EbolaSeveral experts have been looking into the question as to why some people survive Ebola and others don’t. A study published last month based on the analysis of the first Ebola cases in Sierra Leone seems to provide some answers. The factors identified by this study are as follows:

  • Pace at which the virus replicates within the body: Symptoms appear only after enough of the virus is produced. In the cases studied, the incubation period after which the patients developed symptoms was six to 12 days, and 74 percent of the patients in the study died
  • Age: The study showed that of the people who were treated for Ebola and died from the disease, 57 percent under age 21 and 94 percent were over the age of 45
  • Severity: Those who were severely affected deteriorated more rapidly than mild cases
  • Difference in the amount of virus present in patients when they came in for treatment: 33 percent of those with less than 100,000 copies of the virus per milliliter of blood at diagnosis died compared with 94 percent mortality in patients who had more than 10 million copies per milliliter

Another study published earlier this year said that people with a strong immune system that can stand up to the initial attack are more likely to survive the disease. According to another report, while developing immunity is crucial, natural resistance to disease symptoms is also vital to a patient’s chances of recovery from this dangerous viral infection. These researchers say that a drug that targets the genes would be useful as though it may not cure an Ebola patient, but it might give them a greater chance of building up resistance and gaining time to fight infection while the body develops immunity.

The Sierra Leone study which was published in the New England Journal of Medicine also confirmed the typical symptoms of Ebola. Among 89 percent of patients, fever was the most common symptom, followed by headache (80 percent), weakness (66 percent), dizziness (60 percent) diarrhea (51 percent), abdominal pain (40 percent) and vomiting (34 percent). Diarrhea was referred to as a “really big feature of it”, which pointed to the importance of administering intravenous fluids in Ebola patients.

According to the Reuters report on this study, the research team analyzed detailed data relating to 44 Ebola patients, the biggest collection of clinical records of those infected since the disease broke out in West Africa. Most of the findings are consistent with the observations made by doctors treating Ebola patients.

The lead author hopes that such studies on Ebola will provide valuable information for healthcare workers involved in the fight against this disease as well as data that can be used to determine new treatment and develop infectious disease tests.