A mosquito-borne virus that prompted Brazil to declare a state of emergency may cause an unusual and embarrassing new symptom, scientists say.
Dengue fever — which is typically associated with fevers, rashes and internal bleeding — has now been linked to spontaneous erections that last hours.
Doctors in Burkina Faso, West Africa, floated the theory after treating a 17-year-old boy who was in the emergency department with a severe dengue infection.
The youngster had acute ischemia — where blood flow to part of the body is interrupted — and kidney problems due to his infection.
But doctors also noted he was suffering from a ‘soft… persistent’ erection which lasted for 18 hours and had occurred ‘without any sexual stimulation’.
Rio de Janeiro declared a state of emergency amid surging dengue fever cases as millions of tourists prepared to arrive in Brazil for the city’s famous carnival. Pictured: A health worker fumigates against mosquitos in Brazil, February 2
A patient is transferred to a hospital after receiving medical care at an improvised military aid station set up to treat suspected cases of dengue fever in Brazil, February 6
The above map shows states in the US that have reported locally-acquired dengue infections between 2010 and 2023
They believe this may have been caused by the virus infecting blood vessels in the penis and causing plasma to leak fluid into the shaft, making the penis appear larger and firmer than its flaccid state.
Writing in the journal Urology Case Reports, the doctors said: ‘Dengue, by causing vascular leaks, could be a rare trigger for arterial priapism [spontaneous erections].’
US-based scientists told DailyMail.com that it was certainly ‘possible’ dengue could cause spontaneous erections, pointing out that Covid, mumps and even rabies have been linked to the symptom previously.
But they said it is probably an extremely rare complication.
It comes as Florida has reported two cases of dengue fever caught locally so far this year. It has also reported five cases in residents who had recently traveled outside the state. Last year, doctors issued an alert after a rise in the infection.
There is also a major outbreak in Brazil with 340,000 cases reported — four times more than the same time last year.
The country is erecting emergency clinics to deal with the surge of patients, and says 40 deaths from dengue have been confirmed so far.
For the case in Burkina Faso, doctor’s treated the boy’s erection using an ice pack — which caused blood vessels to constrict which reduced the amount of fluid in the penis.
The patient also had no medical history or underlying conditions — such as sickle cell disease, which has previously been linked to spontaneous erections.
He was treated for the infection using antiviral medicines and at a three-month and six-month follow up, was healthy and back to normal.
Doctors said he had no complaints and was able to achieve a normal erection without pain or issues.
Outbreaks of dengue were previously rare in the US, but warming temperatures are making the viral infection more common — as mosquitoes advance further north.
About 1,000 Americans are now infected with dengue fever every year, a ten-fold increase since 2019 when barely 100 infections a year were recorded.
The number of dengue cases per year are currently at their highest level since 2013, after a major outbreak in southern Texas.
Florida is the only state to report dengue cases so far this year in the US, although the infectiosn are becoming more common
About 1,000 people are being infected with dengue every year in the US at present, 10-fold more than before the pandemic. Case numbers are still lower than in 2013, however, when an outbreak in Texas led to nearly 10,000 cases being detected
Dengue fever is spread by mosquitoes, with the virus infecting blood vessels
Erections are normally triggered by blood vessels in the penis dilating, causing fluids to flow into the erectile tissue called the corpus cavernosum.
Dr Richard Murphy, who advised Doctors Without Borders in Africa for seven years, said it was possible that dengue could cause spontaneous erections — or priapism.
‘Viruses have been linked with priapism in the past including Covid, mumps and even rabies,’ he told this website.
‘So, it is possible that other viruses are associated with it.’
He suggested if this symptom was proven it was likely extremely rare because so many infections with dengue fever have previously been recorded.
Dengue fever is spread via the bites of mosquitoes, which inject the virus into humans when they suck on someone’s blood.
Most patients have no symptoms, but just under half will develop warning signs of the disease including a sudden headache, fever and pain behind the eyes.
It can also trigger pain in the joints — such as knees and elbows — that is so severe they feel like they are being shattered, earning it the nickname ‘breakbone fever’.
In severe cases, the disease leads to life-threatening complications such as dengue shock syndrome — characterized by severe bleeding — and encephalitis, or swelling of the brain.
Doctors treat patients using a combination of pain medications, fluids and machines to monitor the illness.
But this is labor intensive, often leading to hospitals having little bandwidth to handle other patients.
There is also a vaccine available for the disease, called Qdenga, which is recommended for children aged six to 16 years old in areas where the disease is endemic.