Virus pandemic history

Novel technologies for rapid diagnostic testing, contact tracing, drug repurposing, biomarkers of disease severity as well as new platforms for the development and production of vaccines are needed for an effective response in case of pandemics. The shift from hunter-gatherers to agrarian societies has favored the spread of infectious diseases in the human population Dobson and Carper, Expanded trades between communities have increased interactions between humans and animals and facilitated the transmission of zoonotic pathogens.

Thereafter, expanded cities, extended trade territories, increased travels as well as effects on ecosystems due to increased human population raised the emergence and spread of infectious diseases leading to higher risks for outbreaks, epidemics and even pandemics Lindahl and Grace, The terms endemic, outbreak, epidemic and pandemic relate to the occurrence of a health condition compared to its predicted rate as well as to its spread in geographic areas Grennan, An endemic condition occurs at a predictable rate among a population.

An outbreak corresponds to an unpredicted increase in the number of people presenting a health condition or in the occurrence of cases in a new area. An epidemic is an outbreak that spreads to larger geographic areas. A pandemic is an epidemic that spreads globally. An emerging infection newly appears in a population or is spread in a new geographic area Morens et al. The zoonotic transmission of pathogens from animals to humans is a pivotal mechanism by which emerging infections have afflicted humans throughout history Wolfe et al.

The probability of cross-species transmission of pathogens was dramatically enhanced with increased interactions with animals through hunting, animal farming, trade of animal-based foods, wet markets or exotic pet trade Bengis et al. The process of cross-species transmission of pathogens involves 5 different stages Wolfe et al. The animal species that harbor the pathogen, the nature of human interaction with that animal and the frequency of these interactions likely modulate the risk of zoonotic transmission.

Furthermore, land use and climate changes are suggested to play important roles in the transmission of pathogens from wildlife to humans El-Sayed and Kamel, ; White and Razgour, There is thus a need to implement surveillance programs to rapidly detect the emergence of pathogens with a potential for zoonotic transmission at the animal-human interface.

Climate changes also influence the transmission of pathogens e. The emergence of vector-borne pathogens in non-endemic regions often results in explosive epidemics. Land use due to increasing human population also affects the distribution of disease-carrying vectors Kilpatrick and Randolph, Control of vector-borne zoonotic pathogens usually requires vector control to reverse the drivers of transmission.

Furthermore, the spread of several infectious diseases e. These diseases show a wider spread as a result of the acquisition of drug resistance, tolerance of mosquito vector to insecticides, poor sanitation, land use and climate changes as well as increased in human mobility and travels Cutler et al.

Furthermore, outbreaks of cholera in regions where natural disasters occurred such as earthquakes and floods were also reported. Surveillance programs should be also implemented to control the spread of these pathogens from endemic to non-endemic regions.

Finally, infectious agents e. These weapons are based on natural microorganisms or microorganisms that are engineered to be more virulent, highly transmissible or resistant to therapy Narayanan et al. The release of these biological weapons is intended to induce diseases in humans or even death.

Therefore, governments should establish biowarfare, bioterrorism and biocrime preparedness plans to protect the population. In this paper, we review major pandemics that have afflicted humankind throughout history such as plague, cholera, influenza and coronavirus diseases, the way they were controlled in the past and how these diseases are managed today.

Infectious diseases still represent threats for human health as pathogens can spread rapidly through global trade and travels. Global surveillance programs are thus needed to detect and identify pathogens spillover from animals to humans as well as to control water-borne pathogens and vector-borne diseases. Furthermore, effective non-pharmaceutical and pharmaceutical measures for the prevention and control of these infections are required to limit their dissemination in the human population.

Plague is caused by the flea-borne bacteria Yersinia pestis that is responsible of at least three human plague pandemics, the plague of Justinian, the Black Death and the third plague Table 1 Zietz and Dunkelberg, Fleas acquire the bacteria by sucking blood from an infected rodent. Bacteria quickly multiply and block the alimentary canal in the gut of the fleas Bacot and Martin, The fleas transmit the bacteria to new rodent hosts by regurgitating the clotted blood.

Plague manifests in three forms, i. The bubonic form is the most common and results from the bite of an infected flea. Clinical manifestations include flu-like symptoms such as fever, chills, headache, body pains, weakness, vomiting and nausea followed by painful swollen lymph nodes.

The mortality rate is higher in patients with septicemic plague than in those with the bubonic form. Pneumonic plague occurs when the bacteria infects the lungs, either primarily by infectious respiratory droplets or secondarily as a complication of bubonic plague.

This form is characterized by a fulminating onset and is rapidly fatal when left untreated. Between and , the plague killed an estimated million people in the Roman Empire and especially in its capital, Constantinople. The highly developed structure of the Roman Empire facilitated the spread of the Justinian plague along its trade and military routes.

The high mortality caused by the disease might have contributed to the weakening and eventually to the decline of the Byzantine Empire. After this initial pandemic, intermittent plague outbreaks occurred every 8 to 12 years for two centuries and then disappeared for unknown reasons. The identification of the causative pathogen involved in the death of victims of past pandemics usually relies on ancient DNA techniques aimed to directly extract DNA from skeletal remains.

A great advance in paleomicrobiology techniques was the isolation of microbial DNA in dental pulp specimens Drancourt et al. Indeed, bacteria are trapped in the dental pulp early in the course of a bacteremia and can be isolated from preserved teeth of victims.

Therefore, analysis of the dental pulp is more efficient than bones to accurately identify microbial DNA from rapidly fatal infections that occurred in the past. Corpses of victims of the Justinian plague could be recovered in burial sites. Ancient DNA techniques from dental pulp samples identified Y.

The second plague pandemic, the Black Death, originated in East Asia and swept across Central Asia into Europe through the land and sea trade routes of the medieval Silk Road Zietz and Dunkelberg, The second plague pandemic lasted in Europe until the early of the 19th century and killed million people. The lineages of Y. It is suggested that the bacteria may have persisted in rodent reservoirs in Europe and periodically re-emerged in the human population Seifert et al.

Another hypothesis could be that climate-driven outbreaks of Y. The bacteria suddenly disappeared from Europe and this could be possibly related to the extinction of local rodent reservoirs Spyrou et al. At that time, there was no effective treatment against plague. Initial institutional responses to disease control began during the Black Death Tognotti, A sanitary cordon was imposed by armed guards along transit routes and at access points to cities. A separation between healthy and infected persons was accomplished in camps and then in permanent plague hospitals called lazarettos.

Port cities were closed to ships arriving from plague-infected areas. Ships with suspicion of plague were put in quarantine, passengers and crew were isolated in lazarettos and vessels were thoroughly fumigated and retained for 40 days. The Black Death decimated Medieval Europe and had major impacts on its socio-economic development, culture, art, religion and politics Bramanti et al. Based on genomic analysis of ancient and recent genomes, it was suggested that a wave of plague may have traveled from Europe to Asia after the Black Death, eventually setting in China and giving rise to the third plague pandemic Spyrou et al.

The latter plague pandemic originated in the middle of the 19th century in the Yunnan region China , reached Canton and spread to Hong Kong Zietz and Dunkelberg, In , Alexandre Yersin discovered the bacteria, Y.

The pandemic then reached Japan, Singapore, Taiwan and India via ships. Over the following years, plague became endemic in many countries around the world Stenseth et al.

Between and , the number of plague cases was estimated at 3, with fatalities worldwide, most of them occurring in Democratic Republic of the Congo, Madagascar and Peru Glatter and Finkelman, The basic reproduction number R o was estimated at 1. The case fatality rate was as high as 8. Plague is seasonal in most endemic countries with a well-defined geographic distribution which corresponds to those of the vectors and rodent reservoirs Prentice and Rahalison, Nowadays, plague should be considered as a neglected human threat due to its rapid spread, its high fatality rate without early treatment and its capacity to disrupt social and healthcare systems Valles et al.

The genetic plasticity of Y. Surveillance and control programs of fleas and animals involved in the life cycle of Y. Individuals should protect themselves against flea bites in regions where plague is present. It is also recommended to avoid contact with infected body fluids and tissues as well as animal carcasses. Public health interventions that can be put in place to prevent or limit plague outbreaks include the killing of fleas with insecticides and, if required, the control of infected rodents; the early isolation of patients, the rapid diagnostic and treatment of infected individuals with antibiotics; the detection and isolation of contacts and the administration of chemoprophylaxis to exposed individuals Prentice and Rahalison, Standard treatments against plague include streptomycin and doxycycline.

Alternative drugs consist of gentamicin and fluoroquinolones Butler, ; Yang, The WHO does not recommend vaccination except for health care workers and laboratory personnel who are highly exposed to the pathogen. Fifty years ago, a plague vaccine based on whole Y. This vaccine was effective against bubonic plague but not against the pneumonic form of the disease.

Furthermore, this vaccine was associated with a high reactogenicity. As highlighted in the Madagascar outbreak, Y. Furthermore, Y. Therefore, the development of a plague vaccine against the most deadly form of the disease is needed. Cholera is an acute often fatal disease of the gastrointestinal tract caused by Vibrio cholerae Faruque et al.

The bacteria colonizes the small intestine and produces the cholera toxin which is responsible for a rapid and massive loss of body fluids leading to dehydration, hypovolemic shock and death.

Humans are infected through contaminated water used for drinking or preparing foods. The infection is often mild or asymptomatic and bacteria are eliminated with feces in 1 or 2 weeks. Cholera was endemic in Asia until , when a first pandemic spread from India to several other regions of the world Table 1 Faruque et al.

This pandemic emerged during a period of increasing globalization resulting from technological progress in transportation. Indeed, the advent of steamships and railways allowed a dramatic decrease in travel time and a rise in trade. At that time, health prevention strategies were essentially the same than those implemented during the Black Death Tognotti, Infected persons were isolated in lazarettos.

Port entry was forbidden for ships arriving from regions where cholera was present. Travelers who had contacts with infected persons or who came from a place where cholera was circulating were quarantined. Thereafter, five additional major pandemics of cholera that originated from India and spread to other continents occurred during the 19th and 20th centuries Table 1 Faruque et al.

The second and sixth pandemics, and presumably the other ones, were caused by the O1 classical biotype of V. The second pandemic of cholera reached the British islands. During the cholera outbreak in Soho London , in , the physician John Snow used for the first time epidemiological methods to trace the source of the outbreak. He described the time course of the outbreak and its geographical spread in the city. He identified the public pumps used for water supply in these areas and understood that water was the source of the contamination.

He then proposed effective measures to prevent the transmission through the removal of pump handle in the city areas where the outbreak occurred Smith, The bacillus of cholera was isolated during the fifth pandemic that extensively affected South America by Robert Koch who also understood the importance of clean water in preventing its transmission.

The toxin responsible for the disease was only discovered in De, The seventh cholera pandemic is the most extensive in terms of geographic spread and duration Mutreja et al. It began in Indonesia in and became endemic in many regions of the world. Cholera epidemics usually ended because of a lack of favorable environmental conditions for the survival of vibrios.

The seventh cholera pandemic was caused by El Tor biotype strain of V. In late , the O serogroup caused a large cholera outbreak in Bangladesh and neighboring countries and raised the fear of a 8th cholera pandemic Albert et al. Cholera cannot be eradicated as it is a natural inhabitant of aquatic ecosystems. However, it is estimated that the global burden of cholera is higher due to underreporting.

Between and , the number of cases was shown to range between 1. Environmental and climate changes may increase the geographical distribution of cholera Chowdhury et al. The persistence of cholera is related to poor living conditions including shortage of safe drinking water, insufficient sanitation, crowded housing and the lack of efficient sewage systems. Re-emergence of the disease can also occur following natural disasters such as earthquakes that disrupt access to safe water supply.

Cholera outbreaks could be predicted based on real-time monitoring of oceanic regions, climate fluctuations and epidemiological surveillance program Chowdhury et al. The disease could be prevented by implementation of public health measures to ensure adequate sanitation and safe water supply Somboonwit et al. The access to safe drinking water and sanitation are among the primary priorities of the Millenium Development Goals and the sustainable Development Goals Igere and Ekundayo, These vaccines should be used in areas with endemic cholera, cholera outbreaks and humanitarian crisis with high-risk of cholera in combination with other cholera prevention and control measures World Health Organization [WHO], Cholera is first identified based on clinical symptoms of severe acute watery diarrhea.

The disease is then confirmed by the detection of V. The majority of infected individuals can be treated by the administration of prompt oral rehydration solution.

Severely dehydrated patients who are at risk of shock require rapid administration of intravenous fluids as well as antibiotics.

First-line drug consists of doxycycline whereas alternative treatments include tetracycline, ciprofloxacin and azithromycin Hsueh and Waters, Influenza viruses belong to the Orthomyxoviridae family.

Influenza viruses are enveloped, negative-sense, single-stranded RNA viruses Wright and Webster, Their genome consists of 7 or 8 RNA segments encoding at least 10 structural and non-structural proteins. Structural proteins include a hemagglutinin HA , a neuraminidase NA , two matrix proteins and a nucleoprotein. Influenza viruses can be distinguished in types A, B, C, and D. Influenza A and B are responsible for outbreaks in tropical regions and seasonal epidemics in temperate regions whereas influenza A viruses are the only ones with a pandemic potential Lofgren et al.

There is still no cure for AIDS. Although the development of antiretroviral drugs starting in the mids turned it into a manageable chronic condition for many patients, particularly in wealthier countries, AIDS still killed nearly , people in The third plague pandemic emerged in China in and later spread to India and Hong Kong. It was mainly spread by fleas, at least at first.

The disease which once killed millions and threatened the survival of nations is now easily treatable with antibiotics. In , a mysterious disease called cocoliztli first surfaced among Indigenous people in Mexico. A similar epidemic struck Mexico in , but no S. The Antonine Plague was a smallpox epidemic which swept through much of the Roman Empire around CE, killing as much as 10 per cent of the population.

It decimated the aristocracy to such a degree that town councils struggled to meet [and] abandoned farms and depopulated towns dotted the countryside from Egypt to Germany. The Spanish flu and bullets were not the only potentially lethal threats faced by soldiers in the First World War.

Centers for Disease Control, typhus is considered a rare disease today , although the lice which cause it still thrive in areas where people are unable to wash regularly. On Dec. On Jan. The World Health Organization estimates that as many as 1. As of this writing, the World Health Organization has reported 2 million deaths worldwide from coronavirus, over , in the United States alone. The development of multiple vaccines has raised hope that the pandemic may be under control in some countries by later this year, but the way we travel, work and socialize may never be the same.

Within a few months, it had spread to much of the world, following major roads, rivers and railway lines. It is often considered the first modern pandemic —the first one in the era of rail and steamship travel. The pandemic had largely burned out in the U. The flu pandemic was caused by a highly contagious flu strain that emerged in Hong Kong in summer , according to Encyclopedia Britannica.

Soldiers returning from Vietnam spread the disease to the United States. Smallpox first emerged in Japan in CE; that epidemic is thought to have killed as much as one-third of the population of the country. Like the smallpox epidemic that would hit Central America centuries later, this was a virgin-soil epidemic, ravaging a population which had no previous exposure to it. Over , deaths worldwide. Cholera is transmitted by fecal-oral transmission, usually as a result of poor sanitation.

Probably Ganges Delta, India. Over 1,, deaths worldwide. Around , deaths worldwide. Reported deaths include: Europe: , The Americas: 50, Germany, Hamburg: 8, Russia: , Spain: , Japan: 90, Persia: 60, Egypt: 58, May Bukhara, Athabasca and Greenland.

Nov Saint Petersburg. By May most of the Southern hemisphere. Asiatic flu was spread from person to person through droplet infection coughing, sneezing. Originally thought to be H2N2. Reported deaths include: India: , Russia: , Philippines: , This was arguably the worst of the cholera pandemics in history.

Spanish flu was transmitted from person to person through droplet infection coughing, sneezing. It was first reported in Spain, which is how it got the name Spanish flu, one of the worst pandemics in modern history.

Asian flu was spread from person to person through droplet infection cough, sneeze. A mutation in wild ducks combined with a pre-existing human strain.

The elderly were particularly vulnerable. Tens of thousands. Reported deaths include: Peru: 10, Zimbabwe: 4, Haiti: 6, By , cholera cases had been reported worldwide. Spread within 2 weeks to Vietnam and Singapore. Dec rest of USA. Before the world completely rid itself of this horrendous disease, it swept through continents killing three out of ten victims. Those who survived were left with deep scars which were even found in year-old mummies , showing that it ravaged ancient civilizations for thousands of years.

But it was in during the Franco-Prussian war that smallpox spread throughout the world. From Europe , it reached Asia through America causing , deaths worldwide. The first of seven cholera pandemics emerged in India in According to the World Health Organization cholera is an acute diarrheal infection caused by the ingestion of food or water contaminated with the bacterium Vibrio cholerae.

Three years after it spread throughout India it reached different countries in Asia. In it was brought by British troops traveling from India even to countries outside Asia. Called the first-ever modern flu pandemic , the Russian flu which started in St. Petersburg, spread through Europe infecting even prominent world leaders.