The clostridium difficile bug is affects mainly the old and the very young and has been cited as a cause in 77 deaths across Northern Ireland, 36 of those in the Northern Trust area alone.

Two more deaths have been linked to C-diff since last Friday, both in the Northern Trust area.

The committee will also cross-examine chief medical officer Dr Michael McBride, over how he is tackilng the problem.

The Department of Health describes C-diff as the major cause of antibiotic-associated diarrhoea and colitis, a healthcare associated intestinal infection that mostly affects elderly patients with other underlying diseases.

The bacteria is of the same family that causes tetanus, botulism, and gas gangrene and produces spores that can survive for a long time in the environment.

It can cause diarrhoea, ranging from a mild disturbance to a very severe illness with ulceration and bleeding from the colon (colitis) and, at worst, perforation of the intestine leading to peritonitis. It can be fatal.

Generally, it is only able to do this when the normal, healthy intestinal bacteria have been killed off by antibiotics.

Committee chair Iris Robinson said her colleagues had some hard questions for the heads of the trusts.
"We will put them through a fairly vigorous scrutiny," she said.

"I want to hear what they are actually doing to prevent C. difficile. We have made a lot of recommendations to the various trusts as to how they can improve their hygiene."

SDLP health spokeswoman Carmel Hanna said confidence needed to be "given back to the public".
"There has to be an absolute thorough clean of all our hospitals, but after that there have to be spot checks and they have to be recorded," said Mrs Hanna.

"There has to be a score for the level of cleanliness in our hospitals to ensure that we maintain a high level."