What does "stretching response teams" mean?
Context:
So why is the outbreak continuing in Guinea, Sierra Leone and Liberia?
In principle, it should be straightforward to bring an Ebola outbreak under control via public health measures alone, namely, identifying all people who have been infected and isolating them, monitoring all those that they have been in contact with for 21 days (the maximum incubation period), as well as promoting basic infection control measures. What's more, since people infected with Ebola do not infect others until they have symptoms, it is easier to trace their contacts than it is for some other diseases. Ebola is out of control in these countries because the sheer size of the outbreak is
stretching response teams, and also because of local sociocultural factors.
More:
http://www.nature.com/news/largest-ever-ebola-outbreak-is-not-a-global-threat-1.15640