ARE WE READY TO BREAK THE NEXT WAVE?

We have coped well with the first effects of the pandemic but as we look to the future we need to modify our strategy, writes Mark Roe

IT is 150 days since Ireland first confirmed a case of Covid-19. We are now on the tailend of the first wave. An average of 20 new cases have been confirmed for each of the past 14 days. That is 3pc of our peak level in mid-April. So, how do we prepare for what comes next?

Much has been spoken about the ‘surge’ of travel-related Covid-19 infections. But since phase three began, for every new travel-related case, four are occurring in healthcare workers. Travel is playing a role but it is small at one-to-two cases per day since phase three began. Across the EU, less than 3pc of cases have been imported into the reporting country. In Ireland, imported cases account for 1.7pc, meaning that the source for most new infections is already here.

When a population of 4.8 million has detected just a handful of cases for a sustained period of time, yet is surrounded by countries facing second waves, it is important to have clarity on the extent of the problem.

In 1969, the World Health Organisation (WHO) reviewed the lessons learned from fighting plague, smallpox, and cholera. The goal was to identify benchmarks for countries to gauge what it would take to deal with future outbreaks of disease. International travel was surging, leading to a fear that pandemics could occur more easily. That year, 310 million aeroplane trips were made. By 2018, this increased to 4.2 billion.

It was determined that much of future responses would rest on two simple principles: ongoing surveillance and clear communication. Countries would need to understand how diseases are spreading so that the source of the problem can be quickly identified, isolated, and communicated to the public. The WHO issued these benchmarks with a warning; vague messages delay responses and make bad situations worse.

The European Centre for Disease Prevention and Control (ECDC) reported on clusters of confirmed cases in Northern Italy on February 22. Their assessment had three clear take-home messages. One, there was a high risk of infection to people travelling to the region. Two, there was a moderate-high risk of outbreaks in countries these travellers returned to. Three, infected people would likely have symptoms so mild that do not cause them to seek medical attention, meaning that they could go undetected for some time. At this stage, two people had died in Northern Italy.

Fifteen days after the ECDC report, Ireland advised against travel to the region. By then Ireland had 18 confirmed cases. Nearly all were travel-related and most had returned from Northern Italy. Many were healthcare workers who introduced the infection into their workplaces.

Biosecurity levels in hospitals were inadequate to prevent the spread of the virus. So far, healthcare workers, hospital inpatients and nursing home residents account for more than half of cases in Ireland — a reality that remains and has yet to be clearly communicated.

By mid-April the demand for testing sky-rocketed. When Ireland had 14,000 confirmed cases, a target of 100,000 tests per week was set. So far 600,000 tests have been completed. The virus has been found in 0.6pc of the population.

Vague communication often reflects an inability to grasp what is taking place. The WHO benchmarks had two solutions for this. First, countries should rapidly adapt their surveillance systems when a novel disease is found. Second, 90pc of health staff should be trained in surveillance and epidemiology so that the detection of new outbreaks can be sustained.

Epidemiology is a simple science that addresses straightforward questions.

The aim is identify how health problems are affecting the population, and for an infectious disease, to determine how it is spreading. First, you start by defining the problem, in this case, Covid-19. Next you measure how common it is in the population. Then you focus on three factors; person, time, and place by asking who has this virus, when did they get it, and where did they get it from. The quicker you collect this data, the sooner you can respond based on a clear understanding of where cases are coming from.

In Ireland, the Health Protection Surveillance Centre (HPSC) has reclassified more than 15pc of cases originally linked to community transmission. So far, community transmission accounts for 32pc of all cases. But when we look at different sections of society, some alarming trends emerge.

Community transmission is associated with 16pc of cases in healthcare workers. In remaining cases that exclude nursing home residents, 59pc are reportedly linked to community transmission.

As community interactions have been highly restricted, it is more likely that these cases are spill-overs from healthcare settings, where staff spread the virus outside of their work. This extended the chain of transmission by creating carriers who had links to healthcare workers, but little-or-no symptoms to seek medical attention.

In April, Spain, France, and Switzerland began testing people for the presence of specific antibodies only found after a recent Covid-19 infection. These countries had already confirmed the disease in 0.3-0.7pc of their populations. Antibody tests showed that 5-11pc of people had recently been infected.

On a per capita basis, Ireland tested twice as many people over the last seven days in comparison to France and Spain. In real figures, Spain and France are testing 320,000-494,000 people every day across land areas seven times the size of Ireland. Even at this scale of testing, estimates suggest they are identifying one-in-12 cases, making it difficult to find the source of the virus.

Ireland is using a hybrid testing strategy; while diagnosing the sick by testing for Covid-19, it also aims to reduce transmission by testing close contacts for infection. Despite the ECDC warning about the impact of mild cases on disease detection in February, our strategy relies on people to have symptoms, seek medical attention, and for confirmed cases to recall close contacts. But this disease has a diverse range of symptoms, and, in some cases, none at all.

We need teams of people who randomly test sections of the population where cases may be going undetected. These teams should have one role — find the virus.

On July 2, the ECDC issued another rapid risk assessment. It listed six responses to avoid a resurgence; beginning with surveillance and ending with clear communication. This might appear to be stating the obvious, but there is a major pitfall when people get caught up in the day-to-day monitoring of numbers. We begin to focus more and more on the random changes, and lose sight of the big picture.

To sustain the progress made so far, Ireland needs clear communication about where infections are coming from and what can be done to address it. Tackling our remaining reservoirs of infection is increasingly important as people begin to gather again at work, schools, sports clubs, and ports of entry. It is also important for easing the burden of Covid-19 on healthcare workers and those that depend on them for treatment.

We need a national screening programme to detect people with Covid-19, many of whom may be asymptomatic, before they spread the virus to others, especially vulnerable groups. As only 49,000 tests are being done each week, instead of 100,000, we have the testing capacity to do this.

To break the next wave of Covid-19, we must start looking for the virus before people require medical attention.

Mark Roe is a post-doctoral researcher at UCD School of Public Health, Physiotherapy and Sports Science

‘We are now on the tailend of the first wave’