UW Virologist Puts Swine Flu in Perspective

"Let's not lose track of the fact that the normal seasonal influenza is a huge public health problem that kills tens of thousands of people in the U.S. alone and hundreds of thousands around the world," said Dr. Christopher Olsen, a molecular virologist who studies swine flu at the University of Wisconsin School of Veterinary Medicine in Madison.

Karen Kaplan and Alan Zarembo of the LA Times offer a precise and less alarmist explanatory piece today, 'Genetic data indicate outbreak won't be as deadly as that of 1918, or even the average winter.'

U.W. Madison and Zoonotic Diseases

U.W. Madison has a tutorial website on Zoonotic Diseases, "diseases caused by infectious agents that can be transmitted between (or are shared by) animals and humans," copyrighted by Dr. Olsen, continuing its tradition as a leader in this research field, and a page on Swine Flu.

From University Place - Wisconsin Public Television, below (posted on YouTube) is a lecture by Olsen: "Influenza: A Disease at the Interface of Animals and Human Beings," delivered on April 17, 2009, shortly before the first cases of this strain of Influenza A, (H1N1) virus [Swine Flu] were confirmed by CDC laboratories as occurring in the United States.

Olsen talks about the pioneering research on Zoonotic Diseases (of which Swine flu is a "classic Zoonotic infection") done at UW-Madison the last six decades [noting for example UW scientist Dr. Robert Hanson's research group that first isolated an influenza virus in pigs in 1949 and predicted the emergence of new Zoonotic diseases as ecological and environmental conditions in human and animal "host populations" change, describing perfectly present-day circumstances leading to the emergence of Ebola virus and Swine Flu for instance], 'genetic mixing" and how pigs for example act as an intermediate host of viruses that can be transmitted to human beings.

A virus needs a host, like a human being or other animal, to successfully reproduce itself.

"Bob Hanson was way, way, way ahead of his time," said Olsen. Great stuff, and so is the Wisconsin Idea and University Place - Wisconsin Public Television!

Answers on the Pandemic

Here is some question and answer on influenza pandemics from the Toronto Public Health site and the CDC offering background on the Swine Influenza (swine flu), "a respiratory disease of pigs caused by type A influenza virus that regularly causes outbreaks of influenza in pigs" that is now affecting human in an imminent pandemic.

On a mildly interesting note, the CDC question and answer references a case in Wisconsin from 1988.

Can humans catch swine flu?

Swine flu viruses do not normally infect humans. However, sporadic human infections with swine flu have occurred. Most commonly, these cases occur in persons with direct exposure to pigs (e.g. children near pigs at a fair or workers in the swine industry). In addition, there have been documented cases of one person spreading swine flu to others. For example, an outbreak of apparent swine flu infection in pigs in Wisconsin in 1988 resulted in multiple human infections, and, although no community outbreak resulted, there was antibody evidence of virus transmission from the patient to health care workers who had close contact with the patient.

And from the Toronto Public Health site:

What is Pandemic Influenza?

An influenza pandemic occurs when there is an abrupt and major change in the protein structure of the Influenza A virus resulting, in a new strain. Because people have little or no immunity to this new strain, it can spread quickly, causing outbreaks in one or more countries or worldwide. This is called a pandemic.

How often do flu pandemics occur?

Flu pandemics have historically occurred three or four times each century. There were three flu pandemics in the last century (1918, 1957 and 1968).

CDC: 'Rapidly Evolving Situation'; WHO Raises Alert

Update: The World Health Organization (WHO) Director-General has raised the level of influenza pandemic alert from phase 4 to phase 5, signaling a broader outbreak among world populations. [WHO graphic has phase 4 circled and has not been updated yet.]

The WHO defines a Phase 5 alert as: follows: "Phase 5 is characterized by human-to-human spread of the virus into at least two countries in one WHO region. While most countries will not be affected at this stage, the declaration of Phase 5 is a strong signal that a pandemic is imminent and that the time to finalize the organization, communication, and implementation of the planned mitigation measures is short."

The CDC site reads:

This is a rapidly evolving situation and CDC will provide updated guidance and new information as it becomes available.

The WHO Director-General's statement:

Ladies and gentlemen,

Based on assessment of all available information, and following several expert consultations, I have decided to raise the current level of influenza pandemic alert from phase 4 to phase 5.

Influenza pandemics must be taken seriously precisely because of their capacity to spread rapidly to every country in the world.

On the positive side, the world is better prepared for an influenza pandemic than at any time in history.

Preparedness measures undertaken because of the threat from H5N1 avian influenza were an investment, and we are now benefiting from this investment.

For the first time in history, we can track the evolution of a pandemic in real-time.

I thank countries who are making the results of their investigations publicly available. This helps us understand the disease.

I am impressed by the work being done by affected countries as they deal with the current outbreaks.

I also want to thank the governments of the USA and Canada for their support to WHO, and to Mexico.

Let me remind you. New diseases are, by definition, poorly understood. Influenza viruses are notorious for their rapid mutation and unpredictable behaviour.

WHO and health authorities in affected countries will not have all the answers immediately, but we will get them.

WHO will be tracking the pandemic at the epidemiological, clinical, and virological levels.

The results of these ongoing assessments will be issued as public health advice, and made publicly available.

All countries should immediately activate their pandemic preparedness plans. Countries should remain on high alert for unusual outbreaks of influenza-like illness and severe pneumonia.

At this stage, effective and essential measures include heightened surveillance, early detection and treatment of cases, and infection control in all health facilities.

This change to a higher phase of alert is a signal to governments, to ministries of health and other ministries, to the pharmaceutical industry and the business community that certain actions should now be undertaken with increased urgency, and at an accelerated pace.

I have reached out to donor countries, to UNITAID, to the GAVI Alliance, the World Bank and others to mobilize resources.

I have reached out to companies manufacturing antiviral drugs to assess capacity and all options for ramping up production.

I have also reached out to influenza vaccine manufacturers that can contribute to the production of a pandemic vaccine.

The biggest question, right now, is this: how severe will the pandemic be, especially now at the start?

It is possible that the full clinical spectrum of this disease goes from mild illness to severe disease. We need to continue to monitor the evolution of the situation to get the specific information and data we need to answer this question.

From past experience, we also know that influenza may cause mild disease in affluent countries, but more severe disease, with higher mortality, in developing countries.

No matter what the situation is, the international community should treat this as a window of opportunity to ramp up preparedness and response.

Above all, this is an opportunity for global solidarity as we look for responses and solutions that benefit all countries, all of humanity. After all, it really is all of humanity that is under threat during a pandemic.

As I have said, we do not have all the answers right now, but we will get them.