21 December 2015 16:29

The Zika virus, carried by Aedes mosquitos and previously a slow pandemic, is on the rise across the Americas – and its rapid spread is causing serious concern to health officials.

Researchers at the University of Glasgow and Lancaster University are stepping up work on mosquito-borne viruses into the study of the Zika virus (Flaviviridae), a much neglected illness, in the hope of understanding it more and, more importantly, aim to develop improved diagnostics, therapeutics and a vaccine. 

There are currently no treatment or vaccines available.

Dr Alain Kohl, from the Medical Research Council-University of Glasgow Centre for Virus Research, is leading the work, along with colleagues from Brazil at Fiocruz in Recife, into how the Zika virus interacts with the cells, and understands the virus genetics to support these efforts.

Dr Kohl’s review paper on Zika is co-authored by Dr Derek Gatherer at Lancaster University and is published in the Journal of General Virology.

Dr Kohl said: “Although this is an emerging virus, with funds from the Medical Research Council, we are working hard to do something about Zika, as it has the potential to spread further and put more people at risk.”

Although the virus is not particularly life-threatening, current data suggests the Zika virus is behind a recent tenfold increase in the number of cases of microcephaly – a serious brain birth defect – in parts of Brazil. And as more and more people are infected, different symptoms emerge.

First discovered in Uganda in 1947, and later elsewhere in the sub-Saharan Africa, the Zika virus arrived in Southeast Asia at latest by mid-century. In the 21st century it spread across the Pacific Islands, reaching South America around 2014. Doctors believe it was imported to Brazil either during 2014’s World Cup or, more likely, during a canoeing event held in Brazil that involved Pacific islanders.

Since then, it has spread rapidly northwards, reaching Mexico only last month.  Its clinical profile has symptoms resembling a dengue-like febrile illness and Chikungunya viruses, until recent associations affiliate it with the previously mentioned microcephaly and Guillain-Barré syndrome.

Dr Kohl said: “In quite a short space of time, the virus moved from one side of the globe to another and is now infecting tens of thousands of people. This is the type of situation when virologists become wary. 

“We need to think about what we can do to stop this virus. Developing improved diagnostics and therapeutics or a vaccine needs to be a priority. The virus has already reached Mexico, but where and how far will it go next? The diagnostics for this virus need to be improved so the virus can be picked up in donated blood, for example.“ 

Dr Gatherer, a lecturer in the Division of Biomedical and Life Sciences at Lancaster University, said the sudden apparently explosive spread of Zika virus across the Pacific and into the Americas showed how unpredictable viruses could be.

“There are many unanswered questions – has the virus changed in some way to be more infectious?” he added.

“Are the newly observed symptoms – the birth defects and the partial paralysis in survivors – something new as well, or were they merely unnoticed before because case numbers were so low?

“Do the new observations of sexual transmission and the presence of virus in non-symptomatic blood donors mean that the virus could sustain itself in a human population without the need for mosquito transmission?“

Dr Gatherer said that in the next 12 months they hoped to have at least preliminary answers to some of those questions.

“In the meantime, we can only urge normal precautions are observed when visiting mosquito-infested areas of the Americas, especially for pregnant women,” he said.