Americans are being warned about a potentially deadly virus spread by mosquito bites that is surging across the US. 

Health officials say soaring temperatures across the country mean infections are only set to increase, and Americans should take steps to protect themselves from bites — which can kill within a week. 

A 'higher-than-expected' number of dengue fever infections have been recorded in the US so far this year, according to the CDC — 1,0000 more than in the whole of 2023.

More than 5,300 people have been killed by the infection across the world, mostly in tourist hotspots like Brazil, Mexico and Costa Rica, although officials warn US-borne cases are also on the rise.  

The CDC warned last week that many infections — which have been spotted across 38 states — were linked to travelers returning to the US from countries where the disease is spreading rapidly.

However, at least eight local cases have been detected within the states. 

In Florida, there are about 200 cases, including at least six locally transmitted, in people who have not recently traveled.

Puerto Rico is currently experiencing an outbreak, recording around 1,500 infections, with an emergency declared in the US territory back in March.

Massachusetts and New York are also experiencing some of the highest case numbers across the country, 50 and 134, respectively.  

Dengue fever cannot be passed from human-to-human. It is transmitted via bites from infected mosquitoes, which transfer the virus into a person's blood stream.

For someone to catch the disease locally, the area's mosquito population has to have picked up the virus — normally via biting an infected person who recently returned to the US from abroad.

It could also be the case that infected mosquitoes have migrated into the area or arrived on boats or airplanes. 

While you can be tested to see if you've contracted dengue fever, there is no known treatment and doctors can only 'support' patients, prescribing medications that manage symptoms. 

About one-in-four people who are infected with dengue fever will show symptoms. These include pain in and around the eyes, muscle aches and joint pain, nausea and vomiting and a rash. 

Symptoms typically occur two weeks after being bitten by an infected mosquito and can last anywhere from two to seven days.

In the United States, there is a dengue vaccine recommended for use in children between nine and 16 years old who have had a previous dengue infection if they are living in an area of the country where dengue is more common.

If a patient's case progresses into severe dengue fever, which can occur in a matter of hours, it is considered a medical emergency and they should be hospitalized. 

In severe cases, people can experience uncontrolled bleeding, dangerously low blood pressure, organ failure and death, according to the CDC.

About one-in-20 people infected with the virus will develop severe dengue, which includes additional symptoms of abdominal pain, vomiting blood or blood in the stool and feeling extremely tired or restless. 

According to the NIH, without proper treatment, fatality rates of severe dengue could exceed 20 percent, especially among vulnerable populations like children.  

Of dengue cases recorded in the US this year, 745 have been in travelers — those who tested positive after recently returning from abroad — which was 'higher-than-expected' for this time of year. 

Dengue fever is endemic in many countries across the world, with countries in South America, Asia and Africa tending to report a higher number of cases. 

The CDC did not say which countries people were returning from, but so far this year Brazil has had the largest outbreak — with 7.8million suspected dengue cases.

Large outbreaks have also been recorded in Argentina — with 505,000 cases — and Paraguay — with 282,000 — with other cases reported among 90 countries across six continents.

Experts attribute the rise in dengue across the globe to warming temperatures, increasingly severe storms that bring large amounts of rain and flooding and more international travel. 

Dr Marty Makary, a doctor at Johns Hopkins University in Maryland, told Fox because the illness is spread through mosquito bites, people should do what they can to reduce exposure and risk of bites.

This can include wearing loose-fitting long-sleeved shirts and pants or clothing treated with insecticides, using mosquito control inside and outside your house and applying bug spray. 

Mosquito populations flourish in standing water, so it is important to prevent and control any areas that could serve as a breeding ground for the bugs.  

Dr Makary added mosquito protection was especially important in southern states where temperatures are warmer. 

He said: 'It is spread by mosquitos and that's a good reminder to try to do what you can to reduce mosquito bites especially in the southern United States where this is more common.' 

The rise in dengue comes at the same time officials are also concerned of two other mosquito-borne illnesses: malaria and West Nile virus. 

The Florida Department of Health issued a 'mosquito-borne illnesses advisory last week' after four cases of locally acquired malaria were diagnosed in an area along the state's western coast. All individuals have been treated and recovered.

Like dengue, malaria is often contracted abroad and the US reports about 2,000 cases a year. 

Symptoms include fever, flu-like illness, muscle aches, vomiting and diarrhea and the chills. If not treated quickly, it can lead to kidney failure, seizures and a coma. 

Another mosquito-borne illness health experts caution of is West Nile virus, which is the most common in the US, with an average of 2,200 cases per year. 

About 20 percent of those infected will exhibit symptoms, which include a fever and flu-like illness. Less than one percent will progress to a severe infection of West Nile neuroinvasive disease, which can be deadly.