Lessons from the 1918 influenza

Hi,

In this TED.com video, Laurie Garrett talks about the lessons we can learn from 1918 influenza. She authored books such as "the Coming Plague" and "Betrayal of Trust" about crises in global public health.

View the short video below and get the answers to the following questions:
Q. Why is indiscriminate use of the anti-viral drug, Tamiflu, against flu pandemic unwise?
Q. Why are quarantine measures not going to work this time?
Q. Why will closing all schools, churches, and other public establishments not work in a pandemic?
Q. Why is washing hands thoroughly not 100% fool proof against spread of flu virus?
Q. What are the side effects of Tamiflu. Is it fatal in some people?
Q. How does use of large scale use of Tamiflu create flu resistant aquatic birds like ducks and geese?
Q. Is H1N1 really 100% lethal to pregnant women?
Q. Will taking pneumonia vaccine reduce death rate in a flu pandemic?
Q. Do H1N1 patients actually drown in their own fluids?
Q. Is 'pandemic' defined as a stage where human to human transmission occurrs in communities such as schools, churches, and workplaces?




Cheers

Influenza H1N1 aka swine flu

Hi all,
Click on the image above to see it at a higher resolution. Source: Wikipedia

Today's entry contains the following:

• Q and A on the recent influenza scare that is sweeping across all the time zones of the earth within 24 hours.


• Link to Discovery New blog entry on the 1918 influenza pandemic


• Five videos of the survivors of the 1918 influenza pandemic. These people were very young children then and they should be in their 90s now.

Teachers may like to use the poster above to teach how genetic shifts occur in live-stock animals when they are infected with Influenza A virus.

Language teachers may like to use the videos to train their pupils to brush up on their listening skills.

Biology teachers of course can use this pandemic to teach how artificial selective breeding in live-stock and food animals can create a conducive environment for genetic shifts in pathogens.


Here is some information that I gathered by reading the newspapers,especially Dr Andy Ho’s articles in the Straits Times, Wikipedia, magazines and other sources. I would like would like to answer some of the usual questions that my students have asked me.

Q: Why is the swine flu called swine flu?

A: It was responsible for the 1918 Influenza pandemic that killed as many as 100 million people worldwide, but what we now know as H1N1 was first isolated and identified in pigs in the 1930s. It was the practice in those days to name germs after the organism where it was first found.

Q: How did this particular virus suddenly come about?

A:There are 3 types of influenza viruses, A, B, and C. Of these, influenza B and C can only infect humans. Influenza A viruses (which include Swine Flu) can infect a variety of animals such as chickens, ducks, pigs, wild birds and humans too. Each of the Influenza A viruses is specialised to infect a particular species of animal best, but some cross infection of other species can occur. For example some Bird Influenza A viruses can infect pigs too. Because of this, a situation could arise where 2 or more Influenza A viruses adapted to different animal species infect the same cells in a sick animal at the same time.

When this happens there is a likelihood that the gene segments of the co-infecting viruses could get mixed up while the viruses reproduce. This produces a new ‘hybrid’ virus in a process called genetic shift.This is exactly what happened in the case of the Swine Flu. Scientists have found that the Swine Flu virus contains gene segments of Pig, Bird and Human Influenza A. In essence, it is a new ‘Frankenstein' A virus that has been pieced together from the other regular viruses. It is a modified descendant of the same virus that caused the Spanish flu in1918.

Q: How do people die from swine flu?

A: The immune response of the body causes an "immune storm" to occur in the lungs. H1N1 has not caused a major pandemic since 1918, so several generations have grown up with no experience of this virus. It is so new to us that our immune systems throw everything at it. Lots of white blood cells swarm to the air sacs or alveoli, the blood capillaries dilate or become wider and more porous. This thickening of the alveoli walls reduces lung capacity, but there is worse to come. Blood fluids or plasma and also blood cells begin to leak into the alveoli and the patient will literally "drown" in these fluids. Due to the layers of white blood cells and other cells gathering at the alveoli and the flooding of the alveoli with fluids, oxygen will not be able to diffuse into the blood capillaries, causing breathlessness. Fluids stagnating in the alveoli will also attract germs to grow in it and cause further congestion.

Q: Why is there a high fever during flu?

A: The body raises its temperature to make conditions less comfortable for the virus and enable the immune system can work at a higher level of efficiency. However, the toxins produced by the immune system in response to the viral infection will travel in the blood to the brain and cause the brain to reset the optimum temperature at an even higher number. So the body thinks that it is still too low and so increases it even higher. (That is why you shiver when you are having a fever. The body thinks you are too cold as the brain thermostat has been set higher.)

Q: What is the difference between this flu (H1N1) and the seasonal winter flu?

A: The seasonal flu kills the very weak, the very old or the very young. But the H1N1 killed the robust, the healthy, the young, and the strongest cohort of the population.

At any one time, a significant proportion of the population has some immunity to each seasonal influenza virus and so it rarely spreads as quickly or causes as many deaths. In contrast, a ‘new hybrid’ virus such as swine flu, to which almost nobody in the population has any immunity to, spreads very quickly through the population and causes much worse symptoms resulting in much greater morbidity and mortality.

I would like to share a very interesting set of videos that I chanced upon. they are produced by Discovery News. It consists of a 5 part YouTube video set, each about 9 to 10 minutes. Briefly these are the salient points I gleaned from these videos. (Or you could skip my commentaries on the videos and go straight to them instead.)

1. A handful of survivors of the 1918 flu epidemic recount their personal circumstances. They were mostly about 5 or 6 years old then.


2. Four out of 10 workers in a young boy's father's shop died in quick succession.


3. Denial of the horrendous death rates was common.


4. People were concentrating on the World War I efforts instead and they did not want to think about death by disease.


5. Sick soldiers lying on the hospital floors were waiting for those on the beds to die, so that they could be upgraded to the beds.


6. The most common mode of catching the infection was in large gatherings.


7. The people in some towns were not allowed to travel out but the mail man brought the germs down the road when he delivered the mail in horse-drawn carriages.


8. Victims' fevers were so high that their hair turned white overnight and fell out.


9. People did not know what caused the disease, only guessing that it was caused by a bacterium. (By the way, the name, 'influenza' is simply Italian for "influence", showing how little was known about its cause.)


10. Maybe the Germans were spreading the bacteria. The Americans did not know about virus yet. (No electron microscope in those days.)


11. Everyone who put on the masks felt safe. But the masks were coarse and not designed for tiny virus particles. It is likened to using chicken wire to keep out dust in the air!


12. Victims drowned in their own fluids in the lungs, but this was passed off as bacterial pneumonia instead.


13. Children sang songs when they played skipping ropes or other games where the lyrics contained words such as influenza. For example:
    
    I had a little bird,
    And its name was Enza.
    I opened the window
    And in-flew-enza.


14. Vaccines were produced and distributed by trains. However they did not work as they were meant to kill bacteria not virus.


15. Folk remedies were prepared and used widely. They had the taste and smell of medicine but it did not harm people but instead helped them through the placebo effect. The smells were so bad that people did not want to go near those wearing them as talismans.


16. When patients arrived at the hospitals in ambulances, toe-tags where put on them even before they died!


17. When the patients looked very sick the nurses were told not to waste food on them, hence not feed them.


18. Mortality rate was close to 100% amongst the Red Indians. This is compared to 40% amongst the whites.


19. The seasonal flu kills the very weak or the very old or the very young.But the H1N1 killed the robust, the healthy, the young, and the strongest cohort of the population.


20. Soldiers who were sent by troop ships across the Atlantic Ocean to fight in WW1 faced an 80% mortality rate due to overcrowding.President Wilson was aware of the figures but he still had to fight the Germans. The people of America supported his decision.


21. Open wooden boxes with the dead persons were placed outside the main door and a government trucks came by to collect them.


22. The coffins were lowered into mass graves dug with excavators.


23. Guards were stationed outside coffin shops as they might get stolen.


24. Some men cut the throats of their wives and children before they killed themselves to avoid the flu.


25. People thought Armageddon itself was upon them. Others thought civilisation was ending.


26. The flu disappeared as suddenly as it appeared.


27. WW1 ended and the Germans were defeated just as the flu died away.


28. Scientists think that the critical number of immune survivors was reached right then and so the virus could not kill any more people and it became less virulent.


29. 'How can we forget so horrendous an event?', say the survivors who are in their 90's now.


30. Some of the survivors who where about 5 or 6 years old then lost their mothers. They suffered from life-long sadness and a feeling of being unsafe without their mothers.



You can read the actual article at this address:
'swine flu linked to 1918 influenza pandemic'

The five videos are copied here for your easy playing.


The 1918 flu pandemic 1 of 5


The 1918 flu pandemic 2 of 5


The 1918 flu pandemic 3 of 5


The 1918 flu pandemic 4 of 5


The 1918 flu pandemic 5 of 5

Note that these videos mostly recount the American experience. The 1918 pandemic was worldwide and killed an estimated 70 - 100m people.
Cheers

Disease scares from our live-stock and food animals

Hi,

Today I will write about the Ebola scare in pork from the Philippines.

Bird flu from China, Sars from Hong Kong, Measles, Cow pox, Mad Cow disease, small pox, Hepatitis, Rabies, AIDS, foot and mouth disease...What do they all have in common?

Answer: They are all diseases that spread from a host animal to man. In the host animal, these diseases are usually not deadly (benign) and they might cause discomfort but not necessarily death.

Some of these disease have been around longer than others. The newer ones are HIV (reported first in 1981 but thought to have originated in non-human primates in sub-Saharan Africa and transferred to humans early in the 20th century.), Ebola in Africa (reported in 1976), Ebola in Philippines (reported in 2008), SARS in China (reported in November, 2002) and Mad Cow Disease (first described in 1921 as Creutzfeldt-Jakob disease with a new variation from eating infected cows emerging in Britain in the mid-1980s).

• Bird flu was first documented as a pandemic in 1918-19; measles was first documented by the Persian physician, Muhammad ibn Zakariya ar-Razi (860-932) and the virus was isolated in 1954.
• Small pox has infected humans for 12,000 years; inoculation of material from smallpox blisters to induce a mild infection was possibly practised in India 3,000 years ago but is documented in China from the 10th Century. This was effective at giving immunity but risky. Edward Jenner in England documented the benign disease, cowpox, as a safe immunisation method in 1796 and thus created the first vaccine.
• Cholera first caused a pandemic in 1816 in Bengal, India. It has no particular animal host but survives in aquatic environments between outbreaks.
• Rabies is a disease of mammals; the name 'rabies' originated at least 5,000 years and was first written about around 1930 BC.

I will write about these in other posts.

What do all these diseases have in common?
The pathogens or causative agents all originated in animals that man handles either as food, as draught or transport animal, or came into contact accidentally.


Ebola in pigs in the Philippines
This is the latest scare, reported on 10th Dec 2008. Pork from 4 piggeries in northern Philippines showed the presence of Ebola-Reston virus.

It was first reported in crab-eating macaque (monkeys) in 1989. Two more outbreaks occurred in 1992 and 1996 in Southern Philippines and it was always confined to the monkey population and people in direct contact with the infected monkeys. It produced flu-like symptoms. The Philippine strain is a non-fatal.

What is so scary about this Ebola if it is never fatal in monkeys?
Ebola-Reston is a monkey virus that produced flu-like symptoms in monkeys and man. When it jumped species, as it did in Dec 2008, and started infecting pigs, then there is a chance that a mutation has occurred and the virus is now a virulent and fatal strain. If the changes that it has inherited makes it possible to jump species to man and people who handle the pigs in piggeries, then it can spread into the general population, i.e. people who do not go near a live pig but only eat pork and live in a neighbourhood where piggery workers live.

Why does the word Ebola evoke such fear in scientists?

SIDE NOTE: Diseases that originated in or are harboured by other animals are called 'zoonoses', or zoonotic diseases. Generally, humans get infected by accident and it is a dead end for the organism, even when they cause major pandemics like bubonic plague. Eventually, humans become too few in numbers where the outbreak occurs, either through death or by gaining immunity and the bug goes back to their natural host. By this definition, malaria is not a zoonosis — the disease needs to pass through both humans and mosquitoes to survive. Sometimes a mutation occurs and a new disease arises that depends solely on humans, like measles, which could have come from cattle or dogs. In other words, the disease can now spread from person to person with the need of any animal host

There are 3 other types of Ebola in Africa which cause fatal haemorrhagic fever and have killed hundreds. That it has not killed mny more is partly due to the extreme fear it induces in people, who flee the towns and villages where it breaks out. If the new strain of virus in pigs is virulent like the ones in Africa, its impact on humans is unimaginably unknown.
Three global watchdogs, the World Health Organisation, the United Nations' Food and Agriculture Organisation, and the World Organisation for Animal Health are testing these farm and the slaughterhouse workers for the virus. Pork from these farms are tested and people in the Philippines are asked to eat only well cooked pork. Pigs from the 4 affected farms are quarantined and transport of pigs from these farms is not allowed.

Why are so many of these new disease deadly? Why are we not afraid of the good old common cold?
These are new diseases to man. The human body has evolved its own immune system over millions of years to protect the body against human diseases. The body's white blood cells "recognise" the old germs (pathogens) and have the correct ammunition to kill them and protect the human body from the invaders. However, when pathogens from other animals get into our body, our body do not even recognise them as pathogens, and leave them alone to ravage the human body. An analogy would be, if the enemy only wears red for many generations, and an enemy that wears green comes along, our armies do not even know that they are enemies and turn a blind eye towards them. The enemy will have a free hand to pillage and plunder your country (=your body). As scientists say, we are "naïve" to the pathogen.

A child with smallpox. Fortunately, smallpox is now extinct — the first disease in history to be eliminated forever.

Hellish Ebola in Africa, for man and gorilla

Ebola haemorrhagic fever was first documented in 1976 in Zaire and Sudan in Africa. It spread rapidly from human to human through to contact with body fluids and blood. It is also spreading fast within the Lowland Gorilla population too, and caused tens of thousands of deaths in the past decade.

A biosuited scientist (top) and a dead gorilla. Click the gorilla image to find out why Ebola is such a serious problem for gorillas and how they can be helped

The host species for the virus is a fruit bat. (The bat does not get sick and is a natural reservoir of the virus.) When the virus jumped species from bat into man or gorilla, it caused internal(haemorrhagic) and external bleeding, fever and diarrhoea and eventually 50% to 90% of the infected died painful and rapid deaths. The disease is not treatable as no vaccines exists for it.

Protozoa, bacteria, viruses and prions (non-living protein disease-causing agents) reproduce much faster than we do. So they can evolve new ways to breach our defences faster than we can acquire natural immunity (which can be gained only at a cost of death and illness). They also thrive in conditions of high population densities and poverty that exist in much of the world. We rely on human ingenuity to devise treatments like new drugs, and preventives like hygiene and vaccines to overcome these shortcomings.

Cheers