Rapid detection of human norovirus in frozen raspberries

Raspberries have lately caused several human norovirus (HuNoV) outbreaks in Europe.

In this study, we developed and evaluated for HuNoV reverse transcription (RT)-PCR detection in frozen raspberries extraction methods that have equal sensitivity but are less time-consuming than widely used methods based on polyethylene glycol (PEG) precipitation and chloroform–butanol purification.

One method was applied to stored frozen raspberries linked to previous HuNoV outbreaks and berries on sale. In the virus elution-based Method 1, sparkling water eluted viruses most efficiently from the berries. Method 2, based on direct nucleic acid extraction with minor PEG supplement, yielded the highest number of positive findings (4 out of 9) at low virus concentration level of 100 genome copies HuNoV genogroup II per 25 g raspberries. Both methods showed approximately equal sensitivity to a method including PEG precipitation and chloroform–butanol purification. Two naturally contaminated berry samples linked to HuNoV outbreaks in 2006 and 2009 were still positive for HuNoV genogroup I, but all berry products purchased from a local store remained negative for HuNoV. In conclusion, this study presents two efficient and rapid methods which can be used in urgent HuNoV outbreak investigations, since the results of the virus analysis are available in a few hours.

We only do fruit so we’re clean: How the berry hepatitis A scare inspired an Aussie farm business

I asked my grandfather, the asparagus baron, what crop he’d go into if he was starting out in 1980 rather than 1960.


Same in Australia.

Rare and expensive.

I want to plant berry bushes around the townhome in Brisbane instad of some decorative plant.

I get voted down.

But spurred by the hepatitis A outbreak from frozen berries earlier this year, a Victorian small family farming business has launched a 100 percent Australian-grown frozen berries product.

Many consumers fell ill in February after consuming Nanna’s frozen berries grown in Chile and China and packaged in Chinese factories.

Matilda’s is the brainchild of husband and wife team Ruth and Matt Gallace, third generation strawberry farmers on Victoria’s Mornington Peninsula.

Alarmed by the outbreak, they fronted $500,000 to construct a purpose-built facility in the Yarra Valley to wash and snap freeze strawberries from Sunny Ridge Strawberry Farm, which has been in the Gallace family for 50 years, and their 800 acres of land in Victoria and Queensland as well as raspberries and blueberries from NSW and Tasmania.

As their facility is dedicated purely to fruit products, the couple insist their frozen berries will be free from contamination.

Um, that’s not the way microbes work, especially hep A which is transferred from human poop to humans.

But good luck.

Denmark: Cook frozen raspberries to avoid norovirus infection

Danish authorities are again recommending frozen raspberries be rapidly boiled before being used in smoothies, desserts and other dishes. The fruit must cook one minute.

Outbreaks of norovirus have stricken hospital staff, canteen and restaurant guests and individuals who have been eating frozen raspberries from abroad.

"Food Administration takes this situation very seriously, and that is why we now recommend the boiling of frozen raspberries both at home and businesses such as restaurants and cafeterias," says Annette Perge in the Food Agency.

Norovirus in frozen raspberries

Albert Amgar, a food safety consultant in Laval, France for the past 21 years and the provider of all things French and food safety for bites.ksu.edu, steps out in his first barfblog post.

National Food Safety Authority Evira recommends that foreign frozen raspberries always be properly heated before use. Norovirus epidemics have occurred in different parts of Finland over the spring and the cause is suspected to be foreign frozen raspberries used in cakes without heating.

Evira urges consumers and mass caterers to check the origin of frozen raspberries and to only use foreign raspberries after adequate heating in order to avoid food poisoning. Frozen raspberries of foreign origin should be heated for at least two minutes at 90 degrees Celcius.

The problem is well known. In 1995, scientists from Denmark reported that "imported frozen raspberries caused a series of norovirus outbreaks". But in the conclusions the authors noted, very friendly to their other European colleagues, "As Polish frozen raspberries are known to be exported to several European countries, it would be extremely surprising, if Denmark were the only country where there were recent outbreaks due to frozen raspberries.”