Knut-Arne Wensaas

Irritable Bowel Syndrome and Chronic Fatigue 6 Years After Giardia Infection: A Controlled Prospective Cohort Study

Giardia infection in a nonendemic setting is associated with an increased risk for irritable bowel syndrome and chronic fatigue 6 years later. These conditions should be considered a differential diagnosis in patients with persisting symptoms after eradication of the parasite.

High rate of fatigue and abdominal symptoms 2 years after an outbreak of giardiasis

The aim of this study was to evaluate the prevalence of fatigue and abdominal symptoms 2 years after Giardia lamblia infection. All 1262 cases who had Giardia-positive stool samples during an outbreak in 2004 in Norway received a questionnaire in 2006 asking about fatigue and abdominal symptoms. Fatigue was reported by 41%, whereas 38% reported abdominal symptoms, and there was a highly significant association between these symptoms. Increasing age was a highly significant risk factor for fatigue. The symptoms were not due to chronic infection in this cohort. Our data warrant further investigations into the late effects of giardiasis.

Severity of Giardia infection associated with post-infectious fatigue and abdominal symptoms two years after

BackgroundA 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.MethodsAll 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.ResultsThe 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.ConclusionProtracted and severe giardiasis seemed to be a risk factor for post-infectious fatigue and abdominal symptoms two years after clearing the Giardia infection.

Chronic fatigue syndrome 5 years after giardiasis: differential diagnoses, characteristics and natural course

BackgroundA 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.MethodsPatients 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.Results53 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).ConclusionThe 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.

Influenza-like illness in Norway: clinical course, attitudes towards vaccination and preventive measures during the 2009 pandemic.

Abstract Objectives. To document clinical characteristics of influenza-like illness, reported use of health preventive measures and attitudes towards vaccination among patients with influenza-like illness in general practice during the influenza pandemic in 2009. Methods. Cross-sectional survey in general practice. Patients, who were identified as having influenza-like illness during the peak of the influenza pandemic activity in Norway, were eligible for inclusion in the study. A questionnaire was sent 2–4 weeks after the patients visit to the GP with influenza-like illness diagnosis during October to December 2009, from general practices in Norway. A sample of responders >18 years also had a blood test to check for serological response to the pandemic H1N1 virus. Results. Questionnaires were sent to 1324 patients, and 357 (27%) were returned. Fever (91% versus 49%, P < 0.01), cough (85% versus 73%, P = 0.016) and gastrointestinal symptoms (58% versus 38%, P < 0.01) were more frequent in the age group <18 years compared to older patients. Serological H1N1 responses were analysed in 72 patients; 34 (47%) were positive (haemagglutination inhibition assay titres ≥40). There were no statistically significant differences in symptoms between seropositive and seronegative patients. Women reported better adherence to personal protective measures, such as hand washing and cough etiquette than men. Women were also more concerned about possible adverse effects of the pandemic influenza vaccine than men. Conclusions. Discrimination between influenza and other viral upper respiratory tract infections is difficult in daily clinical practice, even during an influenza pandemic. A gender difference was found in reported precautions to prevent influenza.

Post-infectious gastrointestinal symptoms after acute Giardiasis. A 1-year follow-up in general practice

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.

Prevalence of recurring symptoms after infection with Giardia lamblia in a non-endemic area

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.

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

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.

Phenotyping of subjects for large scale studies on patients with IBS

Irritable bowel syndrome (IBS) is a complex condition with multiple factors contributing to its aetiology and pathophysiology. Aetiologically these include genetics, life‐time events and environment, and physiologically, changes in motility, central processing, visceral sensitivity, immunity, epithelial permeability and gastrointestinal microflora. Such complexity means there is currently no specific reliable biomarker for IBS, and thus IBS continues to be diagnosed and classified according to symptom based criteria, the Rome Criteria. Carefully phenotyping and characterisation of a ‘large’ pool of IBS patients across Europe and even the world however, might help identify sub‐populations with accuracy and consistency. This will not only aid future research but improve tailoring of treatment and health care of IBS patients.

Systematic review: probiotics in the management of lower gastrointestinal symptoms - an updated evidence-based international consensus

In 2013, a systematic review and Delphi consensus reported that specific probiotics can benefit adult patients with irritable bowel syndrome (IBS) and other gastrointestinal (GI) problems.