[Orginal article posted at http://www.healthtrainingguide.com/the-history-and-future-of-pandemics/. I appreciate author Jennifer Bell contacting me and suggesting that MSO readers may find the information useful. I agree. - Rourke]
The Danger of Pandemics
Without a doubt, a pandemic is a serious – and usually deadly – disease outbreak at a global level. In fact, the Center for Disease Control (CDC) states that “another influenza pandemic is highly likely, if not inevitable”. The word pandemic, itself, comes from the Latin word Pan which means across or all, and the Greek word Demos which refers to a population or people. Thus, pandemic refers to a disease that spreads across to many people in a region, continent or even the world.
A pandemic usually goes through a number of different phases. However, the time span for these different phases can vary from months to years. The World Health Organization (or WHO) keeps a careful record of viruses and their various phases – and the WHO pandemic stages include:
Phase 1: The virus is only circulating in animals, and no humans have yet been infected.
Phase 2: In this stage, the animal virus has infected a human; at this time, there is a basic pandemic level threat since the virus has mutated and become active in humans.
Phase 3: In a single community, small groups of humans become infected with this virus. While the disease may be an epidemic in this single community, the illness has not yet evolved into a pandemic. However, if others from outside this community contact the infected individuals, there is definite possibility that the virus can spread.
Phase 4: As both animal-to-human transmission and human-to-human virus transmission increases, more illness outbreaks occur in many different communities. At this juncture, a pandemic may be more likely to occur.
Phase 5: At this point, most countries are not directly affected by a pandemic; however, a pandemic is considered to be imminent. More specifically, human-to-human virus transmission is occurring in at least two countries in one World Health Organization region. This phase is the signal that governments and health officials must be ready to implement their pandemic mitigation plans.
Phase 6: At this time, the disease is widespread and an international pandemic is in progress. Further, both health experts and governments are working hard to end the spread of the illness through preventative and related methods.
Post-pandemic stage: During this time, the spread of illness will decrease. In addition, an effort is made to help prevent a second pandemic wave.
Plagues and Pandemics Throughout History
Also known as: ‘The black death’
When: 14th to 17th century
Deaths: Approximately 25 million people
Symptoms of the illness: Can include chills, general malaise, headache, diarrhea, vomiting, respiratory distress, and swollen lymph glands. Other symptoms included labored breathing, blood in vomit, red/black skin spotting, and pain caused by decaying skin.
How the illness spread: Caused by the bacteria Yersinia pesti, the disease is spread through infected lice, rodents, and fleas. A pneumonic plague or plague lung infection can also be spread from person-to-person.
Effects: While the disease originated in Asia, reports state that approximately fifty percent of Europe’s population was affected by the illness. Today, there are approximately 1000 to 3000 cases of bubonic plague reported on an annual basis; however, if caught within the first twenty-four hours, antibiotics can effectively treat the illness.
Russian Flu Pandemic
Deaths: About 1 million
Symptoms of the illness: Flu symptoms include fever, typical flu symptoms, and pneumonia
How the illness spread: While the ‘Russian flu’ may have originated in China, this flu spread through Europe and also infiltrated North America, Latin America and Japan.
Effects: The pandemic appeared in the United States just four months after the first cases were discovered.
The Spanish Flu Pandemic
Deaths: Over 20 million people
Symptoms of the illness: As infected individuals were hemorrhaging from the stomach, nose, intestine or ears, most of the initial flu cases were misdiagnosed as typhoid, cholera, or dengue. That said, most people died due to the bacterial pneumonia caused by the flu.
How the illness spread: Researchers believe that this flu may have originated in Tibet and eventually transported to Europe via shipping or trade routes.
Effects: Researchers noted that this flu virus strain was particularly virulent with a 2.5% mortality rate whereas previous flu epidemics have a mortality rate of less than 0.1%. Moreover, India has an especially high mortality rate of around 50 deaths per 1000 infected people while about forty percent of the globe’s population contracted the virus, young adults between the ages of twenty-five and thirty suffered from the most deaths from this flu.
The Asian Flu Pandemic
Deaths: Approximately two million
Symptoms of the illness: Fever Prolonged fever, fatigue, and aches.
How the illness spread: This flu is spread via person-to-person contact.
Effects: Identified in Asia in February of 1957, this particular flu virus was present in wild ducks in Southern China before the virus mutated into the human flu virus. Unlike the 1918 pandemic, due to advances in science, this virus was quickly identified. Blamed for about 70, 000 deaths in the United States, this flu virus was first discovered in this country during the summer of 1957. Elderly people suffered from the highest death rates while pregnant women and children had the highest virus infection rate. While the illness appeared to decrease in numbers in December of 1957, a second wave of the pandemic started again in January/February of 1958.
Hong Kong Influenza
Deaths: Approximately one million
Symptoms of the illness: Mistaken for the common cold, Hong Kong influenza’s symptoms usually lasted longer and worsened over time. More specifically, some of the symptoms include joint pain, a high fever, and a general lack of energy. Not surprisingly then, an infected person becomes bedridden for up to two weeks in duration.
How the illness spread: This virus spread through person-to-person contact such as sneezing and coughing.
Effects: First recognized in 1968 in Hong Kong, the flu again made an appearance in both 1970 and two years later in 1972. However, in December of 1968 and January 1969, deaths due to this virus peaked; in addition, individuals over the age of 65 were most likely to die., elderly people were affected the most by this illness. That said, in the United States alone, 34,000 people contracted this flu between Fall of 1968 and Spring of 1969.
When: 1997 to ?
Deaths: Over 250
Symptoms: Flu-like symptoms that include a cough, fever, sore throat, and muscle aches
How the illness spread: As person-to-person virus transmission is rare, this avian flu is typically transmitted via contact with infected poultry or contact with surfaces that are contaminated with excretions/secretions of infected birds. In an effort to prevent the virus spread, 1.5 million chickens were slaughtered in Hong Kong in 1997.
Effects: In 1997, the first serious outbreak of avian flu occurred in Hong Kong with eighteen flu cases. Of the affected individuals, six of these people died. Then in 2004 another avian flu outbreak occurred. On average, the avian flu has killed over sixty percent of all people that contacted this type of flu.
Severe Acute Respiratory Syndrome (SARS)
Deaths: Over 750
Symptoms of Illness: Sufferers experienced a high fever, a headache and an overall discomfort. In addition, many of the people developed pneumonia while some of the afflicted individuals faced a dry cough and mild respiratory symptoms.
How the illness spread: A member of the corona virus family, SARS spread through person-to-person contact such as through coughing and sneezing. In addition, the disease could also be transmitted when an individual touched a contaminated surface and then touched his or her eyes, mouth, or nose.
Effects: A serious form of pneumonia, the illness is believed to have started when the virus spread from small animals to humans. In the Guangdong province of China, the disease was initially listed as “atypical pneumonia”. However, later, a doctor working in Vietnam – who later unfortunately died of SARS – reported the disease to the WHO. Within a few months, the illness spread to over thirty countries and infected approximately 8000 people.
What Viruses are Likely to Cause a Future Pandemic?
According to the WHO, the avian flu and H1N1 flu (A strain) are the most likely illnesses to become a pandemic threat in the future.
Avian (Bird) flu – first identified in Vietnam in 2004, this virus is also specifically referred to as the H5N1 virus strain. Since late 2003, outbreaks from this pathogenic flu virus have occurred in East Asia. In addition, deaths from this virus have occurred in Thailand, China, Indonesia, Cambodia, and Vietnam.
H1N1 Influenza A Strain – Also referred to as the swine flu, this virus began spreading in Mexico in April of 2009. Just a few months later in June of 2009, this type of flu was declared a pandemic by the WHO. As most of the deaths and illness occurred primarily in young people, this virus does not follow the pattern seen in most other flu viruses. Pregnant women, young children, and people with chronic lung or other health issues were most likely to suffer complications.
Why Should We Be Concerned About Pandemics?
Worldwide health professionals are particularly concerned about the rapid rate in which viruses can spread nowadays for several reasons:
- As international travel becomes easier and more frequent, viruses can also more rapidly move between countries. For instance, if a businessman travels to another country, there is a possibility that he may come into contact with a person who is harbouring a new type of virus without him ever knowing. Thus, when he returns, he can readily infect people at the airport, on the airplane, and in his home country.
- The time window open to track the cause of a virus and how the virus is initially spread is decreasing.
- As vaccines generally take six months or more to develop, the right vaccine may not be available when needed.
- That said, as modern communication has also increased, the ability to spread information about a possible pandemic is much easier as well. However, just as easily, misinformation about the virus can also be spread in a rapid fashion.
In addition, viruses that cause pandemics often originate in areas of the world where there are low levels of public health services. For instance, in South Africa, there are only four nurses available per 1000 people. In turn, it is not so surprising then that these diseases spread at a rapid rate to populations in other countries.
Thus, a future pandemic is without a doubt an extremely serious concern. To further elaborate on the vaccine issue, it is important to keep in mind that a virus can mutate faster than a new vaccine can be created. Since pandemics often arise because a new strain of a virus forms, a new vaccine would be needed as well.
Further, no one can predict with any accuracy where and how a future pandemic will arise. Moreover, since the year 1977, both H3N2 and H1N1 flu viruses caused seasonal epidemics around the world – resulting in about 36,000 deaths in the United States annually. In addition, as the vast majority of the global population has no immunity to viruses such as the H2 subtype flu viruses that circulated during the 1957-1958 time period, this situation is definitely a cause for concern.
Without a doubt then, both predicting and understanding pandemic emergence patterns is an extremely difficult process. As such, in order to prepare for these types of events, governments must consider a wide net of possibilities and of course, prepare for the unpredictable. Further, since vaccines cannot be prepared in a rapid enough fashion to combat these types of pandemics, these types of situations are extremely grave indeed. Thus, in lieu of timely and effective medical treatments, governments and health officials must continue to rely on efficient public health delivery to effectively deal with pandemics in the near future.
© 2012, Rourke. All rights reserved.