Strengthening serological surveillance across Africa

xSTAR – multiplex Serology Testing and Analysis Platform

xSTAR is a Wellcome-funded project providing real-world evidence of arbovirus infection burden across Africa, to inform decision making on the optimal use of control interventions

PARTNERS

About xSTAR

xSTAR is a project funded by the Wellcome Trust to better understand the burden from infectious disease across Africa. To do this, we are testing thousands of blood samples from across the continent for the presence of antibodies to infectious diseases such as dengue and Zika. Antibodies are small molecules that are generated by our immune system in response to infection by a virus or a bacterium that help fight infection. They persist in our blood for many years after the infection has been cleared. By identifying the presence of antibodies to specific diseases in a population, we can identify which viruses or bacteria have circulated in that location. By using a multiplex-based immunoassay, we can test for multiple different infectious diseases at the same time.

Collaborations

We are a network of research and public health institutions based in the UK, France, Sengal, Benin, Togo, Gabon, Nigeria, Ethiopia, Tanzania, Uganda and Madagascar. We have access to residual blood samples from previous population-based serosurveys as well as samples from clinical trials and we are testing them to reconstruct population exposure to multiple arboviruses.

Testing Sites

xSTAR will test more than 47,500 blood samples from across all ages in hundreds of locations in West, Central, East and Southern Africa. The selected locations span urban and rural settings and will generate pointwise and area-level estimates of presence, prevalence and transmission intensity of arboviruses including dengue, Zika, Chikungunya, O'nyong'nyong, Rift Valley, West Nile, Usutu, Crimean Congo Haemorrhagic Fever and other viruses. The xSTAR assay is described in Gasasira et al. JoVe, 2025 (DOI: 10.3791/69259).

Methods

Samples are tested in-country to strengthen local laboratory capacity.
A subset of samples is validated against plaque reduction neutralization tests (PRNTs) for mosquito transmitted viruses such as dengue and Zika.
Laboratory training and workshops support the generation of the largest arbovirus antibody database for Africa.
Teams are trained in advanced serological data analysis and modelling, focusing on quantifying cross-reactivity among related viruses to derive robust prevalence estimates and transmission metrics.

Impact

xSTAR will generate real-world evidence of arbovirus circulation and infection prevalence across hundreds of populations in West, Central, East and Southern Africa. By integrating epidemiological estimates of transmission intensity obtained from serological with climate and environmental datasets, we aim to generate regional arbovirus maps of arbovirus risk and infection burden which can help inform decision-making and interventions planning for arbovirus control.

xSTAR Project Nigeria Awards Fully Funded PhD Scholarship in Arbovirus Serosurveillance and Disease Modelling

The xSTAR Project Nigeria has awarded a fully funded three-year PhD scholarship to Damilare Isaiah Taiwo at the Infectious Disease and Environmental Health Research Group (IDEHRG), Department of Microbiology, University of Ilorin, as part of an international collaboration with Imperial College London supported by the Wellcome Trust.

xSTAR

Apr 1

From London to Dakar: Science, Language and Collaboration in Multiplex Serology Training

On the 18th of October 2025, my journey to Dakar began on an evening departure from London Gatwick Airport aboard Turkish Airlines, connecting through Istanbul before continuing onward to Dakar, Senegal. By the time the plane touched down early Sunday morning, the first light of day was just beginning to stretch across the city.