More than thirty people have been struck down by a salmonella outbreak after High Tea at Melbourne’s prestigious Langham Hotel.

Six people required hospital treatment while reports say another 28 were made sick after the Langham’s luxury afternoon teas on July 11 and 12.

Authorities have confirmed the 34 cases of salmonella, but expect the numbers will rise.

The salmonella scare continues a worrying escalation in food poisonings, with confirmed salmonellosis cases up 130 per cent in the past six years, hitting 3693 cases in 2014.

There have been 2124 salmonella notifications already this year, but the most dangerous months come later in the year as warmer temperatures allow the bacteria to rapidly multiply.

To find out just what is driving the spiralling cases of salmonellosis, Victoria’s Department of Health has established a Salmonella Working Group to look at farming techniques, refrigeration and food preparation at retailers and in homes.

Authorities say about half the cases are traced to food retailers, but almost a third of the poisonings come from dodgy food served at backyard barbecues or in homes.

“We are keeping an open mind in terms of what the possibility might be. There has been speculation about the change in people’s food choices over time and it is conceivable that some of those changes in recent years might be a driver in these increasing numbers,” DOH public health officer Dr Brett Sutton told News Corp.

“When we have a clearer understanding of what the main drivers are for the increase then we can target better what we need to do.”

The Langham hotel claims to conduct daily food safety checks of equipment, produces food in traceable batches, and has performed electronic temperature checks on each delivery and batch of food.

The hotel has reportedly undertaken a chlorine-based wash of its kitchen, and will look to source produce from alternative suppliers.