Question

Background

Case Study: COVID-safeguard System

COVID-19 is a pandemic which is causing social, economic and health issues for the whole world. Many governments around the world are using advanced technologies to prevent COVID-19 outbreaks in their countries. For example, some of these advanced technologies include use of CCTV cameras to monitor people movements, drones to warn people to use face masks and mobile apps to track the social contact among people.

Let’s assume that you are working as a system analyst and your key skills are to design and develop information systems. Australian government has contacted you to develop an information system to collect information to help reduce the spread. The system can be called as COVID-19 safeguard. The main aims of COVID-19 safeguard information system are to identify clusters of infected areas, monitor quarantines, and educate people about social distancing and maintaining hygiene. The overarching goal of this project is to reduce the transmission of COVID-19 among people.

The information system should use advanced technologies such as CCTV cameras, drones, mobile signals such as Bluetooth, mobile phone data (i.e., location, date, time etc.) or any other technology that you think will be helpful in the design of this system.

Task 1. Identify and briefly describe the functional and non-functional requirements for the proposed COVID-safeguard system. (1500 words)

Task 2. List the possible domain classes and their attributes for the proposed COVID-safeguard system and draw a domain model class diagram. Be creative and add those domain classes you think should be included to make the system useful and appealing.

Task 3. Based on the information you obtained for COVID-safeguard system, identify all possible states and exit transitions and then develop a state machine diagram.

Task 4. Write a fully developed use case description using ONLY one use case for the proposed COVID-safeguard system.

Answer 1

Greetings of the day!

Answer:

Task 1. Identify and briefly describe the functional and non-functional requirements for the proposed COVID-safeguard system. (1500 words)

Since it has become apparent that contact tracing apps to be used on smartphones have several drawbacks, it is wise to investigate alternatives. When looking at tracking and tracing in logistics, such an alternative might be anonymous COVID-19 contact tracing using physical tokens.

An outline of a possible system is described. We must called on researchers, innovators, entrepreneurs, industry players and policymakers to contribute with their creativeness, technology and supply chain expertise to come with concrete proposals that can contribute to the further design and development of such alternative, COVID-19 contact tracing system using physical tokens. More than 60 expressions of interest were submitted and are now bundled into consortia that will work on concrete pilots. As part of the Crisis Response Initiative, this activity directly contributes to the European Union’s response to the COVID-19 pandemic.

To effectively contain virus outbreaks, it is essential to quickly reach (possibly) infected individuals in order to prevent them from spreading the virus. Speed is vital given the exponential spreading of viruses. Reaching individuals that have been in contact with persons tested positive is an essential part of the overall approach. Once these individuals have been reached, they can get themselves tested. Thus, contact tracing is only part of the overall approach to contain virus outbreaks. Given that manual contact tracing is labour intensive and slow, institutions and authorities are looking for technological solutions.

The purpose of any technological contact tracing solution is to reach (possibly) infected individuals in order to inform them so they can get themselves tested and if needed go into quarantine to avoid further spreading of the virus.

the following measures for all our people, including contractors, globally. They are most simply broken down into 'musts' and 'must nots':

The must nots:
You must not:

1. Travel by air either internationally or domestically. Any air travel which is currently booked, apart from return-bound flights, will be cancelled centrally by our travel booking partners.
2. Work from any Unilever site other than your principal location.
3. Enter a Unilever site if you are suffering from cold or flu-like symptoms.
4. Invite any visitors onto a Unilever site without the prior approval of the site leader.
5. Attend meetings, conferences or events of more than 20 people.

The musts:
You must:

1. Self-isolate for 14 days if you are experiencing any cold or flu-like symptoms or have returned to your country from another location for either business or personal reasons.
2. Apply hand sanitiser when you enter a Unilever site.
3. Undergo thermal testing upon arrival at any Unilever site as legislation and equipment allows.
4. Use non-physical greetings (ie avoid shaking hands) and maintain appropriate "social distance".

For the avoidance of doubt, all these measures are applicable to all employees, irrespective of role or geography.

We are also applying additional measures which vary based on whether you have an office-based role, work in a sourcing unit, or are one of our field sales or retail staff:

Sourcing units and distribution centres

• All of our sourcing units and distribution centres will apply specialist tiered protocols to protect our workers while supporting business continuity. Country leadership teams will continue to monitor carefully and engage with site leads as appropriate.
• Strict site protocols for hygiene and social distancing are also being put in place.

Field sales and retail staff (including 3p field sales and merchandisers)

• All field sales employees should connect with customers virtually wherever possible and minimise the use of public transport if a customer visit is necessary.
• Strict protocols on social distancing (including non-physical greetings), and hand hygiene (especially after handling cash) will also be put in place and will be communicated shortly.

Office-based roles

• All office-based employees globally should work from home. Any exceptions (which we expect to be few and far between, and most probably due to the need to access data-intensive systems) must be approved by the country General Manager.
• The only country where this does not apply is in China, where people are beginning to return to work per national controls.

R&D

• For R&D colleagues who work in laboratories or pilot plants on essential activities, protocols are now in development and will be shared by R&D site leads.
• It is likely that some R&D roles will follow the office-based protocols and some will follow the Sourcing Unit rules.

More details about these changes, which will be effective from Tuesday 17 March, will be shared by your country General Manager early next week.

I hope you agree that these measures are the right thing to do. They have been developed based on the latest scientific and medical advice and are designed to protect our safety, our families' safety, and the safety of the communities in which we operate and live. They also demonstrate Unilever's leadership as a responsible, purpose-led business.

We are continuing to support global and local authorities by donating hygiene products to support the fight against coronavirus and we will be further stepping-up these efforts in the days ahead.

we are acutely aware that these changes to our working arrangements will have a big impact on our lives. None of the measures have been taken without careful thought and consideration about what this will mean for all of us, and I want to reassure you that we will support you through this change.

Further information – and regular updates – will follow. This will include more details on the protocols being put in place to help protect Sourcing Unit and Distribution colleagues, as well as Field Sales and Retail Staff. Also, for those of you who are about to embark on what we expect to be an extended period of working from home, we will shortly be sharing more guidance to help you during this period.

These are unprecedented times. Now, more than ever we need to stay calm, be resourceful, and do what we do best: focus on supporting each other, meeting the changing needs of our consumers, and on serving our customers

CONTACT TRACING PURPOSE AND REQUIREMENTS

To effectively contain virus outbreaks, it is essential to quickly reach (possibly) infected individuals in order to prevent them from spreading the virus. Speed is vital given the exponential spreading of viruses. Reaching individuals that have been in contact with persons tested positive is an essential part of the overall approach. Once these individuals have been reached, they can get themselves tested. Thus, contact tracing is only part of the overall approach to contain virus outbreaks. Given that manual contact tracing is labour intensive and slow, institutions and authorities are looking for technological solutions.

The purpose of any technological contact tracing solution is to reach (possibly) infected individuals in order to inform them so they can get themselves tested and if needed go into quarantine to avoid further spreading of the virus.

This is key to the design of a contact tracing system. The role of the contact tracing system is only and exclusively to reach individuals that have been in contact with infected persons. Not more. This principle of focussing on the essence is key and well known as Occam’s razor. As a consequence, there isfor example no need for the tracing system to know the identity of citizens. Which is a key ingredient in achieving anonymity and thus user acceptance.

There is broad consensus on the so-called non-functional requirements any technological solution should fulfil. These are anonymity, voluntariness, transparency, security, temporality, and interoperability.

To summarize, the challenge is to have a system that allows to quickly inform (possibly) infected individuals that they have been in contact with an infected person while observing the aforementioned non-functional requirements.

TRACING USING PHYSICAL TOKENS

Physical tokens have only the minimal functionality needed for contact tracing (Occam’s razor) which has, for this specific purpose of contact tracing, several advantages over smartphone apps

• they are small, robust, cheap, and consume little energy
• their proximity technologies could include Bluetooth, but also the more accurate UltraWideBand
• their simplicity, single application, and ‘not always on’ allow for high levels of security

Being able to use the more accurate UltraWideBand on physical tokens may also address another challenge that is identified with smartphone solutions, that of the accuracy of Bluetooth. Unfortunately, UltraWideBand is not available on the average smartphone.

Next to that, physical tokens are proven technology in the logistics domain with established players and well-functioning ecosystems which allows for technical sovereignty.

The beauty of the system is that it allows both for local as well as gradual deployment, which means that after testing and piloting in restricted locations, such as factory plants or even ports, larger deployment can also be foreseen in critical areas and areas at risk. Further gradual deployment could cities, regions and even country-wide as well as cross-border distribution.

Physical tokens will have to be produced and distributed. Setting up production and distribution in Europe of physical tokens will take time, however, based on the existing production and supply chains, European countries should be able to bring physical tokens to their citizens in relevant time.

OUTLINE FOR A POSSIBLE CONTACT TRACING SYSTEM USING PHYSICAL TOKENS

The token itself is a small coloured device of at most the size of a matchbox, featuring a very simple (LED) status indication interface that resembles a traffic light and is only visible on request

• GREEN: NO INDICATION OF AN INFECTION
• RED: ACTIVE INFECTION (determined by a test)
• YELLOW: GO TAKE TEST (been in contact with an infected person)

Tokens can be carried in pockets, as bracelets, necklaces, etc. and should minimally have the following functionalities

• a unique securely stored serial number
• the ability to generate frequently changing identifiers from the serial number
• storage for securely storing identifiers of contacted tokens
• timed proximity identification of other tokens
• secure proximity exchange of token identifier with another token
• secure matching between the contact list, locally stored on the token, with the list of token identifiers of infected individuals
• receive and process a list of infected token identifiers
• switch the status indication

At regular intervals tokens change the identifier that they exchange with other tokens.

The system will have a central registry of serial numbers of tokens that have status indication RED. No other information will be stored in the registry (Occam’s razor).

Tokens are produced by a manufacturer that securely stores a serial number in the token.

Tokens are produced by a manufacturer that securely stores an identifier in the token. Initially all tokens have status indication GREEN.

Tokens are distributed via designated distribution points, which for example in cities might be supermarkets or possible other outlets, where individuals can randomly pick from boxes filled with tokens.

The COVID-19 contact tracing token can also be applied and deployed in demarcated areas or for temporary limited use. Industrial sites such as factories, slaughterhouses or harbours are examples for demarcated areas.

Sports- or cultural events are examples for temporary limited use. The audience would receive a token together with their ticket and would be encouraged to keep and monitor it for 14 days following the event.

At regular intervals, a signed list of recent serial numbers in the registry (signing assures authenticity of the list) is broadcasted and every token with status indication GREEN will intersect this list with the contact list it has stored. If the intersection is not empty the status indicator will be switched to YELLOW.

Also at regular intervals, people should check the status indicator of their token. In case it is YELLOW, they are strongly advised to, for example, contact their general practitioner or a COVID-19 test centre. This, however, is voluntary, and people may decide to ignore the advice.

The system will need to work with cyclic storage buffers with a pre-set duration, typically of two weeks.

THE OUTLINED SYSTEM SHOULD ADRESS THE REQUIREMENTS

The functional requirement is that the solution should reach those individuals that have been in contact with an infected person. The non-functional requirements are anonymity, voluntarily, transparency, security, temporality, and interoperability across systems and borders.

The functional requirement to reach individuals should be assured via the protocols that exchange token identifiers or broadcast them in regular intervals.

For the non-functional requirements of anonymity, voluntariness and transparency, the system should be voluntary; anonymity should be ensured by not having any relationship between the serial number of a token and a specific individual, combined with keeping the contact information as well as the processing of the broadcasted information on the token. Only token owners should be able to determine the outcome. In addition, the registry should not contain any personal or contact data. Finally, token tracing should be avoided for example through the use of pseudo-identifiers.

The requirement of security should be handled through the use of encryption, secure storage, secure identifier exchange, signed broadcasting, private set intersection, as well as frequently changing pseudo-identifiers. This collection of measures should address attacks such as skimming of serial numbers, man in the middle attacks, injection of false alarms, and collusion attacks on serial numbers.

The requirement of being temporary should be handled by time cyclic buffers as well as by the fact that the token system can be stopped any moment by stopping the broadcasting.

The requirement of being interoperable across systems depends very much on the other systems that are deployed. At the overall system level, the system should work hand in hand with existing systems deployed internally by institutions and authorities. In case of cross-border deployment, an interface supporting the interoperability should be provided.

THE AVAILABILTY OF TECHNOLOGY TO BUILD SUCH SYSTEM

As mentioned before token-based tracing is deployed in many logistics applications and the needed technologies to build such a system, such as low energy small size tokens including RFID, Bluetooth Low Energy, or the more accurate UltraWideBand, and long-range broadcast such as for example LoRa, are in principle available. The needed low footprint, low energy, processing, storage, communication, and security (hashing and encryption) technologies are in principle available. It is an important requirement to have a small-size, low power, low cost solution. Using existing state-of-the art technology it is expected to be possible to have a matchbox size token with approximately 1-year battery life at a ballpark cost of around €5.

Technology production and deployment of the tokens should be feasible by existing actors from semiconductor and equipment industry, telecommunication providers, producers of ultra-wideband tokens, embedded software developers, and of course institutions or authorities and distribution supply chains, such as for example for supermarkets. Given that most of this is in place, it is expected that this can be mobilised in reasonable time.

The system should allow both for local as well as gradual deployment, which means that after testing and piloting in restricted locations, such as factory plants or even ports, larger deployment can also be foreseen in critical areas and areas at risk. Further gradual deployment could be cities, regions and even country-wide as well as cross-border distribution.

THE TOKEN ACCEPTANCE

It is important that people accept the system and will actually use the token. Their main motivation should be to contribute to fighting virus outbreaks, as well as to protect their own health through early detection of possible infection. Nevertheless, to have the system accepted it should be trusted, easy to use and easily accessible. Therefore, any successful system should take these considerations as a starting point.

OTHER FUNCTIONAL REQUIREMENTS:

1. Funding COVID response should be quick and clear. A reallocation of existing resources may be necessary and can be done through transfers or supplementary budgets. Additional resources can be drawn from contingency funds or national disaster funds (where these exist). In many jurisdictions, transfers or reallocations can be done (subject to limits) with minimal administrative processes, which allows for immediate action, unlike using supplementary budgets. Donor funding, an important source in some countries, can be efficiently optimized when routed through the country systems. Ministries of Finance and Health should work together to ensure that the total funding envelope is appropriately identified and based on quick costing estimates. Many countries use enterprise resource planning applications to run their financial management information systems (FMIS), which are adaptable to introduce appropriate budgeting and accounting codes within existing structures, thus enabling capture of allocations and expenditures to respond to COVID-19.

2. Controls should be reoriented, not diluted. Some controls related to COVID-19 may need to be reoriented to delegate authority and expedite implementation. Adequate PFM systems can accommodate this during emergency situations. If such protocols do not exist, the guiding principles of controls need to be reoriented, based on a risk assessment. Wherever ex-ante controls are reduced, these need to be replaced with clear, explicit, and credible expectations of ex-post controls.

3. Efficient cash management is crucial. In countries where a treasury single account (TSA) is already in operation, the government has an overall picture of cash available at any point in time and is in a better position to manage cash and ensure liquidity for COVID-19 operations. In cases where large sums of government cash is sitting in commercial bank accounts, it may be appropriate for the Ministry of Finance to quickly collect, aggregate, and establish processes to move funds into bank accounts. For donor funds, in order to ring-fence this money and enhance donor confidence that it will not be mixed with government funds for ongoing expenditures, separate bank accounts could be created as linked accounts to the TSA.

4. Efficient and accountable procurement is needed. The COVID-19 response could warrant more use of single-source procurement with known and trusted suppliers to expedite the process. In such situations, it would be prudent for the Ministry of Finance and/or the procurement regulator to issue additional guidance on how to manage this process, including the potential for change orders. Monitoring international and domestic markets for price comparisons and timely actions could be useful. To mitigate the risks of fraud, it is especially important to maintain audit trails and acceptance of goods/services by responsible officials. In some cases, it may be necessary to do away with some standard requirements like bid securities and guarantees, though this needs to be documented with appropriate justification. Whenever possible, pre-existing framework contracts can be used. Posting all procurement information related to COVID-19 on government portals will enhance transparency and trust.

5. Payment management should be optimized. The emergency situation is likely to constrain liquidity. Hence greater emphasis on optimal use of cash float and credit lines is necessary. The normal payment processes of invoicing, goods / services receipts, and payments can be reviewed, both at the implementing line ministry and the Ministry of Finance, to explore how best to use the time frame allowed by creditors in making payments. In other cases, additional or higher advances may be required by contractors or sellers of goods and services, for which limits need to be established. At the frontline, service delivery units can use mobile money systems to ensure that smaller amounts are recouped quickly. Payments made outside the IFMIS system need to be recorded ex-post in IFMIS with minimal time lag.

6. Internal audit could compensate for some ex-ante controls. Internal audits could be used as a compensatory control to establish “concurrent post audit” to compensate for any pre-audit requirements that are modified. The internal audit function could temporarily reduce its role in systems reviews to focus on conducting post audit of transactions, with little time lag.

7. Financial reporting for timely assurance. Where separate budget lines are created for COVID-19 response, they need to follow the standard financial reporting system (IPSAS or national standards). Governments can benefit from more frequent interim reporting on the specific lines for decision-making.

8. The supreme auditing institution (SAI) needs to stand ready. Audit of emergency transactions by a government’s SAI provides broader reassurance on the value for money spent during emergency operations and helps identifies actions to strengthen systems for the future. SAI auditors need to independently decide on the nature, scope, and approach to COVID-19; and they should conduct their audit with minimal time lag after restoration of normalcy. To be able to conduct it, SAI needs to keep abreast of the modifications done to PFM systems and identify potential risk areas.

Task 2. List the possible domain classes and their attributes for the proposed COVID-safeguard system and draw a domain model class diagram. Be creative and add those domain classes you think should be included to make the system useful and appealing.

The outbreak of the novel coronavirus disease, COVID-19, caused by the new coronavirus 2019-nCoV that is now officially designated as severe acute respiratory syndrome-related coronavirus SARS-CoV-2, represents a pandemic threat to global public health.

Trend in Scientific Publications Related to COVID-19

Since the outbreak of COVID-19, this new disease and its causative virus have drawn major global attention. Scientists and physicians worldwide have been conducting a major campaign to understand this new emergent disease and its epidemiology in an effort to uncover possible treatment regimens, discover effective therapeutic agents, and develop vaccines. Over 500 journal articles were published electronically or in print during this period, and the number of published articles has increased each week since the week of January 13, 2020. Although a large portion of these articles are about clinical manifestations and treatment options, an increasing number of studies are focused on elucidation of virus structure, virus transmission mechanisms/dynamics, as well as identification of antiviral agents and accurate diagnostics for virus detection. These trends reflect immense interest and desire from the scientific community, including both academic and industrial organizations as well as clinicians, to identify new methods to halt the progression of this epidemic disease and to prevent infection and transmission in the future.

As DomainTools strives to deliver the most relevant, high quality data to the industry on issues of critical importance, we have refined the COVID-19 Threat List to ensure that it responds to changes in the market situation.

Accordingly, we’ve updated our monitoring to include additional terms around new treatments, potential vaccines, and masks, and introduced additional granularity around COVID-19-specific risk assessment. DomainTools has also made several technical and operational changes to improve the quality of the list, including:

• Proactive monitoring and analysis to identity, review, and remove potential false positives from the list;
• Improvements to our Risk Score machine learning algorithms in how they analyze and process COVID-19 domains; and
• Finer granularity around COVID-19-specific domain data gathering and scoring.

You will see these changes in the new list published on Thursday, April 23rd.

We've also updated our Iris search hash to include these terms, and you can find the updated hash here.

We hope to continue to serve the community during this ongoing crisis, and we will continue to refine the COVID-19 Threat List as needed to fulfill that goal. Please stay tuned for further updates.

Let's Make the Internet a Safer Place

As many around the world struggle to come to terms with the full impact that the Coronavirus will have on each of our families and communities, people are desperate for both information and hope. Threat actors exploit vulnerabilities, and many see the uncertainty of our circumstances as an opportunity. They are capitalizing on the need for news, guidance, supplies, and treatments by targeting businesses and individuals who need this information with a barrage of COVID-19-related attacks and scams.

Organizations and individuals are faced with critical decisions about what and whom to trust for useful information on the world’s rapidly changing circumstances. At DomainTools, we recognize many other organizations and individuals are working hard to ensure anxiety around the pandemic doesn't result in cybercriminals cashing in on fear and uncertainty during this difficult time. We feel we can give back to our community by taking on the challenge of providing useful information on infrastructure delivering potential threats. It can be difficult to strike a balance between a strong security posture and potentially blocking sites with critical information—especially as communities and support organizations launch new digital infrastructure in response to this epidemic.

While preying on uncertainty and weakness is something expected of threat actors, those of us in the security community have a duty to step in to protect those who are vulnerable and under attack—especially when we have the ability to help. For this reason, DomainTools is releasing a free, publicly-available COVID-19 Threat List to help organizations and individuals make better decisions about the risk posed by domains related to the Coronavirus threat. Unlike a simple keyword-search-based list, the DomainTools COVID-19 Threat List includes only domains that DomainTools considers to be high-risk, displaying domain names in context with their create date and a Domain Risk Score, so that you or your organization can make better decisions about which sites are likely to be threats.

In the COVID-19 Threat List, you can find:

• Domains Names - A selected list of domains with names containing core terms related to the COVID-19 pandemic, as well as common or misleading permutations of those terms. We are monitoring for more than 60 relevant terms, including the following examples:
  • Covid, and permutations like c0vid or c0v1d
  • Corona, and permutations like carona or corrona
• Create Date - Date the domains were first registered, or in the absence of available registration data, the date the domain was first detected by DomainTools. This can be used to identify brand new domains and determine which domains are the newest ones added to the list. In general, newer domains tend to be riskier, so use extra caution in interacting with very young domains.
• Domain Risk Score of 70 or Greater - The highest Domain Risk Score attributed to a domain by any of DomainTools’ Risk Scoring mechanisms. For all scoring types, DomainTools considers scores of 70 or above to be highly indicative of existent or forthcoming threats. As such, the COVID-19 Threat List will include those domains with a risk score of 70 or greater, indicating the highest risk score that a domain received from any of our scoring mechanisms.

Drawing upon data points from over 330 million current Internet domains, DomainTools Risk Score predicts how likely a domain is to be malicious, often before it is weaponized. The score comes from two distinct algorithms: Proximity and Threat Profile. Proximity evaluates the likelihood a domain may be part of an attack campaign by analyzing how closely connected it is to other known-bad domains. Threat Profile leverages machine learning to model how closely the domain’s intrinsic properties resemble those of others used for spam, phishing, or malware. The strongest signal from either of those algorithms becomes the combined Domain Risk Score.

Domains with scores below 70 will not be included in the COVID-19 Threat List, as we want to ensure that list recipients can use this list with high confidence that the domains included therein are likely to be threats. However, please be aware that just because a domain is not on the list, it does not mean that it is entirely risk-free or trustworthy. All sites disseminating information associated with the Coronavirus pandemic should be treated with caution, and the information they deliver should be evaluated critically in the context of local, state, federal, and international authorities and health organizations. Remember not to click on any link from a source you don’t recognize, and, before you interact with any link, examine the full URL of the link destination to ensure that the actual portion of the domain before the TLD (e.g., .com, .org, etc.) is the site you expect to visit.

We’ve seen the list grow dramatically, especially within the last month—rising from only 3,000 domains on March 1st to more than 57,000 domains by March 22nd. To keep the community as informed as possible, domains on this list will be rescored daily, meaning that each domain will be reassessed in light of available data each day. The list will also be regenerated and a new version will be posted daily, delivering all domains that meet the above criteria with creation dates of January 1, 2020 or later. The new version of the list will be made available as a CSV download for free to any and all organizations or individuals who believe this data will protect their employees, customers, or communities during this time of need.

SAFEGUARD PEOPLE:

• Integrate the domains into your organization's internal or consumer-facing products to proactively alert on high risk domains
• Identify and provide information about emerging threats to your organization or consumers to support community awareness and consumer protection
• Aid intelligence researchers in their COVID-19-related investigations by highlighting high-risk domains
• Track activity associated with domains on the list to observe behavior and determine objectives
• Analyze historical logs against the domains on the COVID-19 Threat List to see if any interactions occurred (detect past compromise)
• Create rule-driven action by integrating with in-house platforms, so that, if a domain that’s detected appears on the COVID-19 Threat List, a system can action that domain according to pre-established rules in an integrated system (e.g., Splunk, QRadar)

Technical Information

• The COVID-19 Threat List is available for download as a gzipped text file, updated daily
• Each row of the file is tab-delimited with the following fields:
• domain_name, create_date, risk_score
• The file is sorted by risk_score and create_date such that the most risky (the “99’s”) and youngest domains are at the top
• All domains on the list have a create date of 1 Jan 2020 or newer
• All domains on the list have a Risk Score of 70 or above

Wash your hands

Yes, this is still the No. 1 way to prevent getting the coronavirus, Moorcroft says. "The things you should do to protect yourself from the coronavirus are things you should do every day," he points out. "The No. 1 thing you can do to prevent any respiratory illness is to practice good personal hygiene."

Washing your hands correctly -- using soap and water and washing for at least 20 seconds -- or using hand sanitizer when soap and water aren't available, still stands as the best way to prevent the spread of infectious diseases, according to the CDC.

Wear a face mask

The CDC still recommends that everyone wear a cloth face covering (not a mask meant for a health care worker) when out in public, such as at the grocery store or bank. This is less to protect yourself and more to protect other people from you, in case you have the virus and have the potential to transmit it.

domain model

Task 3. Based on the information you obtained for COVID-safeguard system, identify all possible states and exit transitions and then develop a state machine diagram.

Introduction

Coronavirus disease 2019 (COVID-19) is a major health concern and can be devastating, especially for the elderly. COVID-19 is the disease caused by the SARS-CoV-2 virus. Although much is known about the mortality of the clinical disease, much less is known about its pathobiology. Although details of the cellular responses to this virus are not known, a probable course of events can be postulated based on past studies with SARS-CoV. A cellular biology perspective is useful for framing research questions and explaining the clinical course by focusing on the areas of the respiratory tract that are involved. Based on the cells that are likely infected, COVID-19 can be divided into three phases that correspond to different clinical stages of the disease .

Stage 1: Asymptomatic state (initial 1–2 days of infection)

The inhaled virus SARS-CoV-2 likely binds to epithelial cells in the nasal cavity and starts replicating. ACE2 is the main receptor for both SARS-CoV2 and SARS-CoV . In vitro data with SARS-CoV indicate that the ciliated cells are primary cells infected in the conducting airways . However, this concept might need some revision, since single-cell RNA indicates low level of ACE2 expression in conducting airway cells and no obvious cell type preference . There is local propagation of the virus but a limited innate immune response. At this stage the virus can be detected by nasal swabs. Although the viral burden may be low, these individuals are infectious. The RT-PCR value for the viral RNA might be useful to predict the viral load and the subsequent infectivity and clinical course. Perhaps super spreaders could be detected by these studies. For the RT-PCR cycle number to be useful, the sample collection procedure would have to be standardised. Nasal swabs might be more sensitive than throat swabs.

Stage 2: Upper airway and conducting airway response (next few days)

The virus propagates and migrates down the respiratory tract along the conducting airways, and a more robust innate immune response is triggered. Nasal swabs or sputum should yield the virus (SARS-CoV-2) as well as early markers of the innate immune response. At this time, the disease COVID-19 is clinically manifest. The level of CXCL10 (or some other innate response cytokine) may be predictive of the subsequent clinical course . Viral infected epithelial cells are a major source of beta and lambda interferons [7]. CXCL10 is an interferon responsive gene that has an excellent signal to noise ratio in the alveolar type II cell response to both SARS-CoV and influenza . CXCL10 has also been reported to be useful as disease marker in SARS . Determining the host innate immune response might improve predictions on the subsequent course of the disease and need for more aggressive monitoring.

For about 80% of the infected patients, the disease will be mild and mostly restricted to the upper and conducting airways . These individuals may be monitored at home with conservative symptomatic therapy.

Stage 3: Hypoxia, ground glass infiltrates, and progression to ARDS

Unfortunately, about 20% of the infected patients will progress to stage 3 disease and will develop pulmonary infiltrates and some of these will develop very severe disease. Initial estimates of the fatality rate are around 2%, but this varies markedly with age [1]. The fatality and morbidity rates may be revised once the prevalence of mild and asymptomatic cases is better defined. The virus now reaches the gas exchange units of the lung and infects alveolar type II cells. Both SARS-CoV and influenza preferentially infect type II cells compared to type I cells . The infected alveolar units tend to be peripheral and subpleural . SARS-CoV propagates within type II cells, large number of viral particles are released, and the cells undergo apoptosis and die (figure 1) . The end result is likely a self-replicating pulmonary toxin as the released viral particles infect type II cells in adjacent units. I suspect areas of the lung will likely lose most of their type II cells, and secondary pathway for epithelial regeneration will be triggered. Normally, type II cells are the precursor cells for type I cells. This postulated sequence of events has been shown in the murine model of influenza pneumonia. The pathological result of SARS and COVID-19 is diffuse alveolar damage with fibrin rich hyaline membranes and a few multinucleated giant cells . The aberrant wound healing may lead to more severe scarring and fibrosis than other forms of ARDS. Recovery will require a vigorous innate and acquired immune response and epithelial regeneration. From my perspective, similar to influenza, administrating epithelial growth factors such as KGF might be detrimental and might increase the viral load by producing more ACE2 expressing cells . Elderly individuals are particularly at risk because of their diminished immune response and reduced ability to repair the damaged epithelium. The elderly also have reduced mucociliary clearance, and this may allow the virus to spread to the gas exchange units of the lung more readily.

FIGURE 1

Human alveolar type II cells infected with SARS-CoV. Human type II cells were isolated, cultured in vitro, and then infected with SARS-CoV. Viral particles are seen in double membrane vesicles in the type II cells (a) and along the apical microvilli (b). Reproduced with permission from the American Thoracic Society .

There are significant knowledge gaps in the pathogenesis of COVID-19 that will be filled in over the next few months. I based my comments on the assumption that viral entry by SARS-CoV-2 will be the same as SARS-CoV. We do not know if there are alternate receptors for viral entry. CD209L is an alternative receptor for SARS-CoV . We await detailed studies on infection and the innate immune response of differentiated primary human lung cells. The apical cilia on airway cells and microvilli on type II cells may be important for facilitating viral entry.

In conclusion, COVID-19 confined to the conducting airways should be mild and treated symptomatically at home. However, COVID-19 that has progressed to the gas exchange units of the lung must be monitored carefully and supported to the best of our ability, as we await the development and testing of specific antiviral drugs.

As part of the national and local response to the pandemic, many people experiencing homelessness have been provided with emergency accommodation. It is vital that everyone should be offered long-term, secure housing with access to appropriate support. These responses have demonstrated what can be achieved through political will, local partnership working and flexibility in service provision. It is critical that this progress is not lost. The transition process should start a shift to a more comprehensive housing-led system that improves local resilience to homelessness.

See our overarching principles and guidance to support local transition planning. This should continue to be a clinical, health-led response to manage ongoing risk during the next phase of the pandemic. The resources below are grouped into four key areas to support this:

• Build a shared understanding of what everyone needs and wants
• Develop housing-led solutions and pathways
• Implement a costed transition plan/ strategy
• Take proactive steps to prevent homelessness during and after the pandemic

STATE MACHINE DAIGRAM

Task 4. Write a fully developed use case description using ONLY one use case for the proposed COVID-safeguard system.

There has been a great deal of effort to develop and deploy tests that can be useful in the detection, control and management of COVID-19. The current massive test development effort is reminiscent of the West African Ebola outbreak in 2014, but much more global in nature. Then, tests were needed for a number of different uses such as triage, diagnosis, confirmation, and cause of death. During the Ebola outbreak, on behalf of Grand Challenges Canada, Halteres Associates compiled a list of 10 test use cases for Ebola tests with substantially different target use and performance requirements (e.g. site of use, personal protective equipment [PPE] requirements, sensitivity, specificity, etc). In some situations, the tests meant for one application were of quite limited use in another application, whereas others were more broadly useful in a variety of settings. This was due to the fact that tests that required relatively low clinical performance (e.g. in a site with a current epidemic) were not useful where higher clinical performance was needed (e.g. in a site without known current infections); but typically a test designed for a high performance need was also useful in a site of lower need; that is, high clinical performance tends to be the lowest common denominator for multiple applications. Unfortunately, many organizations developed low clinical performance tests for the Ebola epidemic that were not useful in the post-epidemic world. Other product requirements also differed across use cases, such as site of testing, procedures for sample collection, types of samples that could be employed, and impact of testing while wearing PPE. We see similar issues developing in the COVID-19 epidemic.

So far, most testing organizations interested in addressing the COVID-19 epidemic are looking at at-risk populations such as travelers from epidemic regions, contacts of infected persons, healthcare and other emergency professionals and persons with suspicious fever and a dry cough. As the epidemic expands, we will see additional populations to be tested and sites for them to be tested within. We believe that there is a great need for more point-of-care (POC) testing, even though we recognize the challenges for preferred biomarkers (e.g. RNA, antigens, IgM, IgG, metabolites, cells) within useful assay formats (e.g. PCR devices versus immunoassays without instruments). A large number of companies are already involved in most of these types of SARS-CoV-2 assays (view pipeline). Home sample collection and transport to a lab is useful, but true POC tests would offer many advantages as presented below. Also, we wanted to expand our thinking to a possible future where COVID-19 becomes an entrenched and recurrent problem. We hope that this does not occur; however, if we don’t consider this possibility now, the diagnostics community might very well fail to develop tests that serve the long-term needs of our global healthcare and surveillance systems.

USE CASE CONSIDERATIONS

Nine use cases for SARS-CoV-2 tests are presented here:

1. Triage of symptomatic individuals in an epidemic setting
2. Triage of symptomatic individuals in endemic settings
3. Triage of at-risk pre-symptomatic and symptomatic individuals in endemic settings
4. Confirmatory testing
5. Diagnosis of symptomatic individuals in endemic or epidemic settings
6. Differential diagnosis in endemic or epidemic settings
7. Previous SARS-CoV-2 exposure
8. Surveillance in sites of previous or potential outbreaks
9. Environmental monitoring

Prior to developing assays and systems, it is essential that test developers understand the details of use cases for SARS-CoV-2 testing, including who will be tested, by whom, the site of testing, using which samples, under what conditions, and what the minimum acceptable clinical performance requirements are likely to be. The most important component of a use case is the intended use; that is, what is the clinical decision that will be enabled by the test and in what patient population. Given the early phase and novelty of the COVID-19 epidemic, many things that are known in other disease states are not generally known, such as the presence of virus in body compartments and fluids over time, the breadth of host responses, and the best clinical samples to use (e.g. Wang et al, JAMA, 2020). For the Ebola use cases, we presented information concerning the availability and potential utility of specific biomarkers. Given the early nature of this disease, we will only briefly address those issues in the conclusions. Multiple sample types are used today: nasal and nasopharyngeal swabs, sputum, bronchial lavage, urine, feces, and blood. As we learn more, some sample types will become preferred, while others are discontinued. We present here approximate clinical performance needs and price targets, but have not yet supported these estimates for a SARS-CoV-2 test with robust health economic models.

As far as we know, the scenarios we present concerning triage and confirmation testing are not in common use except for very broad screening tests such as taking a person’s temperature then sending nasal swabs for RNA testing. We believe that there are tests available, or near to market, that can be used as more useful triage tests that could enable the options presented here.

NOTE: Price targets refers to the target price to the end user. This is a highly variable target, depending on the target use setting. Payments and reimbursement amounts are frequently influenced by the type of assay technology used. This may not be the complete price per result if other ancillary equipment or consumables are required. For health economic modeling, the complete price per result must be considered.

USE CASE : Triage of symptomatic individuals in an epidemic setting

DESCRIPTION The intended use is to determine if a symptomatic individual in an epidemic setting has a reasonable likelihood of a current infection warranting temporary isolation pending confirmatory testing. Target use settings can be divided into two groups: Group 1: Sites with temporary (days) or full-time residents such as assisted living centers, cruise ships, hospitals and quarantine facilities. Group 2: Settings could include public and community health centers, primary care facilities, urgent care clinics, and emergency departments in outbreak areas where symptomatic individuals could be expected to visit for work-up. OTHER POSSIBLE TECHNOLOGIES REQUIRED If nasal or nasopharyngeal swabs are required, proper collection (e.g. swab) and sample introduction to testing device (e.g. swab introduction port) will be necessary. Typically, a confirmatory test using different targets is needed, unless triage test clinical performance is very high. It is possible that home self-tests will be deployed for triage — where positive results are not diagnostic, but will indicate that the individual should go to an appropriate confirmatory testing centre or care facility. Information and communications technologies (ICT) to capture and report data for reporting to other stakeholders is needed (e.g. healthcare workers, MoH, public health, CDC, WHO). If a differential diagnostic test is performed, in addition to a confirmatory test, association of the triage test data with these diagnostic test results is desirable. SAMPLES At the time of writing (25 March 2020), the preferred sample type is still under investigation, though nasal and nasopharyngeal swabs remain common choices. Other potential sample types used by some laboratories and test developers for SARS-CoV-2 include oral fluid, bronchial lavage, sputum, blood, urine and faeces. It may not be practical to obtain and process all sample types in all settings. “Sample-to-results” procedures should be carefully considered and matched to the end-user capabilities. For self-tests, sample collection with oral fluid or finger prick blood are preferred if possible since proper self-collection with a nasal swab could be difficult. COMMENTS The turnaround time should be maximally 1 hour, preferably 15 minutes or less. The potential use of a triage test in an epidemic setting is tied to the availability of an acceptable confirmation test. Confirmatory testing solutions and algorithms appropriate for the intended use setting should be recommended. Confirmation testing will not always be available at the site of triage testing. In this situation, it could necessary for the individual to be isolated near the site of testing or at home until confirmation send-out test results are obtained. The intended use settings can be roughly divided into two groups with different testing requirements: In group 1 sites, individuals can likely be isolated and confirmation testing can be conducted remotely (multi-day send out) In group 2 sites, remote confirmation testing is more problematic unless it can be conducted on site and rapidly. With send-out testing it will not be possible to keep patients onsite long enough to isolate them to prevent potential transmissions. A triage test that permits the majority of symptomatic patients to leave if they have a negative result (low probability of SARS CoV-2 infection; high sensitivity, high negative predictive value) would limit the need to isolate and test for confirmation of infection. On the other hand, the test requires an acceptable specificity so that few people are unnecessarily quarantined. Even in an epidemic setting it is likely that most persons with symptoms do not have COVID-19. In most of the intended use settings, a point-of-care (POC) format test is desirable, ideally one that is designed to meet CLIA-waiver requirements. While an instrument-free format has merit in many target use settings, the desire to capture and communicate information as well as features delivering improved test performance may favour automated solutions. Tests designed for decentralized POC testing should take into account the requirements across the wide variety of potential testing locations, environments, operators and regulatory requirements. It is likely that medical practitioners and technical staff in the target use settings will be wearing some form of personal protective equipment (PPE), which has implications for the type of sample that can be obtained (e.g. finger prick blood or nasal swabs while wearing gloves), how it can be processed (e.g. micro-capillary manipulation observation while wearing a mask) and the operator interfaces on the devices used (e.g. sample addition and touch screen while wearing gloves). Price targets (to the end user) are likely to be <US$25 for the US, but considerably less in low- and middle-income countries (LMICs). Frequently in high-income countries (HIC), established reimbursement is dependent on the type of assay technology used.