The Ebola virus disease (EVD) epidemic in West Africa was unprecedented. There were over 11,000 deaths and more than 26,000 infections. The outbreak left over 14,000 survivors with a myriad of health complications. To characterize the clinical sequelae in survivors and to assess whether they can transmit infection to household members and sexual contacts, the Partnership for Research on Ebola Virus in Liberia (PREVAIL) launched a cohort study of survivors and close contacts.
Following joint protocol development and IRB approval, enrollment of survivors > 12 year began in June 2015 followed by contacts and pediatric survivors <12yrs in August 2015. Participants are seen at baseline and every 6 months for 5 years at 3 sites in Liberia. Data collection includes demographics, detailed medical exam, labs including serology to determine the presence of antibodies specific to EVD, and for survivors, information about ETU course, treatment, and discharge. Examinations may also include detailed an ophthalmologic exam, a comprehensive neurologic assessment, collection of semen, lumbar punctures, and the enrollment of newborns and breast milk anal
Through December, 1022 survivors and 754 close contacts have been enrolled. The average age of survivors and close contacts is 30 and 27 years, respectively. For survivors, the median (IQR) time from EVD symptoms to enrollment is 352 days (307,395). A total of 76 individuals have had 1-4 semen samples obtained for PCR analysis. Overall 25% have been positive with 37% of subjects having at least 1 positive sample. The maximum amount of time between the onset of symptoms and a positive result was 488 days. 65% of survivors reported sexual activity without a condom since ETU discharge including 48% of those with a positive semen PCR for Ebola. EVD serology is in progress and has been completed for 527 survivors and 97 close contacts. 88% of survivors and 49% of close contacts had a positive EVD serology.
Preliminary findings indicate the prevalence of eye complications, musculoskeletal problems, and neurological findings are greater among EVD survivors than close contact controls. Most survivors report sexual contact and many do not use condoms. A surprising number of contacts have positive EVD serology, a finding now being confirmed with analysis of blood samples. Study findings have implications for EVD sexual transmission risk and indicate the importance of enrolling close contacts with EVD serology to use as controls.