Clinical, virologic, and immunologic follow-up of convalescent Ebola hemorrhagic fever patients and their household contacts, Kikwit, Democratic Republic of the Congo

A cohort of convalescent Ebola hemorrhagic fever (EHF) patients and their h ousehold contacts (HHCs) were studied prospectively to determine if convale scent body fluids contain Ebola virus and if secondary transmission occurs during convalescence. Twenty-nine EHF convalescents and 152 HHCs were monit ored for up to 21 months. Blood specimens were obtained and symptom informa tion was collected from convalescents and their HHCs; other body fluid spec imens were also obtained from convalescents. Arthralgias and myalgia were r eported significantly more often by convalescents than HHCs. Evidence of Eb ola virus was detected by reverse transcription-polymerase chain reaction i n semen specimens up to 91 days after disease onset; however, these and all other non-blood body fluids tested negative by virus isolation. Among 81 i nitially antibody negative HHCs, none became antibody positive. Blood speci mens of 5 HHCs not identified as EHF patients were initially antibody posit ive. No direct evidence of convalescent-to-HHC transmission of EHF was foun d, although the semen of convalescents may be infectious. The existence of initially antibody-positive HHCs suggests that mild cases of Ebola virus in fection occurred and that the full extent of the EHF epidemic was probably underestimated.