Work that CDC staff has done on surveillance and
contact tracing has been critical to controlling the spread of disease.
So the CDC together with WHO, other partners including MSF,
have improved the quality of contact tracing and follow-up.
In Liberia, the intense contact tracing on the last case in Liberia,
which appears to have been identified in late March of 2015, have followed these
contacts and provided safe facilities for them to stay to be observed.
No subsequent cases have now been detected from that last case.
In Guinea and Sierra Leone the proportion of cases from known contacts has increased
compared to prior weeks,
indicating that the quality of contact tracing is improving.
And that the ability to identify cases and
to isolate them quickly is one that's achieving success.
So Guinea had 43% of cases from known contacts, while Sierra Leone had
67% of cases identified from known contacts as of mid-March.
One of the outstanding success stories has been in Lagos, Nigeria,
where a single traveler from Liberia caused a cluster of cases among
healthcare workers and others in the community in July of 2014.
So the combined use of the Emergency Operation Center,
which had been developed to support the polio eradication effort,
the trained field epidemiology trainee
personnel in country and trained epidemiologist in country, in concert with
CDD staff assistance was able to successfully quell the spread of disease.
So, only 19 confirmed cases and one probable case.
Rapid action controlled the spread of disease.
And this included the coordinated identification of more than 800 contacts,
follow up of those contacts, education of them and
19,000 visits to homes to evaluate those contacts.