It starts with a fever, similar to a bad cold or flu. Within a day or two, a headache appears, along with excruciating pain in the hands and feet.
Within the next 24 hours, you may notice the pain spreading down your arm, which soon becomes numb.
This is the disturbing array of symptoms suffered by victims of the debilitating “sloth fever” virus, which has been detected in 19 people in Europe over the past two months, according to the European Centre for Disease Prevention and Control (ECDC).
Experts have sounded the alarm over the potentially deadly disease, which originated in sloths, warning that the spread could become “unstoppable” in the absence of vaccines.
MailOnline can now reveal three disturbing cases of the infection, which is spread by insect bites, in three Italian patients, as documented by the doctors who treated them.
There is no vaccine against the disease, which originates in pale-throated sloths, non-human primates and birds.
So far, five cases have been reported in Italy, two in Germany and 12 in Spain.
Outside Europe, 8,000 cases have been documented worldwide since January, mainly in South and Central America, where the virus is most common.
While experts say the virus is unlikely to take hold in countries with colder climates such as Britain, it could become a problem for those travelling abroad.
“Climate change has led to infected insects being detected as far away as the south of France, where many Britons spend their holidays,” said Dr Danny Altmann, professor of immunology at Imperial College.
‘Simply put, people travel abroad, catch the virus and bring it back.
‘The virus is a cause for concern for people living in the U.S., as infected mosquitoes have reached the San Francisco region and could spread further.’
The first European case was detailed by doctors at the Sacro Cuore hospital in Calabria, southern Italy.
The patient, a 45-year-old man, had recently traveled to the tropical Caribbean region, near the South American nations where most cases originate.
The pattern of spots on the insect’s wings is characteristic of mosquitoes that transmit sloth virus. Photo: IOC Ceratopogonidae Collection/Fiocruzi
This includes Brazil, Bolivia, Peru, Colombia and Cuba.
The man was suffering from flu-like symptoms, including high fever, headache, muscle and joint pain, Italian doctors said. reported.
After conducting further tests to rule out underlying diseases, doctors tested for the “sloth virus,” medically known as Oropouche, using specialized blood tests.
The patient is said to be under close medical surveillance, but his condition is “stable.”
Another case involved a “traveler” in his twenties who had recently returned from a two-week trip to Cuba; doctors did not specify the patient’s gender.
During the flight back to Italy, the patient developed a high fever, as well as “severe headache, nausea and diarrhea.”
The next day, the patient began to experience severe pain behind the eyes, as well as severe stiffness in the joints.
The patient was tested for other similar viruses, such as dengue and Zika, and the results were negative. Blood tests for Oropouche were positive and the patient is currently being monitored.
A third patient, aged around 50, had a history of high blood pressure, asthma and obesity and travelled to Cuba in May.
Two days after returning in early June, the patient developed fever, as well as pain behind the eyes and nausea.
The symptoms had become so severe within three days that they visited the emergency room at the hospital in Forlì, in the Emilia-Romagna region of northern Italy.
When doctors examined the patient, they noticed that his left arm was slightly numb and round and red spots had appeared on the surface of his skin.
After tests for other viruses came back negative, blood samples tested positive for Oropouche.
Doctors observed no damage to internal organs and all symptoms, except numbness in the arm, disappeared within two weeks.
Doctors noted that the virus has an incubation period of three to ten days, after which symptoms appear. They added that the fever is usually “acute” for two to four days before subsiding and then reappears seven to ten days later.
In severe cases, the disease can lead to meningitis, according to the NHS Travax website.
Although it is potentially fatal, the ECDC said fatal outcomes are extremely rare and recovery from the disease is common, usually within a week.
According to a report in the Lancet journal, two deaths caused by Oropouche were reported for the first time in Brazil on July 25 in two young women who had no other underlying health conditions.
The European authority recommends that those travelling to affected areas, such as Brazil, Cuba, Peru and Colombia, use insect repellent and wear long-sleeved shirts and long trousers to reduce the risk of bites.
The strain behind the recent outbreak was first detected in the small town of Oropouche in Trinidad and Tobago in 1955.
Five years later, during the construction of the Belém-Brasilia highway, a sloth was found carrying Oropouche.
Within a year, people in the area became sick with the virus and there have since been about 30 outbreaks, all centered in the Amazon basin.
The virus spreads in the jungle among sloths, birds and primates through infected mosquitoes.
These insects are believed to circulate in urban environments, where they can also infect humans.
The rise in human cases is thought to be due to a number of factors, including deforestation, which displaces animals such as sloths, and higher temperatures that cause mosquitoes to fly farther.