WEB FOCUS - Avian flu timeline



First recorded recent influenza pandemic



The “Spanish Flu” pandemic, caused by the H1N1 influenza virus, kills more than 40 million people. The origin of H1N1 remains a mystery, but may have involved incubation in an intermediate host, such as the pig, or another as yet unidentified animal host.



Asian flu pandemic kills 100,000 people, due to the H2N2 influenza virus.



Hong Kong flu pandemic kills 700,000 people, due to the H3N2 virus. Both H2N2 (1957 pandemic) and H3N2 are likely to have arisen by exchange of genes between avian and human flu viruses, possibly following dual infection in humans.


21 May 1997

Bird flu virus H5N1 is isolated for the first time from a human patient in Hong Kong. The virus infects 18 patients after close contact with poultry, with six deaths. Fortunately the virus does not spread from person to person. Within three days, Hong Kong's entire chicken population is slaughtered to prevent further outbreak.


Sept 1998

Trial results announced for two new influenza drugs that target the virus’s neuraminidase enzyme, Relenza and Tamiflu, at the Interscience Conference on Antimicrobial Agents and Chemotherapy.



Two new flu drugs, Relenza and Tamiflu, are licensed in US and Europe.



The World Health Organization (WHO) outlines its new global laboratory proposal, aimed at improving the range, speed and quality of influenza virus surveillance (Science 293, 1729; 2001).


Feb 2003

Alarm bells are again raised when the avian virus H5N1 infects two people in Hong Kong, one fatal.


28 Feb 2003

Outbreaks of chicken flu occur in The Netherlands due to the H7N7 avian flu virus. By April the virus has spread to nearly 800 poultry farms and resulted in the culling of almost 11 million chickens. The virus infects 83 people causing conjunctivitis and flu-like symptoms, and kills one man. The drug Tamiflu helps protect people against further spread of the virus.


Dec 2003

South Korea has its first outbreak of avian flu in chickens, caused by H5N1.


Jan 2004

Japan has the first outbreak of avian influenza (H5N1) since 1925.


Jan 2004

WHO confirms H5N1 infection in 11 people, eight fatal, in Thailand and Vietnam, but no cases of person to person transmission. The virus has wreaked havoc among poultry in Thailand, Vietnam, Japan and South Korea, and has also appeared in a duck farm in China.

WHO is developing vaccine candidates using H5N1 viruses isolated in 2003 and 2004, at laboratories in the U.S. and U.K.


Feb 2004

United Nations Food and Agriculture Organization advises governments in affected areas that mass culling of birds is failing to halt the disease and that vaccination of targeted poultry flocks is required as well.


March 2004

Avian H5N1 flu virus becomes more widespread among bird flocks in Asia, and has caused 34 human cases, with 23 deaths.


6 April 2004

Avian influenza virus H7N3 confirmed in two poultry workers in British Columbia who developed flu-like symptoms.


June 2004

Tests on chickens and mice show that avian flu H5N1 virus isolated from ducks in 2004 is more virulent and harmful to mammals than in recent years.


July 2004

Several countries, including Thailand, Vietnam, China and Indonesia, report new infections in poultry with H5N1.


Aug 2004

H5N1 is reported to have killed an additional three people in Vietnam.

Chinese scientists report H5N1 avian flu infection in pigs, raising concerns that the virus could exchange genes with human flu strains in this 'mixing vessel'.

H5N1 virus has spread throughout most of SE Asia, resulting in the culling of over 100 million chickens. In Vietnam and Thailand, the virus has infected at least 37 people, with 26 deaths.


Oct 2004

UK authorities suspend manufacturing of this year’s routine influenza vaccine at the Liverpool factory of Chiron, owing to sterility concerns. The move leads to vaccine shortage particularly in the U.S. where Chiron supplies 50 per cent of the market, and highlights the need for alternative manufacturing sources.


Nov 2004

WHO warns that the H5N1 bird flu virus might spark a flu pandemic that could kill millions of people, and is concerned that "much of the world is unprepared for a pandemic" and needs to enhance preparedness to reduce its potential impact.

WHO officials meet with vaccine makers, public-health experts and government representatives in a bid to speed up the production of flu vaccines to avert a global pandemic.


Dec 2004

WHO reports the first human case of H5N1 in Vietnam since early September.

Sequencing of the chicken-genome (published in Nature 9 December 2004) may help provide insight into which genes prevent the spread of bird flu from person to person.

Since the beginning of 2004, bird flu has caused the deaths of 32 people in Vietnam and Thailand, and millions of chickens across Asia.


Jan 2005

Chinese authorities announce they have developed a new rapid test for bird flu that produces results in hours rather than days.


Jan/Feb 2005

13 additional cases of bird flu have occurred in Vietnam since December 2004, 12 fatal.


Feb 2005

First report of a bird flu case from Cambodia.

A report of probable person to person transmission of bird flu in Vietnam is published (New Engl. J. Med, 352 333–340)

WHO has made prototype H5N1 vaccine strains available to a number of institutions and companies and several vaccines have been developed for clinical testing.


March 2005

15 additional cases of H5N1 infection in Vietnam, and one additional case in Cambodia, are reported.

Bird flu has spread to 10 countries, including Democratic People's Republic of Korea, and killed around 50 million chickens.


April 2005

Vietnam has reported a total of 60 laboratory confirmed human cases of H5N1 avian influenza since the outbreaks began, with 35 deaths; Thailand has confirmed a total of 17 infections of which 12 have been fatal, while Cambodia has confirmed two fatal cases.


May 2005

Rumours of human deaths in China from H5N1 remain unconfirmed, while the virus has killed more than 1000 migratory birds. Indonesia's government confirms reports of H5N1 infection in pigs.


19 May 2005

WHO reports 97 cases and 53 deaths from bird flu in Vietnam, Cambodia and Thailand since January 2004.


June 2005

Indonesia confirms a man exposed to sick chickens has been infected with a deadly strain of avian flu virus. The farm labourer shows no symptoms, but his blood carries antibodies to the H5N1 strain.

Bird flu becomes resistant to the low-cost amantadine family of antiviral drugs. Chinese farmers' use of the compound in chickens is blamed, a claim formally denied by Chinese authorities who pledge to investigate the claim.


July 2005

At the end of a three-day conference in Malaysia, World Health Organization officials announce that $150 million is needed to fight the spread of the disease in people and another $100 million to stop its spread in animals in Asia.

The Philippines, so far the only Asian country unaffected by bird flu, report their first case in a town north of the capital, Manila, but do not confirm whether it is the H5N1 strain.

On 29 July, the World Health Organisation confirms that samples from an 8-year-old girl who died on the 14 July, two days after the death of her father, who was Indonesia's first confirmed human infection of influenza A (H5N1).


August 2005

The World Health Organisation (WHO) confirms three new cases of H5N1 in Vietnam. Of the three individuals infected, two died. Since mid-December 2004, 20 of the 63 cases of H5N1 in Vietnam have been fatal.

The Lancet publishes an article on 12 August 2005 saying the flu drug Relenza is at least as effective as Tamiflu, but has fewer side effects and there is no evidence of resistance to Relenza, compared with resistance levels of up to 18% in those taking Tamiflu. The researchers recommend stockpiling both drugs.

Vaccine manufacturer Maine Biological Labs is fined $500,000 for smuggling a chicken flu virus into the US. In 1998 the Maine biotechnology company illegally imported the virus from Saudi Arabia so that it could develop a vaccine for a disease-plagued poultry farm in that country. The company then used falsified documents to send 8000 bottles of the newly-created vaccine back to Saudi Arabia.

WHO recommends that regional offices stockpile drugs against bird flu. The plan suggests that each office should stockpile drugs for a 5-day course of Oseltamivir (Tamiflu) for 30% of workers and their families.

Both Russia and Kazakhstan report outbreaks of avian influenza in poultry in late July that are confirmed H5N1 in early August. Outbreaks in both countries were attributed to contact between domestic birds and wild waterfowl via shared water sources.

In early August, an outbreak of H5N1 in poultry was detected in Tibet. Mongolia then issues an emergency report following the death of 89 migratory birds at two lakes in the northern part of the country.


September 2005

Three more laboratory-confirmed cases of H5N1 strike Indonesia. A 37-year-old woman dies on 10th September and is the fourth fatality associated with H5N1 to hit the country. Indonesia's third laboratory-confirmed case of H5N1 since July 2005 involves an 8-year-old boy who survives. Later, a 27-year-old woman from Jakarta, who developed symptoms after direct contact with diseased and dying chickens in her household, dies on 26 September.

The Lancet publishes an article on 12 August 2005 saying the flu drug Relenza is at least as effective as Tamiflu, but has fewer side effects and there is no evidence of resistance to Relenza, compared with resistance levels of up to 18% in those taking Tamiflu. The researchers recommend stockpiling both drugs.

Viet Nam officials retrospectively confirm an additional fatal case of H5N1 infection, bringing the total in Viet Nam since mid-December 2004 to 64 cases, a third of which (21) were fatalities.

Two independent studies, each reaching different conclusions, suggest it would be possible to contain an emerging pandemic if the virus was detected quickly, if it did not spread too fast, if sufficient antiviral drugs were deployed around the outbreak's epicentre, and if strict quarantine and other measures were also used employed.

President George W. Bush calls for an international partnership that would require countries facing an influenza outbreak to share information and samples with the WHO. But experts say research would speed up if the US Centers for Disease Control and Prevention's (CDC) influenza branch threw open its databases of virus sequences and immunological and epidemiological data, and complain that too few of the flu data collected by the CDC are made generally available.


October 2005

Greece becomes the first EU country with a bird flu infection as the country's Centre for Veterinary Institutes detects bird flu in one turkey on the eastern Aegean island of Chios. Officials confirm the virus is a member of the H5 strain, but not yet identified as H5N1.

The WHO reiterates that the level of pandemic alert remains unchanged at phase 3: a virus new to humans is causing infections, but does not spread easily from one person to another.

On 13 October WHO states that tests conducted by the World Organisation for Animal Health (OIE) confirm the presence of H5N1 avian influenza in samples taken from domestic birds in Turkey. Days later, the presence of the virus is confirmed in Romania.

A fifth laboratory-confirmed case of H5N1 is reported from Indonesia on 10 October 2005. The 21-year old Sumatran man had contact with diseased chickens shortly before he became ill. The case brings the total number of human infections with influenza A (H5N1) since December 2003 to 117.

WHO confirms the presence of the H5N1 virus in Romania on 13th October and reiterates that The WHO level of pandemic alert remains unchanged at phase 3: a virus new to humans is causing infections, but does not spread easily from one person to another.

The Ministry of Public Health in Thailand confirms its first case of human infection with H5N1 avian influenza since 08 October 2004. A 48-year old man developed symptoms on 13 October, was hospitalized, but died less than a week later. Authorities linked his infection to close contact with diseased poultry.

The Ministry of Health in Indonesia confirms two additional cases of human infection with H5N1 avian influenza. The first, a four-year-old boy from Sumatra Island in Lampung Province, developed symptoms on 4 October and recovered. Though the boy was a nephew of a 21-year-old man from Lampung reported infected on 10 October 2005 who lived in the same village, human-to-human transmission is considered unlikely.

The second confirmed case was a 23-year-old man from West Java, who died on 30 September.


November 2005

Officials in Thailand confirm two non-fatal cases of the disease: an 18-month-old boy and a 50-year-old woman from Bangkok.

The Ministry of Health in Indonesia confirms another non-fatal human infection with the case of a 16-year-old boy who developed symptoms of fever followed by breathing difficulties. A further fatal two cases in Indonesia, a 16-year-old girl and 20-year-old woman from Jakarta bring the total newly confirmed cases total to 12, 7 of which were fatal.

Surveillance for human cases in China intensifies following a recurrence of H5N1 in poultry, with officials reporting 25 fresh outbreaks in poultry in nine provinces.

China confirms the country's first two human cases of bird flu and investigates the possibility of human-to-human transmission. A 24-year-old female from the Anhui Province becomes the country's first fatality and a 9-year-old boy is hospitalized with respiratory symptoms but recovers.

The boy's 12-year-old sister was hospitalized in October and died the following day of severe bilateral pneumonia and acute respiratory distress syndrome. According to WHO, samples from the girl are inadequate for testing and the exact cause of death will probably never be known (WHO reports only laboratory-confirmed cases).

The Chinese Ministry of Health and WHO participate in a joint mission to the Anhui Province of the country to investigate two fatal cases of H5N1 infection that occurred in female farmers aged 24 and 35 years.

A newly confirmed fatal case in Viet Nam coincides with a recurrence of outbreaks in poultry. The Ministry of Health later confirms a further non-fatal case: a 15-year-old boy from Hai Phong Province who recovered after treatment in hospital. Viet Nam has reported 66 cases (22 fatal) since December 2004.


December 2005

A 41-year-old woman from the south-eastern province of Fujian dies on 21 December, China's seventh laboratory-confirmed case and third fatality. To date, China has reported human cases in six provinces and regions: Hunan, Anhui, Guangxi, Liaoning, Jiangxi and Fujian.

The first case occurred in an 8-year-old boy from Central Jakarta. He developed symptoms of fever and cough on 8 December. He was hospitalized on 13 December, and died on 15 December.

The second case occurred in a 39-year-old man from East Jakarta. He first reported symptoms of fever, headache, cough and shortness of breath on 9 December. He was hospitalized on 11 December and died on 12 December.

These newly confirmed cases bring the total number in Indonesia to 16. Of these cases, 11 were fatal.


January 2006

Nature's Avian Flu Web Focus now contains an Internet 'mashup' that catalogues and tracks the spread of the disease, in humans and birds, around the globe. This interactive and regularly updated timeline now replaces the text timeline presented here. Download Google Earth first to access Nature's Avian Flu mashup.