WHO: International threat of global flu pandemic - full text
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The Times reported on May 12 that researchers at London's Imperial College predicted that the swine flu virus was likely to cause an epidemic in the northern hemisphere in autumn 2009, potentially infecting a third of the world's population if it continued to spread at its current rate.
Immediate context
Swine flu was a highly contagious acute respiratory disease of pigs caused by one of several swine influenza A viruses and which, prior to the current "crisis", rarely affected humans. Clinical symptoms of people infected with swine flu ranged broadly from asymptomatic infection to severe pneumonia resulting in death. The H1N1 flu variant, for that there was currently no vaccine, was thought to be similar to the flu strain which caused seasonal outbreaks of flu in humans on a regular basis. However, WHO officials believed that the latest strain of the H1N1 virus had mutated and contained genetic material that was typically found in strains of the virus that affected humans, birds, and pigs.
The World Health Organisation (WHO) on April 29 warned that a global flu pandemic was "imminent", amid growing evidence of threats from the human-to-human spread of a never-before-seen strain of swine influenza (also known as swine flu or the H1NI virus).
The WHO's warning came shortly after US officials announced on April 27 that a 23-month-old Mexican boy, who was visiting relatives in the US state of Texas, died of swine flu. The child's death was the first confirmed loss of life from the H1N1 flu strain outside Mexico, where suspected cases of the virus first emerged (in March) and where as many as 159 people were thought to have died from swine flu.
Further evidence of the threat of human-to-human transmission of H1N1 also emerged in Spain on April 29, when the Spanish authorities reported the first case in Europe of swine flu in a person who had not travelled to Mexico.
As of May 11, the US surpassed Mexico as the country most affected by the outbreak. According to WHO figures, the US had 2,532 confirmed cases in 44 states, with three deaths linked to the illness.
Reaction and outlook
The WHO Director General Margaret Chan, announcing the UN body's warning in Geneva on April 29, said that "influenza pandemics must be taken seriously precisely because of their capacity to spread rapidly to every country in the world". Chan also said that the world was "better prepared for an influenza pandemic than at any time in history", partly because of improved capabilities to "track the evolution of a pandemic in real-time". However, she reminded the world that "new diseases are, by definition, poorly understood", adding that flu viruses were "notorious for their rapid mutation and unpredictable behaviour".
US President Barack Obama described the swine flu outbreak as a "cause for concern but not cause for alarm", with the US government, in common with most governments around the world, advising US citizens against non-essential travel to Mexico.
Television images of Mexican citizens wearing face masks, in an attempt to prevent infection, were widely broadcast around the world. However, Professor John Oxford, a prominent UK-based virologist, said that there was "very little evidence" proving "that masks actually offer much protection against flu". Mexican President Felipe Calderon on April 30 ordered a temporary closure of government offices and some private businesses in an attempt to prevent further infections.
In the UK, Sir Liam Donaldson, the government's chief medical adviser, said that the country would suffer "many, many more cases, and inevitably some serious cases", adding that "on the whole people make a good recovery from flu". The UK Department of Health's advertising campaign (called "Catch it, Bin it, Kill it!") urged citizens to cover coughs and sneezes with tissues, dispose of used tissues, and wash hands with soap and hot water.
Governments around the world reacted to the outbreak by increasing their stockpiles of two antiviral drugs (Tamiflu, known generically as Oseltamivir, and Relenza, known generically as Zanamivir), the Reuters news agency reported on April 29, but it was unclear how effectively the drugs would treat the new strain of H1N1.
Historical context
Globally, between 3 million and 5 million people per year suffered severe illness due to the regular, seasonal, flu strain, resulting in between 250,000 and 500,000 deaths. However, global flu pandemics occurred when a new strain of the flu virus was transmitted to humans from another animal species.
In the 20th century were three notable global flu pandemics affecting humans. In the first such outbreak, in 1918 (which became known as the "Spanish flu pandemic"), between 20 per cent and 40 per cent of the worldwide population became ill and between 40 million and 100 million people died, according to some estimates. In 1957-58, in what became known as the "Asian flu pandemic", about 2 million people died, according to an article published on April 29 by the Reuters news agency. The most recent global flu pandemic, which occurred in 1968 and became know as the "Hong Kong flu pandemic", resulted in the death of one million people globally, according to some estimates.
In December 1997, the Hong Kong Special Administrative Region (HKSAR) authorities announced that they intended to slaughter all 1.25 million chickens in the territory as part of efforts to contain the spread of a deadly bird flu virus (also known as avian influenza and "H5N1") which had raised fears of a global pandemic. By the end of January 1998 the avian flu had killed a total of six people and infected at least 12 others in Hong Kong, marking the first known instances of human infection with the bird flu virus.
China reported its first fatal outbreak of the H5N1 bird flu virus in a human in November 2003, whilst the authorities in Vietnam identified bird flu as the cause of several human cases of severe respiratory disease with high fatality in January 2004. By December 2008, Egypt, which had confirmed its first H5N1 death in March 2006, had suffered 51 human cases of bird flu infection, whilst Indonesia had reported 138 cases.
In March 2003 the WHO issued an emergency bulletin warning travellers of a contagious atypical pneumonia called Severe Acute Respiratory Syndrome (SARS), the cause of which had not yet been determined. By the time of the warning the disease, which was first recorded in southern Guangdong province in China in November 2002, had also been reported in Hong Kong, Vietnam, Singapore, Indonesia, the Philippines, and Canada. Within weeks of the warning, a total of 1,485 cases and 53 deaths had been reported to the WHO, prompting the UN body to recommended screening measures at airports and create an international research project to study disease. Researchers at the University of Hong Kong concluded in May 2003 that the SARS virus had first crossed to humans from masked palm civets, a cat-like member of the Viverridae family, which was eaten as a delicacy in mainland China's southern Guangdong province.
