Culls of flocks at eight poultry farms have begun after a number of salmonella outbreaks were detected.

The Department of Agriculture is investigating the farms to identify the source of the infections, which were found in chickens destined for human consumption.

Salmonella is a bacteria that is considered a risk to public health, and so the discovery of infection in poultry flocks is being treated seriously by authorities.

The Department of Agriculture has confirmed that salmonella has been found in eight poultry flocks, a number of which are understood to be in the Co Cavan area.

Detection of the disease means all birds on the eight farms will be culled and none will enter the food chain.

The salmonella cases were detected as a result of routine testing that always takes place before chickens are sent for processing. Additional testing is ongoing as a result of the discovery and a salmonella scare last week.

Salmonella is a public health concern, and can cause serious illness, although some infected people will only experience mild illness.

The Food Safety Authority of Ireland (FSAI) said people infected with salmonella typically develop symptoms between 12 and 36 hours after infection, but this can range between six and 72 hours.

The most common symptom is diarrhoea, which can sometimes be bloody.

Other symptoms may include fever, headache and abdominal cramps. The illness usually lasts four to seven days.

Diarrhoea can occasionally be severe enough to require hospital admission. The elderly, infants, and those with impaired immune systems are more likely to have a severe illness.

Read more: What is salmonella and how do you avoid it?

The Department of Agriculture, Food and the Marine said it is working closely with the FSAI and the National Reference Laboratory for Salmonella in order to determine the cause of the outbreak, in a number of different areas at the same time.

The FSAI said: "To date, there are no human cases of illness linked to this investigation into the broiler flocks.

"This on-farm incident has arisen following the food recall of Western Brand undertaken last week.

"The FSAI has been notified by the Department of Agriculture that affected flocks will be culled and will not enter the food chain.

"The Department of Agriculture is testing as part of its investigation. The FSAI will continue to liaise with the Department of Agriculture with its ongoing investigation."

Irish Farmers' Association Poultry Chairman Nigel Sweetnam said the cases under investigation involve a "small number of farms", adding that the situation was "devastating for the flock owners".

Mr Sweetnam said "the affected flocks are restricted and there is no threat to human health".

He urged all flock owners to "review their biosecurity measures and to be extra vigilant".

Séamus Fanning, Professor of Food Safety and Director of the Centre for Food Safety at UCD has said that he had confidence in the food chain with regard to the salmonella outbreak.

He said while eggs can be impacted, he said there "is no risk here" as consumers are protected due to existing measures.

He added that it was good news as the alert has been sent out as it shows the controls around the food chain are very effective.

"There are a number of production sites and farms involved and it raises the question of where this comes from, which is important to address," he said.

He said that the department will use a similar approach to Covid-19 to identify the type of salmonella involved, making detailed comparisons across the outbreak sites to establish sequencing to track and trace the virus.

He added that investigators would be looking for a common factor.