Dead calves source of cryptosporidiosis in veterinary medicine students — Philadelphia

My former vet colleague partner in hand washing studies and I used to chat about the microbial risks faced by veterinarian students when we were both at Kansas State University and, based on anecdotal observational studies, we were surprised students sucked at hand washing.

crypto1Especially after dealing with animals.

The U.S. Centers for Disease Control and Prevention reports that on February 20, 2015, a northeastern U.S. university’s student health center was notified of five veterinary medicine students with gastrointestinal symptoms. An investigation was conducted to establish the existence of an outbreak, determine the etiology, evaluate risk factors, and recommend control measures.

All five students had attended a training session at the university’s bovine obstetrics laboratory on February 13, which included the handling of two euthanized calves. Patient symptoms, date of onset, and history of calf exposure suggested cryptosporidiosis. Infection with Cryptosporidium, a protozoa that causes watery diarrhea and is transmitted by infectious oocysts via the fecal-oral route (1), is common among calves (2). Symptoms in humans typically begin 7 days (range = 2–10 days) after infection and include intermittent abdominal cramps, nausea, vomiting, fever, and weight loss, lasting approximately 1–2 weeks (3).

Two calves used in the training sessions had been euthanized and frozen at -1.4°F (-17.0°C) on February 11. Approximately 28 hours later, the calves were thawed and detergent-washed by laboratory staff in accordance with standard protocols. Necropsies were performed on both animals on February 23, and revealed Cryptosporidium oocysts on an acid-fast stain of an intestine smear from one of the calves.

Interviews revealed that 22 students had attended the training session. Sixteen students reported symptoms, including diarrhea (13 students), abdominal cramps (13), nausea (12), fatigue (eight), vomiting (seven), anorexia (five), headache (four), and chills or sweats (four), lasting 2–10 days. Among the 16 symptomatic students, the median age was 25 years (range = 24–30 years), and 13 were female.

Four symptomatic students submitted stool specimens. One case was confirmed by detection of Cryptosporidium oocysts using direct fluorescent antibody testing; the other 15 were classified as probable cases, based on CDC case definitions (1). To account for the possibility of other infectious etiologies, stool specimens were also tested for Giardia, Cyclospora cayetanensis, Isospora, Salmonella, Shigella, Escherichia coli, and Campylobacter; all tests were negative. The positive acid-fast stain from one of the calves and one of the students with a confirmed case implicated the obstetrics laboratory as the source of the outbreak.

The bovine obstetrics laboratory personal protective equipment (PPE) protocol includes donning of gloves and coveralls before animal handling and cleaning boots and doffing of gloves and coveralls after animal handling, followed by 30 seconds of hand washing with warm water and soap. Face protection is not included in PPE protocols for this laboratory. Although all of the 22 students wore gloves during the training session, the number of students who removed their coveralls or washed their hands afterwards is unknown. At least four of the symptomatic students reported that they did not immediately doff their coveralls.

Cryptosporidiosis outbreaks have been reported among veterinary students (4), usually through contact with infected calves, and are associated with lapses in hygiene (5). In this outbreak, students were infected through contact with euthanized calves that had been frozen and thawed before the training session. Cryptosporidium oocysts can survive various environmental pressures, including extended exposures at temperatures as low as -7.6°F (-22.0°C) for >700 hours (6). This cluster highlights the importance of appropriate hygiene and proper animal cadaver handling. Since the likelihood of calves being infected with cryptosporidiosis is high, veterinary medical institutions should ensure that recommendations for PPE and proper hygiene techniques for students and staff are fully implemented.

1University of Pennsylvania.

Corresponding author: Lauren N. Drinkard,, 215-746-0806.


CDC. National Notifiable Diseases Surveillance System (NNDSS): Cryptosporidiosis (Cryptosporidium spp.) 2012 case definition. Available at

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2 sick from crypto linked to raw milk in Tenn

The Tennessee Department of Health is investigating multiple cases of residents who fell ill from consuming raw milk.

colbert.raw.milkThe health department launched the investigation after confirming two Chattanooga-area cases of cryptosporidiosis, a gastrointestinal disease from a parasite that lurks in contaminated water or unpasteurized milk. Both cases are linked to a dairy cow share program, which the state legalized in 2009, allowing greater access to raw milk.

“Consuming raw milk in the belief it’s healthier than pasteurized milk is a perilous risk that shakes off the possibility of a range of serious and occasionally fatal illnesses for the individuals and anyone they share it with,” John Dreyzehne, TDH commissioner, said in a news release. “Our best choice for healthy, nutritious milk is the pasteurized kind. Even if one believes there are health benefits, an upside, is it worth gambling on the downside risk of a serious illness, especially in a child?”

Since the state legalized cow share programs, reports have increased of disease and outbreaks linked to raw milk consumption. In 2013, nine Tennessee children became extremely sick with E. coli after drinking raw milk. Five of those required hospitalization and three developed severe, life-threatening kidney problems.

Crypto and giardia take $5 billion bite out of NYC

Two tiny organisms present a big problem for New York City’s water department: cryptosporidium and giardia.

crypto.waterThe city has spent $5 billion over the last five years combatting these organisms, which can cause fatal illnesses in the sick and elderly and gastrointestinal problems for those with healthy immune systems.

“In the city’s east-of-Hudson Croton watershed, where development has encroached on watershed land, federal regulators forced the city to filter the water; hence the $3 billion Croton filtration plant that recently opened,” City Limits reported.

The plant itself was a giant, politically fraught project.

40 sick in Sweden from Cryptosporidium at kosläpp (letting the cows out)

Apparently it’s a thing in Sweden to go and watch the cows being let out; so is Cryptosporidium.

kosläppSome 40 people have fallen ill after being infected by Cryptosporidium, reports Skovde News.

It is associated with kosläpp, a Hjo and one in Skövde, two outbreaks occurred in May.

Infectious disease doctors in the area now warning parents to let young children petting calves at kosläpp and immediately afterwards eat food or refreshments, writes Skovde News. Then they risk getting upset stomach with abdominal pain and diarrhea.

8 sick in crypto outbreak linked to farm visit in Sweden

A class that has been on kosläpp where eight out of twenty-three children and a teacher have become ill with severe abdominal pain, vomiting and watery diarrhea, said Deputy County Medical in West Bengal, Eva Lind houses Combos. disease is caused by the parasite Cryptosporidium that five years ago affected tens of thousands of people in Östersund.

According to the infectious disease physician’s theory is that the close encounter with calves that children become infected.

8 sick: Suspected outbreak of cryptosporidium hits thousands of homes in Ireland

Almost 6,500 homes in Westport have been placed on a boil water notice after a suspected outbreak of cryptosporidium.

crypto_enlargedThe precautionary notice was issued by Irish Water to a large number of customers in the town and to those on nearby group water schemes this evening.

It will affect thousands of homes and businesses in the busy tourist town.

Irish Water says the HSE has issued the precautionary boil notice, after eight people in the Westport area reported symptoms of crytosporidium.

They say no crytosporidium had been detected in ongoing water samples, however, as a precaution they are urging customers to boil water before using it for drinking, preparing food and baby food or brushing teeth.

Don’t poop in the pool: Cryptosporidiosis surveillance, US 2011–2012

Problem/Condition: Cryptosporidiosis is a nationally notifiable gastrointestinal illness caused by extremely chlorine-tolerant protozoa of the genus Cryptosporidium.

caddyshack.pool.poop-1Reporting Period: 2011–2012.

Description of System: Fifty state and two metropolitan public health agencies voluntarily report cases of cryptosporidiosis through CDC’s National Notifiable Diseases Surveillance System.

Results: For 2011, a total of 9,313 cryptosporidiosis cases (confirmed and nonconfirmed) were reported; for 2012, a total of 8,008 cases were reported; 5.8% and 5.3%, respectively, were associated with a detected outbreak. The rates of reported nonconfirmed cases were 1.0 and 0.9 per 100,000 population in 2011 and 2012, respectively, compared with an average of 0.0 during 1995–2004, and 0.3 during 2005–2010. The highest overall reporting rates were observed in the Midwest; 10 states reported >3.5 cases per 100,000 population in 2011 and in 2012. During 2011–2012, reported cases were highest among children aged 1–4 years (6.6 per 100,000 population), followed for the first time by elderly adults aged ≥80 years (3.4), and 75–79 years (3.3). Overall, cryptosporidiosis rates were higher among females than males during both years. For specific age groups, rates were higher among males than females aged <15 years and higher among females than males aged ≥15 years. Cryptosporidiosis symptom onset increased 4.4 fold during late summer.

Interpretation: Cryptosporidiosis incidence rates remain elevated nationally, and rates of nonconfirmed cases have increased. Rates remain highest in young children, although rates among elderly adults are increasing. Transmission of Cryptosporidium occurs throughout the United States, with increased reporting occurring in Midwestern states. Seasonal onset peaks coincide with the summer recreational water season and might reflect increased use of communal swimming venues.

Public Health Action: Future research is needed to address the evolving epidemiology of cryptosporidiosis cases, with a specific focus on the increase in nonconfirmed cases and increasing incidence rates among elderly adults. National systematic genotyping and subtyping of Cryptosporidium isolates could also help elucidate Cryptosporidium transmission and thus cryptosporidiosis epidemiology in the United States.

Secondary transmission a factor: Crypto in school kids visiting farm in Norway

Two related outbreaks (in 2009 and 2012) of cryptosporidiosis in Norwegian schoolchildren during a stay at a remote holiday farm provided us with a natural experiment to investigate possible secondary transmission of Cryptosporidium parvum IIa A19G1R1.

faith.farmingAfter the children had returned home, clinical data and stool samples were obtained from their household contacts. Samples were investigated for the presence of Cryptosporidium oocysts by immunofluorescence antibody test. We found both asymptomatic and symptomatic infections, which are likely to have been secondary transmission. Laboratory-confirmed transmission rate was 17% [4/23, 95% confidence interval (CI) 7·0–37·1] in the 2009 outbreak, and 0% (95% CI 0–16·8) in the 2012 outbreak. Using a clinical definition, the probable secondary transmission rate in the 2012 outbreak was 8% (7/83, 95% CI 4·1–16·4).

These findings highlight the importance of hygienic and public health measures during outbreaks or individual cases of cryptosporidiosis. We discuss our findings in light of previous studies reporting varying secondary transmission rates of Cryptosporidium spp.

 Symptomatic and asymptomatic secondary transmission of Cryptosporidium parvum following two related outbreaks in schoolchildren

Epidemiology and Infection / Volume 143 / Issue 08 / June 2015, pp 1702-1709


13 sickened: Handwashing is never enough and why I’m wary of animal displays: Crypto outbreak contained in Michigan

An outbreak of cryptosporidiosis at the Centreville High School agriculture program sent one student to the hospital and infected 12 others, according to Branch-Hillsdale-St. Joseph Community Health Agency.

cow.poop2The outbreak is contained and the hospitalized student has been released.

The outbreak came in early March in the co-op vet/ag science program run through St. Joseph Intermediate School District and involving students from throughout the county, according to Rebecca Burns, environmental health director.

The parasite is commonly found near calves, Burns said the health agency identified the calf program as the source.

“The school is all in to make sure this doesn’t happened again,” Burns said. “The problem was traced to poor hand-washing.”

Burns said there was hand sanitizer in the barn, but that alone is not enough.

cow_hug_cumberland“Nothing beats soap, water and friction to get rid of the parasite,” she said.

Two other major outbreaks of crypto were reported in the tri-county health district since 2011. In Hillsdale County in 2012, 28 people were infected at a pool party. In 2011, a Quincy firefighter was hospitalized and 19 others infected while fighting a fire at a calf barn. Firefighters used water from a pond nearby to extinguish the blaze.

Cryptosporidium: 22 years since Milwaukee outbreak killed 69 sickened 400K

Twenty-two years ago this month, residents of Milwaukee started falling ill with nausea, diarrhea and abdominal cramps. At first, a highly contagious intestinal virus was blamed. But as symptoms struck tens of thousands of people – closing schools and businesses and nearly bringing the city to a standstill – health officials discovered the culprit: a tiny, pink-colored parasite.

crypto cystCryptosporidium, also known as crypto, had made its way through Milwaukee’s water treatment plant and into the city taps. Sickening more than 400,000 people and killing 69, it remains the largest waterborne outbreak in U.S. history. Since then, utilities nationwide have made improvements in water treatment and monitoring.

Public water technology to prevent crypto may have improved, but not the drugs to treat it, said Washington State University researcher Jennifer Zambriski of the Paul G. Allen School for Global Animal Health based in the College of Veterinary Medicine. Once the organism infects the small intestines, its onslaught on the body is just as toxic as it was 22 years ago, she said.

“Crypto is hardy and doesn’t die easily. When someone contracts it, there’s simply no drug to make it go away,” said Zambriski, whose research focuses on finding ways to disrupt the parasite’s pathway through the digestive tract – before it gains a stranglehold on its host.

Which is a big deal, because the parasite still lurks – in ponds, streams, day care centers and swimming pools. In developing countries like Kenya and industrial ones like the United States, it continues to make waves.

Cryptosporidiosis, the disease it causes, is one of the most frequently occurring waterborne diseases among humans in the U.S., according to the U.S. Centers for Disease Control and Prevention. And in Asia and Africa, the parasite is a leading cause of diarrheal disease and death among infants. (See Lancet study, 2013:

These soft-pink colored pathogenic foes, appearing “almost cute” under a microscope, according to Zambriski, live in the intestines of infected humans and certain animals and are shed in the stool. Once outside the body, a tough outer shell allows them to survive in dirt, water and food for 18 months or longer.

“Bleach, chlorine, freezing backwater streams and water purifying tablets – they can’t kill crypto,” she said.

Whether through contaminated water or an infected person’s unclean hands, the parasites are easily transmitted to humans.

“Ingesting just a small amount can deliver a severe spell of diarrhea to those who are healthy and a grave illness and even death to infants or people with weakened immune systems,” Zambriski said.