Background

In the past three years, a number of outbreaks associated with Salmonella poona occurred in the USA and were responsible for many illnesses including two deaths and at least 18 hospitalizations.

Salmonellosis casused by Salmonella poona

Although Salmonella is the most frequently reported cause of foodborne outbreaks of gastroenteritis worldwide, Salmonella poona is relatively rare to cause foodborne illness. It causes the same illnesses as other species of Salmonella. It can cause serious and sometimes fatal infections in some people, like children, elderly people and some with weakened immunity. Symptoms generally occur in 1-3 days after eating tainted food, including nausea, vomiting, diarrhea, abdominal cramps, and fever, and will last 2-5 days.

Contaminated foods

Foods containing poultry or other meat, eggs or dairy products are most often the vehicles for foodborne salmonellosis. Fruits and vegetables are not often identified as vehicles for Salmonella infection. However, some outbreaks associated with fresh produce did occur in other countries, like the US and Canada.

Agricultural practices

Fruits and vegetables grow on the ground and may be contaminated on their surface with dirt, chemicals, animal excreta, or bacteria, like Salmonella. In general practices, the harvested fresh produces should be washed and disinfected before transporting to the retail outlets for sale. For disinfection, using chemical agent, like chlorine, and ionizing treatment are good ways to destroy the harmful bacteria on the surface of fresh produce.

Cause of contamination

Unsanitary conditions and poor agricultural practices should be the main factors contributing bacterial contamination. The following is the possible causes of Salmonella contamination -

• If the fresh produces do not receive disinfection treatment, Salmonella spp. may survive on the surface of fresh produces.
• Cutting an unwashed fresh produce through a contaminated rind may lead to contamination of the edible part via the cutting knife or subsequent contact of contaminated and uncontaminated cut fruits.
• Excessive storage time at room temperature may then permit bacterial growth.

Prevention

In order to eliminate the risk, safe handling practices should be adopted. Key points are summarized as follows -

Advice to trade:

• Purchased the fresh produces from reliable and reputable suppliers that clean and disinfect their products after harvesting;
• Refrigerate the incoming produces at 4 C or below to eliminate the bacterial growth on the surface of fruits;
• Wash the outer surface of the fresh produce thoroughly with tap water to remove surface dirt;
• Wash hands thoroughly with soap and water before cutting fresh produces;
• Wash all food-contact equipment and utensils thoroughly with hot soapy water, rinse, sanitize, and air-dry;
• Maintain the storage temperature of cut produces at 4 C or below; and
• Display the cut produce in a refrigerated case

Advice to public:

• Check "use-by" date of prepackaged cut produces when purchasing and store them in refrigerator as soon as possible;
• Wash fresh produces with tap water before cutting;
• Wrap and refrigerate the cut produces at the upper compartment of refrigerator at once after cutting;
• Consume the refrigerated cut produce as soon as possible; and
• Discard all cut produce displayed at room temperature for more than 2 hours.