Olympus workshops teach analysts benefits of using Nomarski differential interference contrast (DIC) and optimised fluorescence microscopy in identification of Cryptosporidium oocysts in water
After the success of the recent 'Cryptosporidium size matters' workshop organised by the Scottish Parasite Diagnostic Laboratory and the Environmental Health Department, University of Strathclyde, Olympus Life and Material Science Europa announce that there are still places available for the next course at the Olympus Academy in Hamburg in February 2007.
The aim of the Olympus-sponsored workshop is to teach new and experienced Cryptosporidium analysts in the water industry the benefits of using Nomarski differential interference contrast (DIC) as well as optimised fluorescence microscopy in the identification of Cryptosporidium oocysts in drinking water.
The 'Cryptosporidium - size matters' workshop is organised by Professor Huw Smith, head of the Scottish Parasite Diagnostic laboratory and Tony Grimason, Department of Environmental Health, University of Strathclyde.
The first afternoon of formal lectures is followed by a two day, hands-on workshop.
The latest UK workshop was held in September (the 11th such annual event) and was a great success.
Delegates worked more efficiently by the end of the workshop and had an increased confidence in identifying Cryptosporidium, thus providing a more thorough assessment of potential risk of Cryptosporidium contamination to the water industry.
The next course will be held in Hamburg in February 20-22, 2007, and there are places still available.
The genus Cryptosporidium consists of at least 16 species, of which seven are highly pathogenic to humans.
In addition, there are up to 40 further genotypes which, as yet, have not been ascribed a species name.
The transmissive oocyst stage is not killed by conventional water treatment processes and can be found in our mains water supplies.
Cryptosporidium species and genotypes that infect humans can cause varying levels of sickness in healthy individuals; chronic disease in the immune-compromised and longer term sequelae in those infected.
Screening for this waterborne parasite was made mandatory in England and Wales in 1999, following a number of serious outbreaks.
As a result, a numerical treatment standard was set.
Identification of oocysts is based on microscopy and relies on using fluorescent adjuncts that bind to the oocyst wall and to sporozoite nuclei to identify the parasite on air dried microscope slides.
Confirmation of the presence of oocysts is based on their size and shape and the presence of sporozoites and their nuclei by DIC microscopy.
A team of parasitologists from Scotland, with the help of Olympus, have been running this course, which has been hailed a success for more than 11 years.
According to the organisers, the secret of success is to encourage delegates to understand the biology of the organism and to show them that optimised DIC and epifluorescence systems on their microscopes can give them the extra confidence in determining whether an object is an oocyst.
Prof Smith said, "This is one of the most difficult analyses that I have performed.
"By the time that analysts look at oocysts they have been flattened and distorted by air drying onto microscope slides.
"It's like trying to identify a three dimensional object that has been flattened by a steam roller.
"We use fluorogenic reporters to identify the location and approximate size of an oocyst and whether it possesses sporozoite nuclei, but DIC is the only microscopy contrast tool available for Cryptosporidium screening that can determine the morphology and morphometry of oocysts, accurately.
"Many Cryptosporidium analysts in the water industry find using DIC difficult, and our 'Cryptosporidium size matters' workshop is meant to address this specific issue and generate confidence in analysts.
"The specialist knowledge provided by our Olympus trainers always convinces delegates that they can optimise their microscopes for maximum performance.
"So with the help of Olympus, we have addressed this issue successfully, over that last 11 years.
"By increasing confidence in the use of DIC, the presence of Cryptosporidium oocysts in a sample can be confirmed more unambiguously, hence the potential public health risk of finding oocysts in treated water can be more readily addressed."