Secondary Infections with Ebola Virus in Rural Communities, Liberia and Guinea, 2014–2015

Abstract

Persons who died of Ebola virus disease at home in rural communities in Liberia and Guinea resulted in more secondary infections than persons admitted to Ebola treatment units. Intensified monitoring of contacts of persons who died of this disease in the community is an evidence-based approach to reduce virus transmission in rural communities.

Variability in Intrahousehold Transmission of Ebola Virus, and Estimation of the Household Secondary Attack Rate

“…Some misclassification is likely and our method may have contributed to the association with severity of illness in the individual-level analysis, but not to the associations with severity of illness in the household analysis or to the higher transmission from those who died away from the home than from those who survived. This last finding, which is in contrast to findings in Liberia and Guinea [ 7 ], may be explained by higher viral loads while at home in those who subsequently died. The association of transmission with severity of illness underscores the importance of early identification and isolation of cases.…”

“…Studies of risk factors for Ebola virus disease (EVD) have focused on the exposure (infection is most likely following contact with dead bodies and bodily fluids [ 3–5 ]) and on the characteristics of the person exposed, with lower attack rates in children than adults [ 4 , 6 ]. Less emphasis has been given to the characteristics of the source cases (other than the severity of disease that they had [ 7 ]) or of the households that may be associated with onward transmission, although behavioral and environmental factors are likely to influence exposure patterns [ 8 ]. A study of 27 households in Kikwit, Democratic Republic of Congo (DRC), in 1995 found no association between household characteristics and secondary attack rates [ 5 ].…”

“…Little is known about who transmits (except for a small number of reconstructed transmission chains; see, eg, [ 1 , 2 , 7 ]). In Yambuku, DRC, in 1976, the secondary attack rate was higher in closer relatives and from female source cases [ 9 ].…”

Household Transmission of Ebola Virus: Risks and Preventive Factors, Freetown, Sierra Leone, 2015

“…All contacts were quarantined and unable to participate in corpse preparation for burial. Dying in the house was associated with secondary infection in rural Liberia and Guinea, and it was postulated that traditional practices of touching the body after death may have contributed to transmission [21]. Very few contacts in our study reported touching a deceased patient and none helped to prepare the corpse for burial; thus, in our primarily urban setting in Sierra Leone this factor appears unlikely to have played a major role in transmission.…”

The factors affecting household transmission dynamics and community compliance with Ebola control measures: a mixed-methods study in a rural village in Sierra Leone

“…The transmission dynamics of the West Africa EVD epidemic have, so far, been reconstructed from EMC and surveillance data, and mathematical modelling [ 4 , 10 – 12 ]. However, poor surveillance systems and limited EMC capacities are likely to have resulted in underestimation of the true extent of the outbreak, limiting the ability to understand the dynamics and experience of the epidemic at community level, in particular in Sierra Leone, the country most affected by the West Africa EVD outbreak [ 13 , 14 ].…”