Clinical Illness, Outcomes for Ebola in Sierra Leone Reviewed
Incubation period six to 12 days, case fatality rate 74 percent; similar to other findings from 2014 outbreak
WEDNESDAY, Oct. 29, 2014 (HealthDay News) -- For patients with Ebola virus disease (EVD) from Sierra Leone, the incubation period for is six to 12 days and case fatality 74 percent, according to a study published online Oct. 29 in the New England Journal of Medicine.
John S. Schieffelin, M.D., from Tulane University in New Orleans, and colleagues reviewed records from patients diagnosed with EVD from May 25 to June 18, 2014, in Sierra Leone. In a subgroup of patients, Ebola virus load (EBOV) was assessed using quantitative reverse-transcriptase polymerase chain reaction. Data were available for 107 patients diagnosed with EVD; outcome was known for 87 and detailed clinical information was available for 44.
The researchers found that the estimated incubation period was six to 12 days, and there was a 74 percent case fatality rate. Fever; weakness; dizziness; diarrhea; and elevated levels of blood urea nitrogen, aspartate aminotransferase, and creatinine at presentation correlated with fatal outcome. A lower case fatality rate was seen for patients younger than 21 versus older than 45 years (57 versus 94 percent; P = 003). The case fatality rate was also lower for patients presenting with <100,000 EBOV copies/milliliter versus ≥100,000 EBOV copies/milliliter (33 versus 94 percent; P = 0.003).
"The incubation period and case fatality rate among patients with EVD in Sierra Leone are similar to those observed elsewhere in the 2014 outbreak and in previous outbreaks," the authors write.