Covid infections in the US have nearly doubled in the past month amid the rise of two highly-mutated variants, official data suggests.

The test positivity rate in the US - the share of swabs that come back positive - has soared from one in 15 in the week ending July 15 to one in eight by August 12, according to the latest Centers for Disease Control and Prevention (CDC) data.

It means test positivity is at its highest level in more than a year. In several states, including Texas, Arkansas and Louisiana, one in six Covid swabs came back positive in the most recent week.

Because regular Americans are no longer testing en masse like they were at earlier points in the pandemic - just 40,000 swabs are being reported to the CDC each week - it has become more difficult to spot new outbreaks early.

But all metrics indicate infections are rising rapidly. Along with the rise in positivity, hospitalization rates for Covid patients have also risen for five weeks in a row - though they still remain near-historic lows.

The above graph shows the percent of positive Covid cases (tan line) and the weekly number of new Covid hospitalizations (blue bars)

Americans wear face masks as they wait in line to vote in the 2020 presidential election. Some colleges and businesses are reinstating mask mandates as Covid cases rise in the US

The rise in cases is thought to be driven by several factors, including the emergence of two highly transmissible variants, the waning of vaccine immunity and the beginning of the school year as more people gather in large groups and mingle, doctors told DailyMail.com.

Testing positivity rates are reported to the CDC by The National Respiratory and Enteric Virus Surveillance System (NREVSS), which receives its reported number of weekly tests from labs that have chosen to send their data to the surveillance system.

Dr Thomas Moore, an infectious disease physician, told DailyMail.com while the US is seeing a rise in cases, they are not severe like past variants

The data shows that positivity soared from 6.7 percent in the week ending July 15 to 12.2 percent in the week ending August 12.

The two new variants, EG.5, or Eris, and BA.X, or Pirola, have been detected in several countries around the globe and in the US recently.

These variants are highly mutated and thought to better at avoiding vaccine and natural immunity to cause infection.

Experts estimate Eris could account for as many as half of Covid infections, and two cases of Pirola were just recently detected last week in Michigan and in Virginia on Tuesday.

Dr Rajendram Rajnarayanan of the New York Institute of Technology campus in Jonesboro, Arkansas, told DailyMail.Com the clinical severity and symptoms of the variants remain largely unknown as the US is only selectively testing for variants in a small sample of positive tests in hospitals or airports.

But while more and more people contract Covid and employers may have to deal with the inconvenience of employees missing work, or students may have to make up school work, Eris and Pirola are not expected to cause a deadly wave like in the past.

The above chart shows Covid variants in the United States. It highlights how EG.5, an emerging variant, has grown rapidly across the country

The above graph shows the percent of positive Covid cases (tan line) and the weekly number of Covid deaths (blue bars)

Dr. Thomas Moore, an infectious disease physician in Wichita, Kansas, told DailyMail.com while the US is seeing a rise in cases, 'they are not severe like past variants', which put a strain on hospitals and healthcare systems.

The new strains are 'absolutely' spreading faster due to the very fact that 'variants emerge because they're more transmissible' and have evolved to be more contagious, Dr Moore explained.

However, he concurs with most experts in saying there are no signs the strains are more severe or dangerous.

He said symptoms of the strains could be similar to those of the common cold or the flu, but also cautioned while it is rare to die from the common cold or flu, Covid still has the potential to be deadly.

Lionsgate studios asks office staff to don face coverings and test again as Covid hospital rates rise for fifth week A major Hollywood studio has reintroduced Covid mask mandates amid fears about rising virus rates and a new highly mutated variant Advertisement

Former FDA commissioner Dr Scott Gottlieb said he was concerned about the rise in Covid cases, but there was no evidence the variants are deadlier than previous strains and he doesn't believe the variants are more likely to cause severe infections or more deaths.

'Certainly, at this point, it doesn't appear to be more pathogenic, so it doesn't appear to be more dangerous [than other variants]', Dr Gottlieb said.

Additionally, health experts have previously told DailyMail.com the emergence of the variants 'is not surprising' and said it was too early to panic.

They reassured despite increased transmissibility, the new variants were unlikely to reverse years of immunity gained throughout the more than three years of the pandemic.

From July 15 to August 12, hospitalizations rose from 7,175 to 12,613, though they still remain three times lower than this time last year.

Additionally, Dr Marc Elieson, a medical director at Baylor Scott and White Health in Texas, said earlier this week his colleagues are seeing Covid patients with less severe illness than at any point during the pandemic.

'What viruses and other organisms do over time [is] they become more contagious but have less power to kill and to hurt people,' he told FOX44.

Despite a rise in cases and hospitalizations, weekly deaths have dropped. In the week ending July 15, there were 484 deaths, compared to 251 deaths in the week ending Aug. 12.

Furthermore, CDC data shows just one percent of intensive care unit beds are occupied by Covid-19 patients and approximately 1.5 percent of all hospital beds are occupied by Covid patients, as well.

This could be because the variants do not produce more severe cases and more than 95 percent of Americans have some level of antibodies against Covid-19 due to vaccines, booster shots and previous infections, which most experts think is sufficient to keep future infections near cold- or flu-like symptoms.

The above map shows the percent positivity rate in each state over the past week. In several states, including Texas, Arkansas and Louisiana, one in six Covid swabs came back positive in the most recent week

While experts say the rising transmissibility isn't cause for alarm yet, their assurances haven't stopped calls for mitigation efforts and experts from recommending the public begin wearing masks again.

A college in Atlanta became the first institution to mandate masks for students and staff just days before classes began.

The new mandate will require students and staff to wear masks in hallways and lecture halls for at least two weeks amid the recent uptick.

Additionally, government physicians and public health officials in Seattle called for face coverings to once again be required in healthcare settings.

Most recently, Lionsgate, a film studio in Santa Monica, California, reintroduced mask mandates at its offices after several employees tested positive for Covid-19. The studio also encouraged its employees to test themselves before coming to work. Lionsgate said the rules for its nearly 5,000 employees would be in place 'until further notice'.