The giardia lamblia bug is treated using antibiotics

It emerged on Thursday that 12 people were suffering from the giardia lamblia bug in Ceredigion.

But health officials said on Friday that eight cases were linked, while three were associated with foreign travel and one was a "sporadic" case.

The source of infection in the eight linked cases has not yet been identified.

Screening process

Ceredigion Council said on Friday that of the eight linked cases, five of those affected were children and three were adults.

The council added that some of the cases were detected by screening children and adults associated with the learning disability unit of Llwyn yr Eos Primary School, in Aberystwyth.

The water supply at the affected school, Llwyn yr Eos in Aberystwyth, was not to blame, added officials.

The team added that the outbreak suggested a "person-to-person spread", and it expected a screening process to be completed early next week.

'Cluster of infections'

In a statement following a meeting in Aberaeron on Friday, officials said: "The initial source of the infection has not been identified, and at present activities are concentrated on reinforcing hygiene measures and cleaning procedures at the school."

Dr Mac Walapu, consultant in communicable disease control with the National Public Health Service for Wales, said: "This is a cluster of related infections and is unlikely to be an extensive community problem.

"People with symptoms should contact their local GP practice for advice."

Symptoms of the giardia lamblia bug include diarrhoea, but it can be treated by antibiotics with no long-term complications.