A medical worker in protective gear tends to a patient on March 24, 2020 at the new COVID 3 level intensive care unit for coronavirus COVID-19 cases at the Casal Palocco hospital near Rome, during the country's lockdown aimed at stopping the spread of the COVID-19 (new coronavirus) pandemic. Alberto Pizzoli | AFP | Getty Images

Demographics, social behavior and lower testing capacity are just some of the reasons why Italy and Spain have the highest number of deaths in the world from the coronavirus, health experts told CNBC. Italy has reported more than twice as many deaths than China, where the virus first emerged in late 2019. As of Friday morning, there had been 8,215 deaths in Italy compared to 3,291 in China, according to data compiled by Johns Hopkins University. At the same time, Spain's death toll has risen sharply in recent days and it is currently at 4,365 — also significantly above China's. The worrying figures have raised questions about what's behind these European countries' high fatality rate. Two health experts told CNBC there are several reasons.

Slow response

"There was a lot of spread before people realized (the virus was present)," Alexander Edwards, an expert in immunology from the University of Reading, told CNBC Thursday about the situation in Italy. He explained that in most European countries, people assumed the outbreak "was a problem elsewhere" and this initial attitude led to the fast spreading of the virus in places such as Italy and Spain. China's Wuhan region, where the virus originated, has been shut off from the rest of the world since mid-January. The area will partially lift its lockdown in early April, given that there have been no new cases reported for a number days. In hindsight, the extreme lockdown appears to have had a positive effect, however at the time, the decision to tell 11 million people to stay at home seemed too drastic to many, and without a guarantee of success. Italy implemented its first lockdown measures in late February, in 11 municipalities in the northern part of the country. A nationwide lockdown was only put in place on March 9. "Italy was a bit behind," Edwards told CNBC.

Testing capacity

The death rate is also linked to how many people are being tested for the virus, Michael Tildesley, an epidemiologist at Warwick University, told CNBC Thursday over the phone. Essentially, the more people who get tested, the better authorities can respond.

As a result in places where many people are being tested, and quickly, such as China, the number of deaths is not as high as those seen in Italy and Spain, where only citizens showing symptoms of the coronavirus are being tested. Edwards added that in China, people with the virus were identified quickly and isolated within the health system, rather than at home, which is what happened in Italy.

Population

There was a "double combination of risk factors" in Italy, according to Edwards. He explained that the first group of people to get hit by the virus in the country were the elderly. OECD data shows that Italy has the second oldest population in the world, after Japan. Those aged above 60 are believed to be at a higher risk of having severe symptoms from the virus. "Every Sunday, (young Italians) go see their grandparents, they kiss them, they go to church or have meals together," Edwards told CNBC, adding that this contact with the elderly helped spread the virus across Italy. Even though Spain does not have one of the oldest populations in the world, the coronavirus also is hitting this age bracket hard. Data from the Spanish government has shown that the age groups with the highest number of cases are: 50-59; 70-79; and above 80. In addition, Spain has a similar family culture to Italy, which according to the experts suggests that contact between the young and the elderly has contributed to a higher number of deaths. "Part of it is also cultural," Tildesley, from Warwick University, said, adding that China saw a higher level of compliance with the lockdown measures compared to Europe. Finally, there have been some suggestions that differences in the types of medicines used in Europe, compared with China, might have had an impact on the coronavirus death rate. However, Edwards from Reading University, said it was hard to say whether "Eastern versus Western" medicine made a difference in this case.