What percentage of people die from the 2009 Swine Flu?

Answer 1

UPDATE 03/07/10

The US Centers for Disease Control and Prevention (CDC) has estimated that, as of 2/12/10, since the beginning of the pandemic, the US has had approximately 57 million cases of A-H1N1/09 Pandemic Swine Flu and approximately 11,690 resulting deaths. Based upon this, an estimate of the mortality rate in the US from the pandemic is 0.02%.

In comparison, the CDC and World Health Organization (WHO) have estimated that with seasonal flu, "we see over 30 million cases in the United States. We see 200,000 hospitalizations and, on average, 36,000 deaths." (During the entire fall and winter flu season.) Based upon this, the average mortality rate of seasonal flu in the US would be 0.12 %.

The statistics of this mortality rate variation and other information gathered during the pandemic are under study by epidemiologists. It may be attributable to the fact that the especially vulnerable demographic group of the elderly (age 65 and older) suffers the majority of the cases and deaths from seasonal flu (because their weakened immune systems are unable to fight it off before their frail bodies must attempt to deal with the symptoms caused by another new strain of virus). In contrast, the majority of cases of the pandemic Swine Flu are among the younger and healthier demographic groups, so that, except for the very young and those with underlying medical conditions, most are able to survive the disease. It is not fully understood yet why the elderly do not contract this virus subtype as easily as the typical seasonal viruses, but speculation is that they may have acquired immunity through prior exposure to a similar virus strain.

PREVIOUSLY:

The mortality rate for the A-H1N1/09 Pandemic Flu was roughly calculated as 0.01%.

It had been difficult to come up with an estimate of the mortality rates of Swine Flu (novel H1N1/09), since the case numbers were being drawn from known cases from hospitalized patients or other laboratory confirmed cases. These were known to be just a fraction of the total number of infections (because those figures excluded the unknown number of mild cases treated at home, untested, and unreported.)

Very rough estimates of the mortality rate of the pandemic A-H1N1/09 influenza have now been calculated from statistics gathered by a French study in late August 2009 and reported in the Public Library of Science (PLOS). Based on their findings, it is estimated that Novel Swine Flu is 100 times more virulent than seasonal flu.

The main cause of death with A-H1N1/09 is viral pneumonia with resulting ARDS (Adult Respiratory Distress Syndrome). Even though treated in a hospital ICU, approximately 50% of ARDS cases result in death. In the French study, the number of ARDS cases was found to be one in every 5000 cases, giving the estimate of ARDS deaths as 1 in 10,000 cases of infection.

The number of deaths from ARDS in seasonal flu cases, based on empirical evidence in France, is calculated to be between 5 and 10 each year out of an average annual number of seasonal flu cases of 6 million infections. Until better counts of cases are available, that gives a rough estimate of the deaths due to ARDS resulting from seasonal influenza of one out of a million infected patients.

The 1 death in 10,000 cases from A-H1N1/09 compared to 1 in 1,000,000 from seasonal flu strains gives the prior mentioned indications of A-H1N1/09 being 100 times more virulent than seasonal flu. (For the full article about the study, see the related links section below.)

Average mortality rate of seasonal flu = 0.12 % (based on WHO statistics below)

From WHO: "With seasonal flu, we see in the United States over 30 million cases. We see 200,000 hospitalizations and, on average, 36,000 deaths." (During the entire fall and winter flu season.)

It is believed that so far it may be a much lower mortality rate than feared for this first wave of the 2009 Swine Flu (Novel H1N1). Future waves of the outbreaks can become more serious if it follows patterns of other epidemics and pandemics in the past, however.

The total number of people originally infected in Mexico was initially underestimated because the diagnosis of it in many who were hospitalized was delayed at the beginning of the outbreak. Without that data to compare to the known deaths attributed to the virus, the Death Rate could only be assumed from the low numbers of confirmed cases at first.

The statistics and conclusions are still being monitored, and there may be future waves of the strain that are more deadly than the first, as occurs in many flu outbreaks. Because this new mutation of the swine flu virus has not infected humans before, there is no historical information to know what the death rate may be. Viruses can vary greatly in their effects on those infected. Some viruses do not affect many people, but the majority of the ones that are infected may die. Other viruses may affect a widespread significant number of people, but have a very low death rate. Some viruses affect only the infirm, very young, very old, or others with compromised immune systems; while other strains of viruses, like this strain of swine flu seems to be doing, are more often caught by people who have been healthy up until the contact with the virus.

(See the related questions and links for additional information.)

Answer 2

The World Health Organization says that there have been 79 confirmed cases of the disease, 7 of which resulted in death, leaving 72 living people with the infection. let's assume there's a few more people out there undiagnosed and say maybe 80 people worldwide with the disease out of a population of round 6.75 bilion.

Yay! Maths time! (80 / 6,750,000,000) x 100 = 1.18518519 x 10-6

Which is roughly 0.0000012%

Answer 3

There are very few people over 65 who are even getting the swine flu, the number who may have died is very low world wide, and they likely had some underlying chronic disease to be vulnerable. It is believed that those 65 and older, who usually are the hardest hit by seasonal influenza each year, may have immunity to the swine flu from a prior exposure to a similar strain of flu, perhaps the one in 1930.