Programmable acoustic modular microrobots.

The field of microrobotics has emerged as a promising area of research with significant applications in biomedicine, both in vitro and in vivo, such as targeted cargo delivery, microsurgery, and cellular manipulation. Microrobots actuated with multiple modalities have the potential for greater adaptability, robustness, and capability to perform various tasks. Modular units that can reconfigure into various shapes, create structures that may be difficult to fabricate as one whole unit, and be assembled on-site, could provide more versatility by assembly and disassembly of units on demand. Such multi-modal modular microrobots have the potential to address challenging applications. Here, we present a biocompatible cylindrical microrobot with a dome-shaped cavity. The microrobot is actuated by both magnetic and acoustic fields and forms modular microstructures of various shapes. We demonstrate the use of these microrobots for cellular manipulation by creating patterns on a surface. Supplementary Information: The online version contains supplementary material available at 10.1007/s12213-024-00175-y.

Impact of the COVID-19 Pandemic on the State Enteric Disease Public Health Workforce in the Western United States, March-April 2022.

OBJECTIVE: To assess the impact of the COVID-19 pandemic on the state-level enteric disease workforce and routine enteric disease surveillance and outbreak investigation activities in the western United States. DESIGN AND SETTING: Key informant interviews conducted using bidirectional video from March to April 2022. PARTICIPANTS: Enteric disease epidemiologists at state public health agencies in the western states served by the Colorado and Washington Integrated Food Safety Centers of Excellence. MAIN OUTCOMES: Key themes were identified using grounded theory. RESULTS: Nine themes were identified including excessive workload, shifts in local and state responsibilities, challenges with retention and hiring, importance of student teams, laboratory supplies shortages, changes to case and outbreak investigation priorities, transitioning back to enterics, adoption of new methods and technology, and current and future needs. CONCLUSIONS: The COVID-19 pandemic response had a substantial impact on state-level enteric disease activities in western states, with many staff members diverted from routine responsibilities and a de-prioritization of enteric disease work. There is a need for sustainable solutions to address staffing shortages, prioritize employee mental health, and effectively manage routine workloads when responding to emergencies.

Using Online Surveys for Routine Campylobacter Case Investigations in Colorado, September 2020-December 2021.

CONTEXT: Routine case investigations are critical for enteric disease control and surveillance. Given limited resources and staffing, public health agencies are exploring more efficient case investigation methods. OBJECTIVE: To identify and describe the advantages and disadvantages of using online surveys to supplement routine enteric disease case investigations. DESIGN: We evaluated routine Campylobacter interview data collected via telephone vs online by interviewers with the Colorado Department of Public Health and Environment. SETTING AND PARTICIPATION: Colorado laboratory-confirmed Campylobacter cases reported from September 1, 2020, through December 31, 2021. MAIN OUTCOME MEASURES: We calculated modality preference, response rates, and data quality (missing and unknown answers) and compared demographics (age, gender, and urban vs rural) by modality. Estimated staff time savings and investigation timeliness were compared. RESULTS: Modality preference was split among the 966 contacted Campylobacter cases (46% telephone, 50% online, and 4% refusal). Among online respondents, 57% completed the survey for an overall 63% response rate. Females and those 18 to 44 years of age were most likely to select (55%, 60%) and complete (57%, 66%) the online survey, while those under 18 and over 65 years of age were least likely to select (47%, 45%) or complete (53%, 46%). Those who identified as non-Hispanic Black were most likely to select online (62%), whereas those who identified as mixed-race non-Hispanic and non-Hispanic White had the highest completion (78%, 60%). Modality preference was comparable by geography; however, rural residents had higher completion rates (61%). Data quality and completeness were comparable between modalities. Completing the 274 online surveys via telephone would have taken an estimated 78 hours of additional staff time. CONCLUSIONS: Online surveys can increase public health efficiency and capacity while maintaining data quality. However, use should be limited to high-burden, low-resource pathogens due to reduced response rates. Understanding implementation best practices and conducting regular evaluation are critical for optimization.

Lessons Learned From a Sequential Mixed-Mode Survey Design to Recruit and Collect Data From Case-Control Study Participants: Formative Evaluation.

BACKGROUND: Sequential mixed-mode surveys using both web-based surveys and telephone interviews are increasingly being used in observational studies and have been shown to have many benefits; however, the application of this survey design has not been evaluated in the context of epidemiological case-control studies. OBJECTIVE: In this paper, we discuss the challenges, benefits, and limitations of using a sequential mixed-mode survey design for a case-control study assessing risk factors during the COVID-19 pandemic. METHODS: Colorado adults testing positive for SARS-CoV-2 were randomly selected and matched to those with a negative SARS-CoV-2 test result from March to April 2021. Participants were first contacted by SMS text message to complete a self-administered web-based survey asking about community exposures and behaviors. Those who did not respond were contacted for a telephone interview. We evaluated the representativeness of survey participants to sample populations and compared sociodemographic characteristics, participant responses, and time and resource requirements by survey mode using descriptive statistics and logistic regression models. RESULTS: Of enrolled case and control participants, most were interviewed by telephone (308/537, 57.4% and 342/648, 52.8%, respectively), with overall enrollment more than doubling after interviewers called nonresponders. Participants identifying as female or White non-Hispanic, residing in urban areas, and not working outside the home were more likely to complete the web-based survey. Telephone participants were more likely than web-based participants to be aged 18-39 years or 60 years and older and reside in areas with lower levels of education, more linguistic isolation, lower income, and more people of color. While there were statistically significant sociodemographic differences noted between web-based and telephone case and control participants and their respective sample pools, participants were more similar to sample pools when web-based and telephone responses were combined. Web-based participants were less likely to report close contact with an individual with COVID-19 (odds ratio [OR] 0.70, 95% CI 0.53-0.94) but more likely to report community exposures, including visiting a grocery store or retail shop (OR 1.55, 95% CI 1.13-2.12), restaurant or cafe or coffee shop (OR 1.52, 95% CI 1.20-1.92), attending a gathering (OR 1.69, 95% CI 1.34-2.15), or sport or sporting event (OR 1.05, 95% CI 1.05-1.88). The web-based survey required an average of 0.03 (SD 0) person-hours per enrolled participant and US $920 in resources, whereas the telephone interview required an average of 5.11 person-hours per enrolled participant and US $70,000 in interviewer wages. CONCLUSIONS: While we still encountered control recruitment challenges noted in other observational studies, the sequential mixed-mode design was an efficient method for recruiting a more representative group of participants for a case-control study with limited impact on data quality and should be considered during public health emergencies when timely and accurate exposure information is needed to inform control measures.

Exploring the association of weather variability on Campylobacter - A systematic review.

BACKGROUND: Previous work has found climate change-induced weather variability is suspected to increase the transmission of enteric pathogens, including Campylobacter, a leading cause of bacterial gastroenteritis. While the relationship between extreme weather events and diarrheal diseases has been documented, the specific impact on Campylobacter infections remains underexplored. OBJECTIVE: To synthesize the peer-reviewed literature exploring the effect of weather variability on Campylobacter infections in humans. METHODS: The review included English language, peer-reviewed articles, published up to September 1, 2022 in PubMed, Embase, GEOBASE, Agriculture and Environmental Science Database, and CABI Global Health exploring the effect of an antecedent weather event on human enteric illness caused by Campylobacter (PROSPERO Protocol # 351884). We extracted study information including data sources, methods, summary measures, and effect sizes. Quality and weight of evidence reported was summarized and bias assessed for each article. RESULTS: After screening 278 articles, 47 articles (34 studies, 13 outbreak reports) were included in the evidence synthesis. Antecedent weather events included precipitation (n = 35), temperature (n = 30), relative humidity (n = 7), sunshine (n = 6), and El Niño and La Niña (n = 3). Reviewed studies demonstrated that increases in precipitation and temperature were correlated with Campylobacter infections under specific conditions, whereas low relative humidity and sunshine were negatively correlated. Articles estimating the effect of animal operations (n = 15) found presence and density of animal operations were significantly associated with infections. However, most of the included articles did not assess confounding by seasonality, presence of animal operations, or describe estimates of risk. DISCUSSION: This review explores what is known about the influence of weather events on Campylobacter and identifies previously underreported negative associations between low relative humidity and sunshine on Campylobacter infections. Future research should explore pathogen-specific estimates of risk, which can be used to influence public health strategies, improve source attribution and causal pathways, and project disease burden due to climate change.

Geometry and length control of 3D engineered heart tissues using direct laser writing.

Geometry and mechanical characteristics of the environment surrounding the Engineered Heart Tissues (EHT) affect their structure and function. Here, we employed a 3D tissue culture platform fabricated using two-photon direct laser writing with a high degree of accuracy to control parameters that are relevant to EHT maturation. Using this platform, we first explore the effects of geometry based on two distinct shapes: a rectangular seeding well with two attachment sites, and a stadium-like seeding well with six attachment sites that are placed symmetrically along hemicylindrical membranes. The former geometry promotes uniaxial contraction of the tissues; the latter additionally induces diagonal fiber alignment. We systematically increase the length of the seeding wells for both configurations and observe a positive correlation between fiber alignment at the center of the EHTs and tissue length. With increasing length, an undesirable thinning and "necking" also emerge, leading to the failure of longer tissues over time. In the second step, we optimize the stiffness of the seeding wells and modify some of the attachment sites of the platform and the seeding parameters to achieve tissue stability for each length and geometry. Furthermore, we use the platform for electrical pacing and calcium imaging to evaluate the functional dynamics of EHTs as a function of frequency.

Improving occupational health surveillance for enteric infections.

AIMS: Enteric pathogens with a livestock reservoir pose a unique risk to people in occupations with regular contact with animals. However, public health surveillance of occupational exposures is inadequate, with surveillance for occupation typically focusing on the risk of transmission and the need for worker exclusion, rather than workplace exposures. To improve surveillance for occupational zoonoses, the Colorado Integrated Food Safety Center of Excellence convened a group of subject matter experts who developed a set of variables on occupation, industry, and exposures, which were integrated into Colorado's surveillance system in 2017. We evaluated the quality and completeness of these new occupational fields for interviewed cases with laboratory-confirmed zoonotic infections and compared occupations to cases with a non-zoonotic infection (Shigella) and to employment data from the Bureau of Labor Statistics. METHODS AND RESULTS: From March 2017 through December 2019, 3668 domestically acquired, laboratory-confirmed sporadic infections of Campylobacter, Cryptosporidium, Shiga toxin-producing Escherichia coli, and non-typhoidal Salmonella among individuals ≥14 years of age were interviewed by public health. We found asking explicitly about occupational exposure risks and focusing on animal exposures, improved data quality and accuracy. Of the cases who stated that they were employed, 262 (13%) reported working in an occupation with regular animal exposure, and 254 (14%) reported an industry with regular animal exposure. Cases with an animal exposure occupation were more likely to be male and live in a rural or frontier county compared to other occupations. All occupations with regular animal contact were reported at a higher frequency than among Shigella cases or the general population. CONCLUSIONS: Public health efforts, both in occupational health and communicable disease sectors, should be made to improve surveillance for enteric zoonoses and identify opportunities for prevention strategies.

Rolling Helical Microrobots for Cell Patterning.

Microrobots, untethered miniature devices capable of performing tasks at the microscale, have gained significant attention in the fields of robotics and biomedicine. These devices hold immense potential for various industrial and scientific applications, including targeted drug delivery and cell manipulation. In this study, we present a novel magnetic rolling helical microrobot specifically designed for bio-compatible cell patterning. Our microrobot incorporates both open-loop and closed-loop control mechanisms, providing flexible, precise, and rapid control for various applications. Through experiments, we demonstrate the microrobot's ability to manipulate cells by pushing them while rolling and arranging cells into desired patterns. This result is particularly significant as it has implications for diverse biological applications such as tissue engineering and organoid development. Moreover, we showcase the effectiveness of our microrobot in a closed-loop control system, where it successfully follows a predetermined path from an origin to a destination. The combination of cellular manipulation capabilities and trajectory-tracking performance underlines the versatility and potential of our magnetic rolling helical microrobot. The ability to control and navigate the microrobot with high precision opens up new possibilities for advanced biomedical applications. These findings contribute to the growing body of knowledge in microbotics and pave the way for further research and development in the field.

Programmable Modular Acoustic Microrobots.

Microrobots have emerged as promising tools for biomedical and in vivo applications, leveraging their untethered actuation capabilities and miniature size. Despite extensive research on diversifying multi-actuation modes for single types of robots, these tiny machines tend to have limited versatility while navigating different environments or performing specific tasks. To overcome such limitations, self-assembly microstructures with on-demand reconfiguration capabilities have gained recent attention as the future of biocompatible microrobotics, as they can address drug delivery, microsurgery, and organoid development processes. Reversible modular reconfiguration structures require specific arrangements of particles that can assume several shapes when external fields are applied. We show how magnetic interaction can be used to assemble cylindrical microrobots into modular microstructures with different shapes. The motion actuation of the formed microstructure happens due to an external acoustic field, which generates responsive forces in the air bubbles trapped in the inner cavity of the robots. An external magnetic field can also steer these structures. We illustrate these capabilities by assembling the robots into different shapes that can swim and be steered, showing the potential to perform biomedical applications. Furthermore, we confirm the biocompatibility of the cylindrical microrobot used as the building blocks of our microstructure. Exposing Chinese Hamster Ovary cells to our microrobots for 24 hours demonstrates cell viability when in contact with the microrobot.