Category Archives: Cryptosporidium

Ireland – EPA finds issues with Fermoy water supply – Cryptosporidium

Irish Examiner


Cryptosporidium had been detected in the public water supply in Fermoy in November last year

The public water supply to the north Cork town of Fermoy could be at risk and placed on a list of water treatment plants needing corrective action, according to the State environmental watchdog.

The Environmental Protection Agency has warned Irish Water that Fermoy’s water treatment plant could be placed on its Remedial Action List which would require the utility to complete an action programme to address problems with the supply.

It follows an audit by EPA inspectors carried out on the facility last November to check if it was providing clean and wholesome water to households and businesses.

Research – An outbreak of Cryptosporidium parvum linked to pasteurised milk from a vending machine in England: a descriptive study, March 2021

Cambridge Org

We describe the investigations and management of a Cryptosporidium parvum outbreak of linked to consumption of pasteurised milk from a vending machine. Multiple locus variable number of tandem repeats analysis was newly used, confirming that C. parvum detected in human cases was indistinguishable from that in a calf on the farm. This strengthened the evidence for milk from an on-farm vending machine as the source of the outbreak because of post-pasteurisation contamination. Bacteriological indicators of post-pasteurisation contamination persisted after the initial hygiene improvement notice. We propose that on-farm milk vending machines may represent an emerging public health risk.

UK – Milk and cheese linked to English E. coli outbreaks

Food Safety News

Three E. coli outbreaks were reported in England earlier this year with two linked to dairy farms.

The Animal and Plant Health Agency (APHA) helped the UK Health Security Agency (UKHSA) investigate Shiga toxin-producing E. coli (STEC) O103, O145, and O26 outbreaks between July and September.

The E. coli O26 outbreak also involved cryptosporidium and began in the previous quarter. There were 11 cases of cryptosporidium and two people also had confirmed E. coli O26.

Cryptosporidium cases visited an open farm attraction during the incubation period of their illness. STEC cases had links to the same premises.

Health officials visited and advised on actions that would improve hygiene for visitors and reduce potential exposure to the pathogens.

APHA collected fresh faeces samples in the O103 and O145 incidents, from the yard where the cows had been prior to milking. In both cases, the outbreak strain was not detected.

The STEC O103 outbreak with 11 cases was associated with soft, raw cheese from a dairy farm in the East of England. An investigation pointed to brie-like unpasteurized soft cheese being contaminated sometime during spring.

The STEC O145 outbreak with 10 patients was linked to the consumption of milk products from a dairy farm in North West England, with illness onset from mid-July. Investigations identified an issue with pasteurization and problems with the cleaning and storage of milk crates which made external contamination of packaging plausible.

Sweden – At least 100 ill in Swedish Cryptosporidium salad outbreak

Food Safety News

water contamination

A rise in Cryptosporidium infections in Sweden has been attributed to contaminated salad by public health officials.

The Public Health Agency of Sweden (Folkhälsomyndigheten) said 101 cases of a certain type of Cryptosporidium parvum had been confirmed in 13 regions of the country.

Patients fell ill from Sept. 25 to Oct. 15 this year and women were more affected than men. Cases range from 4 to 86 years old with an average age of 42.

Link to salad
The agency added there are another 99 potential cases being investigated. The type of Cryptosporidium parvum involved is common so there could be several possible sources.

Local infection control units, the Swedish Food Agency (Livsmedelsverket) and Folkhälsomyndigheten investigated the increase in infections to find a source.

Analysis of information from patients on what they had eaten before becoming ill shows they ate mixed or bagged salad more often than a control group.

Salad has a short shelf life so health officials don’t think it is still available for sale but no products have been sampled.

Livsmedelsverket has looked into possible producers and growers but has been unable to find the likely source of infection.

As reported cases of Cryptosporidium have decreased and are at similar levels to previous years, officials believe the outbreak is over.

Research – Survey of the occurrence of Giardia duodenalis cysts and Cryptosporidium spp. oocysts in green leafy vegetables marketed in the city of Valencia (Spain)

Science Direct


The role of vegetables usually consumed without prior culinary treatment is known to contribute to the prevalence of foodborne diseases. Cysts and oocysts can contaminate food, which can then be the source of infection in humans. The aim of the study was to assess the occurrence of Giardia duodenalis and Cryptosporidium spp. (oo)cysts in green leafy vegetables marketed in the city of Valencia (Spain) combining parasitological methods, two real-time qPCRs and light microscopy. An experimental field study was conducted on 129 vegetable samples, 64 from conventional farms and 65 from ecological (organic) farms. The samples were washed with water, and the resulting solution after removing the vegetables, was subjected to 24-hour sedimentation. The concentrated sediment was used for the search for protozoa. A positive result by both real-time PCRs, or a positive result by one qPCR and confirmation by microscopy was established as a positivity criterion. Giardia duodenalis was detected in 23.0 % of the samples, and Cryptosporidium spp. in 7.8 %. G. duodenalis (41.5 %) and Cryptosporidium spp. (20.0 %) were more frequent in ecological crops. The high level of contamination detected in organic vegetables may be due to the type of fertilizers and the quality of the water used for their irrigation and reinforces the need to take extreme hygiene measures in vegetables that are consumed raw.

Sweden – Sweden searches for the source of Crypto and Salmonella outbreaks

Food Safety News

Swedish officials are investigating a recent increase in reported cases of Cryptosporidium.

A total of 61 people have been confirmed as being infected by the same certain type of Cryptosporidium parvum. These people fell ill from Sept. 25 to Oct. 10 and live in 10 different regions of the country.

Of confirmed cases, 41 are women and 20 are men. They are aged between 11 and 86 years old with an average age of 44.

There are another 98 possible infections that have been reported within the same period and some of these may also belong to the outbreak.

The Public Health Agency of Sweden (Folkhälsomyndigheten) said the increase is under investigation but could be caused by food with wide distribution in the country.

Local infection control units, the Swedish Food Agency (Livsmedelsverket) and Folkhälsomyndigheten are investigating the outbreak to identify the source of infection.

Cryptosporidium is a parasite that, if ingested, can cause cryptosporidiosis. Transmission occurs mainly through contact with contaminated water but can be via food or exposure to infected animals or water contaminated by the feces of infected animals.

The main symptom is watery diarrhea, which can range from mild to severe. It is often accompanied by stomach pain, nausea or vomiting, fever, and sometimes dehydration and weight loss. Symptoms usually appear two to 10 days after infection and last one to two weeks.

Research – A summary of cryptosporidiosis outbreaks reported in France and overseas departments, 2017–2020

Science Direct

water contamination


Cryptosporidium is a known foodborne pathogen, ranked fifth out of 24 among foodborne parasites in terms of importance and a cause of many cryptosporidiosis outbreaks worldwide. In France, very few outbreaks were reported before 2017, and data recently obtained by the Expert Laboratory of the Cryptosporidiosis National Reference Center (CNR-LE-Cryptosporidiosis) have shown that outbreaks are in fact common and frequently underreported. In this work, we aim to report the characteristics of outbreaks detected in France during the period 2017–2020 and present a summary of investigations carried out by the CNR-LE-Cryptosporidiosis. During the study period, there were eleven cryptosporidiosis outbreaks, including three with no identified origin. Among the eight identified outbreaks: six were due to water contamination (five tap water and one recreational water), one was due to direct contact with infected calves, and one was due to consumption of contaminated curd cheese. Among these outbreaks, five of them exceeded one hundred cases. Recent results obtained by the CNR-LE-Cryptosporidiosis revealed the multiannual occurrence of Cryptosporidium outbreaks in France. Waterborne outbreaks were more frequently detected, while foodborne outbreaks which are more difficult to detect were likely underreported.

Research – Transmission of Cryptosporidium by Fresh Vegetables

Journal of Food Protection

water contamination

Consumption of fresh fruits and vegetables is increasing thanks to the awareness to the benefits to human health. Vegetables may become contaminated by enteric pathogens (protozoan parasites, bacteria and viruses) by irrigation with contaminated water, fertilization with fresh animal manure or by infected food handlers. Cryptosporidium spp. are fecal-oral protozoan parasites, known to be highly persistent in the environment, which facilitate the transmission of the infectious oocysts. Efficient methods were developed for releasing and concentrating Cryptosporidium oocysts from leafy vegetables and sensitive and specific methods were applied for their enumeration. The aims of this review are to discuss the development and optimization of methods applied to release oocysts from leafy vegetables, the prevalence of Cryptosporidium oocysts on fresh leafy vegetables from various parts of the world and to discuss cryptosporidiosis outbreaks resulting from the consumption of leafy vegetables. Three solutions were used with comparable efficiency to release oocysts from leafy vegetables 1M glycine solution, 0.1% Alconox and filter elution buffer with an efficiency of 36.2%, 72.6% and 44%, respectively. The prevalence of Cryptosporidium oocysts was reported in developed as well as from developing countries, although simple detection methods were applied. Most of the cryptosporidiosis outbreaks were reported in developed countries, which can be related to their efficient surveillance system. Transmission of infectious pathogens, such as Cryptosporidium may be facilitated by fresh vegetables, which are imported and transferred from less developed to highly developed countries and consumed uncooked. Monitoring of Cryptosporidium oocysts by sensitive detection methods may enhance measures to prevent their transmission by freshly consumed vegetables.

Research – An outbreak of cryptosporidiosis associated with drinking water in north-eastern Italy, August 2019: microbiological and environmental investigations



The enteric parasite , along with norovirus,  and rotavirus, is among the most frequent causes of waterborne disease [1,2]. In humans, transmission of  occurs via the faecal-oral route, either through direct exposure to infected people (person-to-person infection) or animals (animal-to-person infection), or through ingestion of water (drinking water, recreational water such as swimming pools, water parks, lakes, rivers) or consumption of raw or undercooked food contaminated with infectious oocysts [3]. Infection may remain asymptomatic or manifest as acute gastroenteritis (> 80% of infected individuals). Symptoms occur 1 to 12 days (mean: 7 days) after exposure and usually last 6 to 9 days. The severity and duration of symptoms are linked to the immune status of the host, and cryptosporidiosis can be life threatening in immunosuppressed individuals [4].

There are many  species that can infect humans, but the vast majority of cases are due to , a zoonotic species that also infects young ruminants, and , which is essentially only a human pathogen [5]. The environmental route of transmission is of high relevance for  [6]. This is due to several factors including: (i) the high survival rate of oocysts in water (more than 24 months at 20°C), (ii) high resistance to disinfection (30 mg/L of free chlorine are needed to achieve 99% inactivation at pH 7, with a recommended value of 0.2 mg/L for drinking water) [6], (iii) low infectious dose (10–132 oocysts in healthy adults [7]) and (iv) low host specificity [5]. Oocysts lose their infectivity when frozen, boiled or heated over 60°C [6].

The ability of  to survive at high chlorine concentrations [8] and, consequently, at the disinfectant concentrations commonly used in water treatment, has always been a challenge for water treatment plant operators. However, other disinfectants, such as chlorine dioxide, ozone, UV rays and filtration have proved to be rather effective in removing . Water safety mainly depends on the combination of different treatment stages, and a multi-barrier approach is a key paradigm for ensuring safe drinking water [6]. Nonetheless, in small water supplies managed by local communities that serve only few thousand people, multi-barrier treatment systems are usually not implemented. Thus, in order to ensure the safety of drinking water, more traditional treatments, e.g. disinfection, are used and water quality is checked against certain regulatory parameters.

During 2017–20, 60 waterborne outbreaks of cryptosporidiosis have been detected in Europe, the majority of which involving treated recreational water (swimming pools) as the vehicle of infection [9]. The number of outbreaks linked to contaminated drinking water has shown a notable decrease in the past decades, although, when occurring, large numbers of individuals may be involved, as exemplified by the outbreaks reported in 2010–11 in Sweden [10,11].

Ireland – Potentially dangerous parasite in County Limerick water supply – Cryptosporidium

Limerick Post

DRINKING water supplies in Foynes have come under the microscope with the ongoing detection of a parasite that could pose a threat to human health.

Cryptosporidium, a parasite found in human and animal faeces, has been detected in the Foynes/Shannon Estuary water treatment plant this year.

The Environmental Protection Agency said it was “very concerned” after it conducted an audit which detected two breaches of recommended limits of cryptosporidium at the plant on February 23 and April 13.

The EPA said that it was most likely due to “a deterioration in raw water quality combined with significant deficiencies and pressures on the treatment processes at the plant”.

The environmental watchdog said the incident was suitably escalated and managed to protect the health of the population of over 7,200 in the Foynes area who use the water supply.