SUMMARY
There were 20 confirmed cases of Ebola virus disease (EVD) reported in the week to 21 June, compared with 24 cases the previous week. Weekly case incidence has stalled at between 20 and 27 cases since the end of May, whilst cases continue to arise from unknown sources of infection, and to be detected only after post-mortem testing of community deaths. In Guinea, 12 cases were reported from the same 4 prefectures as reported cases in the previous week: Boke, Conakry, Dubreka, and Forecariah. In Sierra Leone, 8 cases were reported from 3 districts: Kambia, Port Loko, and the district that includes the capital, Freetown, which reported confirmed cases for the first time in over 2 weeks. Although cases have been reported from the same 4 prefectures in Guinea for the past 3 weeks, the area of active transmission within those prefectures has changed, and in several instances has expanded.
In the northern prefecture of Boke, which borders Guinea-Bissau, the main focus of transmission has switched from the coastal sub-prefecture of Kamsar to the more urbanised sub-prefecture of Boke Centre. Of particular concern, 2 of the cases reported from Boke in the week to 21 June were health workers.
The single case reported this week from Conakry was from the Matam area of the city, and arose from an unknown source of infection. Three cases reported over the previous 2 weeks in Conakry are suspected to have generated a large number of high-risk, untraced contacts. As has been the case for several months, the prefecture of Forecariah continues to be the most complex in terms of transmission, with multiple chains of transmission active across 3 sub-prefectures. Three of the 5 cases reported from Forecariah in the week to 21 June arose from an unknown chain or chains of transmission, and 2 of those 3 cases were reported from a sub-prefecture, Benty, that has not reported a confirmed case since mid-March. Both cases from Benty and another possibly related case from a neighbouring sub-prefecture were identified after the post-mortem testing of community deaths. Compared with Guinea, transmission in Sierra Leone has been more geographically confined over the past 3 weeks, with cases clustered in several chiefdoms of Kambia and Port Loko districts. However, the week to 21 June saw 2 cases reported from Marampa chiefdom in Port Loko for the first time since the beginning of March. The cases were a mother who died during childbirth, and her newly born child, and are associated with a large number of high-risk contacts. Two cases were also reported from the area that includes the capital, Freetown, for the first time in over 2 weeks. Both cases arose in the densely populated Magazine Wharf area of the city, and although one case has an epidemiological link to a previous case, both cases are associated with multiple high-risk contacts.
Only 6 of the 12 cases reported from Guinea and 4 of the 8 cases reported from Sierra Leone in the week to 21 June were registered contacts of previous cases. Four of the 20 cases reported were identified after post-mortem testing of community deaths. On 21 June there were 2003 contacts being monitored across 4 prefectures in Guinea, with 1023 contacts were under follow-up in 3 districts in Sierra Leone. After over 2 months with no new health worker infections in Guinea, 2 new health worker infections were reported from Boke. In Sierra Leone a new health worker infection was reported for the first time since 14 May. There have been a total of 872 confirmed health worker infections reported from Guinea, Liberia, and Sierra Leone since the start of the outbreak, with 507 reported deaths.