During the period 1974-1983, Yersinia enterocolitica infection was diagnosed in 458 hospitalized patients by antibody response or isolation of the micro-organism. Eight (1.75%) patients showed signs of acute pancreatitis with elevated serum or urine levels of amylase; two patients had acute insulin-dependent diabetes. The patients were followed up for 4-14 years (until 1987). Four patients were readmitted with chronic pancreatitis, and one with acute pancreatitis. Diabetes developed in two males and nine females; in seven cases this was associated with chronic conditions of possible autoimmune aetiology. In 1987 a significantly higher than expected prevalence of diabetes was demonstrated among female subjects aged 30-54 years. Yersinia enterocolitica infection constitutes a differential diagnosis in acute pancreatitis, and might be related to the development of chronic pancreatitis and diabetes.
In this study comprising isolates from 2001 to 2003, resistance was considerably more widespread among Campylobacter jejuni from humans infected abroad than infected within Norway. The discrepancy was particularly notable for fluoroquinolone resistance (67.4% vs. 6.5%). This is probably a reflection of a low resistance prevalence in Norwegian broiler isolates (1.2% fluoroquinolone resistant).
To assess risk factors and clinical impact of campylobacteriosis in Norway, a case-control study of sporadic cases of infection with thermotolerant Campylobacter spp. was conducted. This report describes: (1) the frequency and duration of signs and symptoms, antimicrobial treatment, hospitalization, and faecal carriage among the study patients; (2) diarrhoeal illness and campylobacter carriage among their household members; and (3) antimicrobial susceptibility pattern among bacterial isolates. A total of 135 patients with bacteriologically confirmed campylobacter infection were enrolled in the study. Of these, 58 (43%) were domestically acquired while 77 (57%) were acquired abroad. If the study enrollees are representative of the cases reported to the national surveillance system, the reported infections led to an estimated annual average of at least 8590 days of illness, 78 admissions to hospital, 329 days of hospital stay, 2236 days lost at work or at school, 1000 physician consultations, and 96 antimicrobial prescriptions among the 4.2 million Norwegians. Convalescent carriage of campylobacter was detected in 16% of the patients who submitted follow-up stool specimens; the organism was carried for a mean of 37.6 days (median 31, range 15-69) after the onset of illness. Antimicrobial treatment appeared to have reduced the likelihood of carriage once symptoms had resolved. Diarrhoeal illness was more commonly reported in members of case households than control households (OR = 5.44, p
During October 1988 through January 1990, a study of sporadic Yersinia enterocolitica infections was done in the Oslo region to assess the clinical impact and risk factors for this disease. Sixty-seven case-patients (mean age, 23.4 years) and 132 population-based age- and sex-matched controls were enrolled. Among patients who were well when interviewed, illness lasted a mean of 20 days, but 10% of the others remained symptomatic a year later. Bloody diarrhea occurred only in persons less than 18 years old (P = .002); joint pain was more common in adults (P = .001). Prolonged carriage was found in 47% of patients after resolution of symptoms. Patients were less likely to shed the organism after antimicrobial treatment (relative risk, 0.3; P = .003). Case-patients were more likely than controls to have antecedent enteric illness (odds ratio, 8.2; P less than .001). Y. enterocolitica infection in Norway is notable for its severity and chronicity. Postsymptomatic shedding, which occurs commonly, may be reduced by antimicrobial treatment.
Plasmid profile analysis, restriction endonuclease analysis, and multilocus enzyme electrophoresis were used in conjunction with serotyping, bacteriophage typing, and biochemical fingerprinting to trace epidemiologically related isolates of Salmonella typhimurium from an outbreak caused by contaminated chocolate products in Norway and Finland. To evaluate the efficiency of the epidemiological marker methods, isolates from the outbreak were compared with five groups of control isolates not known to be associated with the outbreak. Both plasmid profile analysis and phage typing provided further discrimination over that produced by serotyping and biochemical fingerprinting. Plasmid profile analysis and phage typing were equally reliable in differentiating the outbreak isolates from the epidemiologically unrelated controls and were significantly more effective than multilocus enzyme electrophoresis and restriction enzyme analysis of total DNA. The greatest differentiation was achieved when plasmid profile analysis and phage typing were combined to complement serotyping and biochemical fingerprinting. However, none of the methods employed, including restriction enzyme analysis of plasmid DNA, were able to distinguish the outbreak isolates from five isolates recovered in Norway and Finland over a period of years from dead passerine birds and a calf.
The antimicrobial resistance of 809 Salmonella Typhimurium isolates collected from humans in Norway between 1975 and 1998 was studied. The material was subdivided into domestic and foreign isolates according to whether the patient had recently travelled abroad or not. In imported isolates the largest increase in resistance was in 1996 when 35% of the isolates were multi-resistant. The first multi-resistant isolate acquired in Norway appeared in 1994, but already in 1998 23% of the isolates domestically acquired were multi-resistant, and a majority were S. Typhimurium DT104. We found no ciprofloxacin resistance in domestically acquired isolates. Amplified fragment length polymorphism analysis was performed on selected multi-resistant isolates. The method discriminated well between different multi-resistant isolates, but not between DT104 isolates. Resistant and multi-resistant S. Typhimurium were until 1998 essentially recovered from patients who had travelled abroad, but multi-resistant isolates, mainly DT104, are now also being transmitted within the country.
Data pertaining to 249 patients with stool cultures positive for thermophilic campylobacters are presented. Campylobacters were isolated from about 3% of all cases of acute enteritis and occupied second place in the bacterial etiology of this syndrome following Salmonella spp. Concomitant isolation of salmonellae or shigellae or both was achieved in 40 (16.1%) of the patients infected with campylobacters. The results suggest a bimodal age distribution with highest rates in young adults aged 20 to 29 years and children below 10 years of age. A majority of the campylobacters were isolated from travellers returning from abroad, and, to a lesser extent, from immigrants, particularly from Asia. Immigrants accounted for 45.2% of the patients below 10 years of age. The number of cases increased during the warmer months of the year. Travelling habits could, at least in part, explain the observed seasonality, age distribution, and geographical origin of infection. Eight outbreaks of Campylobacter enteritis were detected, five of which were family outbreaks, whereas three involved people from different families.
In 1987, a nationwide outbreak of Salmonella typhimurium O:4-12 infection traced to contaminated chocolate bars occurred in Norway. In the 5 years after the outbreak, elevated numbers of sporadic cases caused by the epidemic strain of Salmonella were detected, followed by a decline in subsequent years. To characterize the epidemiology of this infection, the authors analyzed information concerning all sporadic cases reported in Norway from 1966 to 1996. Of the 153 patients infected by the outbreak strain, 43% were less than 5 years of age, and only three persons had acquired the infection abroad. In contrast, 46% of the cases attributable to other S. typhimurium O:4-12 variants and 90% of the total number of Salmonella infections were related to foreign travel. A distinct seasonality was observed: 76% of the cases appeared between January and April. At the same time of year, the epidemic strain was regularly encountered as the etiologic agent of fatal salmonellosis among wild passerine birds, suggesting an epidemiologic link between the avian and human cases. The strain was rarely isolated from other sources. From 1990 to 1992, the authors conducted a prospective case-control study of sporadic indigenous infections to identify risk factors and obtain guidance for preventive efforts. Forty-one case-patients, each matched by age, sex, and geographic area with two population controls, were enrolled. In conditional logistic regression analysis, the following environmental factors were independently related to an increased risk of infection: drinking untreated water, having direct contact with wild birds or their droppings, and eating snow, sand, or soil. Cases were also more likely than controls to report having antecedent or concurrent medical disorders. Forty-six percent of the study patients were hospitalized for their salmonellosis.
The results of the external quality assessment for clinical microbiology in Norway in 1984 are evaluated. Four distributions, each consisting of four simulated clinical specimens, were carried out. The assessment has, as in previous years, revealed some problem areas concerning laboratory procedures which are discussed.