Quarantine Strategies Research Articles

Current and potential distribution of the invasive apple snail, Pomacea canaliculata in Eastern Africa: evidence from delimiting surveys and modelling studies

The invasive apple snail Pomacea canaliculata has become a significant concern in invaded habitats beyond its native range. It was reported in Kenya in 2020 invading one of the largest rice-producing schemes, the Mwea irrigation scheme. Delimiting surveys were conducted across five key rice-producing schemes (Mwea, Bura, Hola, Ahero and West Kano) in Kenya to establish the extent of the invasion and develop effective quarantine and management strategies within the Mwea scheme and other risk areas. Additionally, the ensemble model approach was used to model the potential distribution of P. canaliculata in Eastern Africa (as defined by the United Nations Geoscheme). Over 80% of the Mwea scheme was infested with P. canaliculata, an expansion from the initial infestation point (Ndekia). The mean number of adults/m2 and egg clutches/m2 were 8.4 ± 0.9 (SEM) and 7.7 ± 1.4 (SEM), respectively, with varying densities across sections. No adults or eggs of P. canaliculata were found in the four schemes outside the Mwea scheme. The model predicted high suitability for P. canaliculata in the southwest of Kenya,and in coastal areas, with all surveyed areas marked as highly suitable.. Regionally, high-risk areas include Malawi, Madagascar, and Uganda. Mozambique, Tanzania, and Ethiopia showed localised areas of high suitability. Conversely, Sudan, South Sudan, Eritrea, Djibouti and Somalia were largely unsuitable for P. canaliculata. Given the potential for further spread, strict quarantine measures are essential to prevent the spread of P. canaliculata in Kenya and its introduction to uninvaded regions of Eastern Africa. Alongside this, implementing IPM e strategies is crucial for effective pest management and the protection of agricultural ecosystems.

Post COVID-19 mucormycosis in critical care settings: A prospective cohort study in a tertiary care center in Egypt

BackgroundThe emergence of mucormycosis as a life-threatening fungal infection after the coronavirus disease of 2019 (COVID-19) is a major concern and challenge, but there is limited information on the risk factors for mortality in patients. MethodsWe conducted a prospective cohort study from May 2021 to April 2022 to determine the in-hospital outcomes of post-COVID-19 mucormycosis during the intensive care unit (ICU) stay. The sample of the study was collected as consecutive sampling using all accessible patients in the study period. The Statistical Package for Social Sciences (SPSS), version 25 (IBM, Chicago, Illinois, USA) was used for statistical analysis. ResultsAmong 150 patients with post-COVID-19 mucormycosis, the majority had a primary sinus infection (86.0 %), while 11.3 % had both sinus and ocular infections, and 2.7 % had sinus and cutaneous infections. Around 21 % (n = 31) of patients deceased after staying in the ICU for a median (range) of 45.0 (10.0–145.0) days. The majority of the patients who deceased had pneumonia patches on computed tomography (CT) (90.3 %) while none of the patients who were discharged had pneumonia patches (p < 0.001). The deceased group had higher rates of pulmonary embolism (93.5 %) compared to the surviving groups (21.8 %). In a multivariate Cox regression analysis, the risk of death was higher in older patients above 60 years old (hazard ratio (95 %CI): 6.7 (1.73–15.81)), increase among patient with history of steroid administration (hazard ratio (95 %CI): 5.70 (1.23–10.91)), who had facial cutaneous infection with mucormycosis (hazard ratio (95 %CI): 8.76 (1.78–25.18)), patients with uncontrolled diabetes (hazard ratio (95 %CI): 10.76 (1.78, 65.18)), and total leukocytic count (TLC>10 ×103 mcL) (hazard ratio (95 %CI): 10.03 (3.29–30.61)). ConclusionsIdentifying high-risk patients especially old diabetic patients with corticosteroid administration and detecting their deterioration quickly is crucial in reducing post-COVID-19 mucormycosis mortality rates, and these factors must be considered when developing treatment and quarantine strategies.

A conformable mathematical model of Ebola Virus Disease and its stability analysis

Ebola Virus Disease (EVD) is a viral hemorrhagic fever that affects humans and other primates. It is characterized by rapid virus spread in a short period of time. The disease has the potential to spread to many different regions of the world. In this paper, we have developed a modified mathematical model of the Ebola virus, adding the quarantine population as a control strategy. The quarantine population F and parameters ρ3 represent the rate at which individuals enter the quarantine compartment, which is vital in controlling the virus spread within society. The conformable derivatives have been applied to the modified model to observe the behavior of individuals for fractional derivative values between 0.7 and 1. For a modified model, the threshold parameter (R0) has been determined using the Next-Generation Matrix (NGM) method. We have checked local and global stability at a disease-free equilibrium point using Routh-Herwitz (RH) criteria and Castillo-Chavez, respectively. Numerical results obtained through the Fourth-Order Runge Kutta Method (RK4) demonstrate, a decrease in the virus transmission rate after following the implementation of the quarantine strategy.

A stochastic modeling study of quarantine strategies against foot-and-mouth disease risks through cattle trades across the Thailand-Myanmar border

Foot-and-mouth disease (FMD) is an important endemic disease in livestock in Southeast Asia. Transboundary movement of animals may result in the transnational disease spread. A major cattle market is located at the Thailand-Myanmar border, where most cattle imported from Myanmar are traded. In this study, we built a stochastic susceptible-exposed-infectious-recovered (SEIR) model to investigate the effectiveness of a private animal quarantine service center in preventing FMDV from entering the major cattle market. We computed with different parameters and found that, with 50 % vaccine effectiveness, the risk of releasing infected cattle to the market per batch was generally low during the quarantine period of 21 and 28 days, with the risk ranging from 0.071 to 0.078 and 0.032 to 0.036, respectively. Despite the best scenario, the zero-risk state is difficult to attain. The sensitivity analysis highlights that the percentage of immune animals before entering the quarantine centers and the vaccine effectiveness are important factors. In conclusion, the 21-day quarantine period mitigates the risk of FMDV introduction into the cattle market. This control measure should be rigorously maintained to sustainably prevent FMDV outbreaks through transboundary animal movements, especially among countries in FMD-endemic regions.

Modeling the dynamics of co-infection between COVID-19 and tuberculosis with quarantine strategies: A mathematical approach

Modeling the dynamics of co-infection between COVID-19 and tuberculosis with quarantine strategies: A mathematical approach

Modelling the Study of Hand, Foot and Mouth Disease Using SVEIQAR Derived Model

This study introduces a mathematical model aimed at investigating the intricate dynamics of infectious diseases, incorporating vaccination and quarantine interventions. The model comprises a system of ordinary differential equations that delineate interactions among susceptible, infected, and recovered individuals, alongside the impacts of vaccination and quarantine measures. The disease transmission rate is contingent on the count of infected, asymptomatic, and quarantined individuals. The model undergoes a comprehensive analysis to ascertain pivotal equilibrium points—disease-free and endemic. Additionally, the stability of these equilibria is rigorously examined to discern their resilience in the presence of interventions. Furthermore, the model serves as a strategic tool for crafting effective disease control strategies. The study underscores the potential potency of synergistic vaccination and quarantine interventions by minimising infection rates. Employing sophisticated numerical optimization techniques, the study tackles the equations' complexity. The findings underscore the substantive impact of coordinated vaccination and quarantine strategies in curtailing disease spread. These insights furnish policymakers and health authorities with empirically grounded methodologies to formulate robust responses to infections such as hand, foot, and mouth diseases. Ultimately, this research contributes to the armamentarium of tools that empower the formulation of effective strategies to safeguard public health.

Probabilistic analysis of a disturbed SIQP-SI model of mosquito-borne diseases with human quarantine strategy and independent Poisson jumps

Probabilistic analysis of a disturbed SIQP-SI model of mosquito-borne diseases with human quarantine strategy and independent Poisson jumps

Monitoring strategies during the establishment phase of Aethina tumida on Oahu, Hawaii

AbstractThe small hive beetle Aethina tumida (SHB) Murray,1867, is an invasive bee pest that is expanding its range across Latin America, parts of Australia and the Philippines, and is now established in two regions in Italy. However, despite multiple recent introductions, there is scant information about the dynamics of the initial stages of colonization of the SHB and this knowledge gap could impact management and quarantine strategies decisions for many countries. This note describes the monitoring strategies and the patterns of SHB establishment in a previously SHB‐free apiary on the island of Oahu, Hawaii in 2010–2011. The weekly hive inspections, conducted over a ten‐month period, showed that beetle prevalence increased slowly at the apiary level, and adult beetles were more commonly found (87.9%) inside the oil traps that were placed inside the hives between the outermost frames of the hive. There were relatively few “free roaming” beetles detected at this point and they were more often found on the side frames and underneath the cover of the hive, not on the floor of the hive. The results also suggest that in the early stages of colonization careful visual inspections of the frames of each colony had relatively low detection success when compared to oil traps. Our results support previous modelling studies that suggest the need to inspect a high proportion of colonies per apiary (&gt;80%) to ensure a 5% detection rate during the initial stages of invasion.

An effectiveness study of vaccination and quarantine combination strategies for containing mpox transmission on simulated college campuses

The ongoing transmission of mpox in specific countries and regions necessitates urgent action. It is essential to implement targeted containment strategies that concentrate on high-risk populations and critical locations, such as college campuses, to effectively curb the spread of mpox. This study is dedicated to evaluating the performance of various vaccination and quarantine strategies in curbing the spread of mpox and estimating the outbreak risk. To accomplish this, we constructed a stochastic, agent-based, discrete-time susceptible-latent-infectious-recovered (SLIR) model, to examine mpox transmission on a simulated college campus. Our findings reveal that relying solely on PEP is insufficient in containing mpox effectively. To bolster the population immunity and protect the vulnerable, pre-exposure vaccination among high-risk populations prior to an outbreak is imperative. Our study demonstrates that a pre-exposure vaccination rate of 50% in high-risk populations can led to a remarkable 74.2% reduction of infections. This translated to a mere 1.0% cumulative infection incidence in the overall population. In cases where the desired vaccination coverage is not attainable, enhancing case detection and isolation measures can serve as an effective emergency response to contain mpox outbreaks. For pre-exposure vaccination coverage of 20% or lower, a 40% isolation ratio is necessary to keep the cumulative number of infections in check. However, when the coverage exceeds 30%, a reduced isolation ratio of 20% becomes sufficient to manage the outbreak effectively. These insights underscore the importance of strategic pre-exposure vaccination in conjunction with robust surveillance and isolation protocols to safeguard public health and prevent the escalation of mpox outbreaks.

Monkey Pox and its Impact on the Human Health in the World

This editorial was conducted in year 2023 in which main aim was to investigate Monkeypox (MPX) impact on the human health worldwidely. Several studies were searched through different online available sources including google scholar, pubmed, and researchgate. All studies were critically reviewed and analyzed the findings. MPX was first appeared in Denmark in 1958 among Monkeys, which were kept for research, later it appeared in a nine (9) months old boy in Democratic Republic of the Congo in 1970. The monkey pox was caused by Monkey Pox virus (MPXV) which is double stranded DNA virus. It belongs to Orthopoxvirus genus in Poxviridae family which consist of Variola, Cowpox, Vaccina and other viruses. The two genetic clades of the virus were clades I and II. The natural reservoir of MPXV was unknown and various small mammals such as squirrels and monkeys were susceptible. The sign and symptoms includes, rashes, swollen lymph nodes, sore throat, headache, muscle aches, back pain and muscle fatigue. MPXV transmits through respiratory droplets which creates due to face to face talking, breathing, kissing and also transmit through body touching. It was observed that the virus entered through broken skin, mucosal surfaces or through respiratory tract. Moreover, sexual partners is also the source of spreading MPXV. MPXV virus spread from one region to another through exports which affect different countries of the world. The virus spread to Europe and America from African region and outbreak occurred in 2022-2023. Mostly tecovirimat and smallpox treatment were used for management of MPXV. Several individuals died and also many were severely ill. This mortality and morbidity also affects the world economy. Due to MPXV, many health problems were raised including anxiety, depression and social stigma. Based on studies analysis, it is recommended to implement the quarantine strategy throughout the world for prevention and spreading of MPXV. Focus should be on transportation, imports, and exports of goods region to region. High quality healthcare centers should be design to tackle such outbreaks. Preferred to wash hand properly with sanitizer and soap. Better research laboratories is also advised for better, early and timely diagnosis of MPXV. Stay at home is another strategy in such situation. Moreover, awareness and medical counseling center is also important to aware public about the transmission, diagnosis and treatment of MPXV. Counseling center are important to reduce and remove the social stigma among general public.

Suppression of the alpha, delta, and omicron variants of SARS-Cov-2 in Taiwan.

Taiwan was a coronavirus disease 2019 (COVID-19) outlier, with an extraordinarily long transmission-free record: 253 days without locally transmitted infections while the rest of the world battled wave after wave of infection. The appearance of the alpha variant in May 2021, closely followed by the delta variant, disrupted this transmission-free streak. However, despite low vaccination coverage (<1%), outbreaks were well-controlled. This study analyzed the time to border closure and conducted one-sample t test to compare between Taiwan and Non-Taiwan countries prior to vaccine introduction. The study also collected case data to observe the dynamics of omicron transmission. Time-varying reproduction number,Rt, was calculated and was used to reflect infection impact at specified time points and model trends of future incidence. The study analyzed and compare the time to border closure in Taiwan and non-Taiwan countries. The mean times to any border closure from the first domestic case within each country were -21 and 5.98 days, respectively (P < .0001). The Taiwanese government invested in quick and effective contact tracing with a precise quarantine strategy in lieu of a strict lockdown. Residents followed recommendations based on self-discipline and unity. The self-discipline in action is evidenced in Google mobility reports. The central and local governments worked together to enact non-pharmaceutical interventions (NPIs), including universal masking, social distancing, limited unnecessary gatherings, systematic contact tracing, and enhanced quarantine measures. The people cooperated actively with pandemic-prevention regulations, including vaccination and preventive NPIs. This article describes four key factors underlying Taiwan's success in controlling COVID-19 transmission: quick responses; effective control measures with new technologies and rolling knowledge updates; unity and cooperation among Taiwanese government agencies, private companies and organizations, and individual citizens; and Taiwanese self-discipline.

A deterministic transmission model for analytics-driven optimization of COVID-19 post-pandemic vaccination and quarantine strategies.

This study developed a deterministic transmission model for the coronavirus disease of 2019 (COVID-19), considering various factors such as vaccination, awareness, quarantine, and treatment resource limitations for infected individuals in quarantine facilities. The proposed model comprised five compartments: susceptible, vaccinated, quarantined, infected, and recovery. It also considered awareness and limited resources by using a saturated function. Dynamic analyses, including equilibrium points, control reproduction numbers, and bifurcation analyses, were conducted in this research, employing analytics to derive insights. Our results indicated the possibility of an endemic equilibrium even if the reproduction number for control was less than one. Using incidence data from West Java, Indonesia, we estimated our model parameter values to calibrate them with the real situation in the field. Elasticity analysis highlighted the crucial role of contact restrictions in reducing the spread of COVID-19, especially when combined with community awareness. This emphasized the analytics-driven nature of our approach. We transformed our model into an optimal control framework due to budget constraints. Leveraging Pontriagin's maximum principle, we meticulously formulated and solved our optimal control problem using the forward-backward sweep method. Our experiments underscored the pivotal role of vaccination in infection containment. Vaccination effectively reduces the risk of infection among vaccinated individuals, leading to a lower overall infection rate. However, combining vaccination and quarantine measures yields even more promising results than vaccination alone. A second crucial finding emphasized the need for early intervention during outbreaks rather than delayed responses. Early interventions significantly reduce the number of preventable infections, underscoring their importance.

Northern Australia Quarantine Strategy plant health surveys: over thirty years of a globally unique on- and off-shore solution to island nation biosecurity challenges

Northern Australia Quarantine Strategy plant health surveys: over thirty years of a globally unique on- and off-shore solution to island nation biosecurity challenges

Analysis of Fiscal Policy Strategy in Handling the Impact of Covid-19

The effect of the Coronavirus pandemic has enormously affected financial development. The presence of wellbeing quarantine strategies, social removing, as well as Huge Scope Social Limitations (PSBB) has extraordinarily affected exercises in the travel industry and assembling areas, making financial development delayed down. A diminished labor force, expanded joblessness and destitution will cause state incomes as personal duty (PPh) to diminish. Shortage and postpones in unrefined substances from China can make item costs rise and trigger expansion. This exploration was directed utilizing unmistakable subjective strategies, with information assortment methods and writing surveys. The public authority's financial strategy to accomplish state income targets is amending charge income targets, rearranging state income allotments in the 2020 APBN and executing advanced charges for exercises by means of electronic media. From the consumption side, the public authority will pull together and update the financial plan to decrease the APBN shortage to assist with funding the public authority which has done 3 spending plan upgrades.

Threshold dynamics of stochastic H7N9 model with Markov switching and hybrid strategy

This article aims to study the impact of different environmental states on the transmission dynamics of avian influenza A (H7N9) for poultry by using an epidemic model with general incidence rate and Markov switching. The model couples the essential roles of quarantine and hybrid strategy of vaccination and elimination. By establishing the basic reproduction number R0 as a sharp threshold for the spread of H7N9. When R0<1, the disease almost surely dies out exponentially. We use the compactness of space to prove that when R0>1, the disease almost surely persistent, and this method can be applied to other infectious disease models considering vaccination. In addition, under a mild extra condition, the ergodicity of the Markov process is proved. Our research indicates that: (i) theoretical results and sensitivity analysis show that implementing hybrid strategy is an effective method to control H7N9 propagation; (ii) under the influence of environmental switching, numerical simulations find that the transmission state of H7N9 will neutralize multiple regimes, leading to the possibility of multi wave transmission. This can be used to explain the multiple outbreaks of H7N9 in China.

A novel room-based epidemic model: Quarantine, testing, and vaccination strategies

Epidemic outbreaks pose significant challenges to public health and socio-economic stability, necessitating a comprehensive understanding of disease transmission dynamics and effective control strategies. This article discusses the limitations of traditional compartmental and network-based models and, inspired by the opinion formation models, introduces a room-based model that incorporates social gatherings and intuitive quarantine measures. Through simulations and analysis, we examine the impact of various model parameters, and confinement measures like quarantine and preventive measures like testing, and vaccination on disease spread. Additionally, we explore centrality-based testing and immunization strategies, demonstrating their effectiveness in reducing the spread of diseases compared to a random approach. Finally, we propose a combined strategy, that outperforms the existing strategies. It takes both global and local properties of the network structure into account, highlighting the potential for integrated control measures in epidemic management. This research not only contributes to a deeper understanding of epidemic models, but also provides insights into devising successful intervention strategies, including quarantine measures, testing methodologies, and vaccine programs to combat emerging epidemics and pandemics.

First Report of Viral Nervous Necrosis in Asian Sea Bass, Lates Calcarifer Cultured in Sri Lanka

Viral Nervous Necrosis (VNN) caused by Betanodavirus is a devastating disease in aquatic animals. The virus infects both marine and freshwater fish worldwide. Vacuolating necrosis of neural cells of the brain, the retina of the eye, and the spinal cord of the infected fish are the primary histological lesions of the condition. It causes up to 100% mortality in larvae and juvenile fish and can cause significant death in adult fish. The present study detected viral nervous necrosis in larvae and fry of Asian sea bass (Lates calcarifer) with progressive mortality of up to 95% in one week during the Northeast monsoon when the mean water temperature was 27 to 29°C. Histopathological examination of the moribund fish revealed extensive vacuolation and gliosis in the olfactory bulb, the optic lobe of the forebrain, and the inner and outer layer of the retina. Furthermore, tissues of the brain and the retina had intracellular inclusion bodies suggesting viral etiology, further justified by the negative results of the bacterial and parasitic examinations. The Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) test additionally confirms the etiology diagnosis using specific primers designed previously. The histopathology and RT-PCR results suggest that the mortalities of Asian sea bass were due to the VNN. The present finding is the first report of the VNN associated with mass mortalities in Asian seabass cultured in Sri Lanka. These crucial findings emphasize the need for quarantine and control strategies to prevent the spread of the virus and outbreak of the disease.

Atangana-Baleanu Fractional Dynamics of Predictive Whooping Cough Model with Optimal Control Analysis

Whooping cough, or pertussis, is an infectious disease that causes serious threats to people of all ages, specifically to infant and young children, all over the world. Due to the severe impact on health, it is necessary to construct a mathematical model that can be used to predict future dynamics of the disease, as well as to suggest strategies to eliminate the disease in an optimal way. For this, we constructed a new Atangana–Baleanu fractional model for whooping cough disease to predict the future dynamics of the disease, as well as to suggest strategies to eliminate the disease in an optimal way. We prove that the proposed model has a unique solution that is positive and bounded. To measure the contagiousness of the disease, we determined the reproduction number R0 and used it to examine the local and global stability at equilibrium points that have symmetry. Through sensitivity analysis, we determined parameters of the model that are most sensitive to R0. The ultimate aim of this research was to analyze different disease prevention approaches in order to find the most suitable one. For this, we included the vaccination and quarantine compartments in the proposed model and formulated an optimal control problem to assess the effect of vaccination and quarantine rates on disease control in three distinct scenarios. Firstly, we study the impact of vaccination strategy and conclude the findings with a graphical presentation of the results. Secondly, we examine the impact of quarantine strategy on whooping cough infection and its possible elimination from society. Lastly, we implement vaccination and quarantine strategies together to visualize their combined effect on infection control. In addition to the study of the optimal control problem, we examine the effect of the fractional order on disease dynamics, as well as the impact of constant vaccination and quarantine rates on disease transmission and control. The numerical results reveal that the optimal control strategy with vaccination and quarantine together would be more effective in reducing the spread of whooping cough infection. The implementation of the Toufik–Atangana-type numerical scheme for the solution of the fractional optimal control problem is another contribution of this article.

Modelling potential distribution of Tuta absoluta in China under climate change using CLIMEX and MaxEnt

AbstractThe Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) originated in South America and is a major pest of the economically critical solanaceous crops. It is devastating to tomatoes, attacking mainly the leaves, stems, flowers and fruits of tomato plants, and can cause up to 100% damage. T. absoluta invaded China in 2017 and expanded rapidly, severely impacting the tomato industry. To illustrate the detailed potential distribution of T. absoluta in China, we used CLIMEX and MaxEnt models to predict the potential distribution of this pest using historical and future climate data. CLIMEX predicts a wider potential distribution area for T. absoluta in China than MaxEnt, which suggests that most of China is suitable for its distribution, except for the Tarim Basin in southern Xinjiang, western Inner Mongolia and northwestern Gansu. Both models accurately predicted the known distribution of T. absoluta in the provinces of Yunnan and Guangxi, and the predictions by both models suggest the total distribution range of T. absoluta in China is to increase slightly with future changes in climate temperature. These predictions will help understand the influence of climate change on the potential distribution of T. absoluta in China and thus provide a theoretical foundation for developing early monitoring, quarantine and control strategies.

RETRACTED ARTICLE: Percolation Analysis of COVID-19 Epidemic

AbstractThe spread of COVID-19 can be greatly influenced by human mobility. However, implementing control measures based on restrictions can be costly. That is why it is crucial to develop a quarantine strategy that can minimize the spread of the disease while also reducing costs. This article focuses on determining the percolation threshold of COVID-19 in Tehran province using a square lattice and two types of city connections. The study identifies the number of roads that need to be closed and the cities that should be quarantined. Monte Carlo simulations using the Newman and Ziff and Union-Find algorithms were conducted through the $$\text {SEAIRD}$$ SEAIRD model to assess the effectiveness of the proposed measures. The results showed a possible reduction of 81$$\%$$ % in disease spread. This approach can be used in other regions to assist in the development of public health policies.