We investigated an outbreak of fever most likely due to a contaminated whirlpool among nine adults and six children visiting a holiday home. The outbreak was characterized by a high attack rate, short incubation periods, influenza-like symptoms and rapid recoveries typical of Pontiac fever. The children, however, experienced less characteristic symptoms and no sequelae compared to the adults. Evidence and presumptive evidence of Legionella (L) infection was found in eleven cases; in one case by isolation of L. pneumophila serogroup 1, in two cases by positive test for Legionella by PCR and in eleven cases with seroconversion. In contrast, two adult non-users of the whirlpool had no symptoms and no serological evidence of infection. This investigation demonstrates differences between adults and children in the clinical picture of Pontiac fever, furthermore it shows that culture and PCR of tracheal aspirate for legionellae can be used in a hospital setting for rapid diagnosis although their sensitivities are low.
The purpose of the study was to examine the extent of illness caused by contamination of a waterworks with waste water due to overflow. Structured questionnaires were mailed to all 703 households (the main study group) and four day-care centers supplied by the waterworks as well as a group of 200 randomly chosen households in neighbouring communities with a different water supply. Fourteen hundred and fifty-five persons (88% of respondents in the main study group) reported that they had had symptoms of gastroenteritis, particularly diarrhoea (83%) and vomiting (55%). In the control group, 10% of respondents had had symptoms of gastroenteritis. Onset of diarrhoea correlated well with precipitation (Spearman's correlation coefficient: 0.75; p = 0.0002). No pathogens were found. It is important to be aware of the possibility of water contamination when an increased number of cases of gastroenteritis are observed in a local area and to report even a suspicion of waterborne diseases to the county public health office.
Over a six-year period we detected 30 clinical infections caused by halophilic vibrios in a restricted geographical area. Vibrio parahaemolyticus infections were found in 13 patients (three with wound infections, ten with ear infections), and Vibrio alginolyticus infections in 17 patients, all of whom had ear infections. From 1987 to 1990, infections caused by marine vibrios were found in at most four cases annually, in 1992 in six instances, whereas over a five-month period in 1991 we experienced 15 cases of extraintestinal infections. Fifteen of the infections found in 1991 and 1992 were ear infections, ten of which occurred shortly after exposure to Danish coastal seawater. The disease was mild in most of the patients and all recovered. Most of the patients showed predisposing conditions such as chronic otitis media, perforation of the tympanic membrane or ulcus cruris. The organisms were isolated in minor numbers from coastal water samples from five of 12 bathing areas around Funen at the end of July, but not at the end of November. This study indicates that halophilic marine vibrios may be pathogenic in Denmark in persons exposed to seawater.
Climate changes will likely have an impact on the spectrum of infectious diseases in Europe. We may see an increase in vector-borne diseases, diseases spread by rodents such as Hantavirus, and food- and water-borne diseases. As the effects of climate changes are likely to occur gradually, a modern industrialised country such as Denmark will have the opportunity to adapt to the expected changes.
Hitherto, nosocomial epidemic outbreaks of legionnaire's disease have not been reported in Denmark. Only sporadic cases have been described. A survey of 75 Danish hospitals concerning the dimensions and operation of the hot-water systems revealed that only 13% had a hot water tank temperature above the recommended 60 degrees C. Temperatures of coldest tap water and of returning water were above 50 degrees C in only 31% and 24% respectively. Twelve representative hospitals with 35 independent water systems were investigated for the presence of Legionella pneumophila (Lp). Lp was demonstrated in all the hospitals and in 34 (97%) of the systems. The prevailing serogroups were (in order of frequency) 3, 1, 2, 5 and 6. We conclude that the operation of the hot tap water systems should be optimized. This report indicates that nosocomial epidemics are conceivable and attention should be paid to the disease as a diagnostic possibility in patients with primary atypical pneumonia.
During the autumn and winter of 1993-94 four cases of legionellosis were diagnosed in a Department of Nephrology. Three of the patients were kidney transplanted patients. Two of the patients died. The diagnosis was based on positive culture in two patients and by positive urinary antigen test in the other two patients. Serology was negative for all four patients. Legionella pneumophila was initially found in the cold and hot shower water, in ice-water from the ice machine, from the hot water tank and in the cold water inlet to the building. The isolate from patient no. one and isolates of serogroup 5 from the ice machine and the shower water had identical REA profiles, different from the profiles of the isolate from patient no. four. We concluded that at least one of the four patients was likely to have been infected from the water in the department, either by inhalation of contaminated aerosols from the shower or by aspiration of contaminated ice-water. Precautions were taken to reduce the number of Legionella in the shower- and ice-water. In addition, restrictions in the use of showers and ice-water from the ice machine were introduced.
Out of 16 workers in a trout processing industry, ten experienced work-related cough, dyspnoea, and nasal secretion. A clinical examination was performed including specific IgE, precipitating antibodies IgG for trout and processing water, skin prick testing and peak flow monitoring. A total of four workers showed a positive allergic reaction. Processing water contained endotoxin and bacteria in high amounts. It is concluded, that work-related respiratory symptoms should be investigated and the cause at the workplace identified, so that preventive measures can be introduced.