Knut-Arne Wensaas

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). 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. 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. 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.

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.

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.

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.

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. 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. 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. 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.