The Spanish Flu pandemic was exceptionally severe and had a fatality rate of approximately 2.5% with an estimated death toll of anywhere from 50 million to 100 million people. This extraordinary toll resulted from the extremely high illness rate and the extreme severity of the symptoms, suspected to be caused by cytokine storms (potentially fatal immune reaction consisting of a positive feedback loop between cytokines and immune cells, with highly elevated levels of various cytokines).

The Spanish Flu spread simultaneously in 3 distinct waves affecting North America, Asia and Europe during a period of 12 months between 1918 and 1919. This is part of the reason it is hard to pinpoint a point of original. Before and after the 1918 pandemic, most influenza pandemics developed in Asia and spread from there to the rest of the world. While influenza was not nationally reported in 1918, death rates from influenza and pneumonia had risen sharply in the United States in 1915 and 1916 due to a respiratory epidemic that began in December 1915. Death rates from this epidemic seemed to drop slightly during 1917. The United States experienced the first Spanish flu pandemic wave in the spring of 1918. The first wave began in March 1918 and spread unevenly through the United States, Europe, and possibly Asia during the next 6 months. Reported illness during this wave were high, but the death rate was not much higher than normal.

The first wave was quickly followed by a much more fatal second and third wave in the fall and winter of 1918–1919. The second wave began in September 1918 and lasted until November 1918 and proved to be highly fatal. A third wave followed in early 1919. Another unique aspect of the 1918 Spanish flu is that it nearly simultaneously infected humans and swine.

The pandemic took a huge toll on communities everywhere even in areas where the death rate was lower, there were many times so many people sickened by the virus that it brought every day life to a standstill. Some communities even went so far as to close all stores and would require customers to leave their orders otuside to be filled later. Health care workers with in high demand and short supply because they too were sick. There were even reports that mass graves had to be dub by steam shovel resulting in bodies buried without coffins in many places due to a lack of grave diggers.

Reading back through reports of the 1918 Spanish flu outbreak shows some similarities:

• It started in the spring, March to be precise.
• The spread was uneven at first and not much more deadly than normal flu
• It infected swine and humans
• There were reports that governments around the world downplayed the severity of the virus

Lets hope that those are the only similarities and the reports that the 2009 swine flu is waning are accurate and we don’t see a resurgence come fall and winter. I know one thing though. While I am not panicking, I am taking a lesson form the past and preparing for a potentially devastating flu season come fall and winter. I will be stocking up during summer on face masks, hand sanitizer and wipes, germ killers, disinfectants and the things my family will need to make it through a few weeks on our own. I think I will be watching for deals on chest freezers and vacuum sealers as well.

Mexican Health Secretary Jose Cordova described the outbreak as being in decline in Mexico and authorities there have stated that they believe the virus’s most active period in Mexico was between April 23 and April 28. Health officials in Mexico have reported 568 cases and 22 deaths related to swine flu in their country as of late Sunday. WHO has confirmed 506 of those cases and 19 deaths. There are 898 confirmed cases throughout the world in a total of 18 countries. The United Stated has 226 confirmed swine flu cases in 30 states, they include 1 death.

The following countries have swine flu cases that have been confirmed by the WHO:

• Canada has 70 confirmed cases
• United Kingdom has 15
• Spain has 13
• Germany has 6
• New Zealand has 4
• Israel has 3
• France has 2
• Austria, China, South Korea, Denmark, Netherlands, Switzerland, Costa Rica and Ireland each have one.

Officials in China have placed 68 people under quarantine, including 13 crew members of a Mexico City to Shanghai flight. The flight carried a passenger who tested positive for the 2009 H1N1 virus. A Chinese health official indicated that none of the other passengers has exhibited any flu-like symptoms. China’s state-run Xinhua news agency reported Sunday that approximately 110 other people on the Aeromexico plane went on to other destinations and may face quarantines elsewhere. Aeromexico planes have been barred from landing at Shanghai’s airport, as a result Aeromexico is suspending flights to Shanghai until May 15

New York has the highest number of confirmed cases, 63, within the United States. The Centers for Disease Control and Prevention (CDC) indicated that the following states also have confirmed cases:

• Texas has 40
• California has 26
• Arizona 18
• South Carolina 15
• Delaware 10
• Massachusetts and New Jersey each have 7
• Colorado has 4
• Florida, Illinois, Indiana, Ohio, Virginia, Wisconsin each have 3
• Connecticut, Kansas and Michigan each have 2
• Alabama, Iowa, Kentucky, Minnesota, Missouri, Nebraska, Nevada, New Hampshire, New Mexico, Rhode Island, Tennessee and Utah each have 1

An inmate at Centinela State Prison in Imperial County in California with suspected swine flu prompted officials in that state to suspended visitation and other “nonessential activities”. They are still waiting for the case to be confirmed with lab testing. Health officials in three states announced additional confirmed cases that were not included in the CDC total listed about. North Carolina and Pennsylvania announced their first confirmed swine flu cases and Louisiana’s governor said his state had seven confirmed cases. U.S. Secretary of Health, Kathleen Sebelius warned Sunday that even if the flu outbreak slows, “it could come back with greater force in the winter and fall, when we get into flu season.” she went on to say “this is no time for complacency”.

“I would still propose that a pandemic is imminent because we’re seeing the disease spread to other countries. We have not seen yet that sustained transmission outside one WHO region,” said Dr. Michael J Ryan, the WHO’s director of its global alert and response team. “At this point we expect that phase 6 will be reached; we have to hope that it is not reached,” he said. Dr. Ryan also went on to say that “Pandemics are serious,” and further noted that the phases of a pandemic describe “the geographic spread of the disease, not its severity.” See Phases of a Pandemic for more information about the 6 phases involve din a pandemic.

As of Today, the WHO reported that there are 658 confirmed cases of 2009 H1N1 also known as swine flu, in 16 countries around the world. Most of the confirmed cases have been in Mexico, where there are 397 infected people. There have also been 16 deaths attributed to the swine flu virus in Mexico, According to the WHO. The increase in confirmed cases is from “ongoing testing of previously collected samples and not a surge of people falling sick,” Ryan said.

Mexico’s health minister indicated Saturday that the total cases of swine flu in that country had reached 443, although that number was not reflected in the WHO’s total. The number of confirmed 2009 H1N1 cases by the U.S. Centers for Disease Control and Prevention (click here for a list of updates from the CDC) was also raised on Saturday to 160, up from Friday’s total of 141.

Other countries throughout the world have also reported new confirmed cases of swine flu which will be included in a updated WHO total later Saturday. Those countries include France, Germany, the United Kingdom, Spain and Israel. The WHO noted that the large increase in confirmed 2009 H1N1 cases in Mexico are representative of testing on backlogged specimens. “What the increase reflects is that we are moving forward in confirming many of the swine flu cases that have been left untested for some time, so in an way that’s reassuring,” said WHO spokesman Paul Garwood. “we haven’t seen, say, a spike in new cases or new influenza cases appearing in Mexico City, for example,” Garwood continued. “It’s just the fact that this reporting backlog is bearing fruit and we’re seeing the results of that.”

Researchers worked to develop a vaccine for swine flu, which is also known as 2009 H1N1. According to Michael Shaw, lab team leader for the H1N1 response at the Centers for Disease Control and Prevention, the CDC hopes to have a vaccine to manufacturers within a month. “We’re doing the best we can as fast as we can,” he said. Even with the vaccine getting to manufacturers within a month, it would take four to six months from the time the appropriate strain is identified before the first doses become available, said Dr. Marie-Paule Kieny, WHO director of the Initiative for Vaccine Research. “Of course we would like to have a vaccine tomorrow. We would have wanted to have it yesterday,” she said. “It’s a long journey.” She said there is “no doubt” that a vaccine can be made “in a relatively short period of time.”

The steps involved in producing a vaccine involve isolating a strain of the swine flu virus, which has already been done. Once the strain is isolated, researchers need to tweak it so manufacturers can make a vaccine, Kieny said. The tweaked virus will be shipped to manufacturers, who will fine-tune it. Once that is complete, there will be more tests before national regulatory agencies decide whether or not they will approve a vaccine.

Authorities in Mexico are “beginning to see evidence that the swine flu virus might be letting up, and the number of people who have been hospitalized has leveled out in regards to people who are contagious, at least as of yesterday,” Mexico City Mayor Marcelo Ebrard told reporters. “We do have a problem, but I say this so that we know where we are as a city after we have done all we have done, and in what direction we are heading and how much we have progressed. And what I can say is that we are heading in the right direction.”

While Mexican authorities indicated at least 358 cases and 16 deaths in that country and suspect that more than 150 deaths have been caused by the swine flu. The WHO said there were 156 confirmed cases in Mexico.

The CDC gave the following state-by-state breakdown of the 141 confirmed H1N1 swine flu cases in the United States: Arizona, 4; California, 13; Colorado, 2; Delaware, 4; Illinois, 3; Indiana, 3; Kansas, 2; Kentucky, 1; Massachusetts, 2; Michigan, 2; Minnesota, 1; Nebraska, 1; Nevada, 1; New Jersey, 5; New York, 50; Ohio, 1; South Carolina, 16; Texas, 28; and Virginia, 2. One death in the United States has been attributed to swine flu — a toddler from Mexico whose family brought him to Texas for medical treatment.

Interpandemic period

Phase 1 : No new influenza virus subtypes have been detected in humans. An influenza virus subtype that has caused human infection may be present in animals. If present in animals, the risk of human infection or disease is considered to be low.

Phase 2 : No new influenza virus subtypes have been detected in humans. However, a circulating animal influenza virus subtype poses a substantial risk of human disease.

Pandemic alert period

Phase 3 : Human infection(s) with a new subtype exist. During Phase 3 there is no human-to-human spread or at most rare instances of spread to humans during close contact.

Phase 4 : Small cluster(s) of infection have been detected with limited human-to-human transmission. The spread is highly localized suggesting that the virus is not well adapted to humans at this point.

Phase 5 : Larger cluster(s) of infection are present. The spread from human-to-human is still localized, suggesting that the virus is becoming increasingly better adapted to humans but may not yet be fully transmissible. Phase 5 indicates that there is a substantial pandemic risk.

Pandemic Period

Phase 6 : Pandemic: Phase 6 indicates a pandemic due to increased and sustained transmission of the virus in the general population.

Post-pandemic period

Once the virus has run its course and has no further hosts to infect, it will stop spreading. After the Pandemic period there will be a return to the Interpandemic Period (Phase 1)

The distinction between phase 1 and phase 2 is based on the risk of human infection or disease resulting from circulating strains in animals. The distinction is based on various factors and their relative importance according to current scientific knowledge. Factors may include pathogenicity (the ability of a pathogen to produce an infectious disease in an organism) in animals and humans, occurrence in domesticated animals and livestock or only in wildlife, whether the virus is enzootic (the non-human equivalent of endemic and means, in a broad sense, “belonging” or “native to”, “characteristic of”, or “prevalent in” a particular geography, race, field, area, or environment) or epizootic (a disease that appears as new cases in a given animal population, during a given period, at a rate that substantially exceeds what is “expected” based on recent experience), geographically localized or widespread, and other scientific parameters.

The distinction among phases 3 and 4 is based on an assessment of the risk of a pandemic. Various factors and their relative importance according to current scientific knowledge may be considered. Factors may include rate of transmission, geographical location and spread, severity of illness, presence of genes from human strains (if derived from an animal strain), and other scientific parameters.

The first outbreak occurred during 1918-1919. This was known as “Spanish flu” or A (H1N1). Spanish Flu caused the highest number of known influenza deaths. As a result of Spanish Flu More than 500,000 people died in the United States, and up to 50 million people may have died worldwide. Many people died within the first few days after infection, and others died of secondary complications. Nearly half of those who died from Spanish Flu were young, healthy adults. Influenza A (H1N1) viruses still circulate today after being introduced again into the human population in 1977.

The second occurred from 1957-1958 and was known as [A (H2N2)] or “Asian flu”. Asian Flu caused about 70,000 deaths in the United States. Asian Flu was first identified in China in late February 1957, Asian flu spread to the United States by June 1957.

During 1968-1969 [A (H3N2)] also known as ” Hong Kong flu” caused about 34,000 deaths in the United States. The Hong Kong flu virus was first detected in Hong Kong in early 1968 and spread to the United States later that year. Hong Kong flu or Influenza A (H3N2) viruses still circulate today.

Both the 1957-58 and 1968-69 pandemics were caused by viruses containing a combination of genes from a human influenza virus and an avian flu virus. The 1918-19 pandemic virus appears to have an avian origin.

Pandemic viruses emerge as a result of a process called “antigenic shift,” which causes an abrupt or sudden, major change in influenza A viruses. These changes are caused by new combinations of the HA and/or NA proteins on the surface of the virus. Changes results in a new influenza A virus subtype. The appearance of a new influenza A virus subtype is the first step toward a pandemic; however, to cause a pandemic, the new virus subtype also must have the capacity to spread easily from person to person. Once a new pandemic influenza virus emerges and spreads, it usually becomes established among people and moves around or “circulates” for many years as seasonal epidemics of influenza. The U.S. Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) have large surveillance programs to monitor and detect influenza activity around the world, including the emergence of possible pandemic strains of influenza virus.