|28th July 2020
While lockdown eases across England, local lockdowns are becoming an ever-growing threat across the country. This is a unique response in comparison to other countries across the world and could be indicative of a second spike in infections.
At the beginning of the pandemic, The London School of Hygiene and Tropical Medicine launched a course focussed on understanding COVID-19 and the varying response across the globe. The course provided a good foundation on understanding the virology of COVID-19. Members of our team took part in the course to gain a better understanding of the pandemic, so we could best serve our clients during this challenging time. Here are some of the key learnings.
What is COVID-19?
COVID-19, also known as SARS-COV-2, is a type of coronavirus that is characterised by crown-like spikes and can cause a range of illnesses in humans from the common cold to severe disease. Coronaviruses are commonly found in animals, but rarely people get infected with a new type of virus which they catch from an animal.
Humans have been affected by these types of viruses before such as SARS (from civet cats) and MERS (from dromedary camels). However, COVID-19 is thought to have come possibly from bats.
The symptoms can range from mild to severe, all affecting the respiratory system, from fever and fatigue to complete respiratory failure.
The severity of the disease can be measured by the case fatality rate (CFR). This is the number of people who die from that condition out of the total of number of cases with the condition.
At the time of writing this article, the global CFRs for MERS, SARS, and COVID-19 are 37%, 10%, and 5% accordingly. However, for the UK the current CFR is 14% which is nearly three times higher than the global average.
How did COVID-19 become a global pandemic?
To understand how the pandemic has come to be, it is important to understand the route of transmission which has no doubt contributed to the accelerated spread of the disease. There are three main ways that respiratory viruses are known to spread. First, droplets which are larger particles that are greater than 5mm that travel under 1m.
Second, aerosols which are smaller particles that are less than 5mm that travel over 1m. Third, physical contact with objects that have been infected with droplets and then touching eyes, nose, and/or mouth.
Once someone has contracted the disease, they can be contagious for up to 14 days. This is much longer than the incubation period for the flu, which is only two days. However, often patients do not show symptoms until later in the incubation period.
Epidemiologists use the serial interval to understand the rate of infection. This is the time between the onset of symptoms in the primary case and the onset of symptoms in the secondary case (the person infected by the primary case).
One Japanese study found the serial interval for COVID-19 was four days, which is shorter than the incubation period. As a result, many people could be contagious before showing any symptoms of the disease and may spread the virus without realising they have contracted it. With the prevalence of international travel for work or leisure, numerous people were able to spread the virus across borders without realising.
Scientists also calculate the spread of the disease by calculating the R0. This is the average number of secondary cases produced by one case in a totally susceptible population. R0 is dependent on three factors. These are how long people are infectious for (duration), the probability of the infection being transmitted during contact between a susceptible and an infected individual, and the average rate of contact between susceptible and infected individuals (dependent on population). These factors combined determine how high or low R0 is.
An R0 greater than 1 means that case numbers are increasing. An R0 lower than 1 means that case numbers are decreasing and an R0 equal to 1 means that case numbers are stable. To put this into perspective the R0 for COVID-19 has been between approximately 1.5 and 4.5 in comparison to 3 for SARS and 1.5 – 3 for the flu.
The importance of testing and surveillance
The R0 is an important measure used in Public Health Emergencies of International Concern (PHEICs) – extraordinary events which constitute a public health risk to other countries through the international spread of disease requiring a coordinated international response.
The public health responses to PHEICs are designed to limit onward spread between individuals to contain the epidemic and slow its progression. To do this, countries must ensure prompt and appropriate clinical care to reduce severity and mortality, identify critical knowledge gaps and accelerate the development of new tools to prevent spread and improve treatment.
The routes of transmission largely determine prevention strategies. To prevent the spread of the disease it has been advised to thoroughly wash your hands, maintain distance with other people and avoid touching hands and mouth. Despite these strategies, the disease spread across the world at an alarming rate.
The key measures outlined for COVID-19 were surveillance, point of entry screening, contact tracing, social distancing, public communication and health education. However, it has been challenging for governments to respond to the rapid spread of the disease.
Good surveillance of a disease focusses on rapidly detecting and isolating suspect cases. COVID-19, was first sequenced in Wuhan, China in January 2020. This helped us to identify novel regions of the genome allowing for the development of diagnostic assays to detect the virus.
Accurate testing is arguably one of the most important strategies for tracking and stemming the pandemic. It is the only way to understand how many people are infected and could pass on the disease. The results of these tests are crucial for ensuring effective patient management, guiding treatment of infection and informing any public health measures.
Development of sensitive and specific diagnostic testing involves designing primers for assays and trialling serology assays that look at the immune response. This demonstrates the presence or absence of infection as well as detecting evidence of a previous infection.
However, rolling out national testing became a major challenge for many countries throughout the pandemic. Some rationed of tests, reserving diagnostics for key workers such as healthcare professionals.
The scaling of these tests has proved difficult due to the need to coordinate manufacturing processes, such as the production of the kits and the chemicals used in the tests, along with the need to rapidly train healthcare workers and implement new processes and procedures.
This coupled with the variety of tests on the market, each with its own blend of chemicals, and the lack of government-approved machines in research laboratories made rolling out the tests challenging.
A global response
Information sharing between countries and CDCs combined with highly engaged governments has played a vital role in managing and controlling the outbreak.
For China in early January, the focus was on containment measures, limiting exportation of cases from Wuhan and developing guidelines and testing capacity. There was a national multisectoral response at the highest level and involvement from the engaged wider society. Whilst the country enforced extreme social distancing measures to limit movement and stabilise R0, there was a massive push to understand everything about SARS-CoV-2 and a comprehensive research programme was run in parallel.
This was similar to the response in Singapore where traditional methods of social distancing and isolation were used in conjunction with case monitoring, screening, contact tracing and treatment. There was an emphasis on keeping regular communications with the general public providing guidance, reminders and data updates. There was also investment in providing the public with four face masks per household to only be used when a member presents with symptoms in an effort to reduce public anxiety.
In Africa, a continent-wide approach was taken to respond to the epidemic by forming the African Task Force for Coronavirus Preparedness and Response (AFCOR). AFCOR is led by the African CDC and WHO and focusses on working groups in South Africa, Senegal and Tunisia to provide a coordinated response to support continent infection intervention. The initial strategy concentrated on early detection and containment, expanding testing and proving appropriate care.
The combination of information sharing and disease management across countries gives us the best chance of beating the virus and bringing an end to the pandemic. As more testing occurs and more data is collected, understanding of the genome of the virus will improve allowing for Centres for Disease Control (CDCs) around the world to gather enough data to produce a vaccine.
The Coalition for Epidemic Preparedness Innovation (CEPI), a global alliance financing and coordinating the development of vaccines against emerging infectious diseases, launched in 2017 and is needed now more than ever. Producing a vaccine is our best chance at beating the virus in the long term.
What can we learn from this?
We need to use our learnings from this pandemic to help future proof us against other possible global health crises. There are three main factors that could help us in the future to prevent spread of infection on this scale. Firstly, an increase in rapid communication between CDCs across geographies would help with detecting infectious agents that put us at risk before it spreads out of our control. This influences a second important factor, which is to lockdown countries sooner in order to prevent spread and isolate the infection.
The last factor that would help is increased investment in testing to provide governing bodies with a better understanding of the scale of the outbreak allowing them to tailor the response more accurately.
These three factors all aid into the widely approved strategy of early detection, essential containment, suitable surveillance and necessary treatment required for effective infectious disease control.
Knowing the epidemiology of COVID-19 and how countries across the world are managing the spread of the virus enables us to stay on the front foot of the situation and maintain our position as experts in the field of healthcare. COVID-19 has directly impacted how us and our clients work and gaining insights on the current landscape allows us to proactively manage our projects through this challenging time.
To find out more about our work in infectious disease and how Blue Latitude Health and our parent company Fishawack Health, can help you solve your medical, strategic or creative challenges, get in touch with firstname.lastname@example.org
|27th August 2020
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