units eligible for onchocerciasis elimination mapping, surveys have been planned for 2020 or 2021.

MDA strategy: this is the strategy for a coordinated use of medicines for integrated NTD control interventions based on the combination of MDA rounds implemented against LF-Oncho-STH-SCH, the co-endemic status and the acceptable strategy for lymphatic filariasis, taking into account the coendemicity with loiasis and onchocerciasis.

Treatments to be delivered: this is the number of treatments to be administered taking into account the coordinated implementation of MDAs for each year.