Ebola Situation Report - 5 August 2015

Total confirmed cases (by week, 2015)

 

 
 
 
 

SUMMARY

  • There were 2 confirmed cases of Ebola virus disease (EVD) reported in the week to 2 August: 1 in Guinea and 1 in Sierra Leone. This is the lowest weekly total to have been reported since March 2014, and marks a third consecutive decline in weekly case incidence. This decline is underpinned by continued refinements to all elements of the response. In particular, strengthened capacity for contact tracing and case investigation has increased confidence that the few remaining known chains of transmission are better understood and controlled than was the case several months ago. Maintaining these resources in the months ahead will be critical, as there remains a significant risk of further transmission and an increase in case incidence in the near and medium term. Almost 2000 contacts remain under observation across 5 prefectures in Guinea and 4 districts in Sierra Leone, and despite intensive efforts a small number of contacts in both countries have not been traced or have been lost to follow-up. In addition, recent high-risk transmission events in Guinea and Sierra Leone are very likely to result in further cases in the coming weeks.
  • Illustrating the continuing challenges, the single case reported from Guinea is a contact who was lost to follow-up, and who is likely to have generated a substantial number of further high-risk contacts. The case, a 28-year-old woman, is a registered contact associated with a known chain of transmission that has given rise to several generations of cases in the Ratoma area of the capital, Conakry, over the past several weeks. After being lost to follow-up the case travelled south from Conakry through Forecariah and into Kambia, Sierra Leone, where she reportedly visited a traditional healer, before returning to Ratoma via Forecariah. Intensive efforts are underway to identify and trace all contacts in Guinea and Sierra Leone. 1080 contacts remain under follow-up in 5 western prefectures in Guinea, with the vast majority (>90%) of contacts located in Conakry and Forecariah.
  • An interim analysis of the Ebola ça suffit! ring vaccination trial in Guinea suggests that the investigational rVSV-ZEBOV Ebola vaccine protects people exposed to EVD. The trial will continue in Guinea, with all rings around confirmed cases now receiving immediate vaccination. Previously, rings were randomly allocated to receive either immediate vaccination or vaccination 21 days after the confirmation of a case.
  • No new cases were reported from Liberia in the week to 2 August. All contacts have now completed their 21-day follow-up period. The last case was discharged after testing negative for EVD for a second time on 23 July.
  • In Sierra Leone, the case reported this week is one of over 600 contacts generated by the single case reported in Tonkolili the previous week (the index case). The new case is a family member who provided care to the index case. Over 40 contacts are considered to be at high risk of infection because of the nature of their contact with the index case, and there is a high probability that further cases will arise. Investigations into the source of infection of the index case, who is thought to have acquired infection in Freetown before traveling to Tonkolili, are still ongoing. Across the country a total of 811 contacts remain under follow-up, with the vast majority located in Tonkolili. All contacts associated with known chains of transmission in Kambia have now completed the 21-day follow-up period, although intensive efforts are underway to identify any contacts associated with the case reported from Ratoma, Guinea, in the week ending 2 August.
  • For the first time in 3 weeks, no health worker infections were reported from any of the affected countries. There have been a total of 880 confirmed health worker infections reported from Guinea, Liberia, and Sierra Leone since the start of the outbreak, with 512 reported deaths.

COUNTRIES WITH WIDESPREAD AND INTENSE TRANSMISSION

  • There have been a total of 27 862 reported confirmed, probable, and suspected cases of EVD in Guinea, Liberia and Sierra Leone (figure 1, table 1) up to 2 August, with 11 281 reported deaths (this total includes reported deaths among probable and suspected cases, although outcomes for many cases are unknown). One new confirmed cases was reported in Guinea and one in Sierra Leone in the week to 2 August.
  • The total number of confirmed cases is similar in males and females (table 2). Compared with children (people aged 14 years and under), adults aged 15 to 44 are approximately four times more likely to be affected in Guinea and Liberia, and three times more likely to be affected in Sierra Leone.
  • No new health worker infections were reported in the week to 2 August. Since the start of the outbreak a total of 880 confirmed health worker infections have been reported in Guinea, Liberia, and Sierra Leone; there have been 512 reported deaths (table 5).

Figure 1: Confirmed, probable, and suspected EVD cases worldwide 

View data »

Table 1: Confirmed, probable, and suspected EVD cases in Guinea, Liberia, and Sierra Leone

Country Case definition Cumulative cases Cases in past 21 days Cumulative deaths
Guinea Confirmed 3327 27 2070
Probable 452 * 452
Suspected 5 *
Total 3784 27 2522
Liberia§ Confirmed 3151 -
Probable 1879 -
Suspected 5636 -
Total 10 666 - 4806
Liberia** Confirmed 6 0 2
Probable 0 *
Suspected *
Total 6 0 2
Sierra Leone Confirmed 8695 7 3585
Probable 287 * 208
Suspected 4424 * 158
Total 13 406 7 3951
Total Confirmed 15 179 34
Probable 2618 *
Suspected 10 065 *
Total 27 862 34 11 281

View data »

Table 2: Cumulative number of confirmed cases by sex and age group in Guinea, Liberia, and Sierra Leone

Country Cumulative cases
By sex*
(per 100 000 population)
By age group
(per 100 000 population)
Male Female 0-14 years 15-44 years 45+ years
Guinea 1588
(29)
1734
(32)
528
(11)
1892
(41)
857
(55)
Liberia§ 1911
(96)
1838
(93)
561
(33)
2060
(121)
703
(132)
Sierra Leone 4792
(168)
5081
(175)
1978
(82)
5592
(216)
2129
(288)

View data »

Figure 2: Geographical distribution of confirmed cases reported in the week to 2 August 2015

Geographical distribution of new and total confirmed cases

Table 3: Cases and contacts by district/prefecture/county over the past 3 weeks

table3.png

Data are based on official information reported by ministries of health. These numbers are subject to change due to ongoing reclassification, retrospective investigation and availability of laboratory results. *Data as of 2 August for Guinea, Sierra Leone and Liberia. Includes Freetown. 

Table 4: Location and epidemiological status of confirmed cases reported in the 3 weeks to 2 August 2015

table4.png

Sub-prefectures/chiefdoms/districts that reported one or more confirmed cases in the 7 days to 2 August are highlighted. *Epi-link refers to cases who were not registered as contacts of a previous case (possibly because they refused to cooperate or were untraceable), but who, after further epidemiological investigation, were found to have had contact with a previous case, OR refers to cases who are resident or are from a community with active transmission in the past 21 days. Includes cases under epidemiological investigation. §A case that is identified as a community death can also be registered as a contact, or subsequently be found to have had contact with a known case (epi-link), or have no known link to a previous case. **Includes Freetown. Listed as a contact but subsequently lost to follow-up.

Figure 3: Geographical distribution of new and total confirmed cases in Guinea, Liberia and Sierra Leone

Geographical distribution of new and total confirmed cases

View interactive map »

Table 5: Ebola virus disease infections in health workers in Guinea, Liberia and Sierra Leone

Country Cases Deaths
Guinea 195 99
Liberia* 378 192
Sierra Leone 307 221
Total 880 512

GUINEA

  • Key performance indicators for the EVD response in Guinea are shown in table 6.
  • One confirmed case was reported from the Ratoma area of the capital, Conakry, in the week to 2 August (table 3, table 4, figure 2, figure 3). The case, a 28-year-old woman, is a contact who was lost to follow-up, and who is likely to have generated a substantial number of further high-risk contacts. She is a registered contact associated with a known chain of transmission that has given rise to several generations of cases in the Ratoma area of the capital, Conakry, over the past several weeks. After being lost to follow-up she travelled south from Conakry through Forecariah and into Kambia, Sierra Leone, where she reportedly visited a traditional healer, before returning to Ratoma via Forecariah and making herself known to the authorities there. Investigations are ongoing to establish her precise history of travel, time of symptom onset, and all those who she may have had contact with.
  • No cases were reported from the prefecture of Forecariah for a second consecutive week. However, the situation in the prefecture remains complex, with no origin of infection yet identified for a case reported from Allasoyah sub-prefecture in the week ending 19 July. In addition, 420 contacts remain under follow-up in the prefecture, and new contacts are likely to be identified in association with the case reported in Ratoma in the week to 2 August.
  • An interim analysis of the Ebola ça suffit! ring vaccination trial in Guinea suggests that the investigational rVSV-ZEBOV Ebola vaccine protects people exposed to EVD. The trial will continue in Guinea, with all rings around confirmed cases now receiving immediate vaccination. Previously, rings were randomly allocated to receive either immediate vaccination or vaccination 21 days after the confirmation of a case.
  • There are a total of 1080 contacts being monitored across 5 prefectures (table 3). Most contacts (612) are located in Conakry. 420 contacts are under follow-up in Forecariah, although more contacts associated with the most recent case in Ratoma are likely to identified during the course of investigations.
  • There were 3 (0.6%) unsafe burials reported in Guinea out of 525 recorded community deaths in the week to 2 August, compared with 9 (2%) unsafe burials out of 484 recorded community deaths in the previous week.
  • Including both initial and repeat testing, a total of 758 laboratory samples were tested in the week to 2 August. Most tests (81% in the week to 2 August) are of post-mortem swabs taken to rule out EVD as the cause of death. 
  • Locations of the 8 operational Ebola treatment centres (ETCs) are shown in figure 7. No health-worker infections were reported from Guinea in the week to 2 August.
  • Locations of the 11 operational laboratories in Guinea are shown in figure 8. 

Table 6: Key performance indicators for Guinea

guinea_v2.png

For definitions of key performance indicators see Annex 2. Data are given for 7-day periods. *Includes repeat samples. Data missing for 0–3% of cases. #Outcome data missing for 0–1% of hospitalized confirmed cases. 

Figure 4: Confirmed weekly Ebola virus disease cases reported nationally and by prefecture from Guinea

guinea_facet_plot.png

View data »

SIERRA LEONE

  • Key performance indicators for the EVD response in Sierra Leone are shown in table 7.
  • The single case reported from Sierra Leone in the week to 2 August came from Tonkolili (table 3, figure 2, figure 3, figure 5, figure 6). The new case is one of over 600 contacts generated by the case reported in Tonkolili the previous week (the index case). The case is a family member who provided care to the index case, and was considered to be at high risk of an acquired infection. There are over 40 other such contacts considered to be at high risk of developing EVD because of the nature of their contact with the index case, and there is a high probability that further cases will arise. All contacts are currently under follow-up. Investigations into the source of infection of the index case, who is thought to have acquired infection in Freetown before traveling to Tonkolili, are still ongoing.
  • Across the country a total of 811 contacts remain under follow-up in 4 districts (table 3), with the vast majority (636) located in Tonkolili. All contacts associated with known chains of transmission in Kambia have now completed the 21-day follow-up period, although new contacts are likely to be identified during the course of investigations into the case reported from Ratoma, Guinea, in the week ending 2 August.
  • Locations of the 10 operational Ebola treatment centres (ETCs) in Sierra Leone are shown in figure 7. No health worker infections were reported in the week to 2 August.
  • Laboratory indicators continue to reflect a heightened degree of vigilance, with 1955 new samples tested in the 7 days to 2 August. Fewer than 1% of samples tested positive for EVD. Most tests (80% in the week to 2 August) are of post-mortem swabs taken to rule out EVD as the cause of death. 
  • Locations of the 9 operational laboratories in Sierra Leone are shown in figure 8. 

Table 7: Key performance indicators for Sierra Leone

sierraleone_v2.png

For definitions of key performance indicators see Annex 2. Data are for 7-day periods. §Laboratory data missing for 14 July. Data missing for 4–12% of cases. #Outcome data missing for 25–75% of hospitalized confirmed cases. An outcome is known for only 6 hospitalized, confirmed cases in April. 

 

Figure 5: Confirmed weekly Ebola virus disease cases reported nationally and by district from Sierra Leone

sl_facet_plot.png

View data »

Figure 6: Days since last confirmed case by district in Guinea, Liberia, and Sierra Leone

Days since last reported confirmed case by district in Guinea, Liberia, and Sierra Leone

View interactive map »

OTHER AFFECTED AND PREVIOUSLY AFFECTED COUNTRIES

  • Liberia was declared free of Ebola transmission on 9 May 2015, after reporting no new cases for 42 consecutive days. The country subsequently entered a 3-month period of heightened surveillance, during which approximately 55 blood samples and oral swabs are collected each day from potential cases and tested for EVD. On 29 June, this heightened surveillance detected an EVD-positive community death in Margibi County, Liberia—the first new confirmed case reported from the country since 20 March. The case was a 17-year-old male who first became ill on 21 June, died on 28 June, and subsequently tested positive for EVD. As at 12 July, 5 contacts associated with the first-detected case have since been confirmed as EVD-positive. Of the 6 confirmed cases reported since 29 June, 2 have died, and the remaining 4 have now all been discharged after treatment. The last case was discharged after testing negative for EVD for a second time on 23 July. All contacts have now completed follow-up.
  • Seven countries (Italy, Mali, Nigeria, Senegal, Spain, the United Kingdom and the United States of America) have previously reported a case or cases imported from a country with widespread and intense transmission.

Figure 7: Location of Ebola treatment centres in Guinea, Liberia, and Sierra Leone

Location of Ebola treatment centres in Guinea, Liberia and Sierra Leone

View interactive map »

PREPAREDNESS OF COUNTRIES TO RAPIDLY DETECT AND RESPOND TO AN EBOLA EXPOSURE

  • The introduction of an EVD case into unaffected countries remains a risk as long as cases exist in any country. With adequate preparation, however, such an introduction can be contained through a timely and effective response.
  • WHO’s preparedness activities aim to ensure all countries are ready to effectively and safely detect, investigate, and report potential EVD cases, and to mount an effective response. WHO provides this support through country support visits by preparedness-strengthening teams (PSTs) to help identify and prioritize gaps and needs, direct technical assistance, and provide technical guidance and tools.

Figure 8: Location of laboratories in Guinea, Liberia, and Sierra Leone

Location of Ebola treatment centres in Guinea, Liberia and Sierra Leone

View interactive map »

Priority countries in Africa

  • The initial focus of support by WHO and partners is on highest priority countries – Côte d’Ivoire, Guinea-Bissau, Mali, and Senegal—followed by high priority countries—Benin, Burkina Faso, Cameroon, Central African Republic, Democratic Republic of the Congo, Ethiopia, Gambia, Ghana, Mauritania, Niger, Nigeria, South Sudan, and Togo. The criteria used to prioritize countries include the geographical proximity to affected countries, the relative magnitude of trade and migration links, and the relative strength of their health systems.
  • Since 20 October 2014, PSTs have provided technical support in Benin, Burkina Faso, Cameroon, Central African Republic, Côte d’Ivoire, Ethiopia, Gambia, Ghana, Guinea-Bissau, Mali, Mauritania, Niger, Senegal, South Sudan, and Togo. Technical working group meetings, field visits, high-level table-top exercises, and field simulations have helped to identify key areas for improvement. Each country has a tailored plan to strengthen operational readiness. WHO and partners are deploying staff to the priority countries to assist with the implementation of national plans.
  • Follow-up missions in the four highest priority countries (Côte d’Ivoire, Senegal, Mali, and Guinea-Bissau) were able to strengthen cross-border surveillance and the sharing of outbreak data under the framework of the International Health Regulations (2005), as well as support other technical areas.
  • From October 2014 to 31 July 2015 WHO has undertaken over 285 field deployments to priority countries.
  • WHO provides personal protective equipment (PPE) modules containing minimum stocks to cover staff protection and other equipment needs to support 10 beds for 10 days for all staff with essential functions. PPE modules have been delivered or are in the process of being delivered to all countries on the African continent. In addition, all countries have received one PPE training module.
  • Contingency stockpiles of PPE are in place in the United Nations Humanitarian Response Depots (UNHRD) in Accra and Dubai, and are available to any country in the event that they experience a shortage.

Follow-up support to priority countries

  • Following the initial PST assessment missions to the 14 priority countries undertaken in 2014, a second phase of preparedness strengthening activities have provided support on a country by country basis.  Activities in the last week are highlighted below.
  • In Guinea-Bissau, two WHO sub-offices have been established and staffed in the regions of Gabu and Tombali, which share a border with Guinea. The sub-offices will enhance event-based surveillance and support two Emergency Operations Centres (EOCs) and rapid response teams. Community-level activities (surveillance, social mobilization) have been reinforced, and community engagement has been enhanced through volunteers and community leaders. Cross-border information exchanges occur regularly between Guinea and Guinea-Bissau. Logistics support will be provided through the WHO/WFP logistics framework agreement to meet ongoing equipment needs. WHO is also assisting in the establishment of a strengthened triage and alert system. Refresher training on screening, PPE use, case definitions, and hand hygiene is being planned.
  • In Mali, a set of field and functional exercises took place from 27 July to 1 August to evaluate the country’s capacity to respond to an introduced case of Ebola. Field procedures put to the test included the detection of a case at the international airport in Bamako, the deployment of rapid response teams, the establishment and implementation of contact tracing, and case management and infection control at the national Ebola Treatment Centre in Bamako. The functional exercise tested the performance of the Emergency Operations Centre in coordinating response operations. 

EVD preparedness officers

  • Dedicated EVD preparedness officers have been deployed to support the implementation of country preparedness plans, coordinate partners, provide a focal point for inter-agency collaboration, provide specific technical support in their respective areas of expertise, and provide capacity development to national WHO staff. Preparedness officers are currently deployed to Benin, Cameroon, Central African Republic, Côte d’Ivoire, Ethiopia, Gambia, Ghana, Guinea-Bissau, Mali, Mauritania, Niger, Senegal, and Togo. 

Training, exercises, and simulations

  • Priority countries that have achieved a minimum of 50% implementation of preparedness checklist activities are encouraged to undertake a series of drills on elements of an EVD response, and a functional exercise to test the coordination of the Ebola operations centre.
  • Exercises in Côte d’Ivoire, Mali, and Gambia are currently planned for September 2015.
  • Training in Ghana (safe burials), Mauritania (points-of-entry), and Côte d’Ivoire (clinical management and IPC in Guiglo and Toulepleu) are currently being planned.

Surveillance and preparedness indicators

  • Indicators based on surveillance data, case-management capacity, laboratory testing, and equipment stocks continue to be collected on a weekly basis from the four countries neighbouring affected countries: Côte d’Ivoire, Guinea-Bissau, Mali, and Senegal.
  • An interactive preparedness dashboard based on the WHO EVD checklist is now available online.

 

ANNEX 1: COORDINATION OF THE EBOLA RESPONSE ALONG 4 LINES OF ACTION

WHO continues to work with many partners in response to the EVD outbreak, including the African Union, the Economic Community of West African States, the Mano River Union, national governments, non-governmental organizations, and UN agencies, and technical institutions and networks in the Global Outbreak Alert and Response Network (GOARN). Agencies responsible for coordinating 4 key lines of action in the response are given below.

Lines of action Lead agency
Case management WHO
Case finding, laboratory services and contact tracing WHO
Safe and dignified burials International Federation of Red Cross and Red Crescent Societies (IFRC)
Community engagement and social mobilization UNICEF

ANNEX 2: DEFINITIONS OF PHASE 2 KEY PERFORMANCE INDICATORS

Indicator Numerator Numerator source Denominator Denominator source
Cases and deaths
Number of confirmed cases # of confirmed cases

Guinea: Daily WHO situation reports

Sierra Leone: Daily Ministry of Health Ebola situation reports

N/A N/A
Number of confirmed deaths # of confirmed deaths

Guinea: Daily WHO situation reports

Sierra Leone: Daily Ministry of Health Ebola situation reports

N/A N/A
Proportion of EVD- positive reported community deaths

# of community deaths for which a sample was taken 

# of community deaths with positive EVD swab results

Guinea: Weekly WHO situation reports

Sierra Leone: Daily Ministry of Health situation reports

N/A N/A
Diagnostic services
Number of samples tested and percentage with positive EVD results

# of new samples tested

# of new samples tested with a positive EVD result

Guinea: Laboratory database

Sierra Leone: Daily Ministry of Health Ebola situation reports

N/A

# of new samples tested

Guinea: Laboratory database

Sierra Leone: Daily Ministry of Health Ebola situation reports

Contact tracing
Percent of new confirmed cases from registered contacts # of new confirmed cases registered as a contact

Guinea: Weekly WHO situation reports

Sierra Leone: Weekly Ministry of Health Surveillance Report

of new confirmed cases

Guinea: Daily WHO situation reports

Sierra Leone: Daily Ministry of Health Ebola situation reports

Hospitalization
Time between symptom onset and case hospitalization (days) Time between symptom onset and hospitalization of confirmed, probable or suspected case (geometric mean # of days) Clinical investigation records N/A N/A
Outcome of treatment
Case fatality rate (among hospitalized cases) # of deaths among hospitalized cases (confirmed) Clinical investigation records # of hospitalized cases (confirmed) with a definitive survival outcome recorded Clinical investigation records
Infection Prevention and Control (IPC) and Safety
Number of newly infected health workers # of newly infected health workers

Guinea / Sierra Leone: Daily WHO situation reports

N/A N/A
Safe and dignified burials
Number of unsafe burials reported # of reports/alerts of burials that were not known to be safe

Guinea: Weekly WHO situation reports

N/A N/A
Social mobilization
Number of districts with at least one security incident or other form of refusal to cooperate # of districts with at least one security incident or other form of refusal to cooperate in the past week

Guinea: Daily WHO situation reports

Sierra Leone: UNICEF

N/A N/A