Current Organizations / Institutes

The organizations/institutes from the scholar's latest article


Manuel Döhla has a total of 157 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Testing a Minimal Three-Zone Surgical Setup Under Infrastructure-Degraded Conditions

    by Peter Dorzweiler, Katharina Schötz, Manuel Döhla

    Infrastructure degradation during conflicts and disasters may necessitate temporary surgical capability in improvised environments lacking conventional operating-room infrastructure. We operationally evaluated a minimal 3-zone surgical setup consisting of a contaminated dirty zone (12 m 2 ), a semiclean transition zone (15 m 2 ), and a protected procedural core (14 m 2 ). Workflow simulations demonstrated reproducible separation of patient, personnel, material, and waste flows within a total operational footprint of 41 m 2 . Spatial demand was primarily determined by contamination control, workflow separation, and procedural movement geometry.

  • Open Access

    Hospital Wing Opening Sparks Antimicrobial Resistance in Wastewater Microbial Community Within the First Twelve Months

    by Laura Lohbrunner, Claudia Baessler, Elena Becker, Christina Döhla, Nina Droll, Ralf M. Hagen, Niklas Klein, Nico T. Mutters, Alexander Reyhe, Ruth Weppler, et al.

    Antimicrobial resistance (AMR) in hospital wastewater is a recognized public health concern, yet the dynamics of its emergence remain poorly understood. This study aimed to characterize the quantitative and qualitative changes in the microbial community of a newly built internal medicine intensive care hospital wing following the start of patient treatment. Wastewater samples were collected regularly from eight relevant sites, including seven patient-associated locations within the intensive care ward and the central sanitary sewer where all effluent converged. Culture-based analyses targeted the “ESCAPE-SO” bacterial and fungal groups (“Enterococci”, “Staphylococci”, “Candida”, “Acinetobacter”, “Pseudomonas”, “Enterobacteriaceae”, “Stenotrophomonas”, “Others”). Comparisons were made between a 12-month pre-operation period (only flushing every 72 h to prevent contamination of the drinking water system) and the first 12 months of patient treatment. The results showed a significant increase in mean bacterial concentrations from 53 [0–349] CFU/mL before patient treatment to 8423 [3054–79,490] CFU/mL during patient treatment (p = 0.0224) with a particular focus on Pseudomonas spp. as the dominant genus. Resistance against all four main antibiotic classes of the WHO AWaRe essential “watch” list (carbapenems, third-generation cephalosporins, broad-spectrum penicillin and ciprofloxacin) emerged within the first twelve months and depended on the amount of prescribed antibiotics and the number of patients treated. These findings indicate that hospital activity drives rapid development of antimicrobial resistance in wastewater microbial communities, highlighting the critical role of clinical antibiotic use in shaping environmental resistomes. This study provides quantitative evidence that resistance can emerge within months of hospital operation, emphasizing the need for early monitoring and targeted interventions to mitigate the spread of AMR from hospital effluents into broader environmental systems.


  • Open Access

    Provisional Reprocessing of Medical Devices in Field Hospitals: Evaluation of Chemical Approaches for Feasibility and Effectiveness

    by Ute Bailey-Monje, Elena Becker, Sven Funke, Eugen Gubajdulin, Ralf Matthias Hagen, Gerhard Kirmse, Konstantin Lütz, Nico T. Mutters, Ricarda Maria Schmithausen, Ruth Weppler, et al.

    Objectives: Field hospitals are deployable hospitals that treat patients directly on site before they are transported to permanent medical facilities. The supply of sterile surgical instruments is important, but not every field hospital is equipped with a sterile processing department. This concept therefore attempts to test a method of reprocessing surgical instruments under field conditions that can at least provide a provisional form of disinfection in case of logistic breakdowns. Methods: Development, testing, and evaluation of a provisional chemical reprocessing procedure for reusable surgical instruments using hydrogen peroxide. The evaluation was carried out visually, microbiologically, and with regard to material damage. Results: The concept is easy to implement but requires thorough training. The reprocessed surgical instruments were free of residual protein, showed no bacteriological growth, and were not damaged by the chemical reprocessing even after 10 cycles. Conclusions: Provisional reprocessing of reusable surgical instruments seems possible using high-level chemical disinfection with hydrogen peroxide (3% for 150 minutes or 7.5% for 30 minutes) in case of necessity due to logistic breakdowns and patients that need immediate treatment. In addition, a multibarrier approach that includes hygiene measures and antibiotic stewardship is required to effectively reduce the risk of surgical site infections.


  • Open Access

    Drinking Water and Sanitation Safety Planning for Medical Facilities: An Innovative PoU Approach for a Water System Description Using Ecomaps

    by Lara Kamm, Ralf M. Hagen, Nico T. Mutters, Ricarda M. Schmithausen, Ruth Weppler, Manuel Döhla

    Drinking Water Safety Plans (DWSP) in buildings serve to identify health hazards associated with the drinking water system. Sanitation Safety Plans (SSP) fulfill the same purpose for the sewage system. Water Safety Plans (WSP) include DWSPs, SSPs, and water systems like gray water and firefighting water. WSPs are based on a high-quality description of the water systems. This paper presents a new methodology for describing water systems. In contrast to previous approaches, the system description begins at the point where the water is consumed. These points of use are described using ecomaps, which are then supplemented with information about the pipe network. This approach makes it possible to fulfill four relevant premises: (1) the system description includes all essential parts of the drinking water installation, (2) the system description is possible with usual equipment, (3) the system description can be carried out with the least possible additional personnel costs, and (4) the system description is controllable, versionable, changeable, and forgery-proof. The ecomaps created in this way are suitable for the next step within the WSP framework, namely hazard and risk assessment. In addition, the ecomaps can be integrated into a quality, occupational safety, or environmental management system. Aspects of water security can be added to enable the ecomaps to be used as the basis for a total integrated water management system.


  • Open Access

    Quality Management Outweighs Pandemic: Retrospective Analysis Shows Improved Quality of Care for Staphylococcus aureus Bacteremia Despite SARS-CoV-2

    by Lena Jakoby, Ernst Molitor, Nico T. Mutters, Ruth Weppler, Dominic Rauschning, Manuel Döhla

    Background: Staphylococcus aureus bacteremia (SAB) is of great clinical relevance, as it is the most common type of bacteremia. Several studies show that the quality of care and thus the outcome can be positively influenced by the involvement of infectious disease specialists and structured programs like Antimicrobial Stewardship (AMS). In 2020, the SARS-CoV-2 pandemic occurred, which dominated the healthcare system and global events during this time. At the same time, a standard operational procedure (SOP) for SAB quality management (SABQM) was introduced in a German maximum-care hospital with 500 beds. Additionally, voluntary AMS team consultations were introduced in June 2021. This work addresses whether the introduction of SABQM has led to an improvement in the quality of care for SAB, despite the possible negative influences of the pandemic. Methods: Retrospective statistical analyses were conducted on all 145 cases coded as SAB at this hospital during the “pre-pandemic” period (2017 to 2019, 75 cases) and the pandemic period (2020 to 2022, 70 cases). Population parameters and quality management parameters were extracted from the clinical patient documentation. In a first analysis, the SARS-CoV-2 status served as a discriminatory parameter to determine its influence on the quality of care within the “pandemic period”. In a second analysis, the period served as a discriminatory parameter to determine its influence on the quality of care. In a third analysis, the use of AMS team consultation served as a discriminatory parameter to determine its influence on the quality of care in a subgroup of 42 cases from June 2021 to 2022. Results: The SARS-CoV-2 status had no influence on the population parameters or the quality management parameters. Between both analyzed periods, there was an improvement in the quality management parameters, with statistically significant higher rates of follow-up blood cultures, transthoracic echocardiography and adequate antibiotic therapy. AMS team consultation led to a relevant, but not statistically significant improvement in the quality management indicators. Conclusions: An SOP for SABQM leads to an improvement in the quality of care, even under the possible negative influences of a pandemic. AMS team consultations further strengthen this positive influence, even if this is not statistically significant due to the small number of cases in the subgroup analyzed.


  • Open Access

    Clinical and molecular fingerprint of SARS-CoV-2 among hospital employees in a period of Omicron BA.2 dominance.

    by Dominic Rauschning, Ruth Weppler, Carsten Balczun, Gwendolyn Scheumann, Jasmin Monteiro Marques, Christina Mutschnik, Dominic Preuß, Ricarda Maria Schmithausen, Maximilian Starke, Ralf Matthias Hagen, et al.

    In the spring of 2022, SARS-CoV-2 Omicron BA.2 peaked in Germany. The main burden was staff shortage. To achieve effective identification and management of infected persons as well as early reintegration of recovered persons, an infection-control outpatient clinic was established at the Bundeswehr Central Hospital Koblenz. This article reports a secondary data analysis of 663 people with 1,174 visits to the outpatient clinic. For asymptomatic contacts, no correlation was observed between PCR result and testing time or frequency. Although no significant symptoms were documented, a high correlation was found between a positive antigen self-test and positive PCR. For clearance, a median time until a negative test was obtained was 8-11 days. The PCR gold standard was compared with ECLIA antigen testing for all indications. The results of this study challenge the rationale for testing asymptomatic contacts. Solely symptom-driven diagnostics by PCR also do not seem to be effective. However, contact persons or symptomatic persons with a positive rapid antigen test should be tested further. Whether this testing is done by ECLIA or PCR does not seem to matter. Clearance testing after recovery prior to day 8 is also not appropriate.

  • Open Access

    Additional Investigations of UV-C Irradiation Schemes for Viral Decontamination of FFP2 Masks

    by Franziska Vaupel, Katja Kupke, Nico T. Mutters, Patrick L. Scheid, Ruth Weppler, Manuel Döhla

    The reprocessing of personal protective equipment that is only intended for single use has been brought into focus by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, especially regarding respiratory masks.1–4


  • Open Access

    Logistic Stewardship: Supporting Antimicrobial Stewardship Programs Based on Antibiotics Goods Flow

    by Bianca Leistner, Dominic Rauschning, Ralf Matthias Hagen, Franziska Srečec, Nico Tom Mutters, Ruth Weppler, Christina Mutschnik, Manuel Döhla

    Background/Objectives: Antimicrobial resistance is a global threat to safe health care, and a reduction in antibiotic consumption seems to be an appropriate preventive measure. In Germany, the reporting of hospital antibiotics consumption to an independent institution is only voluntary. Although a high level of willingness to improve can be assumed in the case of participation, the median consumptions of reporting hospitals change only slightly. This study examines the question of whether the logistical consumption figures adequately reflect real consumption, and if not, how to optimize the use of logistical data for clinical decisions. Methods: Four selected wards were analyzed during six months. A retrospective analysis of patient case files was performed to receive “prescribed daily doses” (PDDs). These were compared to “defined daily doses” (DDDs) from logistical data. Additional inventories were performed to calculated stored antibiotics. Antibiotics goods flows were presented via waterfall diagrams to identify logistic patterns that could explain PDD/DDD quotients. Antimicrobial stewardship (AMS) quality indicators were analyzed to give advice for optimized clinical AMS measures. Results: The total PDD/DDD quotient was 0.69. Four logistical patterns were identified. Optimized prophylaxis, AMS consultations and reevaluation of therapy seem to be the most useful measures to reduce PDDs. Conclusions: If AMS programs rely solely on DDDs, measures cannot be optimal. A complete consideration of antibiotic goods flows supports clinical decisions, but is very costly in terms of data collection. The consideration of logistical data can help to identify areas of focus for AMS programs. Therefore, specialists of antibiotics logistics should complement clinical AMS teams.


  • Successful establishment and evaluation of a reprocessing concept via steam at 105 °C for FFP masks in hospitals in case of logistic shortages

    by Manuel Döhla, Elena Becker, Heike Granzer, Eugen Gubajdulin, Peter Langer, Christina Mutschnik, Patrick L. Scheid, Jana Wiemann, Ralf M. Hagen

    Filtering face piece (FFP) masks according to EN 149 Respiratory protective devices - Filtering half masks to protect against particles - Requirements, testing, marking are essential components of personal protective equipment against biological agents from an occupational health and hospital hygiene perspective. Therefore, shortages due to increased demand or supply bottlenecks can lead to staff threats due to the risk of infection. To determine whether FFP masks could be made reusable in a hospital setting, a thermal reprocessing concept (steam at 105 degrees C with a holding phase of 10 min) was evaluated in a bed reprocessing chamber. The results indicate that it is logistically possible to establish a reprocessing concept. Of 267 reprocessed masks, 48 were rejected by inspection because of defect strapping, trapped hair, misfolding, and missing lot number or deformation, and 22 masks were rejected by bacteriological examination because of contamination > 10 CFU of total bacteria per 25 cm(2) or the presence of Staphylococcus aureus. Two selected mask models maintained the expected mask performance equivalent to the FFP2 standard after reprocessing. Thermal reprocessing resulted in a virucidal effect. The results show that reprocessing of FFP masks in hospitals is possible. However, the success of reprocessing depends on the type of mask used. This study identified a suitable mask type for which the reported method is bactericidal and virucidal without impairing mask performance. The reported method required the use of a stationary hospital bed reprocessing chamber (sanitizing washer), so it cannot be used everywhere. Other methods and procedures should be tested to be independent of a bed reprocessing chamber and therefore may be more mobile and flexible.


  • Open Access

    Investigation of Three Different UV-C Irradiation Schemes for Bacterial Decontamination of FFP2 Masks to Make Them Reusable

    by Franziska Vaupel, Ingo Fengler, Nico T. Mutters, Patrick Scheid, Esther Sib, Ruth Weppler, Manuel Döhla

    The effect of filtering face piece grade 2 (FFP2) masks for infection prevention is essential in health care systems; however, it depends on supply chains. Efficient methods to reprocess FFP2 masks may be needed in disasters. Therefore, different UV-C irradiation schemes for bacterial decontamination of used FFP2 masks were investigated. Seventy-eight masks were irradiated with UV light for durations between 3 and 120 seconds and subsequently analyzed for the presence of viable bacteria on the inside. Ten masks served as the control group. Irradiation on the inside of the masks reduced bacteria in proportion to the dose, with an almost complete decontamination after 30 seconds. Outside irradiation reduced the quantity of colonies without time-dependent effects. Both sides of irradiation for a cumulated 30 seconds or more showed almost complete decontamination. Overall, this study suggests that standardized UV irradiation schemes with treatment to both sides might be an efficient and effective method for FFP2 mask decontamination in times of insufficient supplies.