Long Term Circulation of Sars-Cov-2 Related Lineages in Bats in Cambodia

Intro: Recent evidence shows the Greater Mekong Subregion to be a hotspot for Sarbecoviruses in bats, especially insectivorous Horseshoe bats (genus Rhinolophus). However, prevalence, maintenance, and evolution of these viruses in Rhinolophids is still poorly understood. Sampling efforts are still limited and generally only cover cross-sectional surveillance at single points in time. Following the detection of Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2)-related viruses in Rhinolophus shameli from 2010 in Steung Treng, Cambodia, further active longitudinal surveillance in the same area between 2020-2021 continued the detection of these viruses. Method(s): Live bat capture and sampling has been implemented in several sites located in Stung Treng province. All rectal swabs of bats were tested for the detection of SARS-CoV-2 or Sarbecoviruses by real time RT-PCR. RNA samples from positive RT-PCR bats were then sequenced using a highly multiplexed PCR amplicon approach using new designed primers set guided by the ARTIC Network multiplex PCR primers set (https://artic.network/ncov-2019), on Oxford Nanopore technology. Finding(s): The sarbecoviruses were detected in four Rhinolophus shameli bats, a percentage of similarity ranging at the nucleotide level between 98.8% - 99.1% when compared to two other Cambodian bat sarbecoviruses from 2010 and between 92.4% - 94.5% when compared to human SARS-CoV-2 across the whole genome. Discussion(s): The bat SARS-CoV-2 related virus recently detected in four positive bats in 2020-2021 are genetically homologous with the virus detected in 2010, indicating a geographically/host limited population that is stable over time in the past ten years. Conclusion(s): Overall, our findings indicate further complexity in the diversity and evolution of sarbecoviruses and add intricacy to the search for the origins of the Coronavirus Disease 2019 (COVID-19) pandemic.Copyright © 2023

Insight of Zoonotic Viruses at Human-Animal Interfaces in Cambodia

*Presenting author Emerging infectious diseases have been causing outbreaks in humans for centuries and most infectious diseases originate in animals. Re-emerging zoonotic pathogens are rapidly increasing in prevalence or geographic range and causing a significant and growing threat to global health. The present work provides an insight of zoonotic viruses risk at human-bat/rodent interfaces in Cambodia. We conducted studies to investigate the circulation of zoonotic viruses and the risk of exposure in human living at the interfaces with bats and rodents. Rodent's samples were collected in rural and urban areas of Cambodia. Organs were tested for Hantavirus, Orthohepevirus species C and Arenavirus. Bat's samples were collected in Steung Treng for Sarbecovirus and in Battambang and Kandal for Nipah virus detection. People working/living at the human-animal interfaces were screened for IgG antibodies. In rodents (750), hantavirus was detected in 3.3% rodents from urban areas only. Seoul orthohantavirus was the most predominant virus followed by Thottapalayam virus. HEV-C was detected only in rodents from urban settings (1.8%). Arenavirus was detected in both rural (6.8%) and urban (2.5%) areas. In humans (788), the seroprevalence of IgG antibodies against hantavirus, HEV-A and Arenavirus was 10.0%, 24% and 23.4% respectively. NiV was detected in flying fox's urines collected between 2013-2016 in Kandal (0.63%) and in Battambang (1.03%). Blood samples collected in both provinces were negative for NiV antibodies. SARS-CoV-2 related virus was detected in Rhinolphus shameli in Steung Treng in 2010, 2020 and 2021. Blood samples from people living at the vicinity of positive bats were positive for antibodies against CoV (7.7%), but no specific neutralizing SARS-CoV2 antibodies were detected. Our studies provided insight of the risk of zoonoses in Cambodia and highlighted the importance of zoonotic surveillance and further One Health effort to prevent, detect, and respond to future cross-species transmission.Copyright © 2023

Green tourism planning for Danang City after COVID-19, vision to 2050

Danang city is known as the most attractive tourist city in Vietnam as well as in the world. Danang possesses rich and diverse natural resources, urban space facing the river, sea, alternating hilly areas creating an urban structure that is both the modern and the natural. In addition, Danang has won the Vietnam ICT Index award for 12 consecutive years because of its smart, modern, and effective digital technology system in linking and supporting tourism development with the neighboring localities. However, the outbreak of the Covid-19 pandemic had caused millions of deaths in the most countries worldwide since 2019. Leading to the economic activities, the trade in services, tourism, transportation, etc.. have all been seriously affected, even stopped working together for a long time. After that, the appearance of vaccines has partly controlled the epidemic situation. But people's living habits and views relating the tourism have changed significantly. Thus, the trend of 'green tourism country-slow tourism' is being strongly responded by tourists after the Covid-19 pandemic. This is explained that the tourists will travel in small groups, enjoy travel experiences close to nature, immerse themselves in the culture of indigenous people, and combine with local sports activities. Therefore, the authors propose a model of 'diffusion planning' to effectively solve the problems in 'Green tourism planning for Danang City after COVID-19, vision to 2050' to contribute to the orientation of sustainable tourism development in Danang city. © 2022 IEEE.

Predicting the potential for zoonotic transmission and host associations for novel viruses.

Host-virus associations have co-evolved under ecological and evolutionary selection pressures that shape cross-species transmission and spillover to humans. Observed virus-host associations provide relevant context for newly discovered wildlife viruses to assess knowledge gaps in host-range and estimate pathways for potential human infection. Using models to predict virus-host networks, we predicted the likelihood of humans as hosts for 513 newly discovered viruses detected by large-scale wildlife surveillance at high-risk animal-human interfaces in Africa, Asia, and Latin America. Predictions indicated that novel coronaviruses are likely to infect a greater number of host species than viruses from other families. Our models further characterize novel viruses through prioritization scores and directly inform surveillance targets to identify host ranges for newly discovered viruses.

Linear regression model and least square method for experimental identification of AMBU bag in simple ventilator

Purpose In the COVID-19 outbreak periods, people's life has been deranged, leading to disrupt the world. Firstly, the number of deaths is growing and has the potential to surpass the highest level at any time. Secondly, the pandemic broke many countries' fortified lines of epidemic prevention and gave people a more honest view of its seriousness. Finally, the pandemic has an impact on life, and the economy led to a shortage in medical, including a lack of clinicians, facilities and medical equipment. One of those, a simple ventilator is a necessary piece of medical equipment since it might be useful for a COVID-19 patient's treatment. In some cases, the COVID-19 patients require to be treated by modern ventilators to reduce lung damage. Therefore, the addition of simple ventilators is a necessity to relieve high work pressure on medical bureaucracies. Some low-income countries aim to build a simple ventilator for primary care and palliative care using locally accessible and low-cost components. One of the simple principles for producing airflow is to squeeze an artificial manual breathing unit (AMBU) iterative with grippers, which imitates the motion of human fingers. Unfortunately, the squeezing angle of grippers is not proportional to the exhaust air volume from the AMBU bag. This paper aims to model the AMBU bag by a mathematical equation that enables to implement on a simple controller to operate a bag-valve-mask (BVM) ventilator with high accuracy performance. Design/methodology/approach This paper provides a curvature function to estimate the air volume exhausting from the AMBU bag. Since the determination of the curvature function is sophisticated, the coefficients of the curvature function are approximated by a quadratic function through the experimental identification method. To obtain the high accuracy performance, a linear regression model and a least square method are employed to investigate the characteristic of the BVM ventilator's grippers angle with respect to the airflow volume produced by the AMBU bag. Findings This paper investigates the correlation between the exhausting airflow of the AMBU bag and the grippers angle of the BVM ventilator. Originality/value The experimental results validated that the regression model of the characteristic of the exhausting airflow of the AMBU bag with respect to the grippers' angle has been fitted with a coefficient over 98% within the range of 350-750 ml.

Model-free volume and pressure cycled control of automatic bag valve mask ventilator

Ventilators are drawn to many researchers during the Covid-19 pandemic because it's essential equipment that's accustomed to treat severe Covid-19 patients. In low-income countries, there's a shortage of pricy respiratory devices resulting in exceeding the provision of taking care of Covid-19's patients in ICU. This paper attempts to design and implement an appropriate respiratory device referred to as a bag valve mask (BVM) ventilator for those who are Covid-19 patients in medical care, those patients have a requirement of safe transport and also palliative care. The BVM ventilator comprises a man-made manual breath unit (AMBU) bag and paddles for squeezing the AMBU bag which is popular in medical aid settings. The BVM ventilator is required to travel airflow through the system to the patient's lung with the specified volume for every breath cycle within a threshold air pressure. Since the AMBU bag is straightforward to be deformed over time, it's difficult to get mathematical modelling for constructing a reliable controller. Therefore, a model-free control (MFC) control approach is utilized successfully to style a controller for our BVM ventilator model with a PEEP valve and a HEPA filter. Some experimental scenarios are administered to gauge the effectiveness of the proposed controller for the BVM ventilator to control the airflow and control air pressure mode.