Influenza pandemic - part 1.jpg

Influenza pandemic – part 1

Influenza pandemic:

to have it or not to have it, that’s the question!

EXPERTS BELIEVE that avian influenza is a time bomb for human health and that a deadly influenza pandemic is quite likely to be launched by H5N1, the avian virus that has killed millions of birds and dozens of people in Asia. Health authorities want to spread the word that avian influenza has brought the world perilously close to a new flu pandemic, but how should we deal with the many uncertainties surrounding this issue?

Sounding the alarm is not easy. Raising awareness about uncertain threats can itself be perilous. Public health officials have a pandemic-size communication problem. They are more anxious than they have been in decades. It’s hard for officials to know how aggressively to sound the alarm. They don’t want to be accused of needlessly frightening the public, but they also don’t want to be accused, later on, of leaving the public under-prepared for a disaster.

Based on the present evidence, the H5N1 virus does not easily jump the species barrier to infect humans. This conclusion is supported by the small number of human cases, despite the tens of millions of poultry infected over vast geographical areas for more than two years.

Three conditions must be met before a pandemic begins:

1. A new influenza subtype that has not previously circulated in humans must emerge (itself a rare event).

2. This new subtype must be capable of causing disease in humans.

3. The virus must be capable of being passed easily among humans.

Only this last condition has yet to be fulfilled by H5N1.

Sustained human-to-human transmission of a new influenza strain will be the trigger for the start of a pandemic. The more countries in which H5N1 is detected, the greater the risk that the virus will mutate or re-assort with another influenza virus to produce a strain capable of igniting a pandemic. The infection of birds with H5N1 should be the first indication to public health authorities that human avian influenza cases might be possible. The danger posed by wild birds is that they may transmit H5N1 to domestic poultry flocks, which, in turn, are a direct threat to human health.

“Every time the H5N1 virus spreads to new regions, you increase the probability and also the opportunity for the virus to mutate. With every case of human infection, the probability for the virus to mutate increases. This virus is very treacherous.” Dr. Margaret Chan

There are no certain answers for the big questions

Unfortunately, no one is able to accurately predict whether H5N1 will actually trigger a pandemic, and if it does, we have no idea how long it might last or how deadly the virus will be. But H5N1 might not even cause a human pandemic, it might weaken and produce only mild disease, because infectious diseases are unpredictable … and it could disappear.

It may be years before a pandemic hits the world and a virus other than H5N1, that doesn’t even exist yet, may ultimately spark The Great Pandemic of 2???.

Because H5N1 has become established within the poultry populations in South East Asia, as well as proven its continued ability to cross the species barrier and infect humans, it is clear that H5N1 is a strain with pandemic potential.

It is impossible to predict how lethal the pandemic strain might be, so we can only guess how many people might die or be ill in the next pandemic.

But is there anything that can be done to stop a pandemic? Perhaps. If effective anti-virals are rushed to the region in which a pandemic strain first emerges, coupled with certain public health measures, there are studies that consider it may be possible to contain it before it spreads worldwide. The WHO does not know if this can practically be done, but given the potential health, economic and social damage a pandemic can produce, it must be tried.

What if the pandemic cannot be stopped at its source?

Classical influenza is airborne and spreads very easily, not requiring close contact. As people with influenza are often contagious before they are symptomatic, travel recommendations and border closures may not have a significant impact in delaying the arrival of the virus. Past influenza pandemics have spread worldwide within six to nine months. Given the heavy volume of international travel in the 21st century, it is likely that a pandemic would spread globally within approximately three months.

“Throughout history, no human interventions have managed to stop a pandemic once it starts … There’s a chance that we could smother the spark of a fire before it catches on. It will depend then on spotting an outbreak of human transmission quickly, and acting quickly.” Dr. Margaret Chan

Bird flu might arrive in the summer

Specialists consider that it is probable that migratory birds infected with the avian flu virus H5N1 might arrive in Portugal in July and August, namely some species of ducks, although most migratory birds will only arrive in the autumn. According to investigators from the Ministry of Agriculture, the possibility that cases of bird flu, meaning avian influenza in birds, will be registered in Portugal is almost inevitable, but for the common citizen, the risk of contracting bird flu, meaning avian influenza, is very low.

Certainly, it does not mean that we will have pandemic influenza, as this will only be possible when, and if, the virus acquires the capability to spread easily between humans.

Well, here we are again – if, if, if. All “ifs” and nothing is guaranteed! The WHO is doing what they must do – warning governments to be prepared and giving all the guidelines possible. However, in scientific terms, there is no possibility to see the future.

That’s life. To be or not to be, to have or not to have. Too many questions and not enough answers … until it happens … if it happens.    

Best health wishes,

Dr. Maria Alice

Consultant in General and Family Medicine

Director – Luzdoc International Medical Service Tel. 917 811 988