Ebola Situation Report

1 SUMMARY  Since the week ending 10 May, when a 10-month low of 9 cases of Ebola virus disease (EVD) were reported from 2 prefectures of Guinea and 1 district of Sierra Leone, both the intensity and geographical area of EVD transmission have increased. In the week ending 31 May, a total of 25 confirmed cases were reported from 4 prefectures of Guinea and 3 districts of Sierra Leone. Several cases in both Guinea and Sierra Leone arose from unknown sources of infection in areas that have not reported confirmed cases for several weeks, indicating that chains of transmission continue to go undetected. Rigorous contact tracing, active case finding, and infection prevention and control must be maintained at current intensive levels in order to uncover and break every chain of transmission. However, the onset of the rainy season will make field operations more difficult from now onwards.  A total of 13 cases were reported from 4 western prefectures of Guinea in the week to 31 May. Most cases (7) were reported from the prefecture of Forecariah, which borders Sierra Leone. Multiple chains of transmission gave rise to cases in 4 of Forecariah’s 10 sub-prefectures, although all cases were either registered contacts of a previous case or had an established epidemiological link to one. The remaining cases were reported from the north-western prefecture of Boke (1 case), which borders Guinea-Bissau; the west-coast prefecture of Dubreka (4 cases), which borders the capital, Conakry; and the western inland prefecture of Fria (1 case).  Community engagement has proved challenging in all 4 affected prefectures of Guinea, with several reported incidents of violence directed at field staff during the past week. In addition, 4 of the 13 nationally reported cases were identified only after post-mortem testing of community deaths. Of those 4 community deaths, 2 were registered contacts, suggesting that even when contacts can be traced, regular monitoring to ensure they receive prompt testing and treatment as soon as symptoms arise remains a challenge.  Sierra Leone reported a total of 12 cases from 3 districts in the week to 31 May. The majority of cases (8) were reported from a densely populated area of the Kaffu Bullom chiefdom in the district of Port Loko, just north of the capital, Freetown. All but one of the cases were registered contacts of previous cases within quarantined houses in the chiefdom. The additional case is from the same neighbourhood but was not on a contact list and was living in a non-quarantined home at the time of symptom onset. The district of Kambia reported its first case for over 2 weeks on 31 May. The case was identified after a post-mortem test of a community death and was not a known contact of a previous case. The remaining 3 cases were reported from the capital, Freetown. At this time, none of those 3 cases can be linked to previous chains of transmission, although investigations are at an early stage.  As at 31 May, a total of 1880 contacts associated with reported confirmed cases were under follow-up in 6 Guinean prefectures: Boke, Conakry, Dubreka, Forecariah, Fria, and Kindia. A total of 461 contacts were under follow-up in 3 districts of Sierra Leone: Kambia, Port Loko, and Western Area Urban (the area that includes the capital, Freetown).  Two response teams from Guinea-Bissau have been deployed to the border with Guinea to assess several points of entry and sensitize communities.  The last health worker infections in Guinea and Sierra Leone were reported on 6 April and 14 May, respectively. There have been a total of 869 confirmed health worker infections reported from Guinea, Liberia, and Sierra Leone since the start of the outbreak, with 507 reported deaths. EBOLA SITUATION REPOR