Ebola hemorrhagic fever, Kikwit, Democratic Republic of the Congo, 1995: Risk factors for patients without a reported exposure

In 1995, 316 people became ill with Ebola hemorrhagic fever (EHF) in Kikwit , Democratic Republic of the Congo. The exposure source was not reported fo r 55 patients (17%) at the start of this investigation, and it remained unk nown for 12 patients after extensive epidemiologic evaluation. Both admissi on to a hospital and visiting a person with fever and bleeding were risk fa ctors associated with infection. Nineteen patients appeared to have been ex posed while visiting someone with suspected EHF, although the!: did not pro vide care. Fourteen of the 19 reported touching the patient with suspected EHF; 5 reported that they had no physical contact. Although close contact w hile caring for an infected person was probably the major route of transmis sion in this and previous EHF outbreaks, the virus may have been transmitte d by touch, droplet, airborne particle, or fomite; thus, expansion of the u se of barrier techniques to include casual contacts might prevent or mitiga te future epidemics.