Høsten 2004 ble Bergen rammet av en omfattende epidemi med giardiasis og det tok om lag to måneder fra pasienter begynte å bli syke til utbruddet ble erkjent. Klinikeres diagnostiske tankegang i en situasjon der de sto overfor et uventet sykdomsbilde… og en økning av tilfeller av sykdommen Myalgisk Encefalopati.
Høsten 2004 ble Bergen rammet av en epidemi med giardiasis hvor ca. 1 300 pasienter fikk påvist Giardia lamblia i avføringsprøve. Et så omfattende utbrudd av giardiasis er aldri tidligere registrert i Norge, og også i nordisk og europeisk sammenheng er dette spesielt. Utbruddet er beskrevet i flere artikler. Det ble allment kjent gjennom pressemelding og orientering til fastlegene og legevakten i Bergen 1.11. 2004. Dette skjedde etter at smittevernoverlegen i Bergen ble kontaktet av overlegen ved parasittlaboratoriet ved Haukeland Universitetssjukehus, men det er i ettertid vist at de aller fleste pasientene ble syke allerede i løpet av september og oktober. Før utbruddet i Bergen har det vært diskutert om giardiasis er underdiagnostisert i Norge. Fra flere hold har det i ettertid vært kritisert at det tok lang tid fra pasientene ble syke til de fikk riktig diagnose og utbruddet ble erkjent.
Nedenfor følger den publiserte litteraturen
.BMC Immunol. 2017 Jan 28;18(1):5. doi: 10.1186/s12865-017-0190-3.
Giardia-specific cellular immune responses in post-giardiasis chronic fatigue syndrome.
Hanevik K1,2, Kristoffersen E3,4, Mørch K3,5, Rye KP3, Sørnes S3, Svärd S6, Bruserud Ø3, Langeland N3,5.
Abstract
BACKGROUND:
The role of pathogen specific cellular immune responses against the eliciting pathogen in development of post-infectious chronic fatigue syndrome (PI-CFS) is not known and such studies are difficult to perform. The aim of this study was to evaluate specific anti-Giardia cellular immunity in cases that developed CFS after Giardia infection compared to cases that recovered well. Patients reporting chronic fatigue in a questionnaire study three years after a Giardia outbreak were clinically evaluated five years after the outbreak and grouped according to Fukuda criteria for CFS and idiopathic chronic fatigue. Giardia specific immune responses were evaluated in 39 of these patients by proliferation assay, T cell activation and cytokine release analysis. 20 Giardia exposed non-fatigued individuals and 10 healthy unexposed individuals were recruited as controls.
RESULTS:
Patients were clinically classified into CFS (n = 15), idiopathic chronic fatigue (n = 5), fatigue from other causes (n = 9) and recovered from fatigue (n = 10). There were statistically significant antigen specific differences between these Giardia exposed groups and unexposed controls. However, we did not find differences between the Giardia exposed fatigue classification groups with regard to CD4 T cell activation, proliferation or cytokine levels in 6 days cultured PBMCs. Interestingly, sCD40L was increased in patients with PI-CFS and other persons with fatigue after Giardia infection compared to the non-fatigued group, and correlated well with fatigue levels at the time of sampling.
CONCLUSION:
Our data show antigen specific cellular immune responses in the groups previously exposed to Giardia and increased sCD40L in fatigued patients.
KEYWORDS:
Antigen-specific; Chronic fatigue syndrome; Giardia; Immune response; T cell; sCD40L
PMID:28129747
PMCID: PMC5279576
DOI:10.1186/s12865-017-0190-3
.BMC Fam Pract. 2017 Mar 27;18(1):49. doi: 10.1186/s12875-017-0614-4.
From good health to illness with post-infectious fatigue syndrome: a qualitative study of adults’ experiences of the illness trajectory.
Stormorken E1, Jason LA2, Kirkevold M3.
Abstract
BACKGROUND:
Municipal drinking water contaminated with the parasite Giardia lamblia in Bergen, Norway, in 2004 caused an outbreak of gastrointestinal infection in 2500 people, according to the Norwegian Prescription Database. In the aftermath a minor group subsequently developed post-infectious fatigue syndrome (PIFS). Persons in this minor group had laboratory-confirmed parasites in their stool samples, and their enteritis had been cured by one or more courses of antibiotic treatment. The study’s purpose was to explore how the affected persons experienced the illness trajectory and various PIFS disabilities.
METHODS:
A qualitative design with in-depth interviews was used to obtain first-hand experiences of PIFS. To get an overall understanding of their perceived illness trajectory, the participants were asked to retrospectively rate their functional level at different points in time. A maximum variation sample of adults diagnosed with PIFS according to the international 1994 criteria was recruited from a cohort of persons diagnosed with PIFS at a tertiary Neurology Outpatient Clinic in Western Norway. The sample comprised 19 women and seven men (mean age 41 years, range 26-59). The interviews were fully transcribed and subjected to a qualitative content analysis.
RESULTS:
All participants had been living healthy lives pre-illness. The time to develop PIFS varied. Multiple disabilities in the physical, cognitive, emotional, neurological, sleep and intolerance domains were described. Everyone more or less dropped out from studies or work, and few needed to be taken care of during the worst period. The severity of these disabilities varied among the participants and during the illness phases. Despite individual variations, an overall pattern of illness trajectory emerged. Five phases were identified: prodromal, downward, turning, upward and chronic phase. All reached a nadir followed by varying degrees of improvement in their functional ability. None regained pre-illness health or personal and professional abilities.
CONCLUSIONS:
The needs of persons with this condition are not met. Early diagnosis and interdisciplinary rehabilitation could be beneficial in altering the downward trajectory at an earlier stage, avoiding the most severe disability and optimising improvement. Enhanced knowledge among health professionals, tailored treatment, rest as needed, financial support and practical help would likely improve prognosis.
KEYWORDS:
Chronic fatigue syndrome; Disability; In-depth interview; Myalgic encephalomyelitis; Natural course; Patient experiences; Primary healthcare; Qualitative research
PMID: 28347294, PMCID: PMC5369194 , DOI: 10.1186/s12875-017-0614-4 .
Stormorken, Eva, Leonard A. Jason, and Kirkevold, Marit. (2017). From good health to illness with post-infectious fatigue syndrome: a qualitative study of adults’ experiences of the illness trajectory. BMC Family Practice, 18, 49. http://doi.org/10.1186/s12875-017-0614-4 .
.Sleep Health. 2016 Jun;2(2):154-158. doi: 10.1016/j.sleh.2016.03.005. Epub 2016 Apr 26.
Excessive daytime sleepiness, sleep need and insomnia 3 years after Giardia infection: a cohort study.
Hunskar GS1, Bjorvatn B2, Wensaas KA3, Hanevik K4, Eide GE5, Langeland N4, Rortveit G6.
Abstract
OBJECTIVE:
To investigate whether prior infection with Giardia lamblia is associated with excessive daytime sleepiness, insomnia, and level of sleep need.
DESIGN:
A questionnaire was sent to all confirmed cases of giardiasis 3 years after the outbreak and a control group matched on age and gender. Associations were evaluated by use of multiple regression analysis.
RESULTS:
Excessive daytime sleepiness (score ≥11 on the Epworth Sleepiness Scale) was reported by 31.5% of the Giardia-exposed and 14.1% of the controls. In multivariate analysis, excessive daytime sleepiness was independently associated with Giardia exposure, with an adjusted odds ratio of 1.40 (95% confidence interval [CI], 1.06-1.86). Insomnia was reported by 15.4% of Giardia-exposed and 8.8% of controls, adjusted odds ratio was 0.93 (95% CI, 0.65-1.35). Mean (SD) self-reported sleep need was 8 (1.4) hours among Giardia-exposed and 7.5 (1.1) hours in the control group (P < .001). The adjusted regression coefficient was 0.12 (95% CI, 0.01-0.24).
CONCLUSION:
Being exposed to Giardia was independently associated with excessive daytime sleepiness and larger sleep need, but not with insomnia.
Copyright © 2016 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.
KEYWORDS:
Chronic fatigue; Excessive daytime sleepiness; Giardia lamblia; Insomnia; Irritable bowel syndrome; Sleep need
PMID:28923259
DOI:10.1016/j.sleh.2016.03.005
.BMC Nurs. 2015 Nov 28;14:64. doi: 10.1186/s12912-015-0115-5. eCollection 2015.
Fatigue in adults with post-infectious fatigue syndrome: a qualitative content analysis.
Stormorken E1, Jason LA2, Kirkevold M1.
Abstract
BACKGROUND:
Fatigue is a major problem among individuals with post-infectious fatigue syndrome (PIFS), also known as chronic fatigue syndrome or myalgic encephalomyelitis. It is a complex phenomenon that varies across illnesses. From a nursing perspective, knowledge and understanding of fatigue in this illness is limited. Nurses lack confidence in caring for these patients and devalue their professional role. The aim of this study was to explore in-depth the experiences of fatigue among individuals with PIFS. A detailed description of the phenomenon of fatigue is presented. Increased knowledge would likely contribute to more confident nurses and improved nursing care.
METHODS:
A qualitative study with open interviews was employed. In-depth interviews with patients were fully transcribed and underwent a qualitative content analysis. A maximum variation sample of 26 affected adults between 26-59 years old was recruited from a population diagnosed at a fatigue outpatient clinic.
RESULTS:
The fatigue was a post-exertional, multidimensional, fluctuating phenomenon with varying degrees of severity and several distinct characteristics and was accompanied by concomitant symptoms. Fatigue was perceived to be an all-pervasive complex experience that substantially reduced the ability to function personally or professionally. A range of trigger mechanisms evoked or worsened the fatigue, but the affected were not always aware of what triggered it. There was an excessive increase in fatigue in response to even minor activities. An increase in fatigue resulted in the exacerbation of other concomitant symptoms. The term fatigue does not capture the participants’ experiences, which are accompanied by a considerable symptom burden that contributes to the illness experience and the severe disability.
CONCLUSIONS:
Although some aspects of the fatigue experience have been reported previously, more were added in our study, such as the dimension of awakening fatigue and the characteristic beyond time, when time passes unnoticed. We also identified trigger mechanisms such as emotional, neurological, social, financial, and pressure on oneself or from others. This in-depth exploration of fatigue in PIFS provides an overview of the dimensions, characteristics, and trigger mechanisms of fatigue, thus making better clinical observations, early recognition, improved communication with patients and more appropriate nursing interventions possible.
KEYWORDS:
Adult patients; Fatigue; In-depth interview; Myalgic encephalomyelitis chronic fatigue syndrome; Nursing qualitative research; Patient experiences; Post-infectious fatigue syndrome; Qualitative research
PMID: 26617466, PMCID:PMC4662830
DOI:10.1186/s12912-015-0115-5 .
Stormorken, Eva, Leonard A. Jason, and Kirkevold, Marit (2015). Fatigue in adults with post-infectious fatigue syndrome: a qualitative content analysis. BMC Nursing, 14: 64. http://doi.org/10.1186/s12912-015-0115-5 .
.BMC Gastroenterol. 2015 Nov 19;15:164. doi: 10.1186/s12876-015-0393-0.
Perceived food intolerance and irritable bowel syndrome in a population 3 years after a giardiasis-outbreak: a historical cohort study.
Litleskare S1, Wensaas KA2, Eide GE3,4, Hanevik K5,6, Kahrs GE7, Langeland N8, Rortveit G9,10.
Abstract
BACKGROUND:
Studies have shown an increased prevalence of irritable bowel syndrome (IBS) after acute gastroenteritis. Food as a precipitating and perpetuating factor in IBS has gained recent interest, but food intolerance following gastroenteritis is less investigated. The aims of this study were firstly, to compare perceived food intolerance in a group previously exposed to Giardia lamblia with a control group; secondly, to explore the relation with IBS status; and thirdly, to investigate associations with content of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) in foods reported.
METHODS:
This is a historical cohort study with mailed questionnaire to 1252 Giardia exposed and a control cohort matched by gender and age. Differences between groups were investigated using bivariate and multivariate analyses.
RESULTS:
The questionnaire response rate in the exposed group was 65.3 % (817/1252) and in the control group 31.4 % (1128/3598). The adjusted odds ratio (OR) for perceived food intolerance for the exposed group was 2.00 with 95 % confidence interval (CI): 1.65 to 2.42, as compared with the control group. Perceived intolerance for dairy products was the most frequently reported intolerance, with an adjusted OR for the exposed of 1.95 (95 % CI: 1.51 to 2.51). Perceived intolerance for fatty foods, vegetables, fruit, cereals and alcohol was also significantly higher in the exposed group. The groups did not differ in perceived intolerance to spicy foods, coffee or soda. The association between exposure to Giardia infection and perceived food intolerance differed between the IBS group and the no-IBS group, but IBS was not a significant effect modifier for the association. Perceived intolerance for high FODMAP foods (adjusted OR 1.91) and low FODMAP foods (adjusted OR 1.55) was significantly associated with exposure status.
CONCLUSION:
Exposure to Giardia infection was associated with perceived food intolerance 3 years after giardiasis. IBS status did not alter the association between exposure status and perceived food intolerance. Perceived intolerance to high FODMAP foods and low FODMAP foods were both statistically significantly associated with exposure to Giardia infection.
PMID:26585714, PMCID:PMC4653841
DOI:10.1186/s12876-015-0393-0
.Tidsskr Nor Laegeforen. 2015 Oct 20;135(19):1718-20. doi: 10.4045/tidsskr.15.0883. eCollection 2015 Oct 20.
Dogs as the source of Giardia in Bergen in 2004 – barking up the wrong tree?
[Article in English, Norwegian]
Robertson LJ, Tysnes KR, Hanevik K, Langeland N, Mørch K, Hausken T, Nygård K.
Comment on
Giardia outbreak in Bergen 2004 – what was the source of infection? [Tidsskr Nor Laegeforen. 2015]
PMID:26486664, DOI:10.4045/tidsskr.15.0883
.Clin Vaccine Immunol. 2015 Sep 16;23(1):11-8. doi: 10.1128/CVI.00419-15.
Human Memory CD4+ T Cell Immune Responses against Giardia lamblia.
Saghaug CS1, Sørnes S2, Peirasmaki D3, Svärd S3, Langeland N4, Hanevik K4.
Abstract
The intestinal protozoan parasite Giardia lamblia may cause severe prolonged diarrheal disease or pass unnoticed as an asymptomatic infection. T cells seem to play an important role in the immune response to Giardia infection, and memory responses may last years. Recently, TH17 responses have been found in three animal studies of Giardia infection. The aim of this study was to characterize the human CD4(+) T cell responses to Giardia. Peripheral blood mononuclear cells (PBMCs) were obtained from 21 returning travelers with recent or ongoing giardiasis and 12 low-risk healthy controls and stimulated in vitro with Giardia lamblia proteins. Production of tumor necrosis factor alpha (TNF-α), gamma interferon, interleukin-17A (IL-17A), IL-10, and IL-4 was measured in CD4(+) effector memory (EM) T cells after 24 h by flow cytometry. After 6 days of culture, activation and proliferation were measured by flow cytometry, while an array of inflammatory cytokine levels in supernatants were measured with multiplex assays. We found the number of IL-17A-producing CD4(+) EM T cells, as well as that of cells simultaneously producing both IL-17A and TNF-α, to be significantly elevated in the Giardia-exposed individuals after 24 h of antigen stimulation. In supernatants of PBMCs stimulated with Giardia antigens for 6 days, we found inflammation-associated cytokines, including 1L-17A, as well as CD4(+) T cell activation and proliferation, to be significantly elevated in the Giardia-exposed individuals. We conclude that symptomatic Giardia infection in humans induces a CD4(+) EM T cell response of which IL-17A production seems to be an important component.
Copyright © 2016, American Society for Microbiology. All Rights Reserved.
Comment in
Control of Giardiasis by Interleukin-17 in Humans and Mice–Are the Questions All Answered? [Clin Vaccine Immunol. 2015]
PMID:26376930, PMCID:PMC4711086
.BMC Gastroenterol. 2015 Jun 10;15:66. doi: 10.1186/s12876-015-0296-0.
The relationship between irritable bowel syndrome, functional dyspepsia, chronic fatigue and overactive bladder syndrome: a controlled study 6 years after acute gastrointestinal infection.
Persson R1, Wensaas KA2, Hanevik K3, Eide GE4,5, Langeland N6,7, Rortveit G8,9.
Abstract
BACKGROUND:
To investigate in a cohort with previous gastrointestinal infection and a control group the prevalence of overactive bladder syndrome (OAB), and how it was associated with three other functional disorders; irritable bowel syndrome (IBS), functional dyspepsia (FD) and chronic fatigue (CF).
METHODS:
Controlled historic cohort study including 724 individuals with laboratory confirmed giardiasis six years earlier, and 847 controls matched by gender and age. Prevalence and odds ratios (OR) with 95 % confidence intervals (CI) were calculated.
RESULTS:
The prevalence of OAB was 18.7 % (134/716) in the exposed group and 13.6 % (113/833) in the control group (p = 0.007). The association between OAB and IBS was strong in the control group (OR: 2.42; 95 % CI: 1.45 to 4.04), but insignificant in the Giardia exposed (OR: 1.29; 95 % CI: 0.88 to 1.88). The association between OAB and FD was weak in both groups. CF was strongly associated with OAB (OR: 2.73; 95 % CI: 1.85 to 4.02 in the exposed and OR: 2.79; 95 % CI: 1.69 to 4.62 in the controls), and this association remained when comorbid conditions were excluded.
CONCLUSIONS:
Sporadic IBS was associated with increased risk of OAB, whereas post-infectious IBS was not. An apparent association between OAB and previous Giardia infection can be ascribed to comorbid functional disorders.
Comment in
PMID:26058591, PMCID:PMC4460696
.
Clin Infect Dis. 2014 Nov 15;59(10):1394-400. doi: 10.1093/cid/ciu629. Epub 2014 Aug 12.
Irritable bowel syndrome and chronic fatigue 6 years after giardia infection: a controlled prospective cohort study.
Hanevik K1, Wensaas KA2, Rortveit G3, Eide GE4, Mørch K5, Langeland N1.
Abstract
BACKGROUND:
Functional gastrointestinal disorders and fatigue may follow acute infections. This study aimed to estimate the persistence, prevalence, and risk of irritable bowel syndrome and chronic fatigue 6 years after Giardia infection.
METHODS:
We performed a controlled prospective study of a cohort of 1252 individuals who had laboratory-confirmed Giardia infection during a waterborne outbreak in 2004. In total, 748 cohort cases (exposed) and 878 matched controls responded to a postal questionnaire 6 years later (in 2010). Responses were compared to data from the same cohort 3 years before (in 2007).
RESULTS:
The prevalences of irritable bowel syndrome (39.4%) by Rome III criteria and chronic fatigue (30.8%) in the exposed group 6 years after giardiasis were significantly elevated compared with controls, with adjusted relative risks (RRs) of 3.4 (95% confidence interval [CI], 2.9-3.9) and 2.9 (95% CI, 2.3-3.4), respectively. In the exposed group, the prevalence of irritable bowel syndrome decreased by 6.7% (RR, 0.85 [95% CI, .77-.93]), whereas the prevalence of chronic fatigue decreased by 15.3% from 3 to 6 years after Giardia infection (RR, 0.69 [95% CI, .62-.77]). Giardia exposure was a significant risk factor for persistence of both conditions, and increasing age was a risk factor for persisting chronic fatigue.
CONCLUSIONS:
Giardia infection in a nonendemic setting is associated with an increased risk for irritable bowel syndrome and chronic fatigue 6 years later. The prevalences of both conditions decrease over time, indicating that this intestinal protozoan parasite may elicit very long-term, but slowly self-limiting, complications.
© The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.
KEYWORDS:
Giardia; chronic fatigue; irritable bowel syndrome; postinfectious
PMID:25115874, PMCID:PMC4207419
DOI:10.1093/cid/ciu629
.BMC Gastroenterol. 2013 Feb 12;13:28. doi: 10.1186/1471-230X-13-28.
Chronic fatigue syndrome 5 years after giardiasis: differential diagnoses, characteristics and natural course.
Mørch K1, Hanevik K, Rivenes AC, Bødtker JE, Næss H, Stubhaug B, Wensaas KA, Rortveit G, Eide GE, Hausken T, Langeland N.
Abstract
BACKGROUND:
A high prevalence of chronic fatigue has previously been reported following giardiasis after a large waterborne outbreak in Bergen, Norway in 2004. The aim of this study was to describe and evaluate differential diagnoses and natural course of fatigue five years after giardiasis among patients who reported chronic fatigue three years after the infection.
METHODS:
Patients who three years after Giardia infection met Chalder’s criteria for chronic fatigue (n=347) in a questionnaire study among all patients who had laboratory confirmed giardiasis during the Bergen outbreak (n=1252) were invited to participate in this study five years after the infection (n=253). Structured interviews and clinical examination were performed by specialists in psychiatry, neurology and internal medicine/infectious diseases. Fukuda et al’s 1994 criteria were used to diagnose chronic fatigue syndrome (CFS) and idiopathic chronic fatigue (ICF). Self-reported fatigue recorded with Chalder Fatigue Questionnaire three and five years after infection were compared.
RESULTS:
53 patients were included. CFS was diagnosed in 41.5% (22/53) and ICF in 13.2% (7/53). Chronic fatigue caused by other aetiology was diagnosed in 24.5% (13/53); five of these patients had sleep apnoea/hypopnoea syndrome, six had depression and five anxiety disorder, and among these two had more than one diagnosis. Fatigue had resolved in 20.8% (11/53). Self-reported fatigue score in the cohort was significantly reduced at five years compared to three years (p<0.001).
CONCLUSION:
The study shows that Giardia duodenalis may induce CFS persisting as long as five years after the infection. Obstructive sleep apnoea/hypopnoea syndrome, depression and anxiety were important differential diagnoses, or possibly comorbidities, to post-infectious fatigue in this study. Improvement of chronic fatigue in the period from three to five years after giardiasis was found.
PMID:23399438 ,PMCID:PMC3598369
DOI:10.1186/1471-230X-13-28
Mørch, K. et al. (2013). Chronic fatigue syndrome 5 years after giardiasis: differential diagnoses, characteristics and natural course. BMC Gastroenterology, 13, 28. http://doi.org/10.1186/1471-230X-13-28 .
.BMC Infect Dis. 2012 Oct 14;12:258. doi: 10.1186/1471-2334-12-258.
Immunophenotyping in post-giardiasis functional gastrointestinal disease and chronic fatigue syndrome.
Hanevik K1, Kristoffersen EK, Sørnes S, Mørch K, Næss H, Rivenes AC, Bødtker JE, Hausken T, Langeland N.
Abstract
BACKGROUND:
A Giardia outbreak was associated with development of post-infectious functional gastrointestinal disorders (PI-FGID) and chronic fatigue syndrome (PI-CFS). Markers of immune dysfunction have given conflicting results in CFS and FGID patient populations. The aim of this study was to evaluate a wide selection of markers of immune dysfunction in these two co-occurring post-infectious syndromes.
METHODS:
48 patients, reporting chronic fatigue in a questionnaire study, were clinically evaluated five years after the outbreak and grouped according to Fukuda criteria for CFS (n=19) and idiopathic chronic fatigue (n=5) and Rome II criteria for FGIDs (n=54). 22 Giardia exposed non-fatigued individuals and 10 healthy unexposed individuals were recruited as controls. Peripheral blood lymphocyte subsets were analyzed by flow cytometry.
RESULTS:
In peripheral blood we found significantly higher CD8 T-cell levels in PI-FGID, and significantly lower NK-cell levels in PI-CFS patients. Severity of abdominal and fatigue symptoms correlated negatively with NK-cell levels. A tendency towards lower T-cell CD26 expression in FGID was seen.
CONCLUSION:
Patients with PI-CFS and/or PI-FGID 5 years after Giardia lamblia infection showed alterations in NK-cell and CD8-cell populations suggesting a possible immunological abnormality in these conditions. We found no significant changes in other markers examined in this well-defined group of PI-CFS and PI-FGID elicited by a gastrointestinal infection. Controlling for co-morbid conditions is important in evaluation of CFS-biomarkers.
PMID:23061432 , PMCID:PMC3553045
DOI:10.1186/1471-2334-12-258
.
Scand J Gastroenterol. 2012 Sep;47(8-9):956-61. doi: 10.3109/00365521.2012.696681. Epub 2012 Jul 2.
The impact of atopic disease on the risk of post-infectious fatigue and irritable bowel syndrome 3 years after Giardia infection. A historic cohort study.
Hunskar GS1, Langeland N, Wensaas KA, Hanevik K, Eide GE, Mørch K, Rortveit G.
Abstract
OBJECTIVE:
To investigate whether atopic disease influences the prevalence of irritable bowel syndrome (IBS) and chronic fatigue (CF) after giardiasis.
METHODS:
A questionnaire was sent to all confirmed cases of giardiasis after a Norwegian outbreak, with response rate of 65.3% (817/1252). Controls were randomly selected matched on age and sex, with response rate of 31.4% (1128/3598). Associations were evaluated by use of logistic regression analyses.
RESULTS:
In the Giardia exposed group, 47.8% of those with asthma had IBS compared with 45.3% in those without asthma (p = 0.662). For controls, corresponding percentages were 23.9% and 12.2% (p < 0.001). Among those with asthma, the adjusted relative risk (RR) for IBS was 2.03 (95% confidence interval (CI): 1.45, 2.62) for the exposed group compared with controls. In those without asthma, the corresponding RR was 3.80 (95% CI: 3.30, 4.32). In the exposed group, 51.5% of those with asthma had CF compared with 44.9% in those without asthma (p = 0.218). For controls, corresponding percentages were 19.3% and 10.7% (p = 0.004). Among those with asthma, the adjusted RR for CF was 2.73 (95% CI: 1.98, 3.45) for the exposed compared with controls. In those without asthma, the corresponding RR for CF was 4.25 (95% CI: 3.66, 4.85).
CONCLUSION:
For the exposed, having asthma or allergy did not increase the outcome of IBS or CF. For the control group, having an atopic disease made a substantial risk difference, with significantly more IBS and CF.
PMID:22746290 , DOI: 10.3109/00365521.2012.696681
.
BMC Gastroenterol. 2012 Feb 8;12:13. doi: 10.1186/1471-230X-12-13.
Chronic fatigue syndrome after Giardia enteritis: clinical characteristics, disability and long-term sickness absence.
Naess H1, Nyland M, Hausken T, Follestad I, Nyland HI.
Abstract
BACKGROUND:
A waterborne outbreak of Giardia lamblia gastroenteritis led to a high prevalance of long-lasting fatigue and abdominal symptoms. The aim was to describe the clinical characteristics, disability and employmentloss in a case series of patients with Chronic Fatigue Syndrome (CFS) after the infection.
METHODS:
Patients who reported persistent fatigue, lowered functional capacity and sickness leave or delayed education after a large community outbreak of giardiasis enteritis in the city of Bergen, Norway were evaluated with the established Centers for Disease Control and Prevention criteria for CFS. Fatigue was self-rated by the Fatigue Severity Scale (FSS). Physical and mental health status and functional impairment was measured by the Medical Outcome Severity Scale-short Form-36 (SF-36). The Hospital Anxiety and Depression Scale (HADS) was used to measure co-morbid anxiety and depression. Inability to work or study because of fatigue was determined by sickness absence certified by a doctor.
RESULTS:
A total of 58 (60%) out of 96 patients with long-lasting post-infectious fatigue after laboratory confirmed giardiasis were diagnosed with CFS. In all, 1262 patients had laboratory confirmed giardiasis. At the time of referral (mean illness duration 2.7 years) 16% reported improvement, 28% reported no change, and 57% reported progressive course with gradual worsening. Mean FSS score was 6.6. A distinctive pattern of impairment was documented with the SF-36. The physical functioning, vitality (energy/fatigue) and social functioning were especially reduced. Long-term sickness absence from studies and work was noted in all patients.
CONCLUSION:
After giardiasis enteritis at least 5% developed clinical characteristics and functional impairment comparable to previously described post-infectious fatigue syndrome.
PMID:22316329 , PMCID:PMC3292445
DOI:10.1186/1471-230X-12-13
.
Gut. 2012 Feb;61(2):214-9. doi: 10.1136/gutjnl-2011-300220. Epub 2011 Sep 12.
Irritable bowel syndrome and chronic fatigue 3 years after acute giardiasis: historic cohort study.
Wensaas KA1, Langeland N, Hanevik K, Mørch K, Eide GE, Rortveit G.
Abstract
BACKGROUND:
Giardia lamblia is a common cause of gastroenteritis worldwide, but there is limited knowledge about the long-term complications.
OBJECTIVE:
To estimate the relative risk of irritable bowel syndrome (IBS) and chronic fatigue 3 years after acute giardiasis.
DESIGN:
Controlled historic cohort study with 3 years’ follow-up. Data collected by mailed questionnaire.
SETTING:
Waterborne outbreak of giardiasis in the city of Bergen, Norway.
PARTICIPANTS:
817 patients exposed to Giardia lamblia infection verified by detection of cysts in stool samples and 1128 matched controls.
MAIN OUTCOME MEASURES:
IBS and chronic fatigue.
RESULTS:
The prevalence of IBS in the exposed group was 46.1%, compared with 14.0% in the control group, and the adjusted RR=3.4 (95% CI 2.9 to 3.8). Chronic fatigue was reported by 46.1% of the exposed group and 12.0% of the controls, the adjusted RR was 4.0 (95% CI 3.5 to 4.5). IBS and chronic fatigue were associated and the RR for the exposed group of having a combination of the two outcomes was 6.8 (95% CI 5.3 to 8.5). The RR was also increased for having just one of the two syndromes, 1.8 for IBS (95% CI 1.4 to 2.3) and 2.2 for chronic fatigue (95% CI 1.7 to 2.8).
CONCLUSIONS:
Infection with Giardia lamblia in a non-endemic area was associated with a high prevalence of IBS and chronic fatigue 3 years after acute illness, and the risk was significantly higher than in the control group. This shows that the potential consequences of giardiasis are more serious than previously known. Further studies are needed, especially in areas where giardiasis is endemic.
Comment in
Infection: Giardia lamblia is associated with an increased risk of both IBS and chronic fatigue that persists for at least 3 years. [Nat Rev Gastroenterol Hepatol. 2011]
PMID:21911849 , DOI:10.1136/gutjnl-2011-300220
.
J Infect Dis. 2011 Dec 1;204(11):1779-86. doi: 10.1093/infdis/jir639. Epub 2011 Oct 11.
Human cellular immune response against Giardia lamblia 5 years after acute giardiasis.
Hanevik K1, Kristoffersen E, Svard S, Bruserud O, Ringqvist E, Sørnes S, Langeland N.
Abstract
BACKGROUND:
Clinical and epidemiological studies have suggested the development of acquired immunity in individuals previously infected with Giardia lamblia. However, there are no data on the long-term cellular immunity and genotype cross-reactivity. An outbreak of assemblage B giardiasis in a nonendemic area made it possible to evaluate the long-term cellular mediated immunity and its specificity toward the 2 Giardia assemblages known to infect humans.
METHODS:
Peripheral blood mononuclear cells from 19 individuals infected with Giardia assemblage B 5 years previously and from 10 uninfected controls were cultured with antigens from assemblage A and B Giardia trophozoites for 6 days. Cell-mediated immunity was measured by a (3)H-thymidine proliferation assay and flow cytometric analysis of activation markers HLA-DR, CD45RO, CD25, and CD26 in T-cell subsets.
RESULTS:
Proliferation responses were significantly elevated in the group previously exposed to Giardia for nearly all Giardia antigens tested. Individual responses toward Giardia trophozoite whole cell, cytosolic, and excretory-secretory antigens from both assemblages correlated well. Activation marker responses were mainly seen in CD4 T cells.
CONCLUSIONS:
- lamblia infection induces long-term, albeit variable, cellular immune responses that are not assemblage specific and that are largely driven by CD4 T-cell activation.
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PMID:21990423 ,DOI:10.1093/infdis/jir639
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Fam Pract. 2010 Jun;27(3):255-9. doi: 10.1093/fampra/cmq005. Epub 2010 Mar 22.
Post-infectious gastrointestinal symptoms after acute Giardiasis. A 1-year follow-up in general practice.
Wensaas KA1, Langeland N, Rortveit G.
Abstract
BACKGROUND:
Giardia lamblia is endemic in many tropical and subtropical areas of the world, and in Europe and North America a common cause of waterborne outbreaks of gastroenteritis. In 2004, approximately 5000 people were sick with giardiasis during an outbreak in Bergen, Norway.
OBJECTIVE:
To investigate the presence of gastrointestinal complaints and persistent infection in a 1-year period after acute giardiasis.
METHODS:
From a population (N = 7100) assigned to two general practice clinics, a cohort of 134 patients with clinically defined giardiasis was identified. Of these, 118 gave consent to take part in this study. The patients were asked to submit stool samples 6 months after the acute infection and to return questionnaires delivered by mail 6 and 12 months after the outbreak. Main outcome measures were proportion of patients with persistent infection and/or gastrointestinal symptoms.
RESULTS:
Stool samples were submitted by 69.5% (82/118) of the patients after 6 months, and three were positive for G. lamblia. After 6 months, 37.3% (44/118) of the patients reported gastrointestinal symptoms related to their Giardia infection. This proportion went down to 19.2% (19/99) after 12 months. The reported water intake prior to the outbreak was significantly higher in patients with persistent symptoms, but there was no association with gender and neuroticism as has been shown in other studies of functional gastrointestinal disorders.
CONCLUSION:
Persistent gastrointestinal symptoms are a common complication after giardiasis in a population most likely previously unexposed to G. lamblia. The results show the need for further investigation of the mechanism involved.
PMID:20308244 , DOI:10.1093/fampra/cmq005
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In Vivo. 2010 Mar-Apr;24(2):185-8.
Postinfectious and chronic fatigue syndromes: clinical experience from a tertiary-referral centre in Norway.
Naess H1, Sundal E, Myhr KM, Nyland HI.
Abstract
BACKGROUND:
We aimed to compare patients reporting acute infection with those reporting no infection at onset of chronic fatigue syndrome (CFS).
PATIENTS AND METHODS:
This study includes 873 patients with CFS referred to a tertiary centre on average 4.8 years after symptom onset. Assessment was by both observer query and self-reports. Antibody analyses against infectious agents including Epstein-Barr virus and enterovirus were performed in a majority of patients.
RESULTS:
Females comprised 75.3% of the patient group, and the mean age was 33 years. Initial infection was reported by 77%. There was no difference as to antibody analyses. Logistic regression showed that initial infection was independently associated with acute onset of fatigue, improvement of fatigue at referral, and the following symptoms at referral: fever, tender lymph nodes, and myalgia.
CONCLUSION:
CFS patients with initial infection as a precipitating factor more often report acute onset of fatigue, more frequent accompanying symptoms, and more frequent improvement on referral than do patients without initial infection.
PMID: 20363992
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BMC Public Health. 2010 Mar 26;10:163. doi: 10.1186/1471-2458-10-163.
Post epidemic giardiasis and gastrointestinal symptoms among preschool children in Bergen, Norway. A cross-sectional study.
Mellingen KM1, Midtun A, Hanevik K, Eide GE, Søbstad Ø, Langeland N.
Abstract
BACKGROUND:
A surprisingly low number of children became ill with giardiasis during the large waterborne outbreak of Giardia lamblia in Bergen, Norway during autumn 2004. The aim of the present study was to evaluate the prevalence of giardiasis among exposed children one year after an outbreak and compare faecal carriage of Giardia and abdominal symptoms among exposed versus unexposed children one year after the epidemic.
METHODS:
Children between 1 and 6 years old were recruited from the local health care centres in Bergen municipality in the period between June 2005 and January 2006. One faecal sample per child was collected and examined for presence of Giardia with a rapid immunoassay antigen test, and parents were asked to answer a questionnaire. A total of 513 children participated, 378 in the group exposed to contaminated water, and 135 in the in the group not exposed.
RESULTS:
In the exposed group eleven children had been treated for giardiasis during the epidemic and none in the unexposed group. Giardia positive faecal tests were found in six children, all in the exposed group, but the difference between the groups did not reach statistical significance. All six Giardia positive children were asymptomatic. No differences were found between the groups regarding demographic data, nausea, vomiting, different odour from stools and eructation. However, the reported scores of abdominal symptoms (diarrhoea, bloating and stomach ache) during the last year were higher in the exposed group than in the unexposed group.
CONCLUSIONS:
A low prevalence of asymptomatic Giardia infection (1.7%) was found among exposed children around one year after the epidemic (1.2% overall prevalence in the study). In the present setting, pre-school children were therefore unlikely to be an important reservoir for continued transmission in the general population.
PMID:20346102 , PMCID:PMC2851687
DOI:10.1186/1471-2458-10-163
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Trends Parasitol. 2010 Feb;26(2):75-82. doi: 10.1016/j.pt.2009.11.010. Epub 2010 Jan 6.
Giardiasis–why do the symptoms sometimes never stop?
Robertson LJ1, Hanevik K, Escobedo AA, Mørch K, Langeland N.
Abstract
Although giardiasis is considered by most medical practitioners to be an easily treated infection, prolonged symptoms due to, or following, Giardia duodenalis infection can have a significant impact on quality of life. Symptom recurrence, including abdominal symptoms and fatigue, can result from re-infection, treatment failure, disturbances in the gut mucosa or post-infection syndromes. In developed countries, these sequelae can have an enormous impact on quality of life; in developing countries, particularly in children, they add yet another burden to populations that are already disadvantaged. Here, we outline current knowledge, based on individual case sequelae from sporadic infections, observations of population effects following outbreaks and studies of phenotypic and genotypic diversity between morphologically identical isolates of parasites. We also raise further questions, looking for clues as to why giardiasis sometimes becomes an intrusive, long-term problem.
2009 Elsevier Ltd. All rights reserved.
PMID:20056486 , DOI:10.1016/j.pt.2009.11.010
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BMC Infect Dis. 2009 Dec 15;9:206. doi: 10.1186/1471-2334-9-206.
Severity of Giardia infection associated with post-infectious fatigue and abdominal symptoms two years after.
Mørch K1, Hanevik K, Rortveit G, Wensaas KA, Eide GE, Hausken T, Langeland N.
Abstract
BACKGROUND:
A high rate of post-infectious fatigue and abdominal symptoms two years after a waterborne outbreak of giardiasis in Bergen, Norway in 2004 has previously been reported. The aim of this report was to identify risk factors associated with such manifestations.
METHODS:
All laboratory confirmed cases of giardiasis (n = 1262) during the outbreak in Bergen in 2004 received a postal questionnaire two years after. Degree of post-infectious abdominal symptoms and fatigue, as well as previous abdominal problems, was recorded. In the statistical analyses number of treatment courses, treatment refractory infection, delayed education and sick leave were used as indices of protracted and severe Giardia infection. Age, gender, previous abdominal problems and symptoms during infection were also analysed as possible risk factors. Simple and multiple ordinal logistic regression models were used for the analyses.
RESULTS:
The response rate was 81% (1017/1262), 64% were women and median age was 31 years (range 3-93), compared to 61% women and 30 years (range 2-93) among all 1262 cases. Factors in multiple regression analysis significantly associated with abdominal symptoms two years after infection were: More than one treatment course, treatment refractory infection, delayed education, bloating and female gender. Abdominal problems prior to Giardia infection were not associated with post-infectious abdominal symptoms. More than one treatment course, delayed education, sick leave more than 2 weeks, and malaise at the time of infection, were significantly associated with fatigue in the multiple regression analysis, as were increasing age and previous abdominal problems.
CONCLUSION:
Protracted and severe giardiasis seemed to be a risk factor for post-infectious fatigue and abdominal symptoms two years after clearing the Giardia infection.
PMID:20003489 , PMCID:PMC2808308
DOI:10.1186/1471-2334-9-206
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BMC Gastroenterol. 2009 Apr 21;9:27. doi: 10.1186/1471-230X-9-27.
Development of functional gastrointestinal disorders after Giardia lamblia infection.
Hanevik K1, Dizdar V, Langeland N, Hausken T.
Abstract
BACKGROUND:
Functional gastrointestinal disorders (FGID) may occur following acute gastroenteritis. This long-term complication has previously not been described after infection with the non-invasive protozoan Giardia lamblia. This study aims to characterize persistent abdominal symptoms elicited by Giardia infection according to Rome II criteria and symptoms scores.
METHODS:
Structured interview and questionnaires 12-30 months after the onset of Giardia infection, and at least 6 months after Giardia eradication, among 82 patients with persisting abdominal symptoms elicited by the Giardia infection. All had been evaluated to exclude other causes.
RESULTS:
We found that 66 (80.5%) of the 82 patients had symptoms consistent with irritable bowel syndrome (IBS) and 17 (24.3%) patients had functional dyspepsia (FD) according to Rome II criteria. IBS was sub classified into D-IBS (47.0%), A-IBS (45.5%) and C-IBS (7.6%). Bloating, diarrhoea and abdominal pain were reported to be most severe. Symptoms exacerbation related to specific foods were reported by 45 (57.7%) patients and to physical or mental stress by 34 (44.7%) patients.
CONCLUSION:
In the presence of an IBS-subtype pattern consistent with post-infectious IBS (PI-IBS), and in the absence of any other plausible causes, we conclude that acute Giardia infection may elicit functional gastrointestinal diseases with food and stress related symptoms similar to FGID patients in general.
PMID: 19383162 , PMCID:PMC2676300
DOI:10.1186/1471-230X-9-27
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Scand J Prim Health Care. 2009;27(1):12-7. doi: 10.1080/02813430802602393.
Prevalence of recurring symptoms after infection with Giardia lamblia in a non-endemic area.
Wensaas KA1, Langeland N, Rortveit G.
Abstract
OBJECTIVE:
Investigation of the clinical course of infection with Giarda lamblia after a large outbreak in an area where Giardia is not endemic in humans.
DESIGN:
A cohort of patients from primary healthcare with clinically defined giardiasis was investigated by retrospectively analysing data from the patients’ medical records.
SETTING:
Urban primary healthcare setting in Bergen, Norway.
SUBJECTS:
From a population (n = 7100) assigned to two general practice clinics located in the outbreak area 134 patients met the inclusion criteria of at least one of the following: typical symptoms for at least one week, detection of Giarda lamblia in stool samples, or receiving a specific diagnosis. Of these, 119 gave consent to take part in the study.
MAIN OUTCOME MEASURES:
Proportion of patients with clinical giardiasis identified by detection of parasites in stool samples. Proportion of patients with prolonged disease and recurring symptoms.
RESULTS:
A positive test for Giardia lamblia was found in 55% (66/119) of the patients. Specific treatment was given to 89 patients, and after treatment 36% (32/89) returned to their doctor because they experienced recurring symptoms. Compared with those not returning a significantly higher proportion of this group had seen their GP for other GI complaints in the previous two years.
CONCLUSION:
Laboratory-based diagnosis missed a substantial number of patients falling sick with giardiasis during the outbreak. One-third of the patients experienced recurring symptoms after treatment, and there was an association between previous gastrointestinal complaints and recurrence of symptoms.
PMID:19085428 , PMCID:PMC3410471
DOI:10.1080/02813430802602393
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Scand J Infect Dis. 2008;40(6-7):517-22. doi: 10.1080/00365540701827481.
Effects of albendazole/metronidazole or tetracycline/folate treatments on persisting symptoms after Giardia infection: a randomized open clinical trial.
Hanevik K1, Mørch K, Eide GE, Langeland N, Hausken T.
Abstract
After an epidemic of giardiasis, some patients experienced persisting abdominal symptoms despite becoming Giardia-negative in stool samples after metronidazole treatment. The study aimed to determine if these patients were suffering from treatment refractory, chronic, cryptic giardiasis. The design was a prospective randomized open clinical trial with 1 arm receiving anti-Giardia treatment in the form of albendazole and metronidazole (A/M) for 7 d (n=12) and the other arm receiving tetracycline and folic acid (T/F) for 28 d (n=13). Symptom scores and global improvement were outcome measures. Symptom scores were analysed regarding time and treatment using mixed linear modelling. In both groups total symptom scores improved at the end of treatment; the improvement was significant for the T/F group. Bloating decreased significantly in both groups at the end of treatment. One month after treatment, 3 patients in the T/F group (23.1%) and 1 patient (8.3%) in the A/M group reported global symptom improvement. Symptoms recurred in all of these, and after 1 y total symptom scores were unchanged from baseline in either group. Treatment of post-giardiasis persistent abdominal symptoms with T/F or A/M resulted in only temporary symptom relief, possibly due to the anti-inflammatory effect of both treatments. Cryptic chronic giardiasis was not the explanation for the persistent symptoms.
PMID:18584540 , DOI:10.1080/00365540701827481
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Scand J Infect Dis. 2008;40(2):189-92.
Demographics of Giardia infections in Bergen, Norway, subsequent to a waterborne outbreak.
Robertson LJ1, Forberg T, Hermansen L, Gjerde BK, Langeland N.
Abstract
Young women have previously been reported as the predominant group infected during a waterborne giardiasis outbreak, due to elevated water consumption. Here, the demographics of those subsequently infected are described, and young women again predominate. As secondary cases were not waterborne, this cannot be attributed to drinking habits.
PMID: 17852919 , DOI: 10.1080/00365540701558672
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J Infect. 2007 Dec;55(6):524-30. Epub 2007 Oct 26.
Persisting symptoms and duodenal inflammation related to Giardia duodenalis infection.
Hanevik K1, Hausken T, Morken MH, Strand EA, Mørch K, Coll P, Helgeland L, Langeland N.
Abstract
OBJECTIVES:
After a large waterborne outbreak of Giardia infection in Bergen, some patients experienced persisting abdominal symptoms despite metronidazole treatment. This study aimed at investigating possible causes for their symptoms.
METHODS:
Over a 15 month period, 124 referred patients were evaluated in a prospective cohort analysis with a standardised investigation including duodenal biopsies and aspirate, blood tests and faecal parasite and calprotectin tests. Recovered subjects were recruited for symptom analysis.
RESULTS:
Persisting Giardia duodenalis infection was found in 40 patients (32.3%). Duodenal biopsies showed signs of inflammation in 57 patients (47.1%). Microscopic duodenal inflammation was present in 34 (87.2%) of the Giardia positive and 23 (28.0%) of the Giardia negative patients. There were significant associations between persistent Giardia positivity, microscopic duodenal inflammation and a positive calprotectin test. Duodenal aspirate and duodenal biopsies performed poorly in diagnosis of persistent giardiasis.
CONCLUSIONS:
In patients with persisting symptoms after metronidazole treated Giardia infection we commonly found chronic Giardia infection and microscopic duodenal inflammation, especially in illness duration less than 7 months. Both these findings subsided over time. Increasingly, investigations could not determine a definite cause for the persistent symptoms. The very long-term post-giardiasis diarrhoea, bloating, nausea and abdominal pain documented here need further study.
PMID: 17964658 , DOI:10.1016/j.jinf.2007.09.004
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Tidsskr Nor Laegeforen. 2007 Sep 6;127(17):2222-5.
[Uncovering the giardiasis-outbreak in Bergen 2004].
[Article in Norwegian]
Wensaas KA1, Langeland N, Rørtveit G.
Abstract
BACKGROUND:
There was a large community outbreak of giardiasis in Bergen in the autumn of 2004 that was acknowledged about two months after the first patients became ill. The aim of this article is to describe the diagnostic approach of clinicians faced with an unexpected problem, and how they reacted when communicable disease was detected.
MATERIAL AND METHODS:
A focus group interview was conducted with six of the 18 doctors who had requested stool examinations from patients in October 2004 with the aim of detecting parasites. This was after the first patients became ill, but before the outbreak was widely recognized.
RESULTS:
Discussions among doctors were instrumental, both in reaching the correct diagnosis, and in acknowledging a possible outbreak in the community. There was no uniform approach to reaching the diagnosis, but rather a common unravelling of a mutual problem. Doctors contacted or tried to make contact with public health authorities when at least one case was confirmed and this case was linked to other patients with diarrhoeal disease.
INTERPRETATION:
Clinicians need meeting places where they can discuss problems that arise in everyday practice. Public health authorities and clinicians need better procedures for warning, reception and follow-up when outbreaks of communicable diseases are suspected.
PMID: 17828314
Bakgrunn
Høsten 2004 ble Bergen rammet av en omfattende epidemi med giardiasis, og det tok om lag to måneder fra pasienter begynte å bli syke til utbruddet ble erkjent. Formålet med denne artikkelen er å beskrive klinikeres diagnostiske tankegang i en situasjon der de sto overfor et uventet sykdomsbilde, og hvordan de reagerte når meldingspliktig sykdom ble påvist.
Materiale og metode.
Vi gjennomførte fokusgruppeintervju med seks av 18 leger som hadde rekvirert mikroskopisk undersøkelse av avføring med tanke på parasitter i oktober 2004, etter at de første pasientene var blitt syke, men før det var kjent at det forelå et utbrudd med giardiasis.
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Resultater.
Det var ingen ensartet diagnostisk prosess, men flere forskjellige tilnærminger som samlet førte til at pasienter fikk diagnostisert giardiasis. Interne diskusjoner blant legene var viktige, både for den diagnostiske prosessen og for erkjennelsen av et mulig utbrudd. Flere leger kontaktet eller forsøkte å kontakte smittevernetaten når verifisert diagnose hos minst en pasient var kombinert med observasjon av flere pasienter med symptomer.
Fortolkning.
Klinikere har behov for møteplasser hvor man kan diskutere problemstillinger som dukker opp i daglig praksis. Smittevernetaten og klinikere trenger bedre rutiner for varsling av mistenkt ubrudd, samt mottak og håndtering av slike varsler.
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.BMC Public Health. 2006 May 25;6:141.
A large community outbreak of waterborne giardiasis-delayed detection in a non-endemic urban area.
Nygård K1, Schimmer B, Søbstad Ø, Walde A, Tveit I, Langeland N, Hausken T, Aavitsland P.
Abstract
BACKGROUND:
Giardia is not endemic in Norway, and more than 90% of reported cases acquire the infection abroad. In late October 2004, an increase in laboratory confirmed cases of giardiasis was reported in the city of Bergen. An investigation was started to determine the source and extent of the outbreak in order to implement control measures.
METHODS:
Cases were identified through the laboratory conducting giardia diagnostics in the area. All laboratory-confirmed cases were mapped based on address of residence, and attack rates and relative risks were calculated for each water supply zone. A case control study was conducted among people living in the central area of Bergen using age- and sex matched controls randomly selected from the population register.
RESULTS:
The outbreak investigation showed that the outbreak started in late August and peaked in early October. A total of 1300 laboratory-confirmed cases were reported. Data from the Norwegian Prescription Database gave an estimate of 2500 cases treated for giardiasis probably linked to the outbreak. There was a predominance of women aged 20-29 years, with few children or elderly. The risk of infection for persons receiving water from the water supply serving Bergen city centre was significantly higher than for those receiving water from other supplies. Leaking sewage pipes combined with insufficient water treatment was the likely cause of the outbreak.
CONCLUSION:
Late detection contributed to the large public health impact of this outbreak. Passive surveillance of laboratory-confirmed cases is not sufficient for timely detection of outbreaks with non-endemic infections.
PMID: 16725025 , PMCID:PMC1524744
DOI:10.1186/1471-2458-6-141
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NeuroImmunologisk Myalgisk Encefalomyelitt (ME) 