Swine Flu – Swine-Origin Influenza A (H1N1) Virus Infection

Background and Current Information

Out of the blue, a novel influenza virus has emerged in Mexico. The virus seems to have been born from the combination of at least two pig viruses, that themselves carried gene segments that originated in viruses of other species such as birds or humans.

This new virus, although dubbed “swine flu”, has not been identified from pigs in Mexico, nor is it caught directly from pigs, but has the ability to infect and transmit efficiently between humans. Read more…

The strain in most cases causes only mild symptoms and the infected person makes a full recovery without requiring medical attention and without the use of antiviral medications.

Swine flu has pushed the World Health Organization to raise its pandemic alert level to phase 5*, which means that a pandemic is imminent. (April 29th 2009). Note that all of those phases are about how the virus is (or isn’t) spreading — they’re not about the severity of the disease.

*(Requires free registration with Medscape)

Define pandemic: an epidemic that is geographically widespread; occurring throughout a region or even throughout the world.

One must keep in context that whilst there is clear concern the actual number of deaths due to swine flu are still very low. You can track them on this map.

Human Defences

Innate immunity vs Virus. Our innate immune response to the influenza virus is well understood, relying on the supportive action of innate and adaptive immune responses to manage a controlled eradication of the virus rather than the potentially fatal cytokine storm that can occur.

The health of the human host is also an important factor as well as the aggressiveness of the response. Sensible simple precautions are recommended as well as considering a few nutritional support products.

Wash hands often with soap and water. Use waterless alcohol-based hand gels (containing at least 60 percent alcohol) when soap is not available. Cover mouth and nose with a tissue when you cough or sneeze; if you don’t have a tissue, cough or sneeze into your upper sleeve, not your hands. To keep germs from spreading, don’t touch your eyes, nose, or mouth.

Define contagious: The process by which one person infected with a disease passes it to another, either through direct skin contact or via inhaled droplets.

Information on the effectiveness of facemasks and respirators for the control of influenza in community settings is extremely limited. Thus, it is difficult to assess their potential effectiveness in controlling swine influenza A (H1N1) virus transmission in these settings. Guidelines have been prepared by the CDC for the use of masks.

Nutritional Supplements

The addition to the diet of 2 different supplements at this stage of comprehension seems viable and is worth considering for personal and client recommendation.

1. Saccharomyces Boulardii increases sIgA production. This is an effective inhibitor of viral invasion and sIgA may be suppressed when there are changes to the intestinal ecology and/or anxiety is increased.
   Saccahromyces Cerevesiae is the yeast species from which Saccharomyces Boulardii is derived. The chemical extraction of the active component ‘Beta Glucans’ from this yeast results in the exclusion of the beneficial element that stimulates the local production of sIgA. This has the counter productive effect of potentially over stimulating the TLR’s and pro-inflammatory cytokines producing an increase in risk, rather than a decrease. Until more is known about the H1N1 viral – immune response the use of a cautious but evidence based strategy is recommended.
2. Vit D levels have been linked to altered immune resistance and resolution of viral invasion. It has also been implicated in managing appropriate innate to adaptive immune reactivity, and in the production of cathelicidin which appears to limit risk of secondary bacterial infection and destroy influenza virus.

Young children and swine-origin influenza virus (S-OIV)

Little is currently known about how this new S-OIV circulating in people may affect children. However, it is known from seasonal influenza and past pandemics that young children, especially those younger than 5 years of age and children who have high risk medical conditions, are at increased risk of influenza-related complications.

Theoretically, pharmacological doses of vitamin D (2,000 IU per kg per day for three days) may produce enough of the naturally occurring antibiotic cathelicidin to cure common viral respiratory infections, such as influenza and the common cold, but such a theory awaits further science.

Further Information

Swine Flu alert centre*

*(Requires free registration with Medscape)

“The chances of dying from this pandemic are smaller than being killed by lightning, a shark attack, moose attack, hippopotamus attack, an earthquake, tornado, hurricane, or something as mundane as taking a bath or shower.” Joe Sheehy
New Scientist Magazine

Technical Section

Innate and Adaptive Immunity
The immune system is divided into two parts, the innate and adaptive systems. The adaptive immune response depends on B and T lymphocytes which are specific for particular antigens. This system involves clonal selection of antibody producing B cells to respond to foreign antigens, and works well, but has a major limitation in that it takes from 4 to 7 days to ramp up. In that time period, pathogens could overwhelm the organism.

In contrast, the innate immune system is immediately available to combat threats. There is no complicated method of selecting cells that react to foreign substances from those that react to self. There is no memory (except in some specialised NK cells) to change how the system responds to the same threat upon the second or third exposure. Instead, the innate immune system responds to common structures shared by a vast majority of threats.

These common structures are called pathogen associated molecular patterns, or PAMPs, and are recognised by the toll-like receptors, or TLRs. In addition to the cellular TLRs, an important part of the innate immune system is the humoral complement system that opsonises and kills pathogens through the PAMP recognition mechanism.

Summary

An organism’s survival depends on a prompt response to pathogens, but it is equally important to avoid unregulated inflammation that can lead to dangerous pathologies such as sepsis and autoimmune disease. It is this fine balance between protection and self-damage that drives the complexity of the innate immune response.

Innate immunity is recognised to play an important role in the response to challenge by pathogens.

The immune functions in which toll-like receptors play important roles include:

1. Orchestration of the immediate tissue specific and global response of the innate immune system to pathogens. This orchestration is driven primarily by cytokine and chemokine production (TNF, Interferons, IL-1, IL-2, IL-6, IL-8 and IL-12 among others). Perhaps the most important of these early signals are the chemokines that draw the phagocytes to the site of infection.
2. Transition from innate to adaptive immunity. In addition to the role in the innate immune response, TLRs have an important role in adaptive immunity by activating antigen presenting cells.

The cytokine signalling cascade, stimulated by TLR activation, begins a complex series of interactions that has evolved in each organism to maximise the odds for survival. Among the more important of these signals is T cell differentiation and regulation. TLRs, on dendritic cells in particular, are essential in the T-helper-1 (Th1) versus Th2 pathways. Equally important is the maturation of Treg cells to manage inflammatory responses. An important early component of the Th1 response is the activation of cytotoxic T cells that helps to control the infection.

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