Biotech May 2004 Water Newsletter

Text Box: Legionella Incidence Rates The percentage isolation rates for water samples positive for Legionella during the 13 month period up until March 2004 are shown in the following graph. The average isolation rate during the period was 13.7% (compared to 15.8% for the sample period in 2003). Of the positive samples, 4.6% had a Legionella count in excess of 1,000 CFU/mL, 53.5% had a count in the range 100 to less than 1,000 CFU/mL and 41.9% had a count below 100 CFU/mL.

Biological Testing Reg No. 2787

Cert No. 7176 – 10

Editor: Glen Pinna

Text Box: Recent Legionella Outbreaks (Source: http://members.dodo.net.au/~jamgreen/legionnaires'_disease_2004.htm) Baltimore. USA. February 2004. The Department of Health and Mental Hygiene (DHMH), CDC and Worcester County Health Department are working together to find out why several guests who stayed at the Princess Royale Hotel in Ocean City, Maryland developed legionellosis within a week or so after staying at the hotel. Over a four-week period all tests of water samples were negative for Legionella. However there appears to be no other common link to the four people who developed the disease other than staying at the hotel. Oklahoma City. USA. March 2004. More than 60 people who attended a basketball tournament for home schooled students become ill, at least 13 people have tested positive for Legionella. The disease has been described as Pontiac fever and it is suggested that they may have contracted the bacteria from a hotel pool or hot tub. Vienna. Austria. March 2004. Three cases of legionnaires’ disease have been confirmed in Austria’s central Oberösterreich province. Three men, aged between 42 and 65 years, were admitted to hospital in the cities of Ried im Innkreis and Linz on 16, 17, and 19 March respectively. This temporal and spatial cluster prompted an epidemiological investigation, performed by the Austrian Agency for Health and Food Safety. All three patients reported that they had visited the whirlpool stand at an exhibition at approximately the same time. Legionellosis in Australia 2003 (Source: http://www1.health.gov.au/cda/Source/CDA-index.cfm) The figures of legionellosis cases in Australia for this year as of 7 May 2004 were a total of 87 cases. The number of cases per State or Territory were: New South Wales 27, Victoria 25, Western Australia 15, South Australia 9, Queensland 9, Tasmania 1, Australian Capital Territory 1, and Northern Territory had no cases.

May 2004

Issue No.

Text Box: There is an internet newsgroup for Legionella established at http://groups.yahoo.com/group/legionnaires_disease/ I would request that all experts in water treatment and concerned people go to this site, join the group and visit it to ask and answer questions posted by others.

Text Box: Biotech Laboratories Pty Ltd Level 2, Administration Building, Greenslopes Private Hospital, Newdegate Street, Greenslopes Qld 4120 PO Box 505 Indooroopilly Qld 4068 Ph: (07) 3847 9488 Facsimile: (07) 3847 9890 E-mail: technical@biotechlab.com.au Web site: http://www.biotechlab.com.au/

A variety of micro-organisms that can cause illness have been found in water, these can be introduced into the body by drinking and inhalation, or by exposure to skin or mucous membrane. They include bacteria, protozoa, algae and viruses. This discussion will cover the description, significance, water treatment required for elimination and health significance where applicable.

Mycobacteria

No guideline value has been set for Mycobacteria in drinking water.

Environmental mycobacteria, which are also called atypical mycobacteriaor non-tuberculous mycobacteria (NTM), are common saprophytesin all natural ecosystems, including water, soil, food, dust,and aerosols. Some species are alsopathogenic for humans or animals, causing pulmonary and cutaneousdisease, lymphadenitis, and disseminated infections. NTM infections are transmitted by ingestion, inhalation, andinoculation from environmental sources rather than from personto person. Mycobacteria have been isolated from public water distributionsystems and from samples from various other sources, includinghome distribution systems, hot and cold water taps, ice machines,heated nebulizers, and showerhead sprays.

Water distribution systemcan be colonized by several species of mycobacteria, such as M.gordonae, M. nonchromogenicum, M. aurum, M. gadium, M. fortuitum,M. peregrinum, and M. chelonae. A link between the occurrence of Mycobacterium in drinking water and disease has been suggested in specific cases. This has included, M. kansasii (Czechoslovakia, Netherlands and a possible case in Victoria, Australia) and M. avian complex (USA). However, in all these cases the evidence of of the infection being due to drinking water contamination is only circumstantial.

Mycobacteria arenot killed by common disinfectants and can tolerate wide rangesof pHs and temperatures, which allows them to persist in drinkingwater systems for long periods of time. Free available chlorine levels of 0.5 to 1 mg/L are sufficient to control the bacteria in water distribution systems. However, due to the low infectivity of environmental mycobacteria guidelines for acceptable limits and eradication programs are not warranted.

It is important to note that most pathogenic species of Mycobacterium such as M. tuberculosis, M. bovis, and M. leprae are not transmitted by water and only have human and animal reservoirs. These bacteria do not fall into the category of environmental mycobacteria. Although many of the environmental mycobacteria are regarded as non-pathogenic, several species are opportunistic pathogens for humans. The most important of these are the slow growers M. kansasii, M. marinum, M. avium, M. intracellulare, M. scrofulaceum and M. xenopi and the rapid growers M. chelonae and M. fortuitum.

Diseases called by the opportunistic environmental mycobacteria include, tuberculosis lung disease and disseminated infections that may involve the skeleton, lymph nodes, skin and soft tissues. These infections usually result from an environmental exposure to the bacteria in combination with the person infected having predisposing factors such as dust in the lungs, surgical wounds or suppression of their immune system due to medication or underlying disease (AIDS, malignancies).

The next BioTalk will deal with Pseudomonas aeruginosa.

Source: Australian Drinking Water Guidelines - 6: 1996. National Health and Medical Research Council of Australia & Agriculture and Resource Management Council of Australia and New Zealand. Occurrence of Mycobacteria in Water Treatment Lines and in Water Distribution Systems, Applied and Environmental Microbiology, November 2002, p. 5318-5325, Vol. 68, No. 11.