Skip to 0 minutes and 19 secondsOLIVIER LE POLAIN: Strategic objectives may differ slightly in each country or organisation, but the main overall objectives should be broadly similar. The response first aims to limit onward spread in the community and break chains of transmission to stem the epidemic quickly or at least slow its progression. Second, the focus should be on ensuring appropriate clinical care, particularly of vulnerable patients to reduce severity and mortality. Third, to address knowledge gaps and accelerate the development of new tools, vaccines, therapeutics that may help prevent disease spread and improve treatment outcomes.
Skip to 0 minutes and 57 secondsIt is important to note that while principles are similar across settings, the implementation of measures will vary depending on capacity, context, and, importantly, the dynamics of the epidemic within a given country or within a given setting. There are, however, a number of key measures that will be implemented in any response. Surveillance with prompt notification of suspect patients is required to rapidly detect and isolate those cases. This requires a clear case definition for patients to be reported. As the epidemic evolves rapidly, search definition needs to be regularly updated. Screening at ports of entry is undertaken to identify people who are ill on arrival.
Skip to 1 minute and 38 secondsThe effectiveness of such screening can be limited as individuals may become unwell much later and are, therefore, not detected at entry, as illustrated in an article which follows. However, entry screening is also useful in providing advice to people who arrive from affected areas about what to do if they become unwell. Contact tracing refers to the monitoring of close contact of confirmed cases to ensure they can be rapidly isolated and tested should they become well during the incubation period. This is a key measure particularly at the containment phase of an epidemic. Other social distancing measures may be implemented to limit the community spread and prevent geographic extension. With a rapidly evolving epidemic, regular public communication about the outbreak is essential.
Skip to 2 minutes and 23 secondsIn health care facilities, the focus will be on clinical management which requires appropriate triage of patients, rapid isolation of suspect cases, early identification of patients at risk of critical disease, and appropriate supportive treatment. Infection prevention and control includes ensuring adequate personal protective equipment for all health staff who are vulnerable to infection given their proximity to patients. Laboratories will need to provide testing capacity and, where possible, decentralised testing capacity in the country. Given the novel nature of the epidemic, developing guidelines for all aspects of the response is a critical role of any response mechanism and an iterative process as the epidemic unfolds and more evidence is gathered. As previously mentioned, research should also be an integral part of the response.
Skip to 3 minutes and 18 secondsAnd, finally, ensure an appropriate logistics pipeline is a crucial and difficult task required to steadily maintain supplies both medical and non-medical to respond to the outbreak and ensure appropriate allocation of medical supplies. The measures that were just outlined will be implemented in various ways depending on the stage of the epidemic and local context. Conceptually, it is useful to describe the epidemic response for three different scenarios. First, when there are no known cases, the focus is on readiness. This means ensuring appropriate surveillance is in place with rapid identification of suspect cases, isolation, and testing to ensure the entire system is ready to respond.
Skip to 4 minutes and 3 secondsSecondly, when a few cases or clusters of cases are detected, the focus is on rapidly breaking transmission chains and containing the outbreak. This is done through meticulous contact tracing, self-isolation, and other social distancing measures, as well as ensuring suspect cases can be rapidly identified, isolated, and tested. Thirdly, with more widespread person to person transmission in the community, early containment may no longer be possible and the focus is on slowing transmission, for example, through reducing mass gatherings. The main purpose here is to avoid rapid increases in cases that would put pressure on the health care system. Within a country the epidemic may be at different stages at different times in different areas.
Skip to 4 minutes and 52 secondsLet us now briefly consider how this is all coordinated. Various public health measures described earlier should be embedded in a wider multisectoral response and embedded in a well-coordinated response structure. Although there is no set way to respond, generally speaking, existing emergency response mechanisms will be activated. These have various response pillars or response cells organised around specific measures. For example, contact tracing cell, report health cell, a laboratory cell, a guidance cell. Good governance is essential and most governments have mobilised the highest level in the response to COVID-19 to ensure coordination across health but also across many different sectors. International coordination is crucial and there is an important role for the World Health Organisation, the United Nations, and other international organisations.
Skip to 5 minutes and 49 secondsInformation sharing between countries is also important with immediate notification of new cases to all member states through the focal points for the international health regulations. There is also a need for sharing of materials, including guidance, standard operating procedures, scientific outputs, and research protocols. Now, let's look at what we just described in the context of China's experience. Early in January 2020, with the city of Wuhan as the epicentre of the outbreak, focus was on containment measures. At that time, China rapidly set up a national multisectoral response coordinated at highest level.
Skip to 6 minutes and 29 secondsAs cases rapidly increased, efforts on containing and mitigating the outbreak were done through extraordinary response measures, including extreme social distancing measures such as quarantining cities and cluster containment in other provinces. National measures were put in place to limit population movement, such as controlling of transportation hubs and school closures. At the time of recording, the number of cases has started to decrease and stabilise in China. The focus now is on ensuring social economic recovery while maintaining and strengthening response activities and tailor those to each specific area. In addition, a comprehensive research programme was put in place to inform both national and international response efforts.
Skip to 7 minutes and 16 secondsThe response has been described as the-- perhaps most ambitious, agile, and aggressive disease containment effort in history in a report of a recent joint WHO and China mission on coronavirus. China's interventions, however, may not be replicable in other settings, in particular the resources for such interventions may be difficult to find where public health and health infrastructure is much more limited. In more fragile settings, the burden of disease may be high as both surveillance and response capacity is limited and populations may be more vulnerable to severe disease. In all this, global coordination and communication at all levels is essential.
Overview of a public health response
In this mini-lecture, Dr Olivier Le Polain discusses approaches to outbreak response, and illustrates this in the context of the COVID-19 outbreak and its emergence in China (recorded on 2nd March 2020).
Intended learning outcomes
- Describe the general principles and key elements of a response
- Summarise the main considerations for different epidemic contexts
- Briefly describe the response in China and contrast with other countries
© London School of Hygiene & Tropical Medicine 2020