Gecko in chicken egg may be salmonella breakthrough
The Northern Territory president of the Australian Medical Association says he may have accidentally discovered how the potentially deadly salmonella bacteria gets inside chicken eggs.
Just in case people are confused by how to pronounce this, it is oo as in book, not moo. If you are from northern England/Scotland that probably won’t help you much though.
It’s also used in a range of phrases such as “you silly old chook!”
That was your main learning from that article ;)? Not that a gecko can apparently climb up a chickens cloaca and have an egg shell formed around them? I didn't really have a clear mental picture of how eggs are formed, but whatever I did have certainly didn't admit the possibility that something could climb in before the shell arrived. Nature is pretty amazing
I understood that washing eggs also removes a protective skin from the eggs that would otherwise stop bacteria from passing the shell.
Maybe it's a chicken and egg problem then.
It can also be inside the egg: "Salmonella also can contaminate the egg’s contents while it is forming inside the chicken before shells are formed. Today, a lot fewer egg-laying hens have this problem than during the 1980s and 1990s, so eggs are safer. But some eggs are still contaminated with Salmonella."
As far as I've been able to tell salmonella is capable of entering the inside of the egg through the shell, but whether this is the reason eggs are either washed immediately or not at all is something I've not been able to figure out. Salmonella happens to have some tricks to invade various types of tissue, but I don't know if that is related, or even unique to salmonella.
Eggs sold in the US are illegal to sell in the EU. Eggs sold in the EU are illegal to sell in the US. The US mandates washing eggs; the EU forbids it. The rationale being to force egg farmers to raise their hens in more sanitary conditions where the eggs won't get covered in crap in the first place (since consumers are less likely to buy eggs covered in crap).
I believe the rationale for NOT washing eggs is that the process removes a natural coating that prevents bacteria from passing through the shell into the egg contents (the white and yolk), but this leaves the outside of the egg potentially (probably) covered with harmful bacteria.
Sort of. In the US they refrigerate the eggs not because of some coating but in case there is salmonella it's less likely to spread.
You don't actually need to refrigerate eggs in the US if you never eat them raw. I have not refrigerated mine in decades - I buy them, then just leave them on the counter.
That natural coating is just oil. The US washes the egg, then reapplies the oil.
The EU forbids washing to encourage producers not to have salmonella in the first place, the US prevents the salmonella by washing. In practice the EU vaccinates their chickens against salmonella. Around half of US producers do as well.
Washing eggs is correlated with a material reduction in salmonella cases in countries that adopt it, there is science behind the practice. It is why the US adopted this practice several decades ago, and it produced the desired effect.
US food regulations require stronger mitigations against bacterial contamination than most countries pretty consistently. If you look at the long list of foods prohibited for import into the US from Europe, it is almost entirely due to insufficient mitigation of bacterial contamination. This largely revolves around traditional food processing techniques that don’t pass modern food safety standards but which get an exception in Europe for being “traditional”.
The Ministry of Agriculture, Fisheries and Food expressed anger towards Currie's comments and the Department of Health was unable to back up her claims.[1] In addition, the Ministry of Agriculture had previously tested eggs without finding any salmonella. The chance of becoming ill with salmonella was put at less than 1 in 200 million.[8]
In December 2001, a Whitehall report was revealed that had been produced in February 1989, two months after Currie's resignation, and covered up by the government. The report found that there had been a "salmonella epidemic of considerable proportions". However, Chief Medical Officer for England, Donald Acheson had urged at the time that the word "epidemic" should not be used except "in a technical sense".
I think the research still suggests that while alchohol is pretty good at killing most things, cocktails don't sit long enough for the alcohol to do much and you'd need to be 100+ proof.
Freshly laid eggs have no salmonella in them. Despite what many think egg shells are permeable, stuff gets through them, and eggs when laid generally have a fair amount of blood and shit on them which do have salmonella in them. If kept dry and at a reasonably even temperature than this is no problem. But say you stick those fresh unwashed eggs in the fridge, when you take them out moisture will condense on them and absorb into the shell along with anything on the shell, so general wisdom has always been to never refrigerate unwashed eggs.
Problem with not refrigerating eggs is that they start change after a few weeks, going bad is not the proper term, less fresh would be more apt, another few weeks and things start turning green (Dr Seuss did not invent those green eggs) and are still not bad in the sense of not being able to eat them but they are far from appetizing in anyway. Modern world requires eggs to last longer, could be 3 months before an egg hits the shelf at the grocery store, so we wash them and keep them refrigerated.
Salmonella is still on the shell of washed eggs, most comes off with the bloom (the coating on a fresh egg) but the bloom is not perfect. So we keep our washed eggs in the fridge to slow growth and store the eggs in a carton which can absorb anything which condenses on them when you take them out of the fridge.
The best by date on an egg carton mostly refers to raw consumption, moisture in the fridge and moisture that condenses on the shell when you take them out will slowly seep into the egg and carry the salmonella into the part we eat and where the salmonella can grow and multiply to dangerous levels for raw. If you have gone past the use by date you may want to skip those soft boiled or sunny side up eggs but they are fine for more firmly cooked eggs and probably fine for soft boiled and sunny side up unless you are well past the use by date.
I feel like this comment should have been read out loud to me somewhere back at school. That's the most comprehensive guide to "how to interpret best by date on an egg carton" I've ever seen. Thanks.
> But say you stick those fresh unwashed eggs in the fridge, when you take them out moisture will condense on them and absorb into the shell along with anything on the shell, so general wisdom has always been to never refrigerate unwashed eggs.
Do you have a source on this? I'm having trouble finding anything that says refrigerating unwashed eggs has any effect other than simply helping them last longer.
Maybe the general wisdom refers to taking eggs from the fridge and storing them on the counter, rather than using them?
They will last longer in the fridge, but there is little sense in leaving them unwashed if you are going to refrigerate them, you just increase the risk of salmonella getting into the eggs for the reasons I explained. The conventional wisdom I mentioned probably dates back to the days of the ice box which have rather high humidity levels due to the massive block of ice slowly melting, in a modern fridge this is not as big of an issue but humidity levels in the fridge can be quite high, depends on what food you have in there.
I can not provide a source off the top of my head, been a few years since I went through my egg curiosity phase. But it is a simple experiment, take an egg out of the fridge on a hot humid day, you will see water condense on them, and if you let it sit you will see that water absorb in, it will disappear faster than evaporation could explain. This will be easiest to see on a washed egg since the bloom on an unwashed egg helps some, but the bloom is never perfect and each time water condenses on the egg it damages the bloom.
I know fridges certainly used to have those egg compartment things in the doors, but never saw anyone actually use them - tends to be the cardboard egg box is in the fridge, this would probably absorb any extra moisture.
> Modern world requires eggs to last longer, could be 3 months before an egg hits the shelf at the grocery store, so we wash them and keep them refrigerated
Far from true everywhere, including in the UK which the article is about.
Here in Ireland, it would even be illegal to sell washed eggs in a supermarket.
I haven't checked the dates. But going by varying best-by dates, some of them must be older than few days. Ofc, I use so few I always go with the longest available date as such the freshest.
In the UK all eggs are unwashed and we mostly keep our eggs in the fridge.
I've heard the idea that it's temperature change which causes things to cross the barrier, and the fridge is the place in your kitchen with the most stable temperature.
>I've heard the idea that it's temperature change which causes things to cross the barrier, and the fridge is the place in your kitchen with the most stable temperature.
Correct, but it is not temperature change in general, it is when that change is great enough to cause condensation. Everytime you take something out of the fridge it generally will cause water to condense on the surface because of that temperature change from cold fridge to warm kitchen, same reason you glass of cold water sweats on a hot summer day.
The conventional wisdom here probably changes with region (as conventional wisdom often does) since everywhere does not have the same climate. UK is a rather damp place so fridge is probably safer for much of the year. On reflection I did not think that part through completely, did not take into account everyone having a different local climate.
The reason eggs are refrigerated in the USA and not in the EU is all about different methods of salmonella prevention.
USA regulations have eggs externally washed and disinfected, and require they be kept at a low temperature for storage and transportation. The point of washing is to remove external salmonella contamination from the outside of the egg. The washing process removes some of the natural barrier from the egg and leaves it much more susceptible to bacteria penetrating through the shell and contaminating the egg, so they must be kept cool or refrigerated to help limit and slow the bacteria penetration process.
Eggs are not refrigerated in Europe and are still generally healthy to eat. In most of the EU washing eggs is actually illegal, because it removes the protective coat that helps prevent bacteria from entering eggs. To prevent salmonella there have been some vaccination campaigns where EU chickens are mass vaccinated against salmonella (which is not a requirement in the US). I think in the UK you must have vaccinated all your egg producing chickens to be certified, but other countries are less strict.
Refrigerating with or without the protective coat extends the shelf life.
What if an egg floats when placed in a bowl of water? I've always taken this as an indication something inside has transitioned to a gas, and that such eggs are spoiled and will not longer be good to eat.
It's not that something inside has transitioned to a gas, it's that water has evaporated, shrinking the white and enlarging the air bubble (the shell is permeable to air). The egg is probably still safe to eat until it actually starts smelling bad.
Unless the rules changed within the last six years, if a hen house returns a positive environmental Salmonella Enteritidis test and the farm is large enough they must undergo an egg break test to show that the eggs themselves are not infected with SE before they can be sold to consumers. If the egg test is positive the eggs can only be sold as some form of pasteurized egg product until testing shows negative.
From the practical consumer standpoint, it is essentially true. Getting an egg with salmonella in it is like winning the lottery. But good information either way since some people do get their eggs from small farms which are exempt from testing.
Thats interesting because the egg white is rich in avidin which binds biotin which inhibits many bacterial pathogens, but not viruses because flu vaccines are grown in sterile eggs. The BBC broadcasted this with cross rail plague pits when they got a bod from porton down in to explain some of this stuff.
I can find these studies suggesting salmonella inhibits biotin in the gut[1], and this link suggesting a biotin deficiency can increase susceptibility to salmonella [2].
However one thing that can not be disputed is the reduction in choline intake from the egg yolk would have dumbed down the nation much like covid has dumbed down the world aka brain fog.
Maybe we need a law to sue political parties out of existence if they screw the nation.
I’m not sure if this is regionalisms, or an industry jargon I’m not familiar with, but I couldn’t make head or tails of “BBC broadcasted this with cross rail plague pits when they got a bod from porton down in to explain some of this stuff”. Could you help me understand?
Cross-rail is a new underground metro line in London. During digging of the tunnels, they discovered interesting archeological remains, which included plague pits (where plague victims were disposed of).
Portion Down is the site of a UK military facility specialising in research into chemical and biological hazards.
Going off heresay here, but I believe in the US, "washing" the eggs involves a high-acid solution that removes many of the layers that would otherwise keep bacteria and other bugs out. It's also the reason eggs are a such uniform-white colour, whereas elsewhere (at least here in Australia) eggs are mostly various shades of tan.
I usually store eggs outside a fridge. A pack of 18 eggs will last me about 3 weeks and I've not had one spoil yet.
Egg color has to do with breed and diet, the dominant hen type in the US produces white eggs but brown are fairly common. At the co-op I can get eggs that are blue and green, just different breed of hen. Washing does not affect color in the slightest.
I'm guessing that a co-op wouldn't use the same industrial corrosive washing that larger agri-corps do; it'd be a lot closer to how the rest of the world washes their eggs.
I would presume "co-op" here is a market, not a farm. The co-op near where I live is one if not the oldest example and is part of a giant network of co-ops... they certainly don't wash their own eggs: they source them from distributors much like any other market, and it isn't even inherent to the premise that they are using local sources (though mine does care a bit more, as it is a natural foods co-op, the goal of being a co-op is mostly about having a fair and equitable ownership model of the company that enables both employees and customers to have equity).
> Despite what many think egg shells are permeable, stuff gets through them, and eggs when laid generally have a fair amount of blood and shit on them which do have salmonella in them.
In Europe eggs are sold unwashed and I can assure you there is nothing on them except for a white or brownish shell. Occasionally a down gets lost in the packaging - that's it. The shell gets permeable when the protective layers are removed by washing it and that's why eggs are sold refrigerated in the US. In Europe eggs are neither washed nor refrigerated.
They're cleaning the eggs somehow. Maybe they're not washing them, and I don't know about the rest of the comment, but having chickens myself and getting eggs from others all my life, chicken eggs are not clean besides an occasional feather by any stretch of the imagination. Poop is plentiful.
Maybe they're getting a thorough wipe? That's about the only way I could imagine this happening, unless you have 24/7 surveillance to clean as soon as they poop and snatch up the eggs. Even then, both sometimes happen simultaneously.
The whole point is to preserve the protective coating and I don't see how this can happen when you clean the eggs. I'm not a chicken farmer though and maybe the dirt
is removed somehow.
They aren't washing them. More commercial operations might brush them with a dry brush (to remove dirt and chicken poop), while others are just collecting them more immediately, but it's illegal in Europe to wash eggs -- which is required by law in America. Washing eggs removes the bloom, which coats them and protects the permable egg from infection. The trade-off is that European eggs should be washed just before use.
In America, we mandate that eggs are washed in a chemical bath. This diminishes the bloom and replaces it with a chemical wash.
Both mechanisms are ostensibly intended to prevent Salmonella, but I don't have data on which is more effective.
As this piqued my interest I tried to find data but it is complicated mainly by the fact that vaccination rates are vastly different. If we go by raw, reported Salmonella cases the American approach seems to be significantly safer, but then again we seem not to have a good idea about the unreported cases. It probably doesn't help that it is a politically charged topic too - see
"Eggwina" in the UK [1].
I have chickens and as long as I keep their nesting boxes clean, the eggs will be there with no blood or shit on them. In my limited experience I have never seen blood on eggs.
This is a tangent, but Wikipedia is my favorite place for fun facts. Many people I’ve talked to don’t know that Wikipedia has a random button, which will take you to a random article. It’s one of the best ways to kill an afternoon.
If the noise/ratio per roll of the random button is too high for you, I built an infinite scroll version of Wikipedia for myself using a similar mechanism, you’re free to use it:
Salmonella gives you bacterial gastroenteritis, aka food poisoning. Vulnerable people may be hospitalized, very few die. Most people just shit/vomit and are soon better. It's not fun, but it's also not something to freak out about, for healthy people.
Wash your hands with soap and water after handling eggs, poultry, pork, birds, reptiles, or really, just... any time it's convenient. Eat fresh foods. Cook pork and chicken.... enough... and if you don't, just make sure it's fairly fresh and was handled by a reputable source.
> CDC estimates Salmonella bacteria cause about 1.35 million infections, 26,500 hospitalizations, and 420 deaths in the United States every year. Food is the source for most of these illnesses.
When I lived in a rural area I ate hundreds of raw eggs from backyard chickens without issue (though I'd always rinse the shell before cracking). They typically have orange yolks and are rich in flavor so they taste great whisked in a glass with hot or Worcestershire sauce, at the bottom of a beer, in bourbon flips and whiskey sours, on steak tartare, etc. I was always under the impression that the Salmonella thing was mostly a myth, but I'll be sure to do some additional research before resuming this practice.
78 comments
[ 5.2 ms ] story [ 188 ms ] threadI guess this story is related to the egg beaters product becoming popular, since it was pasteurized.
https://www.abc.net.au/news/2008-05-15/gecko-in-chicken-egg-...
It’s also used in a range of phrases such as “you silly old chook!”
Chook is such an every day usage word in my part of the world..
"Cooked chook" (roast chicken) "silly chook" (silly woman)
etc etc
eggs should be washed just before use and not before, but in the us we wash them before shipping
Which is, in fact, what the US does.
https://www.cdc.gov/foodsafety/communication/salmonella-and-...
But you're right that the super market displays them on ordinary (not refrigerated) shelves.
You don't actually need to refrigerate eggs in the US if you never eat them raw. I have not refrigerated mine in decades - I buy them, then just leave them on the counter.
Also you can raise them in special trays that remove both the eggs and the waste immediately, reducing how much gets on the egg.
The EU forbids washing to encourage producers not to have salmonella in the first place, the US prevents the salmonella by washing. In practice the EU vaccinates their chickens against salmonella. Around half of US producers do as well.
US food regulations require stronger mitigations against bacterial contamination than most countries pretty consistently. If you look at the long list of foods prohibited for import into the US from Europe, it is almost entirely due to insufficient mitigation of bacterial contamination. This largely revolves around traditional food processing techniques that don’t pass modern food safety standards but which get an exception in Europe for being “traditional”.
The Ministry of Agriculture, Fisheries and Food expressed anger towards Currie's comments and the Department of Health was unable to back up her claims.[1] In addition, the Ministry of Agriculture had previously tested eggs without finding any salmonella. The chance of becoming ill with salmonella was put at less than 1 in 200 million.[8]
In December 2001, a Whitehall report was revealed that had been produced in February 1989, two months after Currie's resignation, and covered up by the government. The report found that there had been a "salmonella epidemic of considerable proportions". However, Chief Medical Officer for England, Donald Acheson had urged at the time that the word "epidemic" should not be used except "in a technical sense".
Problem with not refrigerating eggs is that they start change after a few weeks, going bad is not the proper term, less fresh would be more apt, another few weeks and things start turning green (Dr Seuss did not invent those green eggs) and are still not bad in the sense of not being able to eat them but they are far from appetizing in anyway. Modern world requires eggs to last longer, could be 3 months before an egg hits the shelf at the grocery store, so we wash them and keep them refrigerated.
Salmonella is still on the shell of washed eggs, most comes off with the bloom (the coating on a fresh egg) but the bloom is not perfect. So we keep our washed eggs in the fridge to slow growth and store the eggs in a carton which can absorb anything which condenses on them when you take them out of the fridge.
The best by date on an egg carton mostly refers to raw consumption, moisture in the fridge and moisture that condenses on the shell when you take them out will slowly seep into the egg and carry the salmonella into the part we eat and where the salmonella can grow and multiply to dangerous levels for raw. If you have gone past the use by date you may want to skip those soft boiled or sunny side up eggs but they are fine for more firmly cooked eggs and probably fine for soft boiled and sunny side up unless you are well past the use by date.
Do you have a source on this? I'm having trouble finding anything that says refrigerating unwashed eggs has any effect other than simply helping them last longer.
Maybe the general wisdom refers to taking eggs from the fridge and storing them on the counter, rather than using them?
I can not provide a source off the top of my head, been a few years since I went through my egg curiosity phase. But it is a simple experiment, take an egg out of the fridge on a hot humid day, you will see water condense on them, and if you let it sit you will see that water absorb in, it will disappear faster than evaporation could explain. This will be easiest to see on a washed egg since the bloom on an unwashed egg helps some, but the bloom is never perfect and each time water condenses on the egg it damages the bloom.
Far from true everywhere, including in the UK which the article is about.
Here in Ireland, it would even be illegal to sell washed eggs in a supermarket.
Here in EU eggs have printed on them the date they were laid, I never seen eggs in a supermarket more than a few days older.
I've heard the idea that it's temperature change which causes things to cross the barrier, and the fridge is the place in your kitchen with the most stable temperature.
Correct, but it is not temperature change in general, it is when that change is great enough to cause condensation. Everytime you take something out of the fridge it generally will cause water to condense on the surface because of that temperature change from cold fridge to warm kitchen, same reason you glass of cold water sweats on a hot summer day.
The conventional wisdom here probably changes with region (as conventional wisdom often does) since everywhere does not have the same climate. UK is a rather damp place so fridge is probably safer for much of the year. On reflection I did not think that part through completely, did not take into account everyone having a different local climate.
USA regulations have eggs externally washed and disinfected, and require they be kept at a low temperature for storage and transportation. The point of washing is to remove external salmonella contamination from the outside of the egg. The washing process removes some of the natural barrier from the egg and leaves it much more susceptible to bacteria penetrating through the shell and contaminating the egg, so they must be kept cool or refrigerated to help limit and slow the bacteria penetration process.
Eggs are not refrigerated in Europe and are still generally healthy to eat. In most of the EU washing eggs is actually illegal, because it removes the protective coat that helps prevent bacteria from entering eggs. To prevent salmonella there have been some vaccination campaigns where EU chickens are mass vaccinated against salmonella (which is not a requirement in the US). I think in the UK you must have vaccinated all your egg producing chickens to be certified, but other countries are less strict.
Refrigerating with or without the protective coat extends the shelf life.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC173326/
Unless the rules changed within the last six years, if a hen house returns a positive environmental Salmonella Enteritidis test and the farm is large enough they must undergo an egg break test to show that the eggs themselves are not infected with SE before they can be sold to consumers. If the egg test is positive the eggs can only be sold as some form of pasteurized egg product until testing shows negative.
Page 47 if you're bored. https://www.govinfo.gov/content/pkg/FR-2009-07-09/pdf/E9-161...
I can find these studies suggesting salmonella inhibits biotin in the gut[1], and this link suggesting a biotin deficiency can increase susceptibility to salmonella [2].
However one thing that can not be disputed is the reduction in choline intake from the egg yolk would have dumbed down the nation much like covid has dumbed down the world aka brain fog.
Maybe we need a law to sue political parties out of existence if they screw the nation.
[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4504957 [2] https://academic.oup.com/nutritionreviews/article-abstract/4...
Portion Down is the site of a UK military facility specialising in research into chemical and biological hazards.
/Brit
I usually store eggs outside a fridge. A pack of 18 eggs will last me about 3 weeks and I've not had one spoil yet.
In Europe eggs are sold unwashed and I can assure you there is nothing on them except for a white or brownish shell. Occasionally a down gets lost in the packaging - that's it. The shell gets permeable when the protective layers are removed by washing it and that's why eggs are sold refrigerated in the US. In Europe eggs are neither washed nor refrigerated.
Maybe they're getting a thorough wipe? That's about the only way I could imagine this happening, unless you have 24/7 surveillance to clean as soon as they poop and snatch up the eggs. Even then, both sometimes happen simultaneously.
In America, we mandate that eggs are washed in a chemical bath. This diminishes the bloom and replaces it with a chemical wash.
Both mechanisms are ostensibly intended to prevent Salmonella, but I don't have data on which is more effective.
[1] https://en.m.wikipedia.org/wiki/Salmonella-in-eggs_controver...
edit: i'm getting down voted for saying that i want eggs directly from a small farm
If the noise/ratio per roll of the random button is too high for you, I built an infinite scroll version of Wikipedia for myself using a similar mechanism, you’re free to use it:
http://wikiscroll.blankenship.io/
Wash your hands with soap and water after handling eggs, poultry, pork, birds, reptiles, or really, just... any time it's convenient. Eat fresh foods. Cook pork and chicken.... enough... and if you don't, just make sure it's fairly fresh and was handled by a reputable source.
https://www.cdc.gov/salmonella/index.html
~2% chance of an infection leading to hospitalization sounds pretty bad to me.
> 26,500 hospitalizations, and 420 deaths
There are 33,000 automobile deaths in the US per year.
You're more likely to die on the way to work than be hospitalized due to Salmonella.
If you do end up in the hospital, you are unlikely to die.
I got salmonella in a verified outbreak almost 20 years ago and my digestion has never been quite the same.