The next pandemic is already happening-targeted disease monitoring helps prevent it

As more and more people around the world are vaccinated, people are likely to hear a breathtaking voice. However, the next pandemic threat may now have already passed through the population.

My research as an epidemiologist of infectious diseases has found that there are simple strategies to mitigate the outbreaks that are occurring. It is active real-time monitoring in situations where animal-to-human disease spillover is most likely to occur.

In other words, don’t wait for a sick person to appear in the hospital. Instead, monitor the population in which the disease spillover actually occurs.

Current pandemic prevention strategy

Health professionals around the world have long known that pandemics are caused by the following factors: Zoonotic disease spilloverOr the transmission of the disease from animals to humans was a problem. In 1947, the World Health Organization established a global network of hospitals. Detect pandemic threats Through a process called Syndrome surveillance..

Based on a standardized symptomatology checklist, this process looks for signs of emerging or re-emerging infectious diseases that may be pandemics among a population of patients with symptoms that cannot be easily diagnosed.

This clinical strategy relies on the visit of infected individuals. Sentinel Hospital And medical authorities Influential and lasting Enough to sound the alarm.

There is only one problem. By the time the sick person arrives at the hospital, an outbreak has already occurred.in the case of SARS-CoV-2, a virus that causes COVID-19, It may have been widespread long before it was detected. This time, only the clinical strategy failed.

Zoonotic disease spillover is complete, not one

Currently, in the world of pandemic prevention, a more aggressive approach, the theory of virus evolution, is drawing attention. This theory is Animal viruses become dangerous human viruses It gradually increases through the spillover of frequent zoonotic diseases.

This is not a one-time transaction. It may be necessary for “mediator” animals such as civets, pangolins, and pigs to mutate the virus so that it can first fly to humans. However, the ultimate host that allows the subspecies to fully adapt to humans may be humans themselves.

The theory of virus evolution is evolving in real time with rapid development. Covid-19 variantIn fact, an international team of scientists suggests that human-to-human transmission is unlikely to be detected after an animal-to-human jump. Origin of SARS-CoV-2..

When the outbreak of viral diseases of new zoonotic diseases such as Ebola first caught the world’s attention in the 1970s, studies on the extent of disease transmission were conducted. Antibody assay, A blood test to identify people who are already infected.Antibody monitoring, also known as Serum survey, Test blood samples from the target population to determine the number of infected people.

Serum tests can help determine if a disease such as Ebola is undetected and prevalent.

Ebola antibody 5% of people tested in Liberia in 1982, Decades before the 2014 West African epidemic. These results support the theory of viral evolution. It takes time, and in some cases, considerable time, to transmit an animal virus to humans, which is dangerous.

This also means that scientists have a chance to intervene.

Measurement of spillover of zoonotic diseases

One way to take advantage of the lead time for an animal virus to fully adapt to humans is to monitor it repeatedly over a long period of time.settings of Pandemic threat alert system With this strategy in mind Detect pre-pandemic virus Before doing any harm to people. The best place to get started is with direct access to the source.

My team Virologist Shi Zhengli Researchers at the Wuhan Virology Institute have developed a human antibody assay to test a very distant cousin of SARS-CoV-2 found in bats. A large study established evidence of spillover of common human and animal infections. 3% of research participants living near bats Having a coronavirus like this SARS was positive for the antibody.

However, there was one unexpected result. None of the previously infected study participants reported any adverse health effects. As with the first SARS outbreak in 2003 and the Middle East Respiratory Syndrome (MERS) in 2012, previous SARS coronavirus spillovers have caused high levels of illness and death. This guy didn’t do that.

Researchers conducted a large-scale study in southern China from 2015 to 2017. The area is home to bats known to carry coronaviruses such as SARS. Original 2003 SARS Pandemic And one Closest to SARS-CoV-2..

Less than 1% of the participants in this study tested positive for antibodies. This means that you were previously infected with a coronavirus like SARS. Again, no one reported any adverse health effects. But surveillance of the syndrome, the same strategy used in fixed-point hospitals, revealed even more unexpected things. 5% of community participants Symptoms consistent with SARS have been reported in the last year.

This study not only provided the biological evidence needed to establish a proof of concept for measuring zoonoses spillover. The pandemic threat alert system also detected signals of infection, such as SARS, which blood tests could not yet detect. Early variants of SARS-CoV-2 may also have been detected.

If surveillance protocols had been implemented, these results would have triggered a search for community members that could have been part of an undetected outbreak. But without an established plan, the signal was missed.

From prediction to monitoring and gene sequencing

Most of the funding and efforts to prevent pandemics over the last two decades have focused on finding wildlife pathogens and predicting pandemics before animal viruses infect humans. However, this approach does not predict a large zoonotic epidemic, including H1N1 influenza in 2009, MERS in 2012, Ebola hemorrhagic fever in West Africa in 2014, or the current pandemic of COVID-19. Hmm.

However, predictive modeling does provide a robust heatmap. Global “hot spot” The place where spillover of zoonotic diseases is most likely to occur.

Long-term, regular monitoring of these “hot spots” can detect spillover signals as well as changes that occur over time. These may include an increase in antibody-positive individuals, increased levels of illness, and changes in the vitals of infected individuals. Similar to prophylactic disease monitoring, if a signal is detected, an outbreak investigation will continue.

People identified in Symptoms that cannot be easily diagnosed You can then use gene sequencing to screen and characterize and identify new viruses.

This is exactly what Duke University’s Greg Gray and his team did in the search. Undiscovered coronavirus A rural area in Sarawak, Malaysia, known as a “hot spot” for zoonotic diseases. Eight of the 301 specimens collected from patients with pneumonia hospitalized between 2017 and 2018 were found to carry canine coronavirus, which was previously unheard of in humans.

Complete viral genome sequencing not only suggested that it recently jumped from an animal host, but also has the same mutations that made both SARS and SARS-CoV-2 very deadly. I did.

Don’t miss the next pandemic warning signal

The good news is that the monitoring infrastructure already exists in the global “hotspots”.Is Regional disease monitoring cooperation organization The program links six regional disease monitoring networks in 28 countries. They were pioneers of “participant surveillance” and contributed to preventative efforts in collaboration with communities at high risk of both the first zoonotic spillover and the most serious health consequences. ..

For example, in Cambodia, which is at risk of a pandemic bird flu epidemic, community members have set up a free national hotline to report animal diseases directly to the Ministry of Health in real time.

This approach to the field is the key to a timely and coordinated public health response to stop outbreaks before the epidemic becomes a pandemic.

It’s easy to miss warning signals when global and local priorities are tentative. You don’t have to repeat the same mistakes.

Maureen Miller, Part-time Associate Professor of Epidemiology, Columbia University

This article is reprinted from the following conversation Under a Creative Commons license.Read Original work..