An influenza pandemic happens when an influenza virus manages to spread on a large geographical surface, infecting a large number of people. While there are several seasonal epidemics every year and they come on a pretty regular basis, the influenza pandemic is irregular. The most recent and serious pandemic took place close to 100 years ago, back in 1918, and it was responsible for the death of 50 million people. Historical documents prove that in the last three centuries there have been three large pandemics, which took place at every 100 years. In 2009 the world has faced the most recent pandemic.
A pandemic happens when a new strain of influenza virus, coming from another species, is transmitted to men and women. Specialists say that viruses coming from pigs, chickens or ducks are easily transmitted to human beings. When such a new strain becomes powerful and is transmitted to people, the humans have no immunity, and this is the explanation why the virus starts spreading so quickly.
The influenza virus travels around the globe due to birds’ migration. Birds get infected and transport the virus in the geographical areas where they migrate. Another means of transportation is represented by the commercial ships that carry bird products and even by people traveling from one place to another.
Pandemic influenzas have been better understood once The World Health Organization has classified them depending on the process in which the virus travels from the first few infected bodies to the human beings. First there is an infected animal; afterwards, the virus infects humans, and then it rapidly infects numerous people, traveling from person to person. The pandemic flu is recognized officially once the virus has reached several geographical areas in the world.
The common influenza may be recognized due to having fever, a sore throat, headache, muscle pain, coughing, general weakness and fatigue. It can get worse when the lungs are affected, and the sick person begins to suffer from pneumonia, which can actually cause death in older or in very young people. These symptoms may sometimes cause confusion, as pneumonia can be considered to be a simple cold.
The influenza virus is transmitted by means of coughing or sneezing. Aerosols are produced as a result, and they contain the virus, which can thus travel from one body to another. Saliva, nasal secretions or blood may transmit the virus. This means that a person may get infected when breathing the infected air, touching the infected secretions and then touching the eyes or nose of an infected person.
The virus can survive for indefinite periods of time at low temperatures, and about one week in the human body. The good news is that detergent, soap and disinfectants can help us avoid getting infected with these viruses.
Between 1900 and 1999 tens of millions of persons died due to influenza, during the three pandemics that took place in this interval. And each one of the pandemics was caused by the appearance of a new strain of the virus, which has been rapidly transmitted from person to person.
Every day specialists all over the world work to create better vaccines, one of the few weapons people have against influenza.
Some of the pandemics are minor, affecting only a certain segment of the population on the globe, while others are major, killing millions of people. In 1918 tens of millions died, and other several hundreds of millions were sick during the pandemic influenza. The crisis was so powerful that there were not enough doctors, nurses, hospital beds and medication. The peoples’ dead bodies were even left unburied, as there were not enough healthy people to take care if this matter.
The pandemics come in the so called “waves”, which in the end increase the number of people that die because of the disease.
During the Spanish flu pandemic about 50 million people died. The virus was a new, very strong one and was extremely easily transmitted. Some statistics even mention close to 100 million people dying back then. That pandemic is still considered to be the greatest medical holocaust in history of mankind, killing as many people as the Black Death.
The symptoms of the Spanish flu were so unusual that many people were wrongly diagnosed with cholera instead of influenza. Bleeding was a very common symptom and sick people suffered from nose, stomach and intestine hemorrhage. Still, the majority of deaths were caused by a secondary infection like pneumonia, for example.
This pandemic reached even the Arctic area and the distant islands in the Pacific Islands. Young adults were the most affected, and this was also unusual compared to other situations when young and old people were killed by the disease.
In cases when influenza is manifested only to animals and there are rare situations when the virus is transmitted to people, the risk of a pandemic is low. To prevent the spread of the virus, many countries invest in vaccines and teach the population to get vaccinated. In all major chicken farms, the workers are mandatory vaccinated against common flu and travel is sometimes restricted in the areas were people suffer already from influenza.
When workers are vaccinated, the risk of combining the chicken flu virus with human viruses is low, decreasing the risk of forming a new, powerful, unknown strain of virus. Another important aspect is the effort of limiting the contact between farm birds and the wild birds that can infect them with viruses, which can then be transmitted to humans.
Farming has evolved a lot during the last decades, and efforts are made to teach people how to grow chickens and other birds in a much more hygienic way, in special areas that are properly separated from the places where people themselves live. A lot of money is also invested in creating better vaccines for the vet use, so the animals and birds are kept healthier and stronger.
When a pandemic strikes, in the very first weeks, there will not be an efficient and available vaccine. Specialists need time to develop new vaccine formulas. This explains why powerful, efficient vaccines are launched on the market five or six months after the first few cases were registered.
In the world there are only 19 countries that can produce such vaccines, and medical authorities have declared that in the best conditions, about 750 million vaccines could be produced per year. It is well known that a person should have two doses in order to be immune competent.
Since 2009 the production of vaccines was focused on the H1N1 virus. The vaccines that have been already made in Canada and the U.S.A. are available not only for their citizens, but also for other countries that want to buy them.
There are also two types of drugs that can be used when it comes to influenza. Many countries in the world are trying to make stock piles of these drugs, in order to be prepared for the worst case scenario when the pandemic would strike once again.
Limiting travel, teaching people to regularly wash their hands and cover the face while sneezing are simple, and yet effective methods of limiting the spread of a virus. There have been made masks to protect people in the affected areas, but just the masks alone cannot provide total protection.
The Influenza Risk Assessment Tool was created to measure the potential pandemic risk posed by influenza. Among the criteria that are used, there are the properties of the virus (the genomic variation, receptor binding, transmission in lab animals, antiviral treatment susceptibility) and the attributes of the population (immunity, disease severity and pathogenesis, antigenic relationship to vaccine candidates).
The Ecology and Epidemiology include global distribution, infection in animal species, human infections. All these aspects, if well measured and approximated, help specialists understand better the situation that they are confronted with.