New discovery about the virus that causes 25-90% of infected people to die

The findings were published in the journal Science Translational Medicine on February 8. This work is appreciated in providing an important warning about the long-term effects of the mysterious virus strain on humanity - Ebola. It is a life-threatening disease with frequent outbreaks and occurs mainly in Africa, with an average mortality rate of 50%.

Ebola virus hides in the brain and causes persistent disease

According to the Independent, some scientists have previously found persistent Ebola infections. However, the exact 'hiding place' of this deadly virus and the mechanism that causes the disease to recur is still unknown.

Work from a team of experts from the US Army's Institute of Infectious Diseases (USAMRIID) has gradually decoded this mystery. They found that Ebola is not an easy disease to completely cure and all patients are at risk of relapse, especially the group that has been treated with monoclonal antibodies.

In the new study, the scientists used a disease model in monkeys that showed signs of Ebola infection similar to humans. Results showed that two monkeys who recovered from Ebola after being treated with antibodies had relapsed and were unable to fight off the virus.

Inflammation and a very large Ebola viral load were present in the left cerebral system without obvious disease. Other organs are also showing signs of being attacked by the virus.

Ebola was found hiding in the brain, semen, and vitreous of patients even though they were cured.

'We found that about 20% of monkeys who recovered from monoclonal antibody therapy still had persistent Ebola infections, particularly in the left brain, where the cerebrospinal fluid is produced' - Professor Xiankun (Kevin) Zeng, lead author of the study, said.

The expert also emphasized that their study is the first to reveal the hiding place of the 'hibernating' Ebola virus, which is the brain. In addition, these viruses cause a fatal second infection in non-human primates.

Ebola virus disease is the deadliest infectious disease facing humans. Its mortality rate ranges from 25% to 90%, averaging 50% in previous outbreaks.

Risk of re-infection with Ebola

Ebola remains a major threat to Africa after three outbreaks in 2021. This virus is transmitted from person to wildlife and has spread between people through contact with infected blood and bodily fluids.

Many previous reports have also shown Ebola re-emergence in people who have recovered from the disease. Typically, a case that was vaccinated and treated with antibodies also relapsed and died during the 2018-2020 outbreak in the Democratic Republic of Congo.

According to the Guardian, experts say this is additional evidence for the thesis that the Ebola virus can hide in the body for a long time after the infected person recovers. Therefore, survivors need to be monitored to protect their health and prevent infection in the long run.

The 25-year-old (unidentified) man, a resident of the Democratic Republic of Congo, relapsed with Ebola despite receiving a preventive vaccine. He first contracted Ebola in December 2018. He was discharged from the hospital after testing negative for Ebola twice. In November 2019, the patient reappeared with symptoms and was diagnosed with Ebola again.

The virus can persist in semen for more than a year, so men are advised to get tested periodically even after recovering from the disease. In August 2019, the 25-year-old man had a semen test and it was negative, however, he did not return for a routine check-up.

Virologist Michael Wiley, of the Nebraska Medical Center, Congo, said the person's immunity was lost after six months or worse, he had never been immune to the disease.

Genetic tests found that the strain of Ebola virus that sickened the man was almost 100% similar to the strain he was first infected with. After re-infection, the male patient infected 29 other people and formed a cluster of up to 91 related cases.

Health workers wearing protective gear work at an Ebola treatment center in Beni, eastern Congo.

Another case was a British nurse who recovered from Ebola after receiving monoclonal antibody therapy during the 2013-2016 outbreak in West Africa. After that, the female patient relapsed with the virus appearing in her brain, causing her to have severe neurological disorders continuously for 9 months.

In early March 2021, scientists have recorded that the Ebola virus silently lives in the body of a patient for up to 5 years, after which it infects others. This is the longest time the virus has been hiding in the body that the world literature has ever recorded.

With the available data, experts are more certain that the Ebola virus can hide for years in specific areas of the body such as the vitreous chamber of the eye, the semicircular canal of the testes, the brain system. left. Even when treatments are confirmed to have cleared the virus from these organs, they still have a way to 'bypass'.

Study co-author Professor Jun Liu added: 'Persistent Ebola virus can reactivate and cause disease relapse in survivors. This is likely to cause a new outbreak."

The findings highlight the need for long-term follow-up of Ebola virus survivors, including those treated with antibodies, to prevent recurrence.