OTTAWA - The head of the Public Health Agency of Canada says the Ebola crisis in west Africa is stretching his resources.

And Dr Gregory Taylor says they'll only be stretched further by this weekend's decision to send a second mobile laboratory to Sierra Leone.

It's the first time Canada has deployed two such teams to work on a single outbreak.

Taylor says the second team will work with the group Doctors Without Borders to determine if cleaning techniques at treatment centres must be stepped up to prevent infection of health-care workers.

The first team is providing diagnostic services.

The mobile lab concept, which Canada pioneered, has substantially sped up the process of figuring out who is sick in an Ebola outbreak so that they can be quickly isolated.

Taylor says that in addition to maintaining teams in Africa, the National Microbiology Laboratory also plays a critical role in Ebola research, which must continue.