Doug Grant of The Packer writes food safety outbreaks have a massive effect not only on growers, but on all stakeholders throughout the fresh produce supply chain. Irrigation water has been identified over the years as a likely cause of fresh produce contamination, so it’s critical that our industry fully understands the potential risk involved and how these risks are being managed by growers.The Center for Produce Safety has numerous research projects involving irrigation water. One 2015 project titled “Evaluation of risk-based water quality sampling strategies for the fresh produce industry,” led by PI Channah Rock, Ph.D., University of Arizona, concluded that “localized environmental conditions play a large role in water quality.”
Further, that “growers must get a better understanding of their water sources through collection of water quality data and historical analysis.” Another outcome from this project was developing a computer app to provide guidance on the frequency of sampling based on risk factors (e.g. after rainfall).
Several other CPS research projects focus on predictive models for irrigation water quality, exploring the relationship between product testing and risk, reuse of tail water and evaluating alternative irrigation water quality indicators.
Let me introduce Natalie Dyenson, head of food safety and quality assurance at Dole. As you can imagine, she has a huge responsibility covering several product lines (fruits, vegetables, leafy greens and packaged salads) sourced from hundreds of growers throughout the Americas and other countries. She’s been involved with CPS for several years and takes a keen interest in new research findings.
With leafy greens as her top priority, she is still very concerned about the three romaine lettuce outbreaks during 2018. With all Dole crops, water quality risk assessment and testing are very important. Dole reviews water source (wells, reservoir, canals, etc.) and type of irrigation (foliar spray, furrow irrigation, flooding farms). All water sources including deep wells are tested monthly, and after weather events such as wind and frost. Enhanced testing of product is done prior to harvest depending on their environmental risk assessments — for example, after an excessive rain event where potential contaminated water run-off could be introduced to the field.
Natalie said, “there is a huge potential to leverage historical water quality test data to help mitigate risk.” She’s also very interested in predictive models and is looking forward to the results of a CPS research project starting in 2019, “Development of a model to predict the impact of sediments on microbial irrigation water quality,” led by Charles P. Gerba, Ph.D, from the University of Arizona.
Previous CPS research has shown that sediments at the bottom of waterways can harbor 10 to 10,000 more fecal bacteria than surface waters. This new project will investigate the conditions where pathogens could be re-suspended in surface water and will design sampling strategies to minimize contamination to crops.
While discussing sediment in irrigation canals Natalie mentioned that it’s been observed that some non-Dole farmers are still laying irrigation intake hoses directly on the bottom of water sources (canals, ponds, etc.). A simple solution is to use a flotation device positioned so that the hose end extracts water just below the surface where there are fewer potential contaminants. While not a complete remedy to eliminate all organic matter and pathogens in the water supply, it is a simple tool to help reduce risk.
We live near the publicly-funded Princess Alexandria hospital in Brisbane.
A helicopter flies over our house a couple of times a day bringing some victim from the outback or the coast.
The state of Queensland is really, really big.
It reminds me of my friend, Jim, and what he went through in the aftermath of the E.coli O157 outbreak in drinking water that killed seven and sickened 2,500 in the town of Walkerton, population 5,000.
Jim knew that every helicopter was someone dead or dying being flown to the medical center in London, Ontario (that’s in Canada, like Walkerton).
I think of Jim and the victims every time a chopper goes past.
The U.S. Centers for Disease Control reports a center pivot irrigation system intended to pump livestock waste water onto adjacent farmland in Nebraska malfunctioned, allowing excessive run off to collect in a road ditch near two wells that fed a municipal water supply, sickening 39 persons who consumed untreated city water. The use of culture-independent diagnostic tests facilitated case identification allowing for rapid public health response.
Access to clean water sources continues to be an important public health issue, and public health professionals should consider exposure to untreated water sources as a potential cause for Campylobacter outbreaks.
In March 2017, the Nebraska Department of Health and Human Services (NDHHS) and the Southwest Nebraska Public Health Department were notified of an apparent cluster of Campylobacter jejuni infections in city A and initiated an investigation. Overall, 39 cases were investigated, including six confirmed and 33 probable. Untreated, unboiled city A tap water (i.e., well water) was the only exposure significantly associated with illness (odds ratio [OR] = 7.84; 95% confidence interval [CI] = 1.69–36.36). City A is served by four untreated wells and an interconnected distribution system. Onsite investigations identified that a center pivot irrigation system intended to pump livestock wastewater from a nearby concentrated animal feeding operation onto adjacent farmland had malfunctioned, allowing excessive runoff to collect in a road ditch near two wells that supplied water to the city. These wells were promptly removed from service, after which no subsequent cases occurred. This coordinated response rapidly identified an important risk to city A’s municipal water supply and provided the evidence needed to decommission the affected wells, with plans to build a new well to safely serve this community.
On March 10, 2017, NDHHS was notified of five reports of campylobacteriosis in the Southwest Nebraska Public Health Department jurisdiction. Two positive culture reports and three positive culture-independent diagnostic tests, specifically a gastrointestinal polymerase chain reaction (PCR) panel, were received from persons not living together. Campylobacteriosis is a reportable condition in Nebraska, and this number of cases was higher than expected; during 2006–2016, an average of one Campylobacter case was reported in a city A resident every 3 years. Initial questioning of ill persons did not include an assessment of exposure to untreated drinking water and suggested ground beef consumption as a possible shared exposure. The Nebraska Department of Agriculture Food Safety and Consumer Protection obtained distribution records for poultry and ground beef for two local restaurants and one local grocery store. The distribution of poultry and ground beef was evaluated by reviewing the routing records of these products to their source, and no evidence of a shared poultry source was identified. The ground beef was not ground in-house at the grocery store, and the distributors that supplied ground beef to the grocery store and each of the two local restaurants were not shared. Through interviews of city A residents and business owners, investigators were made aware of a report of standing water that “smelled of cattle manure” in a roadside ditch near two municipal water wells.
A collaborative on-site investigation revealed that during the pumping of a large volume of livestock wastewater from a concentrated animal feeding operation through a center pivot irrigation system, the system malfunctioned at an undetermined time. The wastewater was intended to be placed on adjacent farmland. This malfunction allowed excessive runoff to flood a road ditch approximately 15 feet (4.6 m) from two municipal water well houses (3 and 4) that had been operating 6 days before the onset of illness in the first patient. The presence of this standing water was confirmed by city A water operators, who reported seeing water in the ditch for 4 days (February 22–25) (Figure). Pump records indicated that during February 22–27, well 3 was in use, and during February 28–March 7, well 4 was in use (Table 1). During both periods, another well (well 2) was also operating. Wells are rotated in and out of service by city operators as part of regular operations. Water is distributed through the well system without any disinfection or filtration. Routine total coliform and Escherichia coli testing of water from the distribution system was performed on March 8; however, only wells 2 and 5 were operating on that date. As part of the investigation, additional coliform and E. coli testing was performed again on March 16 on direct samples from wells 2, 3, 4, and 5; bacterial culture specifically for Campylobacter was performed on March 20 (wells 4 and 5) and 27 (wells 2 and 3). All samples were negative for coliforms and Campylobacter. No additional pump or testing records were reviewed.
On March 16, Nebraska Department of Environmental Quality and the Department of Agriculture conducted an additional investigation of two concentrated animal feeding operation–certified waste lagoons (a manufactured basin that collects livestock waste and water in an oxygen-deprived setting to promote anaerobic conditions as a way to manage refuse)* and associated use of three pivot irrigation systems. The investigation team observed that water from the waste lagoons had been pumped through a pivot onto an adjacent field, which is a common farming practice for fertilizing farm ground or watering crops. City operators confirmed that on February 24 they had observed flow of livestock wastewater into the road ditch near well 4. They followed the wastewater up the road ditch and reported that it came out of the farmland upstream from the wells. Investigators also obtained details of total well depths, static water levels, and pumping water levels (measured during active pumping). Wells 4 and 3 were relatively shallow, with static water levels of 21 and 22 feet, pumping levels of 25 and 26 feet, and total well depths of 43 and 46 feet, respectively; both began service in the 1930s, similar to the other wells in the system, which were also older.
While details around this event were being clarified and environmental testing was pending, an Internet-based questionnaire was designed to aid case-finding and assess potential exposures. A probable case was defined as a diarrheal illness of ≥2 days’ duration with one or more additional signs or symptoms (nausea, vomiting, fever, chills, or headache) in a city A resident, with onset during February 28–March 23, 2017. A confirmed case was defined as a person meeting the probable case definition with either stool culture or PCR-positive results for Campylobacter, or a laboratory-confirmed probable illness in a nonresident who worked, dined, or shopped for groceries in city A. Among approximately 600 city A residents, 94 (16%) completed a questionnaire to report food consumption history, drinking water source, animal exposures, and symptoms. Among questionnaire respondents, 39 (41%) campylobacteriosis cases (six confirmed and 33 probable) were identified, with illness onset from February 28–March 21 (Figure); 25 (64%) cases occurred in females and 14 (36%) in males. The median age was 34.5 years (range = 1.5–85 years). Twelve (31%) patients sought medical care, and three (8%) were hospitalized; no deaths were reported.
Data analysis indicated a significant association between ill persons and consumption of untreated, unboiled municipal tap water (OR = 7.84; 95% CI = 1.69–36.36) (Table 2). Other exposures were assessed, including unpasteurized milk, animal contact, raw poultry, and ground beef, but none demonstrated a significant association with illness. Notably, no cases were reported among the approximately 28 residents of city A’s only nursing home, which used city water but treated it with a reverse osmosis system.
Public Health Response
Wells 3 and 4 were both permanently removed from service on March 16, and no additional illnesses were reported with onset after March 21. On April 25, NDHHS reclassified these wells to Emergency Status, meaning the well can only be pumped during a case of emergency (e.g., fire, drought, etc.) for nonpotable purposes. Furthermore, meetings were held with area stakeholders to present these findings as evidence to support the award of a planning grant to city A to explore options for a new, higher-volume well to be dug to an acceptable depth in a different location.
This investigation implicates Campylobacter jejuni as the cause of this outbreak, most likely from a municipal water system contaminated by wastewater runoff from an adjacent concentrated animal feeding operation (1). In addition to environmental and statistical findings, this conclusion is consistent with prior investigations that demonstrate Campylobacter outbreaks of similar size are historically associated with contaminated water (2–7). Although laboratory testing of the water in this investigation did not yield any positive results, samples were not taken until long after the contamination event, and test results might have been affected by switches among wells supplying the system over time. These findings also suggest that routine coliform testing might not be a good indicator of the presence of Campylobacter species (8). Further, it is possible that Campylobacter in particular might be viable but not necessarily detectable by culture in water systems (9,10). The use of both culture and culture-independent diagnostic tests (PCR) were needed to detect the initial cluster of cases and early recognition of this outbreak. If culture alone had been used, only two cases would have been reported, one of which did not occur in a city A resident. Of those two culture-confirmed cases, one patient refused the interview and the other had typical Campylobacter exposures, such as live poultry, which might not have prompted such a rapid response. This investigation demonstrates the importance of considering exposure to untreated water sources as a potential cause for Campylobacter outbreaks. Including this risk factor in initial questioning could help to expedite outbreak investigations. Ultimately, early recognition and a coordinated response by several state and local agencies greatly facilitated this successful public health intervention.
Campylobacteriosis outbreak associated with contaminated municipal water supply-Nebraska, 2017
According to The Canberra Times, the current drought affecting parts of Australia could lead to a spike in gastro cases around the country, a population health scientist from The Australian National University has warned.
The warning comes from the results of a study, published in the Journal of Water and Health, found reported cases of cryptosporidiosis, rose significantly in parts of Queensland and the Australian Capital Territory along the Murray Darling Basin during the drought that ended in 2009.
Lead researcher Dr Aparna Lal, from the ANU Research School of Population Health, said the study estimated the risk of the gastro bug dropped by 84 per cent in the ACT and by 57 per cent in Queensland once the drought ended.
She said 385 cases of the gastro bug were reported in the ACT and 527 in Queensland, out of 2048 cases in the Murray Darling Drainage Basin, from 2001 until 2012.
“Cryptosporidiosis is one of the most common water-related parasitic diseases in the world, and Australia reports the second highest rate of the illness in humans among many developed countries,” Dr Lal said.
Children under five years old are particularly at risk from cryptosporidiosis, and it can cause developmental problems such as stunted growth.
Dr Lal said droughts reduced river volume and flow, thereby potentially increasing the concentration of pathogens such as those that cause gastro.
“As these gastro bugs can also be spread from livestock, land-use change may also contribute to this pattern, due in part to access around waterways,” she said.
According to Ooska News, a cholera outbreak in Ethiopia’s northern Tigray region has reportedly been blamed on holy water, after at least 10 people died over the past two weeks, while more than 1 200 people have contracted the disease. The authorities have also identified contaminated holy water in some of the region’s monasteries as being behind the outbreak. It was believed that the water is being taken from rivers that carry the disease.
Interfering in religious affairs is a very sensitive matter in the region, but the local government is working with religious leaders to temporarily stop the use of holy water.
Brazilian media report (via ProMed, thanks) that in the past 15 days, the number of cases of confirmed toxoplasmosis has increased from 594 to 621, according to a new epidemic bulletin from the government of Rio Grande do Sul and the city council on the epidemic facing the region.
Of the more than 600 confirmed cases, 54 are pregnant women, with 3 fetal deaths and 3 abortions.
The number of suspected cases increased from 1291 on [29 Jun 2018] to 1486 on Friday. Of these, 350 were rejected and 515 arestill under investigation. The total number of cases related to the disease is 1786, according to the latest newsletter.
The causes of the epidemic, confirmed by the State Secretariat of SAR in April this year , are still unknown, and the authorities continue to investigate the event, under the supervision of the federal prosecution. Last Friday [6 Jul 2018], an examination detected the presence of the protozoan responsible for the disease in the water tank of a town residence. But the relationship between the protozoan and the epidemic has not been confirmed.
Toxoplasmosis, popularly known as cat disease, is an infectious disease caused by a protozoan called Toxoplasma gondii. This protozoan is easily found in nature and can cause infection in many mammals and birds around the world.
According to the Brazilian Society of Infectious Diseases, the disease can occur through the ingestion of oocysts (where the parasite grows) from soil, sand, and bins contaminated with feces from infected cats; ingestion of raw and undercooked meat infected with oocysts, especially pork and mutton; or by transplacental infection, occurring in 40% of fetuses of mothers who contracted infection during pregnancy. The incubation period of toxoplasmosis ranges from 10 to 23 days when the cause is meat consumption, and from 5 to 20 days when the reason is contact with cat feces oocysts.
The Brazilian Society of Infectious Diseases suggests some preventive measures. Do not eat raw or malnourished meats, and eat only well-washed vegetables and fruits cleaned with running water. Avoid contact with cat feces. In addition to avoiding contact with cats, pregnant women must undergo appropriate medical (prenatal) monitoring.
Health officials say they have received reports of more than 500 cases of gastrointestinal illnesses including diarrhea and vomiting from people from multiple states who visited CLIMB Works Zipline Canopy Tour since mid-June 2018.
State and local health investigators are working with the company to identify additional cases, what caused the illnesses and keep more people from getting sick.
State health officials say CLIMB Works has taken appropriate steps and closed temporarily, but has resumed routine operations.
The East Tennessee Regional Health Department says it has taken samples of well water, but the tests are not back yet. A manager at CLIMB Works says they’re not sure what’s causing the illnesses, but they have stopped using and distributing water at the attraction.
Cilmb Works Manager, Brian Turley, says 108 visitors called the business directly to report sickness. He says most of them called, not for a refund, but to inform the business of potential issues.
Turley says they are offering refunds for anyone affected with illness.
Speaking with WATE 6 On Your Side, Turley shared a message for visitors:
“We are so sorry. We obviously had no idea or we never would have never let you [visitors] drink our water. We had no idea. It’s so frustrating it wasn’t something we didn’t catch sooner,” said Turley.
During 2000–2014, 140 untreated recreational water–associated outbreaks that caused at least 4,958 illnesses and two deaths were reported; 80 outbreaks were caused by enteric pathogens.
Swimmers should heed posted advisories closing the beach to swimming; not swim in discolored, smelly, foamy, or scummy water; not swim while sick with diarrhea; and limit water entering the nose when swimming in warm freshwater.
Outbreaks associated with untreated recreational water can be caused by pathogens, toxins, or chemicals in fresh water (e.g., lakes, rivers) or marine water (e.g., ocean). During 2000–2014, public health officials from 35 states and Guam voluntarily reported 140 untreated recreational water–associated outbreaks to CDC. These outbreaks resulted in at least 4,958 cases of disease and two deaths. Among the 95 outbreaks with a confirmed infectious etiology, enteric pathogens caused 80 (84%); 21 (22%) were caused by norovirus, 19 (20%) by Escherichia coli, 14 (15%) by Shigella, and 12 (13%) by Cryptosporidium. Investigations of these 95 outbreaks identified 3,125 cases; 2,704 (87%) were caused by enteric pathogens, including 1,459 (47%) by norovirus, 362 (12%) by Shigella, 314 (10%) by Cryptosporidium, and 155 (5%) by E. coli. Avian schistosomes were identified as the cause in 345 (11%) of the 3,125 cases. The two deaths were in persons affected by a single outbreak (two cases) caused by Naegleria fowleri. Public parks (50 [36%]) and beaches (45 [32%]) were the leading settings associated with the 140 outbreaks. Overall, the majority of outbreaks started during June–August (113 [81%]); 65 (58%) started in July. Swimmers and parents of young swimmers can take steps to minimize the risk for exposure to pathogens, toxins, and chemicals in untreated recreational water by heeding posted advisories closing the beach to swimming; not swimming in discolored, smelly, foamy, or scummy water; not swimming while sick with diarrhea; and limiting water entering the nose when swimming in warm freshwater.
Outbreaks associated with untreated recreational water-United States, 2000-2014
Daniel S. Graciaa, MD1; Jennifer R. Cope, MD2; Virginia A. Roberts, MSPH2; Bryanna L. Cikesh, MPH2,3; Amy M. Kahler, MS2; Marissa Vigar, MPH2; Elizabeth D. Hilborn, DVM4; Timothy J. Wade, PhD4; Lorraine C. Backer, PhD5; Susan P. Montgomery, DVM6; W. Evan Secor, PhD6; Vincent R. Hill, PhD2; Michael J. Beach, PhD2; Kathleen E. Fullerton, MPH2; Jonathan S. Yoder, MPH2; Michele C. Hlavsa, MPH2
Cassius, an adult male, died on April 12, and Naku, a 17-year-old female western lowland gorilla, died on April 29, the zoo said in a press release.
Autopsy results for the gorillas show that they died of gastrointestinal infections believed to have been caused by E. coli in their water supply, according to the zoo.
The water systems in the gorilla and bonobo areas have been disinfected, the zoo said, adding that the water supply available for consumption by the public was never affected.
Zookeepers are also using new protocols to disinfect produce, which can be another source of E. coli, according to the release.
While all animals, including gorillas and even humans, have healthy E.coli in their gut, some variants of E. coli can cause intestinal damage and disease, the zoo said.
Naku had been euthanized after veterinarians found that a portion of her intestine was no longer functioning, ABC affiliate WISN in Milwaukee reported.
Cassius and Nauku’s 8-month-old baby, Zahra, is now an orphan.
Zahra’s diet has consisted mainly of formula in the absence of her mother’s breast milk, zookeepers wrote on Twitter. She is also eating some produce, sweet potato, red pepper, and beans, the zoo said.