Sometime in 1343, Kipchak khan Janibeg, chief of the Golden Horde, found himself in an unhappy situation in Crimea. The formidable general from China had laid siege to the port city of Caffa, from where he was forced to retreat leaving about 15,000 of his Mongol warriors dead.
In 1345, he returned, only to face a greater enemy - the plague. It had arrived in Crimea along the Silk Road, carried by rodents hidden in the grain bags of merchant caravans. The plague swiftly swept through the Mongol army, whose soldiers died in the agony of putrid fever.
Janibeg realised that there was a way to defeat the defiant Caffans after all. He strapped the corpses of dead soldiers on his catapults and flung them inside the city walls. Soon, plague raged through the city, which capitulated in a matter of months.
Those who fled Crimea took the Black Death, as the bubonic plague was called, with them to Europe, Asia Minor and beyond. It took around 200 million lives, nearly 60 percent of Europe’s population and about half of China’s population.
In short, epidemics travel.
Which is the reason why half the world is terrified of the invasion of 2019-nCoV as the coronavirus, which originated from China, has been christened. Infected travellers from China are being quarantined even as cases are mounting in the US, the UK, Asia, Europe, Australia and now India.
Last week, over 100 deaths were reported in the secretive Communist-controlled country; however, Neil Ferguson, a disease modeller at Imperial College, London, estimated that 4,000 patients had contracted the virus. Another model predicted that by February 4, the number of infected people in Wuhan will be greater than 250,000; or between 164,602 and 351,396.
What do we know of this new arrival? Almost nothing.
Is it curable? The only fix for now is just common cold medicine.
Like Janibeg did seven centuries ago, was it biowarfare gone awry? Reports speak of a secret Chinese facility near Wuhan experimenting with germ experiments.
Is climate change causing mutating viruses and unfamiliar pathogens to infect millions of people? Most certainly.
Can large migrations of displaced refugees fleeing warzones to live in refugee camps bring local strains which can interact with other viruses to form lethally morphed pathogens? Check.
Unlike existing deterrents against nuclear warfare, there are few safeguards against mutating viral epidemics, which were previously treatable. A bioweapon in the hands of a terrorist could be a greater nightmare than a dirty bomb. Security experts are concerned about terrorist capability to re-engineer contagious viruses and release them into public utility systems: researchers recently conducted ‘Exercise Mataika’, the simulation of a smallpox bio-terror attack in Fiji, and realised that it could not be diagnosed since the disease is no longer familiar to modern doctors.
FEAR MUTANT ATTACKS
Coronaviruses are not new medical actors. They were behind both the SARS epidemic of 2002-03, which infected 8,098 people across the world and caused 774 casualties and the MERS contagion in 2012, which infected 2,494 and killed 858 as of November 2019. The current Chinese virus’s R0, or basic reproduction number, is scariest part of the pandemic. R0 is the number health organisations such as WHO use to estimate the escalation of any new disease.
R0, pronounced R-nought, refers to the average number of people who will catch the virus from a single infected person, in a previously unaffected population. For example, if the R0 of a disease is 5, then five people will be infected by every single infected person. One data model predicts an R0 of 3.6-4.0 for CoV - which means that if 75 per cent of the patients are not treated and quarantined, the pandemic will continue to spread unabated. Compare this with the SARS estimate of 1.1- 4.2 to calculate the deadliness of the new coronavirus.
“Going by the statistics, it appears that the new coronavirus strain is more infectious but less severe in terms of mortality rate than the SARS. SARS and the novel coronavirus (2019-nCoV) show some common flu-like symptoms, but the former prevalently affected upper respiratory tract, while nCoV is affecting the lungs and causing breathing issues. However, the most important difference is in the incubation period - the time delay between exposure and the appearance of the first symptom - which ranges from one-14 days for nCoV, while it was two-seven days for SARS,” says Dr Vijay Dutta, Consultant, Internal Medicine for Respiratory Diseases, Indian Spinal Injuries Centre, New Delhi.
Since the virus was initially traced to a busy seafood market in Wuhan, an apocalypse theorist quoted Nostradamus quatrains as a prediction of the virus attack: “The great plague of the maritime city, Will not cease until there be avenged the death, Of the just blood, condemned for a price without crime, Of the great lady outraged by pretence.”
Nostradamus or not, the worrisome aspect of CoV is that it could just be a augury of a deadly contagion. WHO scientists had predicted an unknown and lethal new illness they titled Disease X with the power to create a potential global epidemic that could wipe out millions. Each year WHO draws up a list of such ominous diseases; this year it is Disease X accompanied by Ebola, SARS, and Zika. The doomsday scenario, which bio-scientists and researchers paint, is of a pathogen which has no known cause or treatment. Moreover, in the present scenario of antibiotic-resistant diseases and mutating viruses, WHO says that Disease X could be a mutation of a previously common sickness.
The Centers for Disease Control and Prevention (CDC) of the US estimates that at least 23,000 people die every year from germs which have developed resistance to antibiotics. Antimicrobial resistance, associated with inappropriate prescribing and antibiotic overuse, is a serious threat to global public health, according to WHO. According to CDC data, around 23,000 people die every year after developing resistance to antibiotics. Apart from the human cost, the adverse economic impact on epidemic-affected nations could be crippling.
A UN report predicted in 2017 that Zika outbreaks would cost Latin America and the Caribbean up to $18 billion. It required $5 billion in emergency funds to control the Ebola epidemic in West Africa in 2014. Ebola, SARS, CoV and their siblings could be the beginning of the greatest challenge science is likely to face.
A report prepared by a panel, which included former WHO director-general Gro Harlem Brundtland and the Red Cross among others, surmised that the swift penetration of a viral respiratory disease in the world population could kill up to 80 million people and wipe out 5 percent of the world’s economy. Such an epidemic could cause India to lose Rs 3.8 lakh crore or roughly twice the national agriculture budget in 2019-20.
VIRUSES SEEK WARMTH
Climate change campaigners like Greta Thunberg have attracted major attention - both positive and negative - as global warming brings dangerous ecological change. The earth’s surface is heating up. Glaciers and polar ice caps are melting or retreating. Sea waters are becoming acidic. Sea and river levels are rising. Weather patterns are changing, causing powerful changes in animal and bird migrations and earth fertility. All these phenomena encourage epidemics both new and renewed. Scientists studying Siberian polar cap conditions discovered the DNA of a 30,000-year old “giant” virus frozen in the permafrost. French research scientist Chantal Abergel, who studies polar conditions, has warned that ocean sediments and permafrost are “very good preservers of microbes and viruses because they are cold, anoxic and in the dark”.
With glaciers disappearing rapidly, who knows how many other giant viruses lie locked in ancient sleep to be awakened by the man-made thaw? Genetic evidence of the Spanish influenza outbreak in 1918, which killed 50 million people worldwide, and the smallpox virus considered extinct, have been found in graves in Alaska and Siberia. Should a virus like those emerge today, it could travel around the globe in less than 36 hours - the time it takes for a person to travel around the world in an airplane.
Warming temperatures have caused the rising graph in disease vectors such as mosquitoes and ticks which carry agents of Zika, yellow fever, and dengue in places which were previously inhospitable to them. Research by Stanford biologist Erin Mordecai and her colleagues found that warmer temperatures increase the transmission of vector-borne diseases only up to an optimum temperature. For the Anopheles mosquito, which dispenses malaria, the most conducive temperature is 25 degrees Celsius. Zika’s is 29 degrees Celsius.
Natural disasters such as floods and drought caused by rising temperatures and sea levels lead to epidemics like cholera. In the aftermath of the Kerala floods in September 2018, there was an outbreak of leptospirosis or rat fever across the state. Unusually heavy rains could produce a friendly environment for Ebola-carrying bats to flourish. With climate change causing drought and altered agricultural environments, African villagers are consuming bushmeat, such as bats suspected to be a CoV host. Almost 50 per cent of Ebola outbreaks have been directly linked to bushmeat consumption, according to Earth Institute, Columbia University. Rodent populations tend to multiply when drought forces predatory birds and animals to migrate in search of food, resulting in hantavirus pandemics.
Medical scientists are concerned about shifting weather patterns in warm and rain-fed areas leading to the intermingling of different viruses inside mosquitoes to give birth to a hitherto unknown and untreatable pathogen, says Jonathan Day, PhD, professor of medical entomology at the University of Florida. He has predicted that once a weather phenomenon occurs to change the natural habitat of a mosquito, it would inevitably find new hosts to feed on, which could be carrying viruses themselves.
PATHOGENS HAVE GOOD HOSTS
As the world population of around 7.3 billion is expected to bloat to around 10 billion by 2050, according to UN estimates, the pressure on finding new places to live and more foodstuffs to consume will only increase. This will result in more urbanisation, migration and the conversion of pristine habitats to agricultural land: all causes for viral outbreaks. Forests get chopped down and large predators are either killed or migrate, thus vacating their turf to small animals like mice, rats and creatures that host killer pathogens. More international travel and interaction could also spread the viruses and face masks are of little help since they don’t cover the mouth and nose completely. The Asian longhorn tick, which carries and transmits a deadly virus, was discovered in New Jersey.
Between 2004 and 2016, nine new mosquito- and tick-borne germs were discovered or introduced into the US. CDC has included outbreaks of Zika, West Nile, Lyme, and chikungunya among a growing list of diseases caused by mosquitoes, ticks and fleas. The WHO has tracked 1,483 epidemics between 2011 and 2018 in 172 countries, including SARS, Ebola, Zika and the Nipah virus, detecting and mapping man-made and previously unknown viruses in the past half century. Animals and birds cause 60 percent of diseases today. Migrating birds are known to be the age-old carriers of influenza viruses in humans.
To combat viral Armageddon, where and what are the means? Victor Dzau, president of the National Academy of Medicine, who is part of an internationally reputed group of 15 public health experts who prepared a new, independent report for WHO’s Global Preparedness Monitoring Board, has cautioned that the world is unprepared for a viral pandemic of global proportions.
He warned that bird flu and swine flu can morph into unique murderous viruses. Contagions are a national security threat and only action from the top can anticipate, prevent and contain the next epidemic. The report said that pandemic preparedness must be an integral part of national security strategy. It stressed the need for more government spending on simulation exercises, vaccine research, and rapid communication systems. Simple solutions do exist today: basic quarantine and sanitation can stop the viruses from spreading. But given man’s propensity to treat Nature as his slave while exploiting and treating its resources with greed and contempt, it will come as no surprise when she fights back. The nightmare is just beginning.
THE WORLD’S DEADLIEST PANDEMICS
Some of the most brutal killers in human history
HIV/AIDS (2005-2012)
Death toll: 36 mn
First discovered in Congo in 1976, HIV/AIDS has killed more than 36 million people since 1981. Currently, between 31 and 35 million people are living with HIV, of which a vast majority live in Sub-Saharan Africa, where 5 per cent of the population—roughly 21 million—are infected. Of late, awareness and new treatments have made HIV manageable.
Flu (1968)
Death toll: 1 mn
The category 2 Flu pandemic, also referred to as “the Hong Kong Flu”, was caused by the H3N2 strain of the Influenza A virus, a genetic offshoot of the H2N2 subtype. The first case was reported on July 13, 1968, in Hong Kong and in just 17 days, outbreaks of the virus were reported in Singapore and Vietnam. Within three months, it spread to the Philippines, India, Australia, Europe, and the US.
Asian Flu (1956-1958)
Death toll: 2 mn
The outbreak of Influenza A of the H2N2 subtype originated in China in 1956 and lasted till 1958. In these two years, the flu travelled from the Chinese province of Guizhou to Singapore, Hong Kong, and the US.
Flu (1918)
Death toll: 20-50 mn
Between 1918 and 1920, a deadly influenza tore across the globe. Of the 500 million people infected, up to 25 million deaths were reported in the first 25 weeks alone. The pandemic struck down healthy young adults, while leaving children and those with weaker immune systems still alive.
Sixth Cholera Pandemic (1910-1911)
Death toll: 800,000+
Like its five previous incarnations, the Sixth Cholera Pandemic originated in India, before spreading to the Middle East, North Africa, Eastern Europe and Russia. The pandemic was also the source of the last American outbreak of cholera (1910–1911). American health authorities quickly isolated the infected, and only 11 deaths occurred in the US.
Flu (1889-1890)
Death toll: 1 mn
Originally called the “Asiatic Flu” or “Russian Flu”, this strain was thought to be an outbreak of the Influenza A virus subtype H2N2, though recent discoveries have instead found the cause to be the Influenza A virus subtype H3N8. The first cases were observed in May 1889 in three separate and distant locations, Bukhara in Central Asia (Turkestan), Athabasca in northwestern Canada, and Greenland. It was the first true epidemic in the era of bacteriology and much was learned from it.
Third Cholera
Pandemic (1852–1860)
Death toll: 1 mn
Considered the most deadly of the seven cholera pandemics, the third major outbreak of cholera in the 19th century lasted from 1852 to 1860. It spread from India’s Ganges River Delta before tearing through Asia, Europe, North America and Africa and ending the lives of over a million people.
The Black Death (1346-1353)
Death toll: 75-200 mn
An outbreak of the bubonic plague ravaged Europe, Africa, and Asia. Said to have originated in Asia, the plague most likely jumped continents via the fleas living on the rats that lived aboard merchant ships.
Plague of Justinian (541-542)
Death toll: 25 mn
It affected the Byzantine Empire and Mediterranean port cities, in its year-long reign of terror, wiping out perhaps half the population of Europe. Regarded as the first recorded incident of the bubonic plague, the Plague of Justinian left its mark on the world, killing up to a quarter of the population of the Eastern Mediterranean and devastating the city of Constantinople.
Source: MPHOnline.org
Viruses Explained
Viruses are simply packets of nucleic acid, either DNA or RNA, surrounded by a protein shell and sometimes fatty materials called lipids. They are tiny, ranging in size from about 20 to 400 nanometres in diameter. Billions can fit on the head of a pin. Some are rod shaped; others are round and 20 sided; and yet others have fanciful forms, with multisided “heads” and cylindrical “tails”.
Outside a living cell, a virus is a dormant particle, lacking the raw materials for reproduction. Only when it enters a host cell does it go into action, hijacking the cell’s metabolic machinery to produce copies of itself that may burst out of infected cells or simply bud off a cell membrane. For example, if you get the flu, your body will be riddled with some hundred trillion viruses in just a few days—more than 10,000 times the number of people on Earth.
Viruses cause a number of diseases in eukaryotes. In humans, smallpox, the common cold, chickenpox, influenza, shingles, herpes, polio, rabies, Ebola, hanta fever, and AIDS are examples of viral diseases.
Even some types of cancer—though definitely not all—have been linked to viruses.
Transmission
Viruses spread from person to person mainly in droplets that fly out when you cough or sneeze. These tiny drops from a sick person move through the air and land on the mouths or noses of others nearby.
Germs are also passed along when you touch mucus droplets from someone else on a surface like a desk and then touch your own eyes, mouth, or nose before you get a chance to wash your hands. Viruses like the flu can live 24 hours or longer on plastic and metal surfaces like cafeteria tables, doorknobs, and cups.
New Pathogens
In November 2019, the findings of a team from Karl Landsteiner University of Health Sciences under the lead of University of Veterinary Medicine Vienna identified a total of 43 bacteriophages in samples of human bodily fluids, particularly in blood samples. The discovery of such phages in the human body is especially significant because they can pass antibiotic resistance genes on to bacteria.
The fact that viruses like the deadly Ebola and Marburg viruses, as well as the distantly related viruses that cause measles and rabies, are only found in a limited number of species suggests that those viruses are relatively new—after all, those organisms came along somewhat recently in evolutionary time. Many of these "new" viruses likely originated in insects many million years ago and at some point in evolution developed the ability to infect other species—probably as insects interacted with or fed from them.
Sources: National Center for Biotechnology Information, US National Library of Medicine; webmd.com; University of California Berkeley; Scientific American