Latest Ebola Situation Report Contains Good News & Bad
Epidemiologic
Patterns Vary In The Most Affected Countries
In one of the most comprehensive summaries of the Ebola
outbreak to date, the latest WHO situation report documents more than
13,000 cases as of early November in eight countries (Guinea, Liberia,
Mali, Nigeria, Senegal, Sierra Leone, Spain, and the United States)
and almost 5,000 deaths. Among the three West African countries
reporting more than 99% of the cases, weekly incidence appears stable
in Guinea and declining in Liberia. However, the incidence continues
to rise in Sierra Leone, especially in Freetown the capital city.
The Good News
While initial reports of a decline in cases were uncertain, a recent
press release from Doctors Without Borders on November 10 confirms
that cases being admitted to their treatment centers are clearly down
for the first time in the epidemic. Warning that case numbers could
rise again as they have in Guinea, the organization says “priority
should be given to a more flexible approach that allows a rapid
response to new outbreaks and gets the regular health care system
safely up and running again.”
Epidemiologic
Variation
A closer examination of the cases reveals that while
the epidemic started in Guinea, that country has surprisingly had
fewer cases (13%) than neighboring Liberia and Sierra Leone. According
to WHO, the geographic spread of Ebola within country has been less in
Guinea than elsewhere. Liberia accounts for fully half of the cases
and Sierra Leone the remaining 37%. While the data are considered
incomplete because of underreporting, the case fatality rates vary
dramatically between countries with cases in Guinea exhibiting an
almost 3 fold greater mortality rate.
Ebola Cases and Deaths
in the Most Affected Countries
|
Country |
Cases |
Deaths |
Case Fatality |
|
Guinea |
1760 |
1054 |
60% |
|
Liberia |
6619 |
2766 |
42% |
|
Sierra Leone |
4862 |
1130 |
23% |
|
Total |
13241 |
4950 |
37% |
*Adapted from WHO, Nov 7, 2014
Health Care Workers
Another important feature of the outbreak in all countries has been
the number of cases in health workers. According to WHO, 549 such
workers have been infected and the case fatality rate has been 57%,
close to the highest rate seen in Guinea. WHO says a substantial
proportion of these infections may have occurred outside the context
of care and treatment centers. If so, it leaves unexplained why the
health care workers may have been at higher risk outside the health
care setting. Similar to cases among non-health care workers, Liberia
reports by far the largest number of health care worker cases. Also,
the case fatality rates so far among health care workers are
approximately 50% in Liberia and Guinea, not too dissimilar from the
rates in the general population. However, Sierra Leone which has the
lowest case fatality rate in the general population (22%) has by far
the highest case fatality rate among health care workers (80%).
Progress With Control
Measures
In
a detailed report on the progress of implementing control measures,
in the most affected countries WHO provides preliminary data showing
that 22% of the more that 4,000 beds targeted to be available are now
operational, 52% of the cases are being isolated, 27% of the burial
teams are in place, 87% of the dead bodies are being managed well, and
95% of contacts to be traced are being reached daily. WHO’s goal is to
be able to isolate 100% of cases and safely bury 100% of patients who
die by January 1, 2015. WHO points out that the 95% contact tracing
measurement may be that high because the number of contacts being
reported per case may be artificially low. In order to have an
adequate level of readiness to cope with Ebola, countries should be
able to successfully perform the following tasks:
Successful Control
Tasks
1.
Coordinate overall
2.
Respond rapidly
3.
Raise public awareness and community engagement
4.
Prevent and/or control infection
5.
Manage treatment centers
6.
Manage safe burials
7.
Conduct epidemiologic surveillance
8.
Trace contacts
9.
Test laboratory specimens
10.
Check persons at points of entry
To access the WHO situation report,
visit:
http://tinyurl.com/lljkj5h
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