Rapid detection of viable Legionella pneumophila in tap water by a qPCR and RT-PCR-based method.

AIMS: A molecular method for a rapid detection of viable Legionella pneumophila of all serogroups in tap water samples was developed as an alternative to the reference method (ISO). Legionellae are responsible for Legionnaires' disease, a severe pneumonia in humans with high lethality. METHODS AND RESULTS: The developed method is based on a nutritional stimulation and detection of an increase in precursor 16S rRNA as an indicator for viability. For quantification, DNA was detected by qPCR. This method was compared to the ISO method using water samples obtained from public sports facilities in Switzerland. The sensitivity and specificity were 91 and 97%, respectively, when testing samples for compliance with a microbiological criterion of 1000 cell equivalents per l. CONCLUSION: The new method is sensitive and specific for Leg. pneumophila and allows results to be obtained within 8 h upon arrival, compared to one week or more by the ISO method. SIGNIFICANCE AND IMPACT OF THE STUDY: The method represents a useful tool for a rapid detection of viable Leg. pneumophila of all serogroups in water by molecular biology. It can be used as an alternative to the ISO method for official water analysis for legionellae and particularly when a short test time is required.

Outbreak of acute gastroenteritis due to a washwater-contaminated water supply, Switzerland, 2008.

An operating error in a sewage treatment plant led to severe drinking water contamination in a well-defined district of a suburban municipality of Zurich, Switzerland. Despite the alert issued to the local population on the same day advising people not to consume the contaminated water, cases of acute gastroenteric diseases were subsequently observed. Considerable faecal contamination was detected the day after the incident in water samples taken up to 500 m from the sewage plant. In a retrospective epidemiological study involving 240 persons living in the affected area, 126 cases of acute gastrointestinal illness were documented. The epidemic curve revealed a peak incidence two days after the event. Stool samples from 11 of 20 patients were positive for noroviruses or Campylobacter jejuni. Although these microorganisms were not detected in the contaminated water, the subsequently conducted case-control study among the surveyed population showed that consumption of contaminated drinking water was associated with gastrointestinal illness (odds ratio 29.1; 95% confidence interval: 9.8-86.4; p = 0.001). The study also revealed the very probable time period of infection. We present the dimension and chronology of this outbreak and discuss the reasons for its localised and temporary spread.

Update: Multinational listeriosis outbreak due to 'Quargel', a sour milk curd cheese, caused by two different L. monocytogenes serotype 1/2a strains, 2009-2010.

We previously reported an outbreak of listeriosis in Austria and Germany due to consumption of Quargel cheese. It comprised 14 cases (including five fatalities) infected by a serotype 1/2a Listeria monocytogenes (clone 1), with onset of illness from June 2009 to January 2010. A second strain of L. monocytogenes serotype 1/2a (clone 2) spread by this product could be linked to further 13 cases in Austria (two fatal), six in Germany (one fatal) and one case in the Czech Republic, with onset of disease from December 2009 to end of February 2010.

Listeriosis outbreak caused by acid curd cheese Quargel , Austria and Germany 2009.

We report an outbreak of listeriosis in Austria and Germany due to the consumption of Quargel cheese produced by an Austrian manufacturer. At the time of writing this report, the outbreak was known to account for 14 outbreak cases in 2009, including four cases with lethal outcome. On 23 January 2010, the cheese product was voluntarily withdrawn from the market.

Foodborne outbreak of hepatitis A, November 2007-January 2008, Austria.

An outbreak of hepatitis A affecting 21 residents of an Austrian city occurred from the end of November 2007 until mid-January 2008. A case series investigation suggested the consumption of food purchased from supermarket X as the common link. A food handler employed in the delicatessen department of that supermarket had been serologically diagnosed with hepatitis A on 28th November 2007. During the infectious period of approximately 3 weeks, he worked on 11 days. Interviews with the other cluster cases revealed that the hepatitis A virus (HAV)-infected food handler did not practice appropriate hand hygiene. The investigation revealed no other possible source of infection. We hypothesize that the food of the delicatessen department contaminated by the HAV-infected food handler during his infectious period was the source of the outbreak. The district public health authority recommended the reinforcement of hygiene precautions, i.e., access to viricidal hand disinfectant and the use of disposable gloves and single-use paper towels, in the involved supermarket. The federal ministry of health recommended HAV vaccination for all food handlers in food production and gastronomy companies; this recommendation was included in the Austrian national vaccination plan 2008, even though the vaccination of food handlers is costly and its cost-effectiveness is not proven. Appropriate and regular hand hygiene, particularly after toilet visits, is the most effective measure for preventing HAV transmission.

An outbreak of multidrug-resistant tuberculosis among refugees in Austria, 2005-2006.

SETTING: In 2005-2006, the Austrian reference laboratory for tuberculosis (TB) identified multidrug-resistant (MDR) isolates from four cases of TB showing genotypes indistinguishable from each other. OBJECTIVE: To clarify the chain of transmission of this MDR-TB strain. DESIGN: An epidemiological case series investigation by reviewing TB notification reports and hospital discharge letters. RESULTS: The 38-year-old primary case of the MDR-TB cluster had initially been identified as a case of non-MDR pulmonary TB in June 2004, 7 months after being detained for illegal immigration. In March 2005, he was lost to follow-up for 4 months. In June 2005, he presented with pulmonary and laryngeal TB due to MDR-TB. After discharge, the case was again lost to follow-up until April 2006, when he was readmitted with recurrent MDR-TB. A three-case cluster of pulmonary MDR-TB sharing the same strain as the primary case was detected in April 2006: the index case's 5-month-old daughter and a 25-year-old friend with a 6-month-old son. CONCLUSION: As MDR-TB has originated in the human immunodeficiency virus seronegative community in Austria, there is a clear need to implement national guidelines for the management of drug-resistant TB in Austria.

Screening of various foodstuffs for occurrence of Coxiella burnetii in Switzerland.

The epidemiology of Q-fever in Switzerland is largely unknown. For this reason, a screening programme for the presence of Coxiella burnetii in bulk milk samples from cows, sheep and goats and in shell eggs produced in and imported into Switzerland was conducted. In total, 17 of 359 (4.7%) of analysed bovine milk samples from two randomly selected cheese dairies were tested positive for C. burnetii by nested PCR. Furthermore, the findings with samples from one dairy showed that the agent seemed to persist over time in the herds of cattle of certain farms. Although no extensive prevalence study was undertaken, our results indicate that C. burnetii appears to be quite frequent in cattle. As for 81 ovine and 39 caprine bulk milk samples, they were all tested negative for C. burnetii. Finally, 504 shell eggs were also found to be negative for C. burnetii with PCR testing. The results of the study are discussed under inclusion of epidemiological data for human and animal coxiellosis and the current Swiss legal regulations for the control of C. burnetii in cattle.

Outbreaks of gastroenteritis due to infections with Norovirus in Switzerland, 2001-2003.

Viral infections, especially those with noroviruses are the most common cause of acute gastroenteritis in Europe. To obtain information about the epidemic situation of noroviruses in Switzerland, an initial study was launched in the German-speaking part of the country to systematically compile Norovirus outbreak information between 2001 and 2003. In total, 73 outbreaks were registered. Most affected were closed settings, e.g. nursing homes (34%) and hospitals (25%). Transmission pathways were identified in 74% of Norovirus outbreaks. In 81% of these cases person-to-person transmission was the primary route of infection and on seven occasions (13%), a foodborne transmission was the possible cause. Furthermore, Norovirus outbreak characteristics of epidemiological importance are highlighted with a discussion of four selected events.

Risk factors for infections with Norovirus gastrointestinal illness in Switzerland.

Viral infections, particularly those caused by noroviruses (NV, genus Norovirus), are the most common cause of community-acquired gastroenteritis in Europe, with respect to both endemic and epidemic occurrence. For the first time, a general practitioner-based case-control study was performed between July 2001 and July 2003 in the German-speaking part of Switzerland in order to identify risk factors for sporadic NV infections. The consumption of different foodstuffs and of bottled mineral water did not show any significant association with the risk of NV gastroenteritis, nor was there any significant effect of individual ABO histo-blood group or household size on the incidence of NV gastroenteritis. The findings are consistent with person-to-person transmission as the most important route of transmission for community-acquired, sporadic NV infection, in that 39% of all patients reported they had had contact with ill persons before their illness. The fact that 33% reported contact with ill persons, mainly within family groups, after their own illness suggested that a substantial proportion of patients were part of family mini-outbreaks.

Frequency of Norovirus in stool samples from patients with gastrointestinal symptoms in Switzerland.

To determine the frequency of sporadic community-acquired Norovirus (NV) infection in the German-speaking part of Switzerland, an evaluation of gastroenteritis cases seen in physicians' practices between July 2001 and July 2003 was conducted. A total of 699 stool specimens documented to be free of common bacterial pathogens was screened for the presence of NV by RT-PCR. NV was detected in 125 (17.9%) of these specimens. In the seasonal analysis, the highest rate of NV-positive samples (38.3%) was found between January and March 2002. After July 2002, the study was expanded to additionally test for NV in stool samples containing a known bacterial pathogen. Among 132 such specimens, NV was detected in only one. This suggests that NV mixed-infections are playing a marginal role in Switzerland.

Rapid propagation of norovirus gastrointestinal illness through multiple nursing homes following a pilgrimage.

Reported here is an outbreak of gastroenteritis due to Norovirus infection that affected at least 450 persons from nursing homes and similar institutions in Switzerland during and after an organised pilgrimage to Lourdes in France. The outbreak was characteristic of direct person-to-person transmission, with the primary cases occurring in the hospital that harboured some of the pilgrims in Lourdes.

Genotyping of Cryptosporidium spp. isolated from human stool samples in Switzerland.

In a study to estimate the frequency of Cryptosporidium infections in Switzerland, stool samples from patients found to be positive for Cryptosporidium spp. by modified Ziehl-Neelson staining and fluorescence microscopy were used for genotyping experiments. With 9 of 12 samples, DNA extraction and subsequent genotyping was successful. All Cryptosporidium-isolates belonged to the bovine genotype. In one stool sample, two strains of Cryptosporidium were demonstrated, suggesting a mixed infection. In comparison with reference strains from calves, one of the isolates showed a full sequence identity and the other a similarity of 97.5%. The fact that only bovine genotypes were detected suggests, that cryptosporidiosis must primarily be considered as a zoonotic disease in Switzerland. This is in contrast to other countries, where the human genotype of C. parvum was shown to dominate the epidemiological situation. The results of our study are supported by the previous finding, that two of the analysed strains originated from patients who used to consume raw milk or raw cream, a known risk factor for cryptosporidiosis.

Design and function: a physical and electrical description of the 3M House cochlear implant system.

A patient-wearable, single-electrode cochlear implant was first used by a patient in 1972 at the House Ear Institute. Since early 1982, a redesigned version of this system has been in clinical use. This new system, called the 3M House cochlear implant system, consists of an implanted receiver and a patient-worn signal processor, transmitter, and microphone. Also available are instruments to assist the audiologist and patient in proper fitting and testing of the equipment. Physical and electrical characteristics of the devices are described, with attention given to improvements over the older system and features important to the use in children.