Using a stochastic continuous-time Markov chain model to examine alternative timing and duration of the COVID-19 lockdown in Kuwait: what can be done now?

BACKGROUND: Kuwait had its first COVID-19 in late February, and until October 6, 2020 it recorded 108,268 cases and 632 deaths. Despite implementing one of the strictest control measures-including a three-week complete lockdown, there was no sign of a declining epidemic curve. The objective of the current analyses is to determine, hypothetically, the optimal timing and duration of a full lockdown in Kuwait that would result in controlling new infections and lead to a substantial reduction in case hospitalizations. METHODS: The analysis was conducted using a stochastic Continuous-Time Markov Chain (CTMC), eight state model that depicts the disease transmission and spread of SARS-CoV 2. Transmission of infection occurs between individuals through social contacts at home, in schools, at work, and during other communal activities. RESULTS: The model shows that a lockdown 10 days before the epidemic peak for 90 days is optimal but a more realistic duration of 45 days can achieve about a 45% reduction in both new infections and case hospitalizations. CONCLUSIONS: In the view of the forthcoming waves of the COVID19 pandemic anticipated in Kuwait using a correctly-timed and sufficiently long lockdown represents a workable management strategy that encompasses the most stringent form of social distancing with the ability to significantly reduce transmissions and hospitalizations.

Modeling the effect of lockdown timing as a COVID-19 control measure in countries with differing social contacts.

The application, timing, and duration of lockdown strategies during a pandemic remain poorly quantified with regards to expected public health outcomes. Previous projection models have reached conflicting conclusions about the effect of complete lockdowns on COVID-19 outcomes. We developed a stochastic continuous-time Markov chain (CTMC) model with eight states including the environment (SEAMHQRD-V), and derived a formula for the basic reproduction number, R0, for that model. Applying the [Formula: see text] formula as a function in previously-published social contact matrices from 152 countries, we produced the distribution and four categories of possible [Formula: see text] for the 152 countries and chose one country from each quarter as a representative for four social contact categories (Canada, China, Mexico, and Niger). The model was then used to predict the effects of lockdown timing in those four categories through the representative countries. The analysis for the effect of a lockdown was performed without the influence of the other control measures, like social distancing and mask wearing, to quantify its absolute effect. Hypothetical lockdown timing was shown to be the critical parameter in ameliorating pandemic peak incidence. More importantly, we found that well-timed lockdowns can split the peak of hospitalizations into two smaller distant peaks while extending the overall pandemic duration. The timing of lockdowns reveals that a "tunneling" effect on incidence can be achieved to bypass the peak and prevent pandemic caseloads from exceeding hospital capacity.

Using expert judgments to improve chronic wasting disease risk management in Canada.

ABSTARCT Chronic wasting disease (CWD) is a neurodegenerative, protein misfolding disease affecting cervids in North America in epidemic proportions. While the existence of CWD has been known for more than 40 years, risk management efforts to date have not been able to curtail the spread of this condition. An expert elicitation exercise was carried out in May 2011 to obtain the views of international experts on both the etiology of CWD and possible CWD risk management strategies. This study presents the results of the following three components of the elicitation exercise: (1) expert views of the most likely scenarios for the evolution of the CWD among cervid populations in Canada, (2) ranking analyses of the importance of direct and indirect transmission routes, and (3) rating analyses of CWD control measures in farmed and wild cervids. The implications of these findings for the development of CWD risk management strategies are described in a Canadian context.

Prionet Canada: a network of centres of excellence for research into prions and prion diseases.

PrioNet Canada's strength in basic, applied, and social research is helping to solve the food, health safety, and socioeconomic problems associated with prion diseases. Prion diseases are transmissible, fatal neurodegenerative diseases of humans and animals. Examples of prion diseases include bovine spongiform encephalopathy (BSE, commonly known as "mad cow" disease), Creutzfeldt-Jakob disease in humans, and chronic wasting disease (CWD) in deer and elk. As of March 31, 2008, PrioNet's interdisciplinary network included 62 scientific members, 5 international collaborators, and more than 150 students and young professionals working in partnership with 25 different government, nongovernment, and industry partners. PrioNet's activities are developing strategies based on a sustained, rational approach that will mitigate, and ultimately control, prion diseases in Canada.

Multi-jurisdictional expert opinion for improving children's environmental health protection.

Expert opinion from Canada, the United States and European Union countries was solicited to examine the regulatory and non-regulatory approaches used to protect children's environmental health. Thirty-five experts were interviewed by telephone from June 2004 to March 2005 using an open-ended survey questionnaire. Experts were asked to name legislative and non-legislative tools used to protect children's environmental health in their jurisdiction as well as the effectiveness of approaches taken, barriers, facilitators, methods of evaluation, and recommendations for improving children's health protection. A number of common themes were revealed by experts in different countries as well as novel approaches that could be used to improve children's environmental health. Determining what types of governance and non-governance instruments are most effective based on experience from other jurisdictions, allows for the determination of common, effective, policy choice from shared children's health environmental risks. It also provides a broad classification of different approaches that have been used for children's environmental health. Three main areas suggested for strengthening children's environmental health protection included: research and surveillance, institutional organization, and regulatory capacity.

Management of natural and bioterrorism induced pandemics.

A recent approach for bioterrorism risk management calls for stricter regulations over biotechnology as a way to control subversion of technology that may be used to create a man-made pandemic. This approach is largely unworkable given the increasing pervasiveness of molecular techniques and tools throughout society. Emerging technology has provided the tools to design much deadlier pathogens but concomitantly the ability to respond to emerging pandemics to reduce mortality has also improved significantly in recent decades. In its historical context determining just how 'risky' biological weapons is an important consideration for decision making and resource allocation. Management should attempt to increase capacity, share resources, provide accurate infectious disease reporting, deliver information transparency and improve communications to help mitigate the magnitude of future pandemics.