Article

A water contamination incident in Oslo, Norway during October 2007; a basis for discussion of boil-water notices and the potential for post-treatment contamination of drinking water supplies

Parasitology Laboratory, Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, Postbox 8146 Dep, 0033, Oslo, Norway.
Journal of Water and Health (Impact Factor: 1.17). 02/2009; 7(1):55-66. DOI: 10.2166/wh.2009.014
Source: PubMed

ABSTRACT Over a 5 day period in October 2007 a boil-water notice was served on the majority of Oslo, capital city of Norway, as a result of a combination of bacteriological findings (coliforms, intestinal enterococci, and E. coli), and very low numbers of Cryptosporidium oocysts and Giardia cysts in 10 L water samples taken from the water distribution network. The water source had been regularly monitored for these parasites and generally found to be negative. Over 460,000 residents were affected by the boil-water notice, as were many thousands of businesses. Despite an extensive outbreak of waterborne giardiasis in Bergen, Norway during 2004/2005, occurrence of parasites in Norwegian drinking water supplies has apparently continued to be considered to be of minimal relevance by Norwegian health authorities. Here we describe the background and occurrence of the episode in Oslo, including the species of Cryptosporidium detected, and use this event, in conjunction with incidents from other countries, as a basis to discuss the following issues: (1) under which circumstances should the occurrence of Cryptosporidium oocysts and Giardia cysts in water supplies trigger the issue of a boil-water notice, and (2) the possibilities and probabilities of post-treatment contamination events in the water distribution network.

0 Bookmarks
 · 
61 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Giardiasis may present with dyspeptic symptoms that may mimic other gastrointestinal and/or biliary disorders. The objective of this study was to determine the prevalence of giardiasis in stool and duodenal aspirate of patients with NUD, assess symptomatic benefit of therapy, and compare the diagnostic tools for giardiasis utilizing stool and duodenal aspirates microscopic evaluation versus ELISA testing. 109 Patients with endoscopic diagnosis of NUD out of 278 consecutive patients with dyspepsia were included. The severity of dyspepsia and the quality of life were assessed utilizing Rome II criteria and SF-36 for Quality of Life and concomitant stool and/or duodenal aspirate samples were submitted for ELISA antigen test for Giardia intestinalis. Those who tested positive for giardiasis (Group 1) were assigned to receive Tinidazole 2.0g. single dose plus omeprazole for 4weeks and the remaining patients (Group 2) omeprazole alone for 4weeks. One month after therapy, both groups were reassessed and Stool ELISA antigen test for G. intestinalis for Group 1, was performed. ELISA testing of stool (19%) and duodenal aspirates (19%) had significantly better results than microscopic ones in stool (11%) or duodenal aspirates (7%). The two groups were well matched with respect to age, sex, initial results on the Glasgow Dyspepsia Severity Score, prevalence of previously prescribed antisecretory-drug therapy, prevalence of smoking, predominant symptom at presentation, and quality of life. The outcome of patients at 1month, on an intention-to-treat basis, showed that the symptoms were resolved (defined as a score of 0 or 1) in 17 of 21 patients (81%) in Group 1 as compared with 31 of 88 patients (35%) in Group 2 P<0.001. The scores in both groups were lower than those at base line and there was a highly statistically significant difference between both groups. G. intestinalis as a cause of dyspepsia should be considered in patients with negative endoscopy and in those who remain symptomatic in spite of adequate treatment for known upper G.I. disorders. NUD associated with the presence of Giardia, had better symptomatic benefit (81%) with specific treatment than controls (35%). ELISA testing of stool (19%) and duodenal aspirates (19%) had significantly better results than microscopic ones in stool (11%) or duodenal aspirates (7%).
    Arab Journal of Gastroenterology 09/2013; 14(3):126-9. DOI:10.1016/j.ajg.2013.08.004
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Giardia lamblia is a cosmopolitan parasite that occurs worldwide and generally effects gastrointestinal tract. Water played a media for transmission of Giardia to different hosts. A total of 300 water samples were examined from different water sources, i.e. tap, open well, bore well and drain waters and DNA was extracted by trizol method through prescribed protocol. DNA was amplified through PCR. The overall prevalence of G. lamblia was 27.66% (83/300). Among these 2.5% (1/40) in bore well water, 29% (29/100) open well, 18.83% (11/60) tap water and 42% (42/100) drain water. It is concluded from the study that Giardia is frequently found in all water sources and is the main cause of ill health.
  • Applied Geography 03/2014; 48:112–121. DOI:10.1016/j.apgeog.2014.02.001 · 3.08 Impact Factor