The United States is quickly becoming the new epicentre of the COVID-19 pandemic, with cases in the country rising rapidly.
There are now at least 83,000 cases in the US and around 1,300 people have died from the coronavirusin the country.
On Thursday, the country overtook China and Italy to become the place with the most reported cases of the disease.
The large number of cases is in part due to the size of the United States, as it has a population of around 330 million, around five times larger than both the UK and Italy.
However, China has a larger population than the US, so the size of the country is clearly only one factor.
The density of the population is also important, as the disease has spread quickest through cities like Milan and London where people live close together.
Crucially, it’s not just the number of cases in the US that will be worrying health authorities.
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More important still is the rate at which the number of cases is increasing – and it is this measure that suggests the US is the new epicentre of the pandemic.
As recently as a week ago the US had just 25,000 cases, but that number has more than tripled in the last seven days.
On Thursday, more than 18,000 new coronavirus cases were reported in a single day.
Of late the number of cases in the US has doubled every 3.7 days, although in some places the rate is much higher.
This means the number of cases is likely to double again in the next few days and could continue to grow exponentially.
Growth like this is particularly dangerous, as it can cause a surge in demand for medical care – and the country’s health system may struggle to meet this demand.
One place where the number of cases has risen quickly is the state of New York
Around 45% of the country’s confirmed cases are from the state, with at least 37,877 people infected with the disease.
There have also been 385 deaths from the virus in New York, a third of the United States total.
The state has been in lockdown for a week to try to slow the spread of the disease, but so far this has had a limited effect.
Since the 100th case was recorded in New York the number of cases has doubled on average every 2.2 days, although it has now slowed slightly to doubling around every four days.
Cases in New Jersey and Michigan are also doubling rapidly, meaning cases in all three states are likely to escalate.
The current surge of cases of COVID-19 in the US has not yet been seen in the number of deaths in the country.
China, Italy, Spain and Iran have all had more deaths than the US, despite having fewer cases.
However, the outbreak in the US is relatively recent, with the vast majority of cases only being reported in the last week.
This means that the number of deaths in the country should be expected to rise rapidly over the next week, as there is a delay between people being diagnosed with the disease and the virus proving fatal.
This can already be seen in New York, where the number of deaths is doubling every two days.
At the moment the US is only leading the way in terms of the number of cases, but if the number of deaths does continue to rise, it could top anything seen so far in Asia or Europe.
Then the country will unquestionably be the new epicentre of the coronavirus pandemic.