Asia

In Iran, the covid-19 killed so many people that the government was forced to bury them in mass graves. In neighboring Iraq, however, the victims are less than a hundred. The Dominican Republic has recorded nearly 7,600 cases of contagion, but just beyond the border, in Haiti, the toll has stopped at 85. In Indonesia, thousands of people are believed to have died from the epidemic, while in neighboring Malaysia a series of Extremely rigid measures has kept deaths around a hundred.

The covid-19 has hit almost every country in the world, but its impact appears extremely erratic. Where global metropolises such as New York, Paris and London have been devastated, megacities such as Bangkok, Baghdad, New Delhi and Lagos have been substantially spared. At least so far.

The fact that the virus has swept some areas of the planet leaving others almost unscathed is a puzzle that has fueled a series of theories and conjectures, without however producing any definitive answer. Understanding this phenomenon could have profound consequences on how countries deal with the epidemic, making it possible to determine who is taking the greatest risks and when it will be possible to resume a semblance of normal life.

Theses and denials
At the moment, hundreds of researches are underway in the four corners of the planet on the possible effects of demographic conditions, previous diseases and genetic characteristics.

In Saudi Arabia, doctors are evaluating the possibility that genetic differences affect the severity of covid-19 symptoms, while Brazilian scientists are analyzing the relationship between genes and complications of the disease. In several countries, researchers are testing a theory that hypertension medications could worsen the severity of covid-19, while a specific tuberculosis drug could have the opposite effect.

The fact that many developing countries with warm climates and a young population have been spared the more catastrophic consequences of the virus suggests that temperature and demography are determining factors, but this thesis is denied by the high number of cases in countries tropical like Peru, Indonesia and Brazil.

In general, timely measures to impose social distancing and blocking of activities have been effective. Yet two countries such as Cambodia and Burma, where strict isolation measures have not been taken, have experienced a limited number of infections.

In this regard, there is a theory that has not been proven, but it is impossible to refute: perhaps the virus has not yet affected these countries. Russia and Turkey initially seemed unscathed, but then the situation suddenly precipitated.

There is always the possibility that time will eliminate these differences. The Spanish fever that hit the United States in 1918 seemed to have disappeared during the summer, but returned with much more vehemence in the following autumn and then again in a third wave the following year. Eventually the virus reached remote locations such as the islands of Alaska and the South Pacific, infecting a third of the world’s population.

“We are still at an early stage of the epidemic,” confirms Dr. Ashish Jha, director of Harvard University’s Institute for Global Health Research. “If it were a baseball game we would be in the second inning. We do not know if at the ninth inning the countries that currently seem spared will have the same conditions as the others. ”

Doctors studying infectious diseases around the world point out that they don’t have enough data to compose a complete epidemiological picture. In many countries, the lack of information makes any conclusion dangerous. Often the analysis of the samples proceeds slowly, and this creates a strong underestimation of the number of infections. The deaths from covid-19 are almost certainly much more numerous than those recorded.

Yet general trends seem quite clear. A country may have enormous administrative difficulties and an inefficient health system, but it is still difficult to hide mass graves or hospitals that refuse thousands of patients. So it is undeniable that several countries are not experiencing a dramatic situation. At the moment.

According to the statements of about twenty infectious disease experts, health officials, epidemiologists and academics from around the world, there are four factors that could help explain where the virus thrives and where it encounters difficulties: demography, culture, environment and the speed of response from the authorities.

However, every possible explanation is accompanied by abundant reservations and evidence that seems to contradict it. If an older population is automatically more vulnerable, for example, Japan should be at the top of the list of infections. But that’s not the case at all. In any case, these are the factors that experts believe are most convincing.

The power of youth
Many countries spared from a mass epidemic have relatively young populations. According to Robert Bollinger, an infectious disease professor at Johns Hopkins University medical school, young people are more likely to be asymptomatic or exhibit mild symptoms, and transmit the virus less frequently. Furthermore, according to the World Health Organization (WHO) young people have a minor tendency to develop a series of problems that can increase the mortality of covid-19, the disease caused by the Sars-cov-2 virus.

Africa, where 45 thousand confirmed cases represent an infinitesimal portion of the 1.3 billion inhabitants, is the youngest continent in the world. 60 percent of the African population is under 25 years old. In Thailand and the Iraqi city of Najaf, local health authorities have verified that the age group between 20 and 29 years has the highest rate of contagion, but often does not develop particular symptoms.

By contrast, the average age of Italy, one of the most affected countries, is over 45 years old, while the average age of the victims is around 80 years old.

Younger people tend to have a firmer immune system that can reduce the symptoms of the disease, says Josip Car, global health expert at Singapore’s Nanyang Technical University.

In Saudi Arabia and Singapore, for example, most of the infection affects migrant workers, many of whom live in crowded dormitories. However, these are often young and healthy people who have not needed hospitalization.

According to some US researchers, a good state of health, together with young age, can lessen the impact of the virus, while some pre-existing diseases – hypertension, diabetes and obesity – can worsen its effects.

However, there are significant exceptions to demographic theory. Japan’s population is the oldest in the world, but the country has recorded fewer than 520 deaths, although the number of cases has increased with the intensification of sample analyzes.

The Ecuadorian region of Guayas, the epicenter of an outbreak that could have caused the death of seven thousand people, has one of the youngest populations in the country: people over the age of 60 represent just 11 percent of the population.

Dr Jha points out that some asymptomatic young people are still extremely contagious, for reasons that are not yet clear at the moment.

Cultural distancing
According to epidemiologists, cultural factors such as the natural tendency of some societies to keep their distance may have protected some states more.

In Thailand and India, where the numbers of the virus are relatively low, people greet each other without contact, reaching the palms of their hands as they do in prayers. In Japan and South Korea people greet each other with a bow, and even before the advent of the covid-19 they often wore masks in case of malaise.

In most developing countries, the habit of caring for the elderly in the family has reduced the number of rest homes, structures that in the West have been fertile ground for the epidemic.

But even in this case there are important exceptions. In many Middle Eastern countries, such as Iraq and the Persian Gulf states, men have a habit of hugging and shaking hands. Yet contagions are rare.

Another advantage could derive from the so-called “national distancing”: relatively isolated countries have experienced positive health effects.

Remote states such as those in the South Pacific or sub-Saharan Africa, for example, have not been invaded by foreigners who brought the virus with them. According to African health experts, the reduced number of international journeys is the main reason for the low rate of infection on the continent.

The least accessible countries for political reasons (such as Venezuela) or because of armed conflicts (Syria and Libya) have been protected from the relative absence of travelers. The same goes for countries like Lebanon and Iraq, marked by violent protests in recent months. Furthermore, the lack of public transport in developing countries could be another factor that has limited the spread of the virus.

Heat and light
The geography of the contagion – which spread rapidly during the winter in temperate countries such as Italy and the United States while it was virtually absent in warm countries such as Chad or Guyana – seems to suggest that the virus does not like the heat. Other coronaviruses, such as those that cause the common cold, are less contagious in hot, humid climates.

However, according to the researchers, the idea that hot weather is enough to repel the virus is an illusion. In fact, some of the worst outbreaks in developing countries have exploded in areas such as the Brazilian Amazon, where the climate is tropical. “The most convincing hypothesis is that the summer climate contributes but is not sufficient to slow down the increase in cases or to cause a reduction”, explains Marc Lipsitch, director of the Center for communicable disease dynamics of Harvard University.

According to Dr. Raul Rabadan, a computational biologist at Columbia University, the virus that causes covid-19 appears to be so contagious as to mitigate any beneficial effect of heat and humidity. However, other aspects related to hot climates, such as the tendency to spend more time outdoors, could have positive effects. “Living indoors can encourage virus recirculation, increasing the chance of contracting the disease,” says Dr. Car.

According to a study conducted by some ecological model specialists of the University of Connecticut, ultraviolet rays from direct sunlight inhibit Sars-cov-2. This means that surfaces are more difficult to contaminate in sunny places. But the fact remains that transmission usually occurs through contact with an infected person, not with a surface.

Unlike Donald Trump, no scientist has ever argued that projecting light rays inside an infected person can be an effective cure. In addition, the tropical climate may have created a false sense of security in some people. “Here people said ‘there isn’t, we can’t take it’,” says Ecuadorian researcher Doménica Cevallos. “Some went out to sunbathe, convinced that this would protect them from infection.”

Timely and rigid blocking
Countries that promptly introduced isolation measures, such as Vietnam and Greece, have avoided an out-of-control contagion. This data demonstrates the effectiveness of social and physical distancing and quarantine in containing the virus.

In Africa, countries that have accumulated some experience with deadly diseases such as AIDS, drug-resistant tuberculosis and Ebola were better prepared and reacted promptly.

In countries such as Uganda and Sierra Leone, airport staff began to wear masks, track contacts and measure the temperature (a measure that has in the meantime proved less effective than expected) much earlier than the United States and European countries.

Senegal and Rwanda closed their borders and announced a curfew when there were still few cases of contagion. In both countries, the ministry of health promptly initiated the procedures for tracing contacts.

All of this happened in a region where funds, personnel and health care equipment depend on the generosity of foreign countries, many of which are currently focused on the health emergency within their borders, emphasizes African executive director Catherine Kyobutungi population and health research center.

“Governments wake up one day and understand that the burden of the whole country is now all on their shoulders, and therefore they have to do it alone,” explains Kyobutungi. “In the end they proved to be up to the situation. I have to admit that some of the responses have been exciting. ”

Sierra Leone has adapted the protocols for the detection of diseases developed during the 2014 ebola epidemic, which claimed the lives of nearly four thousand people. The government has set up emergency operations centers in each district and has hired 14,000 health workers, including 1,500 trained to track contacts, despite the fact that Sierra Leone has recorded just 155 cases.

However, it is still unclear who will pay the wages and equipment such as motorcycles and raincoats, essential during the rainy season that is just around the corner.

Uganda, another country affected by the ebola epidemic, promptly quarantined travelers from Dubai after confirming that the first case of infection had come from the emirate. The authorities tracked down 800 other travelers arriving from Dubai in the previous weeks. Health workers in the country are testing over a thousand truck drivers per day. However, most of the infected people come from Tanzania and Kenya, two countries that are not performing equally intense monitoring. This feeds the fear that the infection could spread across the country’s borders, far from solid.

According to the WHO, the isolation measures, with the ban imposed on religious and sporting events, are evidently effective. More than a month after the closure of national borders, schools and most commercial activities, countries such as Thailand and Jordan have experienced a collapse in new cases of contagion.

In the Middle East, the closure of mosques, temples and churches has been fairly timely and has probably helped stem the epidemic.

A notable exception is represented by Iran, which waited on March 18 before closing its most important places of worship, or a month after the confirmation of the first case in the sacred city of Qom. Since then, the epidemic has spread rapidly, killing thousands of people and spreading the virus across borders, through pilgrims returning home.

However effective blocking measures are, in countries where adequate social assistance is lacking and where most people depend on the informal economy, it will be difficult to maintain business closure and domestic isolation. When people are forced to choose between social distancing and the possibility of feeding their families, they usually don’t have many doubts.

Strangely, some countries where the authorities reacted late and in fits and starts seem to have been spared the virus. In a context marked by scarce measures of social distancing, Cambodia and Laos have been hit by short waves of contagion, but they have not recorded new cases for three weeks now.

Lebanon, from which many Muslim and Christian pilgrims leave for countries overwhelmed by the virus such as Iran and Italy, should present widespread contagion, but this is not the case. “We are not collecting the data we had expected,” says Dr. Roy Nasnas, a consultant specializing in infectious diseases at the Geitaoui University Hospital in Beirut. “We can’t explain it.”

The case
Most experts agree that there may not be a single reason why one country is hit hard while another is spared. The cause of the phenomenon is probably a combination of the factors discussed, together with one last element often cited by researchers: pure chance.

Countries with similar culture and climate can present radically different situations: it is sufficient for a single infected person to participate in a particularly crowded social event, triggering what researchers call a “super-diffusing” event.

This is exactly what happened when a passenger infected 634 people on board the Diamond Princess cruise ship, off the coast of Japan; or when an infected man attended a funeral in Albany, Georgia; or even when a 61-year-old woman entered a church in Daegu, South Korea, transmitting the virus to hundreds of people who in turn infected thousands of Koreans.

Since an infected person may not show symptoms for a week or even longer (not to mention asymptomatic), the virus spreads without anyone detecting it, exponentially and following an apparently random path. If on that Sunday in February the Daegu woman had stayed at home, it is possible that the numbers of the epidemic in South Korea would have halved today.

Yet some countries that were supposed to be swept away by the virus right now are not, and researchers can’t find a reason.

In mid-January, Thailand registered the first case of contagion outside China. It was a traveler from Wuhan, the city where the pandemic is thought to have originated. In those crucial weeks Thailand has continued to welcome visitors from China, but for some reason tourists have not triggered an exponential outbreak.

Some countries seem to have made every possible mistake, yet they have not been overwhelmed by the virus as would be expected. For many it remains a mystery.

“In Indonesia we have a health minister who is convinced that we can recover from covid-19 by praying, and we practically do not swab,” said Dr. Pandu Riono, infectious disease specialist at the University of Indonesia. “But we are fortunate to have many islands and this limits travel and perhaps even infections. Apart from islands, however, we are doing everything wrong. ”

(Translation by Andrea Sparacino)