AfOx Travel Grant leads to breakthrough research on Zika virus in Angola

The AfOx Travel Grant facilitated the development of a new research collaboration between the Ministry of Health in Luanda, Angola and the Department of Zoology at Oxford University.

In June 2018, Dr Sarah Hill and Dr Nuno Faria, from the Department of Zoology, travelled to Luanda, the capital city of Angola. The purpose of the visit was to work with Angolan scientists at the Ministry of Health to use a new technology- the portable “MinION” sequencing device- to read the genome (i.e., all DNA or RNA genetic material) of viruses that cause severe disease, such as Zika virus. Zika virus is passed between humans by infected mosquitos.

Most people with Zika virus won’t have serious symptoms, but if a woman becomes infected during pregnancy there is a risk that the baby may be born with severe birth defects.

Since 2013, the ‘Asian genotype’ strain of the virus has spread rapidly across locations in the Pacific and the Americas, and more recently into Africa. Understanding the spread of the virus is critical to help governments of affected or at-risk areas design programmes that can best protect human populations.

Information encoded in virus genomes can be very useful to help accurately track the spread of the virus over time and space. This is particularly important for a virus such as Zika that is very difficult to detect based on symptoms alone.

The project enabled researchers to use the MinION device to generate the first genomes of Zika virus detected in patients in Angola. As a single virus particle reproduces itself within the human body, the descendent virus genomes can have mutations (i.e., small changes within the genome) that result from inaccurate copying of the original virus genome. This means that the Zika virus detected in different patients may all have slightly different genomes, even if they are quite closely related. The researchers can then use computational methods to reveal the ‘family tree’ of these viruses, by reconstructing how these small differences may have built up over time. In this way, the researchers can look at how closely related those viruses present in Angola are to other Zika virus samples studied elsewhere across the world. They can therefore better understand how these viruses have spread across the world.

The work has had several important findings. Firstly, the researchers showed that the Zika virus from Angola was most closely related to other Zika viruses detected in Brazil, and that the virus was probably introduced to Angola from Brazil within the past few years. Secondly, the researchers showed that the virus circulated in Angola for a least a year.

This is important because the genetic sequencing showed that the Zika virus present in Angola was the type of Zika virus (the ‘Asian genotype’) that has been shown to sometimes cause birth defects in new-borns if their mothers are infected during pregnancy. The Angolan Ministry of Health has recently seen a rise in the number of babies born with this defect, which may therefore have been caused by the new presence of this Zika virus in Angola.

Following the success of studying Zika virus in Angola, the researchers have also started to sequence additional viral genomes from people infected with dengue virus and yellow fever virus, in order to conduct similar studies on these viruses. Long Term Outcomes The team of Oxford and Angolan researchers are applying for additional funding to help support long-term activities in Angola, including a more detailed investigation into the immune responses to Zika in the babies born with birth defects such as microcephaly.

Researchers from both Luanda and Oxford are leading the authorship of several research papers, that will describe the work conducted in Angola. The research facilitated by the travel grant was presented at the American Society of Tropical Medicine and Hygiene Annual Meeting in New Orleans, and the Tofo Advanced Study Week in Mozambique. Researchers from both countries will present additional conference abstracts based on the work at conferences during 2019, and will be authoring more research papers together. More information The preprint of the paper that describes the findings in Angola in more detail is available here: https://doi.org/10.1101/520437