Predicting the next epidemic: DHIS2-based risk modeling

Project summary

Unexpected onset of large-scale epidemics caused by climate-sensitive vector-borne diseases (VBDs) present a growing risk to human health and societal stability throughout the world. The situation is especially critical in LMICs as health systems struggle to absorb the full scale of mass hospitalizations due to acute VBD epidemics, while public and private sectors may suffer substantial productivity and commercial losses.
Tanzania is experiencing significant changes in VBD transmission patterns in particular with respect to mosquito-borne diseases, such as malaria and dengue. Notably, dengue epidemics recently became a recurrent phenomenon, while observed changes in malaria epidemiology suggest a shift from stable, holoendemic-, to unstable, hypoendemic transmission marked by increasing risk of malaria epidemics. The complex processes that drive VBD epidemics are not fully understood-yet climatic, environmental and socio-economic factors are known modulators.
This project addresses the need for improved prediction and prevention of epidemic risks by assessing novel modelling approaches and opportunities for translating complex model outcomes into easily disseminated risk assessments for targeted and timely interventions.
Specifically, we aim to explore key predictors and to combine modelling approaches, coupling
vector ecological niche models with mathematical micro-epidemiological models, in order to obtain timely, high-resolution risk projections of VBD epidemics. To ensure that these projections are readily available, we will develop an adjunct application on top of the existing DHIS2 platform, through which risk assessments are presented to end-users in the form of user-friendly risk maps and epidemic alerts. The project will use dengue and malaria as tracers for epidemic VBDs in Tanzania - and Unguja and Tanga Regions as specific study areas as they cover diverse climatic, environmental and socio-economic settings for comprehensive model development.

Outputs

Midterm report
Monthly entomological surveys in 11 sites in Tanga region and 4 sites on Unguja, United Republic of Tanzania have been performed for almost 2 years and will be completed in Nov. and Sept., 2023 respectively. Additionally, human clinical-serological cross sectional sampling was done twice in these sites during malaria peak transmission seasons of June and Dec. 2022. A database on the distribution and abundance of vectors (of malaria and arboviruses), climatic variables, as well as data obtained from the cross sectional studies are being established and constantly being evaluated by the team. In Nov. 2022, we had a project progress meeting in Tanga with participation of researchers from the majority of involved institutions, which paved the way for the remaining field studies, presentations of PhD studies and spin-off projects.
Neema Kulaya (WP1 PhD student) is conducting laboratory analysis of the mosquito samples by implementing PCR for vector identification and detection of the arboviral infections (dengue, zika, chikungunya and yellow fever virus) as well as malaria Plasmodium parasites. Lembris Njotto (WP2 PhD student) is performing the initial model explorations using the database and as well working with the DHIS2 team on implementing a DHIS2 prototype for the entomological data collected.
Three joint workshops that shared experiences and created a common understanding of procedures of field and laboratory work between NIMR, Tanga and Suza, Unguja was performed.