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Coronavirus was already in Italy by December, waste water study shows

The coronavirus was already present in northern Italy in December, more than two months before the first case was detected, a national health institute study of waste water has found.

Coronavirus was already in Italy by December, waste water study shows
The first coronavirus outbreak was reported in Codogno, Lombardy, in February - but the virus may have been circulating months earlier. Photo: AFP
Researchers discovered genetic traces of Sars-Cov-2 – as the virus is officially known – in samples of waste water collected in the northern cities of Milan and Turin at the end of last year, and in Bologna in January, the ISS institute said in a statement seen by AFP on Friday.
 
Italy's first known native case was discovered in mid-February.
 
The results “help to understand the start of the circulation of the virus in Italy,” the ISS said. They also said they “confirm the by-now consolidated international evidence” that sewer samples work as an early detection tool.
 
 
Italy was the first European country to be hit by the virus and the first in the world to impose a nationwide lockdown. Italy has now recorded over 34,500 deaths.
 
The first known case, other than a couple of visiting Chinese tourists in Rome, was a patient in the town of Codogno in the Lombardy region.
 
On February 21st the government designated Codogno a so-called “red zone” and ordered it shuttered, followed by ten other towns across Lombardy and Veneto.
 
 
In February, medical experts in Milan said they believed the virus had already been “circulating unnoticed for weeks” in Italy.
 
 
ISS water quality expert Giuseppina La Rosa and her team examined 40 waste water samples from October 2019 to February 2020.
 
The results, confirmed in two different laboratories by two different methods, showed the presence of SARS-Cov-2 in samples taken in Milan and Turin on December 18th, 2019 and in Bologna on January 29th, 2020.
 
Samples from October and November 2019 were negative, showing the virus had yet to arrive, La Rosa said.
 
 
The data was in line with results obtained from retrospective analysis of samples of patients hospitalised in France, which found cases positive for SARS-CoV-2 dating back to the end of December, the institute said.
 
It also pointed to a recent Spanish study that found genetic traces in waste water samples collected in mid-January in Barcelona, some 40 days before the first indigenous case was discovered.
 
Since the beginning of the epidemic, researchers across the world have been tracing the spread of the coronavirus through waste water and sewage, finding genetic traces from Brisbane to Paris and Amsterdam.
 
Given the large number of coronavirus cases that have little or no symptoms, waste water testing could signal the presence of the virus even before the first cases are clinically confirmed in areas untouched by the epidemic or where it has ebbed.
 
The ISS said it had urged the health ministry to coordinate the collection of samples regularly in sewers and at the entrance to purification plants “as
a tool to detect and monitor the circulation of the virus in different territories at an early stage”.
 
It is launching a pilot study on priority sites identified in tourist resorts in July, and is expected to setup a nationwide surveillance network of waste water by autumn.
 
Find all of The Local's coverage of the coronavirus crisis in Italy here.

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HEALTH

Q&A: What you need to know about Italy’s West Nile virus outbreak

As Italy records a surge in cases of West Nile fever, we look at what the disease is and where in the country it's spreading.

Q&A: What you need to know about Italy's West Nile virus outbreak

Mosquitos are unfortunately one downside of summer in Italy. But as well as being a nuisance, they may also pose a health risk in the country – one of the few in Europe to record cases of West Nile virus (WNV)

READ ALSO: Cases of West Nile fever surge in northern Italy

Last week Italy recorded 50 more cases of the mosquito-borne virus, bringing the total number of infections to 144 according to the latest report from Italy’s Higher Health Institute (ISS).

This marked a 53-percent increase in cases against the previous week, while ten people have died so far.

As the number of infections continues to rise, here are the answers to the most pressing questions about the disease and the outbreak in Italy.

What is it?

The West Nile Virus (WNV) is a single-stranded RNA virus that can cause West Nile fever in humans.

It’s a member of the Flavivirus family together with other endemic viruses such as the Zika and Dengue viruses.

The virus was first identified in 1937 in Uganda’s West Nile district but has since spread to many other parts of the world, to the point that it is now considered indigenous to Africa, the Middle East, Asia and Australia. 

Carried by birds, West Nile virus is transmitted to humans by mosquitoes.

The West Nile virus is primarily transmitted by mosquitoes of the Culex species, which infect humans and other mammals through their bite, according to Italy’s health ministry.

There is no evidence that human-to-human transmission is possible.

Where are cases being reported in Italy?

Infections have been largely concentrated in the north of the country, especially in the Veneto region, where six people have now died of the disease. Other deaths were recorded in Lombardy, Piedmont and Emilia-Romagna.

The city of Padua, which is located in Veneto’s mainland, around 35 kilometres away from the Adriatic coast, is currently regarded as the hotspot of the virus. 

It isn’t yet clear why Veneto has been the worst-hit region so far, but experts fear that its marshy lowlands might be the perfect breeding ground for disease-carrying mosquitoes. 

A mosquito of the Culex species viewed under a microscope.

Mosquitoes of the Culex species, a specimen of which is pictured above, are responsible for transmitting the West Nile Virus to humans and other mammals. Photo by Jon CHERRY Getty Images / AFP

How severe is the outbreak in Italy?

West Nile virus is not new to Italy. However, this summer has brought the highest number of cases recorded yet.

National infection levels remain relatively low but the country has by far the largest number of cases in Europe.

According to the most recent report from the European Centre for Disease Prevention and Control (ECDC), dated August 3rd, 94 out of 120 recorded cases were in Italy.

Greece had 23 reported cases. Romania and Slovakia had two and one respectively. 

Italy is the only European country that has reported fatalities.

What are the symptoms?

According to the Italian Higher Health Institute (ISS), around 80 percent of infected people show no symptoms whatsoever.

In symptomatic cases, however, symptoms generally resemble those of a common flu and include fever, headaches, nausea and diarrhoea. 

The infection is usually only dangerous for people with weakened immune systems such as the elderly, and the most severe symptoms occur in fewer than one percent of infected people.

In healthy people, the virus is unlikely to cause more than a headache or sore throat, and symptoms generally last only a few days.

According to the data currently available, around one in 150 infected people can show symptoms as serious as partial vision loss, convulsions and paralysis. 

In very rare cases (around 0.1 percent, or one in 1000) the disease can cause brain infections (encephalitis or meningitis) which may eventually be fatal.

Brazilian biologists handle mosquito larvae.

There is currently no vaccine against West Nile disease, though several are being tested. Photo by Apu GOMES / AFP

Is there a cure?

There is no vaccine against West Nile fever. “Currently vaccines are being studied, but for the moment prevention consists mainly in reducing exposure to mosquito bites,” the ISS states.

There is also no specific treatment for the disease caused by the virus.

Patients showing the more serious symptoms are usually admitted to hospital and treated with IV fluids and assisted ventilation.

What should you do to protect yourself?

Seeing as there is currently no vaccine against the virus, the best way to protect oneself is by reducing exposure to mosquitoes as much as possible.

Italian health authorities have listed a number of official recommendations to help residents avoid mosquito bites. These include: 

  • Use repellent
  • Wear long-sleeved shirts and long trousers when being outdoors and especially during ​​mosquitoes’ peak activity times, i.e. sunrise and sunset
  • Use mosquito nets on your windows or sleep in rooms with air-conditioning and keep the windows closed
  • Make sure there are no pools of stagnant water around your house

See more information about West Nile virus in Italy on the health ministry’s website.

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