Authorities in an Australian state are investigating an outbreak of Salmonella linked to contact with or consumption of eggs from backyard chickens.

The Victorian Department of Health and Human Services is looking into nine cases of gastroenteritis caused by Salmonella Enteritidis. People became sick between late April and the end of May.

Professor Brett Sutton, chief health officer in Victoria, said investigations so far have not identified a common source, but most cases had contact with, or consumed eggs from backyard chickens.

The Department of Health and Human Services is following up all notified cases of Salmonella Enteritidis and working with Agriculture Victoria and the chief veterinary officer to manage the infection in these chickens.

Salmonella Enteritidis in Australia
Salmonella Enteritidis is not usually found in Australia and is typically acquired overseas. However, the recent cases acquired their infections locally, according to the agency.

In 2019, Australia was hit by a large Salmonella Enteritidis outbreak linked to eggs.

It affected at least 171 residents in New South Wales since the strain was detected in May 2018. There were five patients in Victoria, three in Queensland and one in Tasmania.

Eleven New South Wales poultry facilities and a Victorian egg layer farm had detected Salmonella since late 2018. All sites were quarantined and decontaminated.

Chickens infected with Salmonella Enteritidis can produce eggs which have the bacteria inside them when they are laid. This can increase the chance of a person becoming infected with Salmonella if the egg is consumed raw or not cooked thoroughly.

People who have close contact with infected chickens, their coops or litter are also at risk of becoming sick if they don’t maintain good hygiene practices, such as washing hands well after coming into contact with chickens, their coops or litter, and before eating and preparing food.

The Centers for Disease Control and Prevention (CDC) in the United States is currently investigating a Salmonella Hadar outbreak with contact with backyard poultry, such as chicks and ducklings, being the likely source.

One person has died and there are 465 confirmed patients across 42 states with 86 people requiring hospitalization. A third of those ill are children younger than 5 years old.