739 sickened in 2007: Cryptosporidium outbreak cost Ireland €19m

Paul Melia of the Irish Independent reports a Cryptosporidium outbreak that resulted in 120,000 people being forced to boil their water for five months cost €19m, a new study shows.

cryptoThe 2007 outbreak in Galway cost each household €95 and resulted in one in eight hotel and guesthouse bookings being cancelled.

One in five people in the city refuse to drink the tap water today due to concerns about its safety, the study says.

It found that had the water supply to the city and surrounding areas been subjected to an adequate treatment process costing just €1.6m, it would have resulted in an €11 saving for every €1 invested.

The ‘Economic Assessment of the Waterborne Outbreak of Cryptosporidium Hominis in Galway 2007’ study, which was funded by the Environmental Protection Agency (EPA), says the outbreak lasted for 158 days and resulted in 242 confirmed cases of cryptosporidiosis, “although it was likely the actual number affected was far higher”.

– There were 242 notified cases of cryptosporidiosis, with another 497 non-reported cases.

– 45,160 households were affected, and around 120,000 people.

– There was an 80pc increase in bottled water consumption during the outbreak, with a spend of €3.5m. Another €400,000 was spent boiling water.

– Hotels and guesthouses were obliged to provide 4.2 litres of water per day to guests, and the hospitality industry bore costs of €50,000 per day.

Cryptosporidium remains a problem across the country, with the latest data showing that 17 water supplies require upgrades to remove the threat.

The report, compiled by researchers at NUI Galway with an official from the HSE, found that households bore costs totalling €3.9m, the hospitality sector another €8m, while the local authorities spent almost €6m.

Possums, birds and tank water in Queensland: A microbial risk

As Australians begin the workweek with a hung parliament after yet another federal election, I aptly turn my attention to the politicians of the rodent world: possums.

rainwater.brisbane.feb.14The Australian climate can be harsh, in a No-Country-for-Old-Men sorta way, with temperature extremes, flooding, followed by five years of drought.

So we have new-fangled rain barrels that my grandparents used to have in Ontario (ours, right, exactly as shown and I know there’s possums wandering around there at night because possum poop accumulates).

The rainwater is supposed to be used for toilets, dishes, laundry and other non-potable uses, but is there a risk (no drinking from the garden hose here)?

Here’s the most recent from researchers:

Avian and possum fecal droppings may negatively impact roof-harvested rainwater (RHRW) water quality due to the presence of zoonotic pathogens. This study was aimed at evaluating the performance characteristics of a possum feces-associated (PSM) marker by screening 210 fecal and wastewater samples from possums (n = 20) and a range of nonpossum hosts (n = 190) in Southeast Queensland, Australia.

The host sensitivity and specificity of the PSM marker were 0.90 and 0.95 (maximum value, 1.00), respectively. The mean concentrations of the GFD marker in possum fecal DNA samples (8.8 × 107 gene copies per g of feces) were two orders of magnitude higher than those in the nonpossum fecal DNA samples (5.0 × 105 gene copies per g of feces). The host sensitivity, specificity, and concentrations of the avian feces-associated GFD marker were reported in our recent study (W. Ahmed, V. J. Harwood, K. Nguyen, S. Young, K. Hamilton, and S. Toze, Water Res 88:613–622, 2016, http://dx.doi.org/10.1016/j.watres.2015.10.050). The utility of the GFD and PSM markers was evaluated by testing a large number of tank water samples (n = 134) from the Brisbane and Currumbin areas. GFD and PSM markers were detected in 39 of 134 (29%) and 11 of 134 (8%) tank water samples, respectively. The GFD marker concentrations in PCR-positive samples ranged from 3.7 × 102 to 8.5 × 105 gene copies per liter, whereas the concentrations of the PSM marker ranged from 2.0 × 103 to 6.8 × 103 gene copies per liter of water. The results of this study suggest the presence of fecal contamination in tank water samples from avian and possum hosts.

possum.baby.nov.11This study has established an association between the degradation of microbial tank water quality and avian and possum feces. Based on the results, we recommend disinfection of tank water, especially for tanks designated for potable use.


The use of roof-harvested rainwater (RHRW) for domestic purposes is a globally accepted practice. The presence of pathogens in rainwater tanks has been reported by several studies, supporting the necessity for the management of potential health risks. The sources of fecal pollution in rainwater tanks are unknown. However, the application of microbial source tracking (MST) markers has the potential to identify the sources of fecal contamination in a rainwater tank. In this study, we provide evidence of avian and possum fecal contamination in tank water samples using molecular markers. This study established a potential link between the degradation of the microbial quality of tank water and avian and possum feces.

Evidence of avian and possum fecal contamination in rainwater tanks as determined by microbial source tracking approaches

Ahmed a, K. A. Hamilton a,b, P. Gyawali a,c, S. Toze a,c and C. N. Haas b

A CSIRO Land and Water, Ecosciences Precinct, Brisbane, Queensland, Australia

B Drexel University, Philadelphia, Pennsylvania, USA

C School of Public Health, University of Queensland, Herston, Queensland, Australia

Applied and Environmental Microbiology, Volume 82, Number 14, Pages 4379-4386, doi:10.1128/AEM.00892-16


Irrigation water safety in Penn.

Recent produce-associated foodborne illness outbreaks have been attributed to contaminated irrigation water. This study examined microbial levels in Pennsylvania surface waters used for irrigation, relationships between microbial indicator organisms and water physicochemical characteristics, and the potential use of indicators for predicting the presence of human pathogens.

A total of 153 samples taken from surface water sources used for irrigation in southeastern Pennsylvania were collected from 39 farms over a 2-year period. Samples were analyzed for six microbial indicator organisms (aerobic plate count, Enterobacteriaceae, coliform, fecal coliforms, Escherichia coli, and enterococci), two human pathogens (Salmonella and E. coli O157), and seven physical and environmental characteristics (pH, conductivity, turbidity, air and water temperature, and sampling day and 3-day-accumulated precipitation levels).

Indicator populations were highly variable and not predicted by water and environmental characteristics. Only five samples were confirmed positive for Salmonella, and no E. coli O157 was detected in any samples. Predictive relationships between microbial indicators and the occurrence of pathogens could therefore not be determined.

Microbial survey of Pennsylvania surface water used for irrigating produce crops

Journal of Food Protection®, Number 6, June 2016, pp. 896-1055, pp. 902-912(11)

Draper, Audrey D.; Doores, Stephanie; Gourama, Hassan; LaBorde, Luke F.



Hepatitis A is endemic in Tunisia wastewater

Hepatitis A virus (HAV) is the main causative agent of hepatitis infection associated with waterborne outbreaks worldwide. In Tunisia, there is no specific surveillance system for HAV and current secondary wastewater treatment processes are unable to remove viral particles, which present a potential public health problem.

tunisia.wastewaterQualitative and quantitative analysis of HAV in 271 raw and treated wastewater samples from five sewage treatment plants (STPs) during 13 months was performed. Moreover, the efficiency of three secondary wastewater treatment processes (conventional activated sludge, extended aeration, and oxidation ditch activated sludge) was evaluated.

Data obtained demonstrated that HAV is endemic in Tunisia and circulates with high prevalence in both raw (66.9%) and treated (40.7%) wastewater. HAV circulates throughout the year in the coastal areas, with the highest rates found during summer and autumn, whereas in central Tunisia, high levels were shown in autumn and winter. Total virus removal was not achieved, since no difference in mean HAV loads was observed in effluents (6.0 × 103 genome copies [GC]/ml) and influents (2.7 × 103 GC/ml). The comparison of the HAV removal values of the three different wastewater treatment methods indicates that extended aeration and oxidation ditch activated sludge had better efficiency in removing viruses than conventional activated sludge did.

Molecular characterization revealed that the vast majority of HAV strains belonged to subgenotype IA, with the cocirculation of subgenotype IB in wastewater treatment plants that collect tourism wastewater.

Detection and molecular characterization of Hepatitis A virus from Tunisian wastewater treatment plants with different secondary treatments

Appl. Environ. Microbiol. July 2016 vol. 82 no. 13 3834-3845, DOI: 10.1128/AEM.00619-16

Imen Ouardani, Syrine Turki, Mahjoub Aouni, and Jesús L. Romalde



Norovirus: Best way to assess risk?

The application of quantitative microbial risk assessments (QMRAs) to understand and mitigate risks associated with norovirus is increasingly common as there is a high frequency of outbreaks worldwide.

norovirus.qmraA key component of QMRA is the dose–response analysis, which is the mathematical characterization of the association between dose and outcome. For Norovirus, multiple dose–response models are available that assume either a disaggregated or an aggregated intake dose. This work reviewed the dose–response models currently used in QMRA, and compared predicted risks from waterborne exposures (recreational and drinking) using all available dose–response models.

The results found that the majority of published QMRAs of norovirus use the 1F1hypergeometric dose–response model with α = 0.04, β = 0.055. This dose–response model predicted relatively high risk estimates compared to other dose–response models for doses in the range of 1–1,000 genomic equivalent copies. The difference in predicted risk among dose–response models was largest for small doses, which has implications for drinking water QMRAs where the concentration of norovirus is low.

Based on the review, a set of best practices was proposed to encourage the careful consideration and reporting of important assumptions in the selection and use of dose–response models in QMRA of norovirus.

Finally, in the absence of one best norovirus dose–response model, multiple models should be used to provide a range of predicted outcomes for probability of infection.

Comparison of risk predicted by multiple norovirus dose–response models and implications for quantitative microbial risk assessment

Nicole Van Abel, Mary E. Schoen, John C. Kissel, J. Scott Meschke

Risk Analysis, June 2016, DOI: 10.1111/risa.12616


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


Exposure to Norovirus at the beach

Swimming in fecally-contaminated natural waterbodies can result in gastrointestinal (GI) infections and associated symptoms. However, the pathogenic microorganisms responsible are often unidentified because studies nearly always rely on self-reported symptoms. Noroviruses have been considered a likely cause because they are relatively resistant to conventional wastewater treatment and can survive in the environment.

norovirus-2Symptoms among swimmers usually occur within a few days of exposure, consistent with a short incubation period characteristic of noroviruses.

In the summer of 2009, we conducted an epidemiology study at a beach in Puerto Rico. We previously reported no association between swimming and self-reported GI symptoms at this beach. As part of this study, we also collected saliva samples from a subset of participants (N=1300) using an Oracol oral swab: on the day of the beach visit (S1); after 10-12 days (S2); and after approximately three weeks (S3), and tested them for IgG antibody responses to two common noroviruses (Norwalk and VA387) using a Luminex platform and a previously published method. An immunoconversion, indicating a potential new infection, was defined as at least a fourfold increase in norovirus-specific median fluorescence intensity (MFI) from the S1 to the S2 sample with the S3 sample remaining at least two times above the baseline (S1) MFI.

Approximately 4.7% (N=61) immunoconverted to at least one of the noroviruses. Swimmers who immersed their head in water had a higher rate of immunoconversion (5.5%) compared to non-swimmers (2.0%) (OR=3.32, 95% CI 1.2-9.5). Immunoconversion to norovirus was not associated with increased self-reported GI symptoms, indicating these infections were largely asymptomatic.

To our knowledge, this is the first epidemiology study to show an association between norovirus infection and swimming exposure. This abstract does not reflect EPA policy.

Evidence for asymptomatic norovirus infection transmission associated with swimming at a tropical beach

Soceity for Epidemiology Research, Miami, FL, June 07 – 16, 2016

Wade, Tim, S. Augustine, S. Griffin, K. Simmons, T. Eason, K. Oshima, E. Sams, A. Egorov, AND A. Dufour


FDA to Horizon Air: No handwashing, no ice

The FDA has a warning for Horizon Air: If there’s no hand-washing, don’t serve ice.

upintheairAccording to The Seattle Times, the FDA sent a letter to Horizon Air, operating by Alaska Airlines, reprimanding employees for serving ice with drinks on their Bombardier Q400 airplanes, which don’t have hand-washing sinks in their bathrooms.

Without hand-washing facilities, the lavatories aren’t sufficient for employees to handle food and ice, which “can increase the potential spread of communicable disease,” said the letter.

The letter comes after several FDA inspections last winter, which led to correspondence with Horizon on the issue for months. The Times reports Horizon fixed other problems noted in the inspections, but employees continued to serve drinks with ice.

“Directing your employees to wash their hands in the airport between flights or to use hand sanitizer does not meet the requirements for suitable lavatory facilities for food-handling employees. We recommend that you discontinue the use of ice and serve only food and beverages that are in closed containers,” the FDA wrote to Horizon.

Crypto in the US

Cryptosporidium is the leading aetiology of waterborne disease outbreaks in the United States. This report briefly describes the temporal and geographical distribution of US cryptosporidiosis cases and presents analyses of cryptosporidiosis case data reported in the United States for 1995–2012.

pool.safety.signThe Cochran–Armitage test was used to assess changes in the proportions of cases by case status (confirmed vs. non-confirmed), sex, race, and ethnicity over the study period. Negative binomial regression models were used to estimate rate ratios (RR) and 95% confidence intervals (CI) for comparing rates across three time periods (1995–2004, 2005–2008, 2009–2012). The proportion of confirmed cases significantly decreased (P < 0·0001), and a crossover from male to female predominance in case-patients occurred (P < 0·0001). Overall, compared to 1995–2004, rates were higher in 2005–2008 (RR 2·92, 95% CI 2·08–4·09) and 2009–2012 (RR 2·66, 95% CI 1·90–3·73). However, rate changes from 2005–2008 to 2009–2012 varied by age group (Pinteraction < 0·0001): 0–14 years (RR 0·55, 95% CI 0·42–0·71), 15–44 years (RR 0·99, 95% CI 0·82–1·19), 45–64 years (RR 1·47, 95% CI 1·21–1·79) and ≥65 years (RR 2·18, 95% CI 1·46–3·25).

The evolving epidemiology of cryptosporidiosis necessitates further identification of risk factors in population subgroups. Adding systematic molecular typing of Cryptosporidium specimens to US national cryptosporidiosis surveillance would help further identify risk factors and markedly expand understanding of cryptosporidiosis epidemiology in the United States.

Evolving epidemiology of reported cryptosporidiosis cases in the United States, 1995–2012

Epidemiology and Infection, Volume 144, Issue 08, June 2016, Pages 1792–1802, http://dx.doi.org/10.1017/S0950268815003131

J.E. Painter, J.W. Gargano, J.S. Yoder, S.A. Collier, M.C. Hlavsa


It has excellent sanitation: Winter’s coming so people stop going to the heated pool

I miss the hot tub we had in Kansas.

Yet in the U.S., thousands of public pools, hot tubs are closed each year due to serious violations.

caddyshack.pool.poop-1The U.S. Centers for Disease Control and Prevention reports that inspections of public pools and other aquatic venues enforce standards that can prevent illness, drowning, and pool-chemical–associated injuries such as poisoning or burns.

“No one should get sick or hurt when visiting a public pool, hot tub, or water playground,” said Beth Bell, M.D., M.P.H., director of CDC’s National Center for Emerging and Zoonotic Infectious Diseases. “That’s why public health and aquatics professionals work together to improve the operation and maintenance of these public places so people will be healthy and safe when they swim.”

Inspection data were collected in 2013 in the five states with the most public pools and hot tubs: Arizona, California, Florida, New York and Texas. Researchers reviewed data on 84,187 routine inspections of 48,632 public aquatic venues, including pools, hot tubs, water playgrounds and other places where people swim in treated water.

Among the key findings:

Most inspections of public aquatic venues (almost 80 percent) identified at least one violation.

1 in 8 inspections resulted in immediate closure because of serious health and safety violations.

1 in 5 kiddie/wading pools were closed—the highest proportion of closures among all inspected venues.

The most common violations reported were related to improper pH (15 percent), safety equipment (13 percent), and disinfectant concentration (12 percent).

“Environmental health practitioners, or public health inspectors, play a very important role in protecting public health. However, almost one third of local health departments do not regulate, inspect, or license public pools, hot tubs, and water playgrounds,” said Michele Hlavsa, R.N., M.P.H., chief of CDC’s Healthy Swimming Program. “We should all check for inspection results online or on site before using public pools, hot tubs, or water playgrounds and do our own inspection before getting into the water.”

When visiting public or private pools, swimmers and parents of young swimmers can complete their own inspection using a short and easy checklist that will identify some of the most common health and safety problems:

Use a test strip (available at most superstores or pool-supply stores) to determine if the pH and free chlorine or bromine concentration are correct. CDC recommends:

diaper.poolFree chlorine concentration of at least 1 ppm in pools and at least 3 ppm in hot tubs/spas.

Free bromine concentration of at least 3 ppm in pools and at least 4 ppm in hot tubs/spas.

pH of 7.2–7.8.

Make sure the drain at the bottom of the deep end is visible. Clear water allows lifeguards and other swimmers to see swimmers underwater who might need help.

Check that drain covers appear to be secured and in good repair. Swimmers can get trapped underwater by a loose or broken drain cover.

Confirm that a lifeguard is on duty at public venues. If not, check whether safety equipment like a rescue ring with rope or pole is available.

If you find problems, do not get into the water and tell the person in charge so the problems can be fixed. For more information and other healthy and safe swimming steps, visit www.cdc.gov/healthywater/swimming.

Before CDC-led development of the Model Aquatic Health Code, there were no national standards for the design, construction, operation, and maintenance practices to prevent illness and injury at public treated recreational water venues. Now, local and state authorities can voluntarily adopt these science- and best practices–based guidelines to make swimming and other activities at public pools and other aquatic venues healthier and safer. The second edition of the code will be released during the 2016 swim season. For more information about the Model Aquatic Health Code, visitwww.cdc.gov/mahc.

hot.tubProblem/Condition: Aquatic facility–associated illness and injury in the United States include disease outbreaks of infectious or chemical etiology, drowning, and pool chemical–associated health events (e.g., respiratory distress or burns). These conditions affect persons of all ages, particularly young children, and can lead to disability or even death. A total of 650 aquatic facility–associated outbreaks have been reported to CDC for 1978–2012. During 1999–2010, drownings resulted in approximately 4,000 deaths each year in the United States. Drowning is the leading cause of injury deaths in children aged 1–4 years, and approximately half of fatal drownings in this age group occur in swimming pools. During 2003–2012, pool chemical–associated health events resulted in an estimated 3,000–5,000 visits to U.S. emergency departments each year, and approximately half of the patients were aged <18 years. In August 2014, CDC released the Model Aquatic Health Code (MAHC), national guidance that can be adopted voluntarily by state and local jurisdictions to minimize the risk for illness and injury at public aquatic facilities.

Reporting Period Covered: 2013.

Description of System: The Network for Aquatic Facility Inspection Surveillance (NAFIS) was established by CDC in 2013. NAFIS receives aquatic facility inspection data collected by environmental health practitioners when assessing the operation and maintenance of public aquatic facilities. This report presents inspection data that were reported by 16 public health agencies in five states (Arizona, California, Florida, New York, and Texas) and focuses on 15 MAHC elements deemed critical to minimizing the risk for illness and injury associated with aquatic facilities (e.g., disinfection to prevent transmission of infectious pathogens, safety equipment to rescue distressed bathers, and pool chemical safety). Although these data (the first and most recent that are available) are not nationally representative, 15.7% of the estimated 309,000 U.S. public aquatic venues are located in the 16 reporting jurisdictions.

Results: During 2013, environmental health practitioners in the 16 reporting NAFIS jurisdictions conducted 84,187 routine inspections of 48,632 public aquatic venues. Of the 84,187 routine inspection records for individual aquatic venues, 78.5% (66,098) included data on immediate closure; 12.3% (8,118) of routine inspections resulted in immediate closure because of at least one identified violation that represented a serious threat to public health. Disinfectant concentration violations were identified during 11.9% (7,662/64,580) of routine inspections, representing risk for aquatic facility–associated outbreaks of infectious etiology. Safety equipment violations were identified during 12.7% (7,845/61,648) of routine inspections, representing risk for drowning. Pool chemical safety violations were identified during 4.6% (471/10,264) of routine inspections, representing risk for pool chemical–associated health events.

Interpretation: Routine inspections frequently resulted in immediate closure and identified violations of inspection items corresponding to 15 MAHC elements critical to protecting public health, highlighting the need to improve operation and maintenance of U.S. public aquatic facilities. These findings also underscore the public health function that code enforcement, conducted by environmental health practitioners, has in preventing illness and injury at public aquatic facilities.

Public Health Action: Findings from the routine analyses of aquatic facility inspection data can inform program planning, implementation, and evaluation. At the state and local level, these inspection data can be used to identify aquatic facilities and venues in need of more frequent inspections and to select topics to cover in training for aquatic facility operators. At the national level, these data can be used to evaluate whether the adoption of MAHC elements minimizes the risk for aquatic facility–associated illness and injury. These findings also can be used to prioritize revisions or updates to the MAHC. To optimize the collection and analysis of aquatic facility inspection data and thus application of findings, environmental health practitioners and epidemiologists need to collaborate extensively to identify public aquatic facility code elements deemed critical to protecting public health and determine the best way to assess and document compliance during inspections.

Immediate Closures and Violations Identified During Routine Inspections of Public Aquatic Facilities — Network for Aquatic Facility Inspection Surveillance, Five States, 2013

Surveillance Summaries / May 20, 2016 / 65(5);1–26

Michele C. Hlavsa, MPH; Taryn R. Gerth, MPH; Sarah A. Collier, MPH; Elizabeth L. Dunbar, MPH; Gouthami Rao, MPH; Gregory Epperson; Becky Bramlett; David F. Ludwig, MPH; Diana Gomez, MPH; Monty M. Stansbury; Freeman Miller; Jeffrey Warren; Jim Nichol; Harry Bowman; Bao-An Huynh, MPH; Kara M. Loewe; Bob Vincent; Amanda L. Tarrier, MPH; Timothy Shay; Robert Wright; Allison C. Brown, PhD; Jasen M. Kunz, MPH; Kathleen E. Fullerton, MPH; James R. Cope, PhD; Michael J. Beach, PhD