How the screwworm’s sex life saved steaks

NPR’s Goats and Soda reports that over the past 70 years, the U.S. has been waging a war against a miniature menace: the New World screwworm.

The fly survives by eating warm-blooded flesh: A fly lands on a wound in the skin and lays hundreds of eggs. The eggs hatch into swarms of wormlike larvae, which then burrow into the wound. The larvae have little ridges on their surface, which makes them look like screws inserted into skin. The larvae gorge on the flesh for a few days until they’re full and then fall out of the wound.

screwworm_1-0e3313ab520bc20e0c62493961b88c9b1ae98d53-s1100-c85In the early 20th century, the critters were wreaking havoc on the beef industry. They were costing farmers millions of dollars each year, not just in the U.S. but also in Central and South America. One infection could “kill a fully grown steer in 10 days,” The New York Times wrote in 1977. So in the 1930s, the U.S. Department of Agriculture hired a bunch of scientists to study the fly.

One of them was Edward F. Knipling, a young entomologist who had grown up on a Texas cattle farm. Specifically, Knipling wanted to sterilize a bunch of male flies in the lab and then unleash them into the wild. With enough impotent flies out there courting the ladies, the fly population would eventually plummet, Knipling theorized. Other scientists balked at the idea. They didn’t think it would work.

“Scientists would say, ‘You just can’t castrate enough flies,’ ” says Knipling’s son, Edward B. Knipling. “Telling people you’re going to study the sex life of the screwworm gets some chuckles even today,” the son says. “But in the 1930s, it was such a brand new idea. The scientific community thought my dad was pulling their leg.” But Knipling was dead serious. And for more than two decades, he worked on the fly sterilization project with his colleague Raymond Bushland. They devised a way to grow millions of flies in the lab, using big vats of ground beef, warmed up to body temperature. They figured out how to sterilize the flies using gamma rays — a new technology that came out of research on the atomic bomb. By 1958, Knipling and Bushland had convinced the U.S. government to start air dropping the sterilized male flies across Florida. Each week they unleashed 50 million flies. And what do you know? It worked. Screwworm flies started to disappear. Cattle no longer died from larval intrusion. By early 1959, the screwworm had disappeared from the entire Southeast U.S. “From there, the snowball got rolling,” Edward B. Knipling says. The government started airdropping the flies across Texas, the Southwest and eventually into Mexico and Central America. By 1997, the project had wiped out screwworms all the way from Texas to Panama. Even today the USDA continues to release flies in Panama to prevent fertile males from sneaking out of South America and reinfecting the U.S.

 “It creates a buffer zone,” Edward B. Knipling says. Eradication of the screwworm has saved farmers in North and Central Americas billions of dollars, the USDA says. It has reduced the price of beef. The U.N. called it one of the “greatest achievements in animal health” in the 20th century. This September, Knipling and Bushland will posthumously be given theGolden Goose Award, which honors “seemingly obscure, federally funded research” that has led to big breakthroughs.

Family graduation party in Michigan sickens six

A graduation party in the Sturgis area is suspected of being the source of foodborne illness last weekend that affected six people.

diploma-cookiesAccording to Steve Andriaachi, environmental health officer for Branch-Hillsdale-St. Joseph Community Health Agency, a member of the family with food service background catered the party. There has been no laboratory report completed yet regarding what caused the illness. Andriaachi said it is too early to release any details about the investigation.

Australia: Almost 200 children home sick from Adelaide school

Some classes at Modbury West Primary School, which has 420 enrolments, had less than 10 students in attendance Friday.

Modbury West Primary SchoolPrincipal Deb Hancock told the school sent a text message to parents on Thursday informing them many children had been unwell.

The text message also asked parents to keep children at home if they felt sick.

Ms Hancock said a dozen students were sent home on Thursday on the same day there were 80 children absent from class, after they showed gastro symptoms.

Food safety raid on flour, curry powder units

I never knew what masala was until Sorenne really liked the Indian chicken takeaway.

sorenne.jacques.jun.16So I’ve been trying to recreate the dish at home.

Guess it can suck at food safety too.

Food safety officials inspected 21 large-scale manufacturing units making curry, masala powders and flour on Wednesday. Six of the units were issued improvement notices while a fine of Rs.75,000 was imposed on five others.

Officials collected 20 statutory samples of curry powders and 36 surveillance samples for quality checks.

Food safety officials closed down a Nirapara roller flour mill at Attingal where raw materials like wheat were found to be stored in unhygienic and unclean conditions.

In Palakkad district, food safety officials seized and sealed stocks of cumin, coriander and turmeric from the Aanakkara Food Processing and Export Pvt. Ltd., as these were found to be sub-standard.

People are barfing: Bolthouse Farms once again messes up food safety

In Sept. 2006, carrot juice produced by Bolthouse Farms sickened 2 people in Toronto, one in Quebec, and two people in Atlanta and two others in the U.S. with botulism.

recalled-Bolthouse-Farms-protein-shakesThe company maintained – and still does – that all these consumers in these different places were at fault because they did not properly refrigerate the juice, all at the same time.

All of these people fell into comas.

The juice was ordered off North American store shelves toward the end of September, 2006.

Carrots are grown in soil. Clostridium botulinum is everywhere. Sporulation is controlled by refrigeration. This was a failure by Bolthouse Farms, not consumers.

Now, the same company is recalling a selection of protein drinks due to possible spoilage that may cause the beverages to appear lumpy, taste unpleasant and have an off odor.

These products should not be consumed. The issue was identified after the company received consumer complaints, including reports of illness. The cause of this issue is currently under investigation.

The recall affects 3.8 million bottles that have been distributed nationally in the United States.

Bolthouse Farms is advising people not to drink these beverages and return them to the store where purchased for a full refund. For more information call 1-866-535-3774 between 6:00am to 7:00pm PST, Monday to Friday or visit Facebook/BolthouseFarms.

These folks really need to boost their food safety game.


56 sickened with campy in chicken liver pate in 2013 at Aust. National University: the scientific write-up

In Oct. 2013, 56 students were stricken by Campylobacter linked to poorly prepared liver pate and severed at an end-of-year celebration at Burgmann College, part of Australian National University.

chicken-liver-pate-2The Canaberra Times reported in 2014 some of the students planned to sue Scolarest, the company that feeds the college of 350 students.

No idea if that ever went anywhere.

But here’s that scientific paper that was recently published.

In October 2013, public health authorities were notified of a suspected outbreak of gastroenteritis in students and guests following a catered function at a university residential college. A retrospective cohort study was undertaken to examine whether foods served at the function caused illness.

A total of 56 cases of gastroenteritis, including seven laboratory-confirmed cases of Campylobacter jejuni infection, were identified in 235 eligible respondents. Univariate analysis showed a significant association with a chicken liver pâté entrée [relative risk (RR) 3·64, 95% confidence interval (CI) 2·03–6·52, P < 0·001], which retained significance after adjustment for confounding via multivariable analysis (adjusted RR 2·80, 95% CI 1·26–6·19, P = 0·01). C. jejuni and C. coli were also isolated in chicken liver pâté recovered from the college’s kitchen.

Subsequent whole genome multilocus sequence typing (wgMLST) of clinical and food-derived C. jejuni isolates showed three genetically distinct sequence types (STs) comprising ST528, ST535 (both clinically derived) and ST991 (food derived).

The study demonstrates the value of utilizing complementary sources of evidence, including genomic data, to support public health investigations. The use of wgMLST highlights the potential for significant C. jejuni diversity in epidemiologically related human and food isolates recovered during outbreaks linked to poultry liver.

A large outbreak of Campylobacter jejuni infection in a university college caused by chicken liver pâté, Australia, 2013

Epidemiology and Infection; May 2016

DOI: 10.1017/S0950268816001187

Hygiene hypothesis variation: The parasite underground

human.whipwormVik was in his late 20s, blood started appearing in his stool. He found himself rushing to the bathroom as many as nine times a day, and he quit his job at a software company.

He received a diagnosis of severe ulcerative colitis, an inflammatory condition of the colon. Steroids, which suppress inflammation, didn’t work for him. Sulfasalazine suppositories offered only the slightest relief. A year and a half after his diagnosis, Vik’s gastroenterologist warned him that because his disease was poorly controlled, he risked developing a condition called toxic megacolon: His inflamed intestines might rupture, leading to blood infection, septic shock or death.

The doctor recommended infusions of cyclosporine, a powerful immune-suppressant drug. Vik looked it up and learned that the drug, often given to transplant recipients, in rare instances can increase the risk of fatal infection and certain cancers. And if cyclosporine didn’t work, the next intervention would probably be the surgical removal of his colon. Vik might have to wear a colostomy bag for the rest of his life.

“I had a feeling there had to be a better way,” he told me recently. (Worried about being stigmatized, Vik asked that I identify him only by his first name.) He began researching ulcerative colitis and discovered that the prevalence of inflammatory bowel disease — an umbrella term that includes both ulcerative colitis and Crohn’s disease — had increased markedly in the United States over the 20th century. Yet the disease was less common in the developing world. He learned that exposure to dirt and unsanitary conditions early in life seemed to protect against these and other inflammatory diseases later. And then he encountered an explanation for the correlations in the research of a scientist named Joel Weinstock.

Weinstock, a gastroenterologist now at Tufts University, thought that parasites were to blame. But it wasn’t their presence in the human digestive system that was causing the rise; it was their absence. To survive for years in another animal, parasitic worms, known as helminths, counter their hosts’ defenses. Because an out-of-control immune response against native bacteria was thought to drive inflammatory bowel disease, Weinstock’s insight was that parasites’ ability to disarm the immune system might prevent the disorder. The broader implication was that the disappearance of parasites — largely eradicated from American life in the early 20th century through improvements in sanitation — might have left our immune systems unbalanced, increasing our vulnerability to all types of inflammatory disorders.

Whipworm-Pictures-1To Vik, Weinstock’s idea was the first cogent explanation for his disease. It also pointed toward a solution. Weinstock was already experimenting with “re-parasitizing” people with inflammatory bowel disease, using a helminth called Trichuris suis, the pig whipworm. He had chosen the species because, in theory, it can’t reach sexual maturity in humans and spread from one person to another. Early, small studies yielded impressive results, with 43 percent of colitis patients seeing improvement after 12 weeks of whipworm eggs, but Vik thought the use of pig whipworm had a flaw. It required continual dosing, and it could cost tens of thousands of dollars a year (a German company was producing the eggs for human consumption; in the United States, selling them to treat a disease is illegal). And most important, if he expected a parasite to change his immune system, he believed, a species adapted to humans, not pigs, was likely to do a better job.

Vik wanted human whipworm. This helminth, which reaches about 1.5 inches in length, fixes itself into the wall of the large intestine and feeds off the organ’s secretions for perhaps two years. The potential results of severe whipworm infection include anemia, clubbed fingers and, in children, stunted growth. But after exhausting his other options, Vik began to think of infecting himself with parasites as the most rational course of action. After all, the parasite had been with people since prehistory; Ötzi the Iceman, the 5,300-year-old mummy found frozen in the Italian Alps, had whipworm. Besides, the worst possible outcome of a whipworm infection was a kind of inflammatory bowel disease. And he already had that.

His doctor was dead set against the idea, Vik told me. So was his wife, a doctor in training. (They later divorced.) Vik is a driven, entrepreneurial type, though, and undeterred, he began emailing any expert who “would listen to my crazy ideas.” In 2004, he flew to Bangkok to meet a parasitologist who agreed to hear him out. He brought along his father, a professor and internist, for “gravitas.” (Vik’s father, who worked in Southeast Asia as a young doctor, told me it was common then to leave light whipworm infections untreated.)

The Thai parasitologist later handed him a vial of fluid containing whipworm eggs. Microscopic in size, they had come from an 11-year-old girl in southern Thailand, he was told. Vik flew home.

Next began what Vik describes as “the most difficult part” of his life. He set up a lab in his parents’ Southern California home and stocked it with a microscope, petri dishes, slides and flasks purchased on eBay. But he couldn’t get the eggs to “embryonate.” Just as chicken eggs need to incubate to hatch, helminth eggs require “embryonation” to produce infective larvae. Parasite eggs are excreted in feces, and in their native tropics, that embryonation occurs naturally after the eggs spend time in warm, humid conditions. But reproducing those conditions in his parents’ house proved difficult. He tried various conditions — warm, wet, cool, dry, light, dark — to no avail: The eggs remained inert. Swallowed in this state, they would pass right through his gut without hatching.

The breakthrough came when, imagining defecation under a tree, Vik abandoned his goal of antiseptic incubation and began using nonsterile tap water in the petri dish. Now the eggs, football-shaped and translucent under the microscope, began to display a knotted, ropy shape within — developing larvae — indicating embryonation. Months after returning from Thailand, he finally drank a glass of water containing a few hundred whipworm eggs.

Three months later, he swallowed another thousand eggs. Ova began showing up in his stool, indicating that his body now hosted living, breeding parasites. When he tapered off his drugs, his colitis remained quiescent. Instead of triumph, though, Vik felt doubt. Was this real? Or was it a natural ebb in his disease? “I wanted proof,” he told me.

The story goes on to say that over the past decade, thousands of people around the world have introduced parasites into their bodies on purpose, hoping to treat immune-related disorders. Some have drawn inspiration directly from Vik’s case study, which appeared in the journal Science Translational Medicine in 2011. But many more have been inspired by the same research that inspired Vik. A confluence of factors is driving what is essentially an amateur quest to “rewild” the modern body and restore it to an imagined prelapsarian state. The internet has facilitated the sharing of information, both reliable and not. But maybe more important, scientists are wrestling with germ theory, a cornerstone of modern medicine, and beginning to articulate a more nuanced idea: that the organisms in our bodies not only make us sick but also keep us healthy. Participants in the parasite underground see themselves as acting on this new emerging paradigm.

Homemade or prison-made, hootch has risks

The Centers for Disease Control and Prevention is investigating a botulism outbreak at the federal prison in Yazoo City after 17 inmates became ill from drinking homemade alcohol.

27-Alcohol-Still-Heating-CoilLast week, the inmates consumed alcohol they made in the prison, according to Mississippi Department of Health spokesperson Liz Sharlot.

The inmates then began showing signs of botulism and required hospitalization. They were transferred to three hospitals in the Jackson area and each received an anti-toxin, Sharlot said.

To date, 15 of the 17 inmates remain hospitalized, according to a press release issued by the Federal Bureau of Prisons. One inmate was transferred to a federal prison in Oklahoma City before he began showing signs of botulism. He was also hospitalized.

According to Sharlot, the inmates were hospitalized over the course of the week, with one hospitalized over the weekend.

The outbreak is the sixth botulism  in the United States prison system since 2004, Sharlot said.

Meanwhile, a Queensland father has been found guilty of killing his son and two friends — and seriously injuring a second son — by accidentally giving them a toxic home brew.

The jury delivered its verdict against William Neil Clarence Lynam after three hours of deliberation, finding him guilty of three counts of manslaughter and one of grievous bodily harm.

Lynam had pleaded not guilty to each of the four charges.


Better environmental control, less Legionnaires’ disease

Background: The number of reported cases of Legionnaires’ disease, a severe pneumonia caused by the bacterium Legionella, is increasing in the United States. During 2000–2014, the rate of reported legionellosis cases increased from 0.42 to 1.62 per 100,000 persons; 4% of reported cases were outbreak-associated. Legionella is transmitted through aerosolization of contaminated water. A new industry standard for prevention of Legionella growth and transmission in water systems in buildings was published in 2015. CDC investigated outbreaks of Legionnaires’ disease to identify gaps in building water system maintenance and guide prevention efforts.

legionaires.jun.16Methods: Information from summaries of CDC Legionnaires’ disease outbreak investigations during 2000–2014 was systematically abstracted, and water system maintenance deficiencies from land-based investigations were categorized as process failures, human errors, equipment failures, or unmanaged external changes.

Results: During 2000–2014, CDC participated in 38 field investigations of Legionnaires’ disease. Among 27 land-based outbreaks, the median number of cases was 10 (range = 3–82) and median outbreak case fatality rate was 7% (range = 0%–80%). Sufficient information to evaluate maintenance deficiencies was available for 23 (85%) investigations. Of these, all had at least one deficiency; 11 (48%) had deficiencies in ≥2 categories. Fifteen cases (65%) were linked to process failures, 12 (52%) to human errors, eight (35%) to equipment failures, and eight (35%) to unmanaged external changes.

Conclusions and Implications for Public Health Practice: Multiple common preventable maintenance deficiencies were identified in association with disease outbreaks, highlighting the importance of comprehensive water management programs for water systems in buildings. Properly implemented programs, as described in the new industry standard, could reduce Legionella growth and transmission, preventing Legionnaires’ disease outbreaks and reducing disease.

Deficiencies in environmental control identified in outbreaks of Legionnaires’ disease — North America, 2000–2014


L.E. Garrison, J.M. Kunz, L.A. Cooley, M.R. Moore, C. Lucas, S. Schrag, J. Sarisky, C.G. Whitney

Blame celebrity chefs and lack of thermometer use: Campy increases in undercooked chicken livers

In the United Kingdom, outbreaks of Campylobacter infection are increasingly attributed to undercooked chicken livers, yet many recipes, including those of top chefs, advocate short cooking times and serving livers pink.

chicken-liver-pate-2During 2015, we studied preferences of chefs and the public in the United Kingdom and investigated the link between liver rareness and survival of Campylobacter. We used photographs to assess chefs’ ability to identify chicken livers meeting safe cooking guidelines.

To investigate the microbiological safety of livers chefs they preferred to serve, we modeled Campylobacter survival in infected chicken livers cooked to various temperatures. Most chefs correctly identified safely cooked livers but overestimated the public’s preference for rareness and thus preferred to serve them more rare.

We estimated that 19%–52% of livers served commercially in the United Kingdom fail to reach 70°C and that predicted Campylobacter survival rates are 48%–98%. These findings indicate that cooking trends are linked to increasing Campylobacter infections.

Restaurant cooking trends and increased risk for Camplyobacter infection

Emerging Infectious Disease Journal, Volume 22, Number 7, July 2016, DOI: 10.3201/eid2207.151775

A.K. Jones, D. Rigby, M. Burton, C. Millman, N.J. Williams, T.R. Jones, P. Wigley, S.J. O’Brien, P. Cross