Amid fear of resurgence of the Covid-19 infections in various pockets of the world, the WHO has sounded the alarm that arboviruses carried by Aedes aegypti mosquitoes is spreading its wings into new territories causing spurt in cases of dengue and chikungunya with zika epidemics looming large.
“Climate change has played a key role in facilitating the spread of the vector mosquitoes,” said Raman Velayudhan, who coordinates WHO’s dengue and arbovirus initiative.
He and colleague Diana Rojas Alvarez, WHO’s technical lead on chikungunya and zika, stressed the need for urgent action to rein in the spread of the mosquitos, amid fears of larger outbreaks in new areas.
Painting a scary picture where pathogens are expected to take the large number of people in its grip, the global health agency cautioned that about half of the world’s population is now at risk of dengue with an estimated 100-400 million infections occurring each year.
Chikungunya virus (CHIKV) is found on nearly all continents and to date, 115 countries have reported transmission.
While Zika virus disease has declined globally, to date, 89 countries have current or previous spread of Zika virus.
These diseases, that spread from mosquitoes to people, are causing an increasing number of outbreaks worldwide, with climate change, deforestation and urbanisation being some of the major risk factors, that allow mosquitoes to adapt better to new environments and spread the risk of infection geographically further, including to the European region.
“We are really at the right time to scale up the advocacy for the threat of arboviruses globally,” Dr Raman Velayudhan said at a media briefing session recently.
Velayudhan said around 129 countries are at risk of dengue and it is endemic in over 100 countries. From about half a million cases in 2000, it has exponentially grown to 5.2 million in 2019.
The number of people at risk of dengue is predicted to reach 60% of the world’s population by 2080 as a result of climate change, rapid urbanization and population growth.
With dengue, which comes in four closely related serotypes, people who are reinfected with another serotype often develop severe disease.
This “can lead to organ failure and death”, Velayudhan warned while Rojas Alvarez talked about the ill-effects of chikungunya which can leave its impact on the patients for months and even years.
“It can cause lifelong disability,” Alvarez warned.
Stating that the WHO warning should come as a wakeup call, Dr Kavita Singh, Director, Drugs for Neglected Diseases initiative (DNDi South Asia) lamented that compared to the funds and research carried out on Covid-19 during the past two years, only a fraction of that has been invested to develop dengue vaccine and drugs, despite the disease being around for decades and wreaking havoc every year across countries.