Today, the tests for Ebola virus cannot identify the disease after the person shows symptoms. Thus, a potential infected person has to wait to see if he or she is infected with Ebola virus. Current tests for Ebola look for the virus in the blood. But Ebola virus first infect the internal organs, so blood tests cannot detect it until it spreads to the bloodstream, which takes time. It takes between 2 to 21 days before a person infected with Ebola virus shows symptoms.
A new study at Boston University School of Medicine has found potential early markers of diseases similar to Ebola. It suggests that it may be possible to tests for Ebola virus much earlier than the current treatment methods.
The researchers of the study infected monkeys with Marburg virus or Lassa virus, which is similar to Ebola virus. Both Marburg and Lassa, like Ebola, can cause hemorrhagic fevers – fevers accompanied by damage to the blood vessels. These viruses can result to bleeding.
Unlike other research studies, the researchers checked for clues that the immune cells of the body were responding to the virus in order to find early signs of infection. Other research studies focus on search of the viruses themselves. The researchers looked for specific patterns of gene expression to find early signs of infection.
Researchers found gene expression “signatures” distinct enough to distinguish Lassa virus infection, before the monkeys showed any symptom of either disease.
According to John Connor, associate professor of microbiology at Boston University School of Medicine, there are very early and distinct ways that the immune system is responding to different diseases, which is an important method of trying to find people that are infected with the disease even before they show evident symptoms.
Connor added that the findings are preliminary and additional work is needed to see if this method is applicable into practical tests for use in people. Furthermore, additional studies are needed to look for gene expression signatures of immune cells that are reacting specifically to an Ebola infection.
A challenge in developing a screening test for Lassa, Marburg or Ebola is that it needs to be very specific. This means that the tests need to have a low number of false positives.
Connor stated that the diagnoses for these viruses must be accurate. If a person is infected with one of these viruses, then there are consequences such as being quarantined.