Microbiological Surveillance of Heater-Cooler Units Used in Cardiothoracic Surgery for Detection of Mycobacterium chimaera.

Mycobacterium chimaera is a nontuberculous mycobacterium that was identified as causative agent in a global outbreak of severe infections following open-chest cardiothoracic surgery. Heater-cooler units (HCUs), which were contaminated during the manufacturing process, were elucidated as the origin of this outbreak. Regular surveillance of water-containing HCUs used for cardiac surgery was recommended as one preventive measure. We present data on the occurrence of M. chimaera and other mycobacterial pathogens in different HCUs from one surgical center in Germany over a 42-month period. Water samples and swabs from seven different HCUs were taken between 2015 and 2018, and mycobacteria were detected in 50.6% (78/154) of water samples and 21.1% (4/19) of swabs. M. chimaera accounted for the majority of detected pathogens (77/83 isolates in water samples), but other species such as Mycobacterium gordonae were also found. Despite strict adherence to an intensified, regular disinfection procedure, the majority of HCUs remained positive for mycobacteria until the end of the study. In conclusion, additional measures are needed to reduce the risk of intraoperative transmission of M. chimaera, and our observations underscore the inherent infections risks associated with water-containing medical devices.

Clinical implications of Mycobacterium chimaera detection in thermoregulatory devices used for extracorporeal membrane oxygenation (ECMO), Germany, 2015 to 2016.

Mycobacterium chimaera, a non-tuberculous mycobacterium, was recently identified as causative agent of deep-seated infections in patients who had previously undergone open-chest cardiac surgery. Outbreak investigations suggested an aerosol-borne pathogen transmission originating from water contained in heater-cooler units (HCUs) used during cardiac surgery. Similar thermoregulatory devices are used for extracorporeal membrane oxygenation (ECMO) and M. chimaera might also be detectable in ECMO treatment settings. We performed a prospective microbiological study investigating the occurrence of M. chimaera in water from ECMO systems and in environmental samples, and a retrospective clinical review of possible ECMO-related mycobacterial infections among patients in a pneumological intensive care unit. We detected M. chimaera in 9 of 18 water samples from 10 different thermoregulatory ECMO devices; no mycobacteria were found in the nine room air samples and other environmental samples. Among 118 ECMO patients, 76 had bronchial specimens analysed for mycobacteria and M. chimaera was found in three individuals without signs of mycobacterial infection at the time of sampling. We conclude that M. chimaera can be detected in water samples from ECMO-associated thermoregulatory devices and might potentially pose patients at risk of infection. Further research is warranted to elucidate the clinical significance of M. chimaera in ECMO treatment settings.

Simple Questionnaires to Improve Pooling Strategies for SARS-CoV-2 Laboratory Testing.

Background: Liberal PCR testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is key to contain the coronavirus disease 2019 (COVID-19) pandemic. Combined multi-sample testing in pools instead of single tests might enhance laboratory capacity and reduce costs, especially in low- and middle-income countries. Objective: The purpose of our study was to assess the value of a simple questionnaire to guide and further improve pooling strategies for SARS-CoV-2 laboratory testing. Methods: Pharyngeal swabs for SARS-CoV-2 testing were obtained from healthcare and police staff, hospital inpatients, and nursing home residents in the southwestern part of Germany. We designed a simple questionnaire, which included questions pertaining to a suggestive clinical symptomatology, recent travel history, and contact with confirmed cases to stratify an individual's pre-test probability of having contracted COVID-19. The questionnaire was adapted repeatedly in face of the unfolding pandemic in response to the evolving epidemiology and observed clinical symptomatology. Based on the response patterns, samples were either tested individually or in multi-sample pools. We compared the pool positivity rate and the number of total PCR tests required to obtain individual results between this questionnaire-based pooling strategy and randomly assembled pools. Findings: Between March 11 and July 5, 2020, we processed 25,978 samples using random pooling (n = 6,012; 23.1%) or questionnaire-based pooling (n = 19,966; 76.9%). The overall prevalence of SARS-CoV-2 was 0.9% (n = 238). Pool positivity (14.6% vs. 1.2%) and individual SARS-CoV-2 prevalence (3.4% vs. 0.1%) were higher in the random pooling group than in the questionnaire group. The average number of PCR tests needed to obtain the individual result for one participant was 0.27 tests in the random pooling group, as compared to 0.09 in the questionnaire-based pooling group, leading to a laboratory capacity increase of 73% and 91%, respectively, as compared to single PCR testing. Conclusions: Strategies that combine pool testing with a questionnaire-based risk stratification can increase laboratory testing capacities for COVID-19 and might be important tools, particularly in resource-constrained settings.

Incidence of notified Lyme borreliosis in Germany, 2013-2017.

Lyme borreliosis (LB) is the most commonly reported tick-borne disease in Germany. In 9/16 states, notification of erythema migrans (EM), acute neuroborreliosis (NB) and Lyme arthritis (LA) is mandatory. We describe incidence measures, time trends, geographical distribution and frequencies of manifestations to better understand LB epidemiology and target prevention measures. We used cases notified in the 9 states and confirmed by local health offices, 2013-2017, to calculate incidences by time, place and person. Altogether, we observed 56,446 cases. Disease onset peaked yearly in July. Incidence ranged from 26/100,000 (2015) to 41/100,000 (2013) with mean annual incidences 2013-2017 on district level between 0.5/100,000 and 138/100,000. Median age was 54 years with peaks in boys (5-9 years, mean incidence 36/100,000) and women (50-69 years, mean incidence 57/100,000). 95% experienced EM only, 2.7% NB and 2.1% LA. 54% were female, but more men had NB (56%) and LA (53%, p < 0.001). Hospitalisation was recorded for 10% of LA and 71% of NB cases. LB remains an important public health concern in Germany with marked regional variation. To facilitate early diagnosis and treatment, health authorities should raise awareness among physicians and promote prevention strategies among the general population: tick-bite-protection, prompt tick removal and medical consultation.

Nosocomial legionellosis and invasive aspergillosis in a child with T-lymphoblastic leukemia.

Invasive aspergillosis of the lungs and the central nervous system and Legionella pneumophilia serotype 1 infection of the lungs were diagnosed in a 22-month old child during inpatient induction treatment for T-lymphoblastic leukemia. Environmental investigations i.e. samples from the hospital water system did not reveal any Legionella. The patient may have been exposed to waterborne pathogens despite terminal water filtration due to a technical device to release residual tap water from the hose after showering. A sodium chloride nose spray was found to be contaminated with the A. fumigatus isolate of the patient.