A new study found that 25 percent of people infected with Ebola in a Sierra Leone village were asymptomatic, or didn't show symptoms of having the virus. The discovery suggests that the transmission of the virus is broader and more easily done than previously thought.
The study was conducted by scientists from the Stanford University School of Medicine with specialists from other institutions. Using enzyme-linked immunosorbent assays, the researchers measured the concentration of Ebola virus antibodies among adults in the village of Sukudu, where there were 34 reported cases, including 28 deaths. They were able to identify 14 people who had contracted the virus but did not show signs of illness.
Ebola Infection Without Symptoms
For the study, the researchers tested 187 males and females from different age groups who had shared a home or a toilet with the 34 people who were diagnosed with Ebola. Of those who had been exposed to the virus, 14 had Ebola virus antibodies, which meant that they had been infected at one time.
However, 12 of them said they did not remember having had any type of symptom associated with the disease during the outbreak in the village. The remaining two recalled having had a fever.
The research shows that it is entirely possible for anyone infected during the four-year Ebola outbreak in Africa to not have had any symptoms at all.
Possible Ebola Contamination From Patients With No Symptoms
The research is all the more baffling to the scientists, as the symptoms that people who contract the virus usually experience are severe, from fever to symptoms similar to cholera, such as diarrhea and violent vomiting. The death rate among patients was correlated to a series of medical care conditions, among which are fluid and electrolyte replacement.
The immediate research focus will fall on identifying if people who don't have any manifestations of the symptoms, but are infected with the virus, can pass it on to other people, regardless of the lack of effects it has on them. The starting point of this research will most likely be the sexual partners of males who were found not to experience symptoms, as the virus can remain in semen months after the infection.
However, this hypothesis is yet to be confirmed. As more undocumented survivors of the disease will be found, the research methods and results will be more conclusive, allowing the medical teams to have a better understanding of the ways of this virus.
The study was presented at the annual meeting of the American Society of Tropical Medicine and Hygiene on Nov. 14 and published in PLOS Neglected Tropical Diseases on Nov. 15.