West Nile virus cases are increasing rapidly in Italy. Do we need to worry?

Mosquitoes are known to be the bane of the Italian summer, as the hottest and wettest months of the year result in an abundance of pesky insects at any time of the day.

Italians are used to it and are rarely caught unprepared, as each summer they are armed with anti-mosquito sprays, citronella-scented candles and raised hands ready to smack midges in mid-flight.

But Italians are less willing to face the threat of mosquitoes, which may carry West Nile Virus (WNV), a disease native to Africa, the Middle East, Asia and Australia that has recently migrated to Europe and North America .

This summer in particular, there has been a dramatic increase in cases, raising concerns among health authorities in Italy. Here’s what we know.

How widespread is West Nile virus in Europe?

Since 1999, the virus that causes what is known as West Nile fever has spread widely from areas where it is traditionally prevalent.

It is now found on every continent on earth except Antarctica and is the leading cause of mosquito-borne diseases in the United States.

In Europe it is still relatively rare; according to the European Center for Disease Prevention and Control (ECDC), about 55 cases of WNV had been reported in Europe by July 27 this year.

But the data reveals an alarming fact: of the 55 cases, 42 were reported in Italy alone. That’s more than triple the cases reported in Greece (12), the country with the second highest number of cases among the four in Europe that have reported the virus on their territory.

The other countries, Serbia and Slovakia, reported 16 cases and one isolated case respectively.

More worryingly, of those who contracted the virus and developed West Nile fever, five people had died from the disease by the end of July.

How big is this year’s outbreak?

In the last week, the number of infections reported in Italy has risen to 94 as of August 4, with 52 new cases recorded in one week alone.

The total death toll from the virus has also risen from five to seven over the past week, with five deaths in the Veneto region, one in Emilia-Romagna and one in Piedmont.

Cases in Italy have been largely concentrated in the Northwith the city of Padua in Veneto considered the hotspot of the virus in the country.

The geographic spread of the outbreak is perhaps surprising given that southern Italy is hotter and wetter than the north and provides a better habitat for virus-carrying mosquitoes. But the Veneto plain with its natural habitat is actually the perfect breeding ground for mosquitoes; Entomologists this year found that mosquito numbers in the area had increased by 27 percent, an Italian newspaper reported correct.

How do you recognize West Nile Virus?

Not all mosquitoes are known to transmit West Nile virus. Scientists have specifically identified the Culex species as those responsible for spreading the virus.

But what might sound like very helpful information is less than useful given that there is no salient distinguishing feature to distinguish the species that is considered the “average joe” of mosquitoes.

Culex mosquitoes are 4-10mm in size, brownish in color and have no specific pattern on their body. They are distinguished from other European mosquitoes by their proboscis (their small biting “mouth”). Her legs also lack the same pale and dark ring patterns, and her stomach remains round instead of flat.

You’re unlikely to have the opportunity to watch a mosquito long enough to identify it, and by the time you do, chances are it’s already sucked your blood.

When a mosquito has been infected with WNV, the virus is transmitted through its bite.

Most people don’t develop any symptoms at all, while those who do show symptoms show them two to 14 days after the bite.

Symptoms of WNV infection usually take the form of fever accompanied by flu-like symptoms such as headache, body aches and diarrhea.

In rare cases, the virus can cause infection of the brain and its lining (encephalitis or meningitis), which can be fatal.

Why are cases increasing?

Cases of WNV are not new in Italy, but never before have so many cases been reported in one summer alone.

Though experts have yet to figure out why cases are now booming, recent studies suggest a link between higher temperatures brought on by global warming and the explosion in mosquito-borne infections.

A few years ago, experts warned that climate change could lead to an increase in the number of disease-carrying mosquitoes.

A 2020 study by Imperial College London and Tel Aviv University found that higher temperatures by 2030 could indicate the presence of dengue, yellow fever and Zika-carrying mosquitoes in Europe.

The experts behind it the study found that disease-carrying mosquitoes have already benefited from recent climate change around the world, and as this accelerates, more are likely to be introduced to Europe.

A previous study had predicted in 2019 that as temperatures rise, disease-carrying mosquitoes will reach 500 million more people around the world than they do today. Higher temperatures also mean that the breeding season for mosquitoes is getting longer, which also extends the time for disease transmission.

What are the Italian authorities doing about it?

There is not much Italian authorities can do except tell people to stay away from mosquitoes as there is no vaccination against WNV.

Italy recommends People wear long trousers and long sleeves when going outside at dawn and during sunset (despite the current high temperatures), keep mosquito nets on their windows, and take care not to let water stagnate in flower and plant pots or dog water bowls.

Other recommendations include mowing the grass to prevent mosquitoes from breeding, and putting fish in ponds and the like so the insects can be eliminated naturally.

Should you be concerned?

Less than 1 percent of people infected with WNV (1 in 150) actually develop the most severe symptoms, and only 1 in 1,000 infected people die from the virus.

Those who develop only mild symptoms, 20 percent of those infected, overcome the virus like a normal fever in a few days or, in the worst case, a few weeks.

Older people are more vulnerable to the virus than young people, with most victims in Italy in their late 70s and 80s.

But things could get worse in Italy before the end of the summer. Virologist Giorgio Palù, president of the Italian Medicines Agency (Aifa), expects cases to continue to rise until September, Italian newspaper Il Gazzettino reports.