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Avian Influenza
A study of the H5N1 virus
--general info and chapters
--introduction
--full document (pdf)

Superficial Dermatitis
Ringworm
Dermatophytosis
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--research
--treatment
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Malassezia
Malassezia pachydermatis
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Mud Fever
D. congolensis
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--barrier-cream
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--treatment

MRSA in Pets
Methicillin Resistant
Staphylococcus aureus
--MRSA Research
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--Barrier-cream
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--Press Release
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Anti-microbial research applications
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Equine cutaneous microflora
Normal resident bacteria
--general info
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Equine gut microflora
probiotics
--general info
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Chapter 1 Introduction
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1.1 Introduction
A highly pathogenic avian influenza (HPAI) virus, H5N1, is making people sit up all over the world. It is able to infect and kill humans with no prior reassortment, and is now killing the very hosts that carried it for decades and is threatening the world with the next pandemic.

The natural reservoirs of influenza A viruses are the aquatic birds which are generally in evolutionary stasis with these viruses (Lipatov et al., 2004). However, occasionally, the influenza viruses are transmitted to other hosts, such as terrestrial birds or mammals. This can cause transitory infections or, less frequently, cause continual infections in the new hosts with permanent lineages (Lipatov et al., 2004). The fear is that the latter will happen in humans, creating a pandemic.

In the twentieth century there have been three pandemics of influenza origin. The first, the 1918-19 H1N1 'Spanish influenza' was the most devastating, causing about 20 million human deaths which was about 1% of the world's population (Kobasa et al., 2004; Mackenzie, 2006). Worryingly, the hallmarks of this virus were lung infection and induction of high levels of macrophage-derived chemokines and cytokines (Kobasa et al., 2004), which are the patterns of pathogenesis found in the current H5N1 (Cheung et al., 2002). It is thought that this H1N1 virus originated form an avian virus (Figure 1.1). The next two pandemics, the H2N2 'Asian influenza' in 1957 and the H3N2 'Hong Kong' influenza in 1968, were both reassortments of avian and human viruses (Figure 1.1) (Belshe, 2005). However, this is not necessary for a pandemic, as Taubenberger et al. (2005) discovered, when investigating the 1918 pandemic.

Figure 1.1 The two different origins of the influenza pandemics of the twentieth century. The 1918 pandemic originated from an avian virus that adapted to replicate and be transmitted efficiently in humans. The 1957 and 1968 viruses were a reassortment of avian and human viruses (Belshe, 2005)

The development of the H5N1 virus since its initial outbreaks in Hong Kong will be explored. The effects of the virus on its natural reservoir, the warfare between H5N1 and the host's immune system and the implications and strategies for both humans and animals will be discussed. Unfortunately it will be evident by the end that no one really knows what to predict or when to predict it even with the wealth of scientific information at our fingertips. Vaccine development or antiviral prophylaxis or treatment, as discussed in Chapter 7, may not be enough leaving billions of humans and animals vulnerable to the disease.

Full Text