Tuesday, April 7, 2020

Epidemiologist: Distancing Measures Should Help Slow Spread of Covid-19

By on March 17, 2020

Photo by Markus Spiske on Unsplash

Characteristics of Puerto Rico Population Make Impact of Outbreak Hard to Predict

SAN JUAN — Dr. Melissa Marzán, a professor of epidemiology at the University of Puerto Rico School of Medicine, said that given the highly infectious nature of the novel coronavirus, the economically disruptive social distancing measures being implemented by Puerto Rico, the states and other governments throughout the globe are justified.

“Seeing how other health systems are about to collapse with this disease, I would not hesitate taking measures that would avoid such a situation,” she told Caribbean Business. “The people who implement these measures the earliest will remain under the [crisis] threshold and will be able to provide [medical] services to meet the demand.”

Stressing that the contagion grows exponentially, the professor said these measures aim to reduce the spike in cases of the Covid-19 disease that could flood emergency rooms and spread them out over time, adding that the novel coronavirus “has the ability to propagate faster than other viruses such as influenza and other coronaviruses” that were also declared public health hazards.

“This was declared a pandemic because it was an epidemic that was not addressed in time, because no matter how universal or advanced your health system is, it will not be able to handle the demand of patients sickened by the coronavirus,” the physician said, noting that about 6 percent of coronavirus patients will be in critical condition and will need to be in intensive care. “The pandemic declaration is to give those countries’ health systems international support and prompt these governments to take measures to encourage social distancing, which if implemented in time you can avoid a scenario in which demand is greater than what you can provide; so that health systems don’t collapse.

“The more people you receive in emergency rooms, the greater number of people will develop complications and die,” she assured.

The Covid-19 crisis is complicated by how much more interconnected the world is in terms of travel and transportation, Marzán said. The virus was first identified in December in the Chinese city of Wuhan, a university, industrial and transportation hub.

The U.N. World Health Organization (WHO) has estimated that between 40 percent and 60 percent of the population could get the novel coronavirus, the expert in infectology said.

“However, those numbers will depend on the characteristics of the population,” she said. “If a population has many senior citizens, this will have a significant impact. We also have a high prevalence of chronic diseases, which complicates cases. So it will behave differently according to population characteristics. We don’t have big mass transportation systems here, while New York does.”

Covid-19 is “very similar” to the Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS), but in terms of severity measured as the rate of mortality, SARS’ and MERS’ mortality rates were higher, Marzán said. The H1N1 swine flu virus had a fatality rate of between 15 percent and 17 percent, and SARS, between 9 percent and 10 percent, she said, noting that for the novel coronavirus, she has seen figures ranging from 0.4 percent to 3 percent. The influenza fatality rate is about 0.1 percent, she added.

While all of the population is susceptible to Covid-19 because it is a new disease, older people are at higher risk of developing complications, including death, particularly in those over 60, she said. “In younger populations, especially those 18 years old and under, are those with the fewest reports.”

The progression of the novel coronavirus begins with individual cases, then builds up to social clusters, and ends in sustained community contagion between people who have not had contact with the person who brought the disease to that community.

Carriers

Although data from Covid-19 patients indicate that the more symptomatic a person is, the greater the chance of transmission, asymptomatic people can spread the virus, Marzán said.

“The WHO has determined that asymptomatic transmission is not a main form of transmission of the virus. The incubation period is from one to 14 days,” she said. “The quarantine measures are based on those 14 days. About 9 percent of cases are asymptomatic the first few days.”

Marzán did not rule out that neighborhoods or entire municipalities in Puerto Rico could be closed off by authorities to prevent further spread of the virus. 

“This could remain as a seasonal disease like the H1N1 virus, which is the most prevalent flu strain in Puerto Rico,” she said. “The difference now is that we have a vaccine to prevent the virus.”

The H1N1 global pandemic affected the United States and Puerto Rico in 2009-2010, and according to a 2012 study by The Lancet caused the deaths of an estimated 151,700 to 575,400 deaths worldwide, with 12,469 of these in the United States alone. About 59 million people stateside contracted the H1N1 virus, of which 265,000 were hospitalized as a result (0.4 percent of the estimated total number of people who contracted it), according to the U.S. Centers for Disease Control.

“H1N1 did affect the global economy, and this virus will not be an exception. On this occasion we will see extreme measures such as social distancing becoming the norm,” she said. “Obviously this has a direct impact on the economy. I would hypothesize that this impact will be greater now than with H1N1 because with H1N1 not all of these measures were taken in all countries. This will have an impact in the long- and short-term because people are canceling activities and travel during the next months.”

There is no vaccine or effective antiviral medication yet for Covid-19, Marzán said. Clinical trials for the novel coronavirus vaccines are being conducted in China and the United States, she said.

“Right now there is no specific treatment. There are several clinical trials to try to identify other antiviral medicines that could be effective to mitigate this novel coronavirus,” the infectology expert said. “This type of study is very rigorous. It requires a lot of time, because it has to determine if the medication is making the change. Doctors now are limited to giving out prescriptions for medications addressing the symptoms, such as cough, pain and fever.”

The World Health Organization declared last week the coronavirus a pandemic and urged aggressive action from all countries to fight it, as U.S. stocks plunged into bear market territory and several American cities joined global counterparts in closing schools and banning large gatherings.

As of Tuesday, Covid-19 has infected 190,943 people in 163 countries and territories since the virus was first detected in December in the city of Wuhan, capital of the Hubei province of China. The death toll from the virus has reached 7,546—with half these cases in China but a growing majority of cases being registered in hard-hit countries such as Italy, Iran, Spain, and South Korea, with France and Germany following closely.

There have been 5,696 new coronavirus cases in the United States and the death toll there has climbed to 97.  

Of the 102,508 people who are currently infected by the novel coronavirus, 95,987 people, or 94 percent, are in mild condition, while 6,521 people, or 6 percent, are in serious or critical condition. Some 80,889 people, or 91 percent, have recovered from the virus or have been discharged from hospitals.

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