‘Tuna poisoning’ reports on the rise in Stockholm

Over the last year, the Swedish Institute for Communicable Disease Control (Smittskyddsinstitutet, SMI) has seen a rise in reports from people in Stockholm contracting food poisoning from tuna.

'Tuna poisoning' reports on the rise in Stockholm

However, the agency stopped short of issuing a warning to consumers to avoid eating the popular fish.

“Tuna is something that we all eat and there’s no reason to stop eating it,” Sofie Ivarsson, an epidemiologist at the agency, told The Local.

She added that the issue is something that those who handle fish professionally, such as distributors and restaurants, need to be aware of, as it is during the shipping and preparation process that the fish can become contaminated.

According to Ivarsson, there’s not much the individual consumer can do.

She added that reason the rise in reports is limited to Stockholm may be due to the introduction in 2009 of a system allowing Stockholm residents to report suspected food poisonings online.

Since then, nine out of ten reports of histamine poisoning in 2010 originated from the Swedish capital.

It is fairly uncommon to get histamine poisoning, sometimes called scombroid poisoning, from fish. When it happens, however, it is usually when eating fish from the scombridae family, which includes tuna, mackerel and wahoo fish.

These fish naturally contain histidine, which is an essential amino acid for humans and other mammals, but if food is not refrigerated or stored cold enough, bacteria can turn the amino acid into the more poisonous histamine.

The sudden rise in reports in Stockholm has also led researchers to believe that there are probably many cases across the country that go undetected and unreported.

“We believe there is a large number of unreported cases of food poisoning in general,” she said, adding that many don’t take the trouble to report sudden stomach ache or nausea.

Recently a middle aged couple in Skåne sought medical assistance when experiencing a red, burning and itching rash on their upper bodies.

About an hour earlier they had both eaten a tuna salad from a pizzeria, and doctors concluded that as the source of their poisoning.

The couple recovered after a few hours, which is usually the case with histamine poisoning, but symptoms might also last for several days, and include nausea, dizziness, headache, palpitations, stomach ache and diarrhea.

Ivarsson explained that histamine poisoning is not a contagious disease, and for most people it will appear almost as an allergic reaction.

“People might just assume they are allergic to fish when they experience the symptoms,” she said, “but that might not be the case if you’ve never had allergic reactions before.”

Histamine poisoning only amounts to five percent of reported food poisonings In Sweden annually, with 124 individual cases reported between 2003 and 2010.

Member comments

Log in here to leave a comment.
Become a Member to leave a comment.
For members


Five sweet treats you should be able to identify if you live in Sweden

Do you know your biskvi from your bakelse? Your chokladboll from your kanelbulle? Here's a guide guaranteed to get your mouth watering.

Five sweet treats you should be able to identify if you live in Sweden


The most famous of all Swedish cakes outside Sweden, the classic kanelbulle (cinnamon bun) is the symbol of Sweden abroad, no doubt helped by the fact that Swedish furniture giants IKEA stock frozen buns in their food stores for customers to bake off at home.

Forget American tear-apart cinnamon rolls baked in a pan and slathered with cream cheese frosting: a classic Swedish cinnamon bun is baked individually using a yeasted dough spread with cinnamon sugar and butter. The dough is then rolled up, sliced into strips which are then stretched out and knotted into buns, baked, glazed with sugar syrup and sprinkled with pearl sugar.

Home-made varieties skip the stretching and knotting step, rolling the cinnamon-sprinkled dough into a spiral instead which, although less traditional, tastes just as good.

Kanelbullar in Sweden often include a small amount of Sweden’s favourite spice: cardamom. If you’re a fan of cardamom, try ordering the kanelbulle‘s even more Swedish cousin, the kardemummabulle or cardamom bun, which skips the cinnamon entirely and goes all-out on cardamom instead.

Sweden celebrates cinnamon bun day (kanelbullens dag) on October 4th.

Photo: Lieselotte van der Meijs/


A great option if you want a smaller cake for your fika, the chokladboll or ‘chocolate ball’ is a perfect accompaniment to coffee – some recipes even call for mixing cold coffee into the batter.

They aren’t baked and are relatively easy to make, meaning they are a popular choice for parents (or grandparents) wanting to involve children in the cake-making process.

Chokladbollar are a simple mix of sugar, oats, melted butter and cocoa powder, with the optional addition of vanilla or coffee, or occasionally rum extract. They are rolled into balls which are then rolled in desiccated coconut (or occasionally pearl sugar), and placed in the fridge to become more solid.

Some bakeries or cafés also offer dadelbollar or rawbollar/råbollar (date or raw balls), a vegan alternative made from dried dates and nuts blended together with cocoa powder.

Chocolate ball day (chokladbollens dag) falls on May 11th.

Photo: Magnus Carlsson/


The lime-green prinsesstårta or ‘princess cake’ may look like a modern invention with it’s brightly-coloured marzipan covering, but it has been around since the beginning of the 1900s, and is named after three Swedish princesses, Margareta, Märta and Astrid, who were supposedly especially fond of the cake.

The cake consists of a sponge bottom spread with jam, crème pâtissière and a dome of whipped cream, covered in green marzipan and some sort of decoration, often a marzipan rose.

Prinsesstårtor can also be served in individual portions, small slices of a log which are then referred to as a prinsessbakelse.

Although the cakes are popular all year round, in the Swedish region of Småland, prinsesstårta is eaten on the first Thursday in March, due to this being the unofficial national day of the Småland region (as the phrase första torsdagen i mars is pronounced fössta tossdan i mass in the Småland dialect).

Since 2004, the Association of Swedish Bakers and Confectioners has designated the last week of September as prinsesstårtans vecka (Princess cake day).

Photo: Sinikka Halme, Creative Commons BY-SA 4.0.


Belonging to the more traditional cakes, a Budapestbakelse or “Budapest slice” is a type of rulltårta or “roll cake” similar to a Swiss roll, consisting of a light and crispy cake made from whipped egg whites, sugar and hazelnut, filled with whipped cream and fruit, often chopped conserved peaches, nectarines or mandarines, and rolled into a log.

The log is then sliced into individual portions and drizzled with chocolate, then often topped with whipped cream and a slice of fruit. 

Despite its name, the Budapest slice has nothing to do with the city of Budapest – it was supposedly invented by baker Ingvar Strid in 1926 and received the name due to Strid’s love for the Hungarian capital.

Of course, the Budapestbakelse also has its own day – May 1st.

Kanelbullar (left), chokladbollar (centre) and biskvier (right). Photo: Tuukka Ervasti/


Another smaller cake, a biskvi (pronounced like the French biscuit), consists of an almond biscuit base, covered in buttercream (usually chocolate flavoured), and dark chocolate.

Different variants of biskvier exist, such as a Sarah Bernhardt, named after the French actress of the same name, which has chocolate truffle instead of buttercream.

You might also spot biskvier with white chocolate, often with a hallon (raspberry) or citron (lemon) filling, or even saffransbiskvier around Christmastime.

Chokladbiskviens dag is celebrated on November 11th.