Table 2. Priorities questions identified in discussion with WHO and how modelling can help to address them.
| Priority question / issue identified in discussion
with WHO |
How can modelling address this? |
|---|---|
| 1. Identify countries where intensification of
interventions is required to reach the target of elimination as a public health problem by 2030. |
Use models to make spatially-explicit predictions of the end-year of MDA,
considering baseline endemicity (as estimated by a geospatial model) and history of MDA (start year, frequency, achieved coverage). Compare model- based spatially-explicit predictions of the end-year of MDA with the end-year as estimated by WHO using other approaches. |
| 2. What is the probability that there are still locations
with mf prevalence >1%, in spite of passing TAS? How frequently does this occur and what are the drivers of this? Identify countries and subnational areas at highest risk. |
Apply the models to simulate trends in infection in large number of villages
together forming an evaluation unit, assuming that the same MDA was applied in all villages (MDA regimen, duration of MDA) and assuming variation in both baseline endemicity and achieved MDA coverage. Sample settings and children within settings according to TAS methodology. Assess under which circumstances and how frequently there are still locations with >1% mf prevalence, despite passing TAS. Investigate the same under modified TAS sampling schemes (e.g. improving site selection, adjusting critical threshold, using different diagnostics). |
| 3. Are current criteria for stopping MDA and the
design of post-MDA surveillance appropriate after treatment with IDA (instead of DA)? If not, how should they be adapted? |
Similar to 2), but focusing specifically on sites using IDA instead of DA. Work with
data collected in clinical and field trials of IDA to model dynamics of antigen in response to IDA in different settings and the simulate sampling. |
| 4. What are the best ways to design post-validation
surveillance to detect resurgence with limited resources? |
Simulating dynamics of transmission once the <1% mf population prevalence has
been met to estimate probability of and timeline to true elimination of transmission or resurgence. Identify the main drivers and early indicators of elimination of transmission and resurgence. |
MDA, mass drug administration; TAS, transmission assessment surveys; IDA, ivermectin, diethylcarbamazine and albendazole; DA, diethylcarbamazine and albendazole.