The impact of COVID-19 on hunters in Vietnam, Cambodia, and Laos: a qualitative analysis

The COVID-19 pandemic has accelerated efforts to engage critically with forest-adjacent, rural, communities who rely on wildlife. In this study, we interviewed 109 hunters of wildlife across Vietnam, Cambodia, and Laos regarding the effect the COVID-19 pandemic has had on them individually, as well as more generally within their communities. We found that negative economic impacts such as loss of employment and constrained finances due to rising prices was an especially prevalent theme due to city-wide lockdowns, factory closures, and border closures. In Vietnam, hunting was stated to have increased as young men were forced to return to their villages to work; however, trade in wildlife was believed to have decreased due to the inability of middlemen traders to easily leave urban spaces or cross-country lines. This theme of barriers to trade was found in Cambodia and Laos as well. Our results show the importance of establishing sustainable, non-wildlife-dependent livelihoods within rural communities, to mitigate hunting and mitigate the potential for emerging infectious disease transmission. Overall, our results show the value in engaging with hunters to understand locally and spatially-specific trends, and provide direction for future avenues of research.

Investigating methods for using genetic data to estimate the association between host factors and being an infection source with application to probing the association between HIV infection and tuberculosis transmission

Identifying host factors that influence infectious disease transmission is an important step toward developing interventions to reduce disease incidence. Recent advances in methods for reconstructing infectious disease transmission events using pathogen genomic and epidemiological data open the door for investigation of host factors that affect onward transmission. While most transmission reconstruction methods are designed to work with densely sampled outbreaks, these methods are making their way into surveillance studies, where the fraction of sampled cases with sequenced pathogens could be relatively low. Surveillance studies that use transmission event reconstruction then use the reconstructed events as response variables (i.e., infection source status of each sampled case) and use host characteristics as predictors (e.g., presence of HIV infection) in regression models. We use simulations to study estimation of the effect of a host factor on probability of being an infection source via this multi-step inferential procedure. Using TransPhylo - a widely-used method for Bayesian estimation of infectious disease transmission events - and logistic regression, we find that low sensitivity of identifying infection sources leads to dilution of the signal, biasing logistic regression coefficients toward zero. We show that increasing the proportion of sampled cases improves sensitivity and estimation of logistic regression coefficients. Application of these approaches to real world data from a population-based TB study in Botswana fails to detect an association between HIV infection and probability of being a TB infection source. We conclude that application of a pipeline, where one first uses TransPhylo and sparsely sampled surveillance data to infer transmission events and then estimates effects of host characteristics on probabilities of these events, should be accompanied by a realistic simulation study to better understand biases stemming from imprecise transmission event inference.

Disposal of Waste from Tattoo and Beauty Parlors in Poland: A Survey-Based Analysis on Epidemiological Safety

Appropriate waste management is increasingly relevant due to environmental and infectious disease transmission concerns. An anonymous observational cross-sectional study was conducted from 2013–2017 of 262 tattooists and 824 beauticians throughout Poland. Knowledge, attitudes, behavior, and compliance with blood-borne infection controls and correct waste disposal were assessed. Tattooists correctly addressed hazardous waste significantly more often than did beauticians (83.3% vs. 44.8%). Medical waste was collected by a specialist company in 90.1% of tattoo parlors and 63.3%of beauty parlors. Tattooists correctly used and disposed of sharps more frequently than beauticians (93.1% vs. 68.9%); however, 46.4% of beauticians and 12.4% of tattooists discarded waste into municipal trash, including sharps (27.1% and 2.6%, respectively). Incorrect collection and labeling of biological waste present occupational risk to waste disposal personnel. Education and instructional controls could improve health safety in this industry. Biological waste management processes are restrictive for medical services and liberal for beauty services, an industry for which they should also be applied more comprehensively.

HVAC system requirements for protection against epidemics similar to Covid-19

Tuberculosis and in some cases, flu, colds and other airborne diseases. Since research is one of the biggest concerns of causing influenza pandemics, most research surrounding aerosol contamination revolves around environmental influences on the influenza virus. Many literatures suggest that influenza is transmitted primarily through close contact, such as exposure to large respiratory droplets, direct mouth-to-mouth contact and short-term exposure to infectious aerosols. Diffusion can be accelerated or controlled by heating, ventilation and air conditioning (HVAC) systems. Researches continue that advances state of knowledge in the specific techniques that control airborne infectious disease transmission through HVAC systems, including ventilation rates, airflow regimes, filtration, and ultraviolet germicidal irradiation (UVGI). In this paper three methods of transmission of Airborne Infectious Diseases are discussed, namely through direct contact, large droplet contact, inhalation of droplet core. An extensive literature review of many papers was conducted infectious diseases spread in several different ways and the transmission of infectious viruses. This review targets direct and indirect contact as well as infectious viruses known to be transmitted from the air. And he focused on preventive ventilation systems for these targets. This paper will give idea to support further research on engineering controls to reduce infectious disease transmission.

Impact of Social Distancing on COVID-19 and Other Related Infectious Disease Transmission: A Systematic Review

Background Similar to other coronaviruses, COVID-19 is transmitted mainly by droplets and is highly transmissible through close proximity or physical contact with an infected person. Countries across the globe have implemented public health control measures to prevent onwards transmission and reduce burden on health care settings. Social or physical distancing was found to be one of appropriate measure based on previous experience with epidemic and pandemic contagious diseases. This study aims to review the latest evidence of the impact of social or physical distancing implemented during COVID-19 pandemic towards COVID-19 and other related infectious disease transmission. Methodology The study uses PRISMA review protocol and formulation of research question was based on PICO. The selected databases include Ovid MEDLINE and Scopus. Thorough identification, screening and eligibility process were done, revealed selected 8 articles. The articles then ranked in quality through MMAT. Results A total of eight papers included in this analysis. Five studies (USA, Canada, South Korea and the United Kingdom) showed physical distancing had resulted in a reduction in Covid-19 transmission. In comparison, three other studies (Australia, South Korea and Finland) showed a similar decline on other infectious diseases (Human Immunodeficiency Virus (HIV), other sexually transmitted infections (STI), Influenza, Respiratory Syncytial Virus (RSV) and Vaccine-Preventive Disease (VPD). The degree of the distancing policy implemented differ between strict and lenient, with both result in effectiveness in reducing transmission of infectious disease. Conclusion Physical or social distancing may come in the form of extreme or lenient measure in effectively containing contagious disease like COVID-19, however the stricter the measure will give more proportionate impact towards the economy, education, mental health issues, morbidity and mortality of non-COVID-19 diseases. Since we need this measure to ensure the reduction of infectious diseases transmission in order to help flattening the curve which allow much needed time for healthcare system to prepare adequately to response, ‘Precision physical distancing” can be implemented which will have more benefit towards the survival of the community as a whole.

Redefining snakebite envenoming as a zoonosis: disease incidence is driven by snake ecology, socioeconomics and anthropogenic impacts

Snakebite is the only WHO-listed, not infectious neglected tropical disease (NTD), although its eco-epidemiology is similar to that of zoonotic infections: envenoming occurs after a vertebrate host contacts a human. Accordingly, snakebite risk represents the interaction between snake and human factors, but their quantification has been limited by data availability. Models of infectious disease transmission are instrumental for the mitigation of NTDs and zoonoses. Here, we represented snake-human interactions with disease transmission models to approximate geospatial estimates of snakebite incidence in Sri Lanka, a global hotspot. Snakebites and envenomings are described by the product of snake and human abundance, mirroring directly transmitted zoonoses. We found that human-snake contact rates vary according to land cover (surrogate of occupation and socioeconomic status), the impacts of humans and climate on snake abundance, and by snake species. Our findings show that redefining snakebite as zoonosis provides a mechanistic eco-epidemiological basis to understand snakebites, and the possible implications of global environmental and demographic change for the burden of snakebite.

Adaptive data-driven age and patch mixing in contact networks with recurrent mobility

Infectious disease transmission models often stratify populations by age and geographic patches. Contact patterns between age groups and patches are key parameters in such models. Arenas et al. (2020) develop an approach to simulate contact patterns associated with recurrent mobility between patches, such as due to work, school, and other regular travel. Using their approach, mixing between patches is greater than mobility data alone would suggest, because individuals from patches A and B can form a contact if they meet in patch C. We build upon their approach to address three potential gaps that remain. First, our approach includes a distribution of contacts by age that is responsive to underlying age distribution of the mixing pool. Second, different age distributions by contact type are also maintained in our approach, such that changes to the numbers of different types of contacts are appropriately reflected in changes to the overall age mixing patterns. Finally, we introduce and distinguish between two mixing pools associated with each patch, with possible implications for the overall connectivity of the population: the home pool, in which contacts can only be formed with other individuals residing in the same patch; and the travel pool, in which contacts can be formed with some residents of, and any other visitors to the patch. We describe in detail the steps required to implement our approach, and present results of an example application.Graphical Abstract