Sunday, July 15

New math turns up salmonella not European diseases might have caused 'genocidal' epidemic in Aztec Empire

The passage I found the scariest in the stunning report is that the epidemic was exacerbated by drought. As to salmonella, it's still very much with us. So before I turn to the Aztec empire,  a couple reports about recent salmonella outbreaks in the USA. I had no idea, until I read the second report, that salmonella could occur 'in shell' -- not just in prepared egg dishes and shelled eggs. 

And to think the contaminated eggs came from America's second-largest egg producer is unsettling; those eggs went to many stores and restaurants across America.  

Emphasis throughout the following reports is mine.

1. "Do Not Eat" Kellogg's Honey Smacks cereal, CDC Warns by Patrick Jarenwattananon; NPR, July 13, 2018

The Centers for Disease Control and Prevention is telling people not to eat Kellogg's Honey Smacks cereal, which has been linked to an outbreak of salmonella infections now numbering at least 100 people in 33 states.

"Do not eat this cereal," the agency declared on Twitter.

An updated advisory from the CDC recommends that consumers throw away the sweetened, puffed wheat cereal "regardless of package size or best-by date." It's still not clear how the contamination might have occurred.

According to the CDC, Salmonella mbandaka bacteria have been found in unopened Honey Smacks cereal in California as well as opened boxes collected from the homes of ill people in Montana, New York and Utah. A case count map breaks down the location and prevalence of cases, the first of which was reported in early March.

The warning issued Thursday strengthens the guidance associated with a voluntary Honey Smacks recall by Kellogg's a month ago. Since then, 27 more salmonella infections have been reported. No deaths have been reported but there have been 30 hospitalizations.

According to the Food and Drug Administration, people infected with salmonella can experience diarrhea, abdominal cramps and fever. The illness usually resolves itself within a week if people are properly hydrated.

Salmonella bacteria live in intestinal tracts and are usually transmitted through contaminated food or water or contact with animals.

The CDC estimates that approximately 1.2 million illnesses and 450 deaths are caused by salmonella every year. This year alone has seen announcements of smaller salmonella outbreaks linked to pre-cut melon, eggs [see second report below], dried and frozen coconut, raw sprouts, prepared chicken salad, and the plant kratom [never heard of kratom before]
, as well as backyard chickens and pet guinea pigs.

2. 207 Million Eggs Are Recalled Over Salmonella Fears; NPR, April 16, 2018

The Rose Acre Farms company is voluntarily recalling 206,749,248 eggs in a total of nine states, saying they "have the potential to be contaminated with salmonella braenderup" — which can sicken healthy adults and have serious and possibly fatal effects for young children and the elderly.

The eggs came from a farm in Hyde County, N.C., and have been labeled under a number of brands, including Coburn Farms, Country Daybreak, the Food Lion store brand, Crystal Farms, Great Value and Sunshine Farms. Some were sold to restaurants, including Waffle House.

So far, contaminated eggs have been linked to 22 reported illnesses, according to the recall notice on the Food and Drug Administration's website, which includes a full list of the recalled products.

Retail outlets and some restaurants in the following states should be on the lookout for the eggs, Rose Acre Farms says: Colorado, Florida, New Jersey, New York, North Carolina, Pennsylvania, South Carolina, Virginia and West Virginia.

The recall covers egg cartons that have the plant number P-1065 and Julian date ranges of 011 through 102. (The three-digit Julian Code refers to consecutive day of the year, meaning the recalled eggs were packed from Jan. 11 through April 12.)

"If anyone has the recalled eggs in their home, they should not eat them," the FDA says.

The recall of more than 206 million eggs prompts a question: What will happen to all those eggs? In food recall cases such as this, the FDA says, the point isn't to regather all of them — but instead to protect the public. The FDA and Rose Acre Farms are urging consumers either to throw the eggs away or to return them for a refund. Consumers and restaurants also should thoroughly clean any surfaces or utensils that might have come into contact with the eggs.

Rose Acre Farms is based in Seymour, Ind., and says it is the second-largest egg producer in the U.S.

The FDA says its investigators worked with state health officials to trace a number of recent salmonella infections to egg dishes — and eventually linked them to the Rose Acre Farms location in North Carolina. Testing of samples from that farm revealed the same strain of the bacteria that was recorded in the illnesses.

The investigation is continuing, the FDA says.


Salmonella May Have Caused Massive Aztec Epidemic, Study Finds
By Rebecca Hersher
January 15, 2018

In 1545, people in the Mexican highlands starting dying in enormous numbers. People infected with the disease bled and vomited before they died. Many had red spots on their skin.

It was one of the most devastating epidemics in human history. The 1545 outbreak, and a second wave in 1576, killed an estimated 7 million to 17 million people and contributed to the destruction of the Aztec Empire.

But identifying the pathogen responsible for the carnage has been difficult for scientists because infectious diseases leave behind very little archaeological evidence.

"There have been different schools of thought on what this disease was. Could it have been plague? Could it have been typhoid fever? Could it have been a litany of other diseases?" says Kirsten Bos, a molecular paleopathologist at the Max Planck Institute in Germany, and an author of a new study published Monday in Nature Ecology and Evolution.

The study analyzes DNA from the teeth of 10 people who died during the epidemic and pinpoints a possible culprit: a type of salmonella that causes a deadly fever.

A new algorithm allowed Bos and her team to identify fragments of ancient salmonella DNA with extreme specificity.

"It was an analytical technique that was really the game-changer for us," Bos explains. While scientists have been able to extract ancient DNA from bones and other tissue, until recently it was impossible to compare that extracted DNA to a wide variety of potential matches.

But a new computer program called MALT allowed them to do just that. "The major advancement was this algorithm," Bos says. "It offers a method of analyzing many, many, many small DNA fragments that we get, and actually identifying, by species name, the bacteria that are represented."

Bos and her team used MALT to match up the DNA fragments extracted from teeth of epidemic victims with a database of known pathogens. The program didn't entirely  save them from mind-numbing work — at one point PhD student and study author Ashild Vagene had to go through the results of the program by hand.

In the end, they found evidence of the deadly Salmonella enterica Paratyphi C bacteria.

The study does not pinpoint the source of the bacteria, which is an area of great interest for biologists and archaeologists alike. The authors note that many epidemics of the period are believed to originate with European invaders who arrived in the region in the early part of the 16th century, but the new research doesn't present biological evidence for or against that.

A previous study suggested the pathogen responsible for the epidemic originated in Mexico, and that the epidemic was exacerbated by drought. And, Bos notes, "the Europeans who were observing the symptoms didn't know what it was, and Europeans got it as well," which suggests it wasn't a disease endemic to Europe.

But even if Europeans did not introduce the pathogen, they may still be responsible for its profound deadliness among indigenous people. "We know that Europeans very much changed the landscape once they entered the new world," Bos says. "They introduced new livestock, [and] there was lots of social disruption among the indigenous population which would have increased their susceptibility to infectious disease."


I don't have statistics to back up my impression that food  recalls have gotten more frequent in the USA during the past few years. In any case, a variety of factors other than bad food could be greatly responsible for any perceived increase in food poisoning cases in the USA: 
  • Increased public awareness about food poisoning
  • More stringent government food safety standards
  • Better food industry oversight methods
  • Faster government reporting on food recalls
  • Better coordination between medical facilities that treat food poisoning and government agencies that deal with food safety.
With all that said, the processing of foodstuffs has become a mega-industry in the United States (and of course in several other countries), and this includes the gigantic trade in food imports and exports. With the huge volume of food products, even the best safety standards can't ward off every instance of bad food. Often it's not until an outbreak of food poisoning that there's warning about a bad food. Then comes the race to identify the exact source, which can be just a few batches of a particular product. 

I guess the lesson is to be vigilant not only about food but also about symptoms of illness that could easily be dismissed at first as 'upset stomach' and treated with OTC medications.  Get thee to a doctor if symptoms that could be associated with salmonella poisoning linger for more than a day.  




sykes.1 said...

It is important to note that all versions of salmonella infection are the result of lack of simple personal hygiene, such as washing one's hands after using the toilet or handling poultry. Infection is by direct contact with infected persons or the objects and food and beverages they handled. Salmonellosis is a classical food/beverage/contact borne disease, and the preventive measures have been known for over 100 years. But some people are still unaware. It is not transmitted by air. It's infective powers are somewhat limited, because stomach acids kill the bacterium, and it takes a significant dose to cause the disease. Sixteenth Century Indians and Europeans were still in the dark ages regarding all kinds of disease.

Pundita said...

Sykes -- Your note explains why drought exacerbates epidemics. Overcrowding would then finish the job of transforming an epidemic into pandemic.

The big surprise for me was that chicken embryos could be infected with salmonella -- although granted I never thought about it before. The poultry 'factories' in the USA stuff so many chickens together that the carcasses are rinsed in chlorine, although this does not necessarily kill all the bacteria on chicken meat sold commercially. But chlorine rinse wouldn't have any effect on infected egg embryos.

So if just one employee handling chickens in a chicken factory doesn't observe proper hygiene, one infected chicken used for egg-laying could touch off an outbreak of salmonella that could spread to hundreds of thousands of factory chickens. Maybe that's how Rose Acre Farms ended up trying to 'recall' 207 million suspect eggs -- an impossible task.