Year End Report Provides In-Depth Look At Source, Causes, And
Evolution Of Ebola Outbreak
It’s no secret that the response to the outbreak of
Ebola in West Africa has been judged inadequate by many observers. The
large numbers of cases and deaths, larger than for any previous
outbreak, speak for themselves.
Too little, too late has been an often heard refrain.
But what really best explains the ability of the Ebola virus to spread
in an unprecedented manner in West Africa may involve a larger set of
causative factors. Now the World Health Organization has published a
set of 14 papers examining the entire one year period from the likely
index case of the epidemic in Guinea to the present day with over
21,000 cases and 8,400 reported deaths. Looking forward to 2015, the
report also seeks to identify how the outbreak may evolve further and
what must be done in the coming months to bring the countries to zero
cases.
Index Case
The
index case appears to have been a 2 year old boy living in Meliandou,
a remote village with only 31 households in the Forest Region of
Guinea. He fell ill in late December 2013 and died two days later. He
infected his immediate family who died rapidly in the first wave of
cases along with traditional healers, midwives, and health workers. In
a second wave, members of an extended family who participated in
funerals and patient care were infected.
Diagnosis
Initial suspicions focused on cholera and Lassa fever
as potential causative agents. It took more than 12 weeks between the
onset date of the index case and eventual confirmation of the
diagnosis as Ebola by the Institut Pasteur in Lyon France. By then, 49
cases and 29 deaths had been officially reported and the outbreak was
widely dispersed and had also spilled over into neighboring countries
of Liberia and Sierra Leone which also took additional weeks to be
recognized. At this point multiple chains of transmission were
established and cases became too numerous to trace.
Animal Reservoir
Interestingly, deforestation in the area of the
infected village may have brought potentially infected wild animals
and the bat species thought to be the reservoir into closer contact
with village residents. WHO reports that the young index case was seen
playing in his backyard near a hollow tree heavily infested with bats.
Causal factors
The list of reasons given for failing to control the
outbreak in West Africa are numerous and varied. It is difficult to
identify the root causes from a long list of contributing causes. In
summing up the causes of the outbreak in broad terms, the WHO states
that the first cause was a tenacious and unforgiving virus, and the
second was fear and misunderstanding that fuelled high risk behaviors.
But were these really the root causes?
In examining the more particular causes, it is
difficult to escape the conclusion that the lack of familiarity with
Ebola in West Africa and its associated lack of preparedness have been
root causes of the increased spread in West Africa. In Equatorial
Africa where the virus has appeared multiple times and the health
systems know what to do, Ebola has been controlled successfully.
Likewise, authorities in Senegal, Nigeria, and Mali, although part of
West Africa, knew ahead of time that Ebola had appeared in the region
and were able to implement control measures before the virus was
widespread.
It is difficult to argue that the virus itself was more
tenacious or virulent in Guinea, Liberia, and Sierra Leone than it was
in the other West African countries or that the fears and
misunderstandings were less in the countries with imported cases. Even
in the US, the fears and misunderstandings were widely prevalent.
Most plausibly, the multiple factors often listed as
causes for the failure to control the outbreak such as lack of
resources, cultural practices, population mobility, poor
communication, and occurrence in urban rather than only rural areas
served to amplify the spread which was already out of control when the
outbreak was first recognized. Perhaps the familiar refrain of too
little, too late should be modified to say too late, too little.
Requirements for
Control in 2015
In an equally exhaustive paper in the series, WHO
identifies four key lessons learned in 2014 and what will need to
happen in 2015 to bring about zero cases in West Africa.
Lesson 1.
Countries with weak health systems and few basic public health
infrastructures in place cannot withstand sudden shocks. WHO calls for
fair and inclusive health systems to help countries withstand future
challenges.
Lesson 2.
Preparedness including a high level of vigilance for imported cases
and a readiness to treat the first confirmed case as a national
emergency made a night and day difference
Lesson 3.
No single control measure is powerful enough to bring an epidemic of
this size under control. Control measures must be implemented in
unison.
Lesson 4.
Community engagement or cooperation underlies the success of all other
control measures. Communities must be given incentives to comply.
Getting to zero cases will mean breaking all the chains of
transmission and working within the context of existing cultural
beliefs and practices to implement control measures, as was done to
improve the safety of burials.
Specific Actions
More specifically and urgently to get to zero cases,
WHO has called for a long litany of actions. The list is daunting and
includes:
-
tackling community resistance,
-
improving the quality and completeness of contact tracing,
-
tailoring response strategies to match distinct local needs,
-
developing capacity to respond with more agility to changing disease
patterns,
-
solving logistical problems to build community confidence that
control measures are effective and worthwhile,
-
establishing fully functional emergency operation centres in local
areas to enhance basic field epidemiology capacity,
-
sharing information more widely and effectively,
-
more analytical epidemiology to achieve high quality surveillance
and case-finding and comprehensive contact tracing,
-
reducing case-fatality rates in affected countries
-
cross-border coordination to limit transmission between countries,
-
development of a well-functioning health system
-
more research to develop vaccines, better treatments, diagnostic
tests, and
-
improving incentives for all workers both national and
international,
To view the WHO report, visit:
http://tinyurl.com/mzu3nqc
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