Bird Flu Outbreaks 2023

Authored by
Staff
Last reviewed
November 25, 2023
Content Overview
Avian influenza outbreaks have occurred in various countries in 2023. Bird flu vaccines have been U.S. FDA approved.

Avian Influenza (Bird Flu) Outbreaks

Avian influenza (Bird Flu) is a disease caused by influenza type A viruses that occur naturally among birds. Highly Pathogenic Avian Influenza (HAPI) viruses carrying the H1N1, H2N2, and H3N2 combinations were responsible for the Spanish flu of 1918, the Asian flu in 1957, and the Hong Kong flu in 1968. HAPI virus subtypes (H5, H7, H9) A(H5N1) emerged in southern China in 1997. Avian influenza A (H5N1) was first detected in the Americas in birds in December 2014. During the 2014-2015 outbreak, 70% of HPAI cases were attributed to the lateral spread of H5N1.

In December 2021, H5N1 HPAI viruses were detected in St. John's, Newfoundland and Labrador, Canada. A phylogenetic analysis showed that these viruses were most closely related to HPAI GsGd viruses circulating in northwestern Europe in spring 2021. In July 2022, a study published by Nature suggested that these viruses may have been carried across the Atlantic via Iceland, Greenland/Arctic, or maritime (sea) routes.

The U.S. Centers for Disease Control and Prevention (CDC) published an updated Technical Report: Highly Pathogenic Avian Influenza (HAPI) A(H5N1) Viruses in June 2023, that confirmed the overall risk to human health associated with the ongoing outbreaks of highly pathogenic A(H5N1) viruses in wild birds and poultry remains low. According to the CDC FluView dashboard, 54 countries reported bird flu outbreaks to the World Health Organization (WHO) from 2021 through August 2023. Bird flu outbreaks in the U.S. are mainly located along the Pacific Flyway. The U.S. CDC Current Situation Summary,  updated as of August 9, 2023, confirmed the current risk to the public from HPAI viruses remains low. However, continued sporadic human infections are anticipated. The U.S. Department of Agriculture's (USDA) Animal and Plant Health Inspection Service (APHIS) stated the Eurasian (H5 clade 2.3.4.4b.) appeared in North America in January 2022. These are the U.S.'s first HPAI A(H5) virus detection since 2016. The CDC posted: Ask the Experts: HAPI A(H5N1) Viruses.

As of 2023, the Pan American Health Organization (PAHO) reported H5N1 viruses (clade 2.3.4.4b) had been in 15 countries in Latin America, the Caribbean, the U.S., and Canada. Except for pockets of endemic clade activity in South and Southeast Asia, clade 2.3.4.4b viruses have predominated over other A(H5Nx) clades over the past 18 months. Clade 2.3.4.4b viruses have become entrenched in Asia, Europe, and probably in parts of Africa. The WHO published an updated FAQBirdCast applies weather surveillance radar to gather information on the numbers, flight directions, speeds, and altitudes of birds aloft to expand the understanding of migratory bird movement.

Human Bird Flu Cases

The World Health Organization (WHO) report #907 confirmed in 2023 that sporadic influenza A(H5N1) clade 2.3.4.4b virus detections in humans. On July 12, 2023, WHO, the Food and Agriculture Organization of the United Nations, and the World Organisation for Animal Health issued a joint statement confirming the ongoing avian influenza outbreaks in animals pose a risk to humans. Globally, from January 2003 to July 14, 2023, 878 cases of human infection with avian influenza A(H5N1) virus were reported from 23 countries. Of these 878 cases, 458 were fatal (CFR of 52%). The WHO recently published its Influenza Pandemic Framework's  Partnership Contribution High-Level Implementation Plan III, outlining preparedness strategies for 2024 to 2030.

Nearly all reported human bird flu cases since 2022 were associated with recent poultry exposures. On November 18, 2023, the CDC Emerging Infectious Diseases confirmed the genotype analysis of sequences from 48 animals, indicating that the HAPI cases represent spillover infections from wild birds.

Human Bird Flu Cambodia

In October 2023, Two fatal human infections with highly pathogenic avian influenza (HPAI) A H5N1 (bird flu) virus were reported by Cambodia. These are the third and fourth human infections with HPAI H5N1 bird flu reported by Cambodia in 2023. On March 3, 2023, the CDC issued an update providing results of a preliminary assessment of the H5N1 viruses identified in two human infections detected in Cambodia in 2023. @PasteurCambodia is collaborating with Cambodian authorities surrounding these cases, and no implications of human-to-human transmission have been found. The Ministry of Health and the WHO reported bird flu has been endemic in Cambodia since 2005, with 57 infections and 38 deaths.

Human Bird Flu China

The Centre for Health Protection (CHP) of the Department of Health closely monitors human cases of avian influenza in the Mainland and urges the public to maintain strict personal, food, and environmental hygiene locally and during travel. The CHP reported on August 23, 2023; from 2014 to date, Mainland health authorities have reported 86 human cases of avian influenza A(H5N6). On January 5, 2023, and July 23, 2023, the Alert Response Level under the CHP's Government Preparedness Plan for the Influenza Pandemic was activated. The public may visit the CHP's weekly Avian Influenza Report, global statistics, and affected areas of avian influenza for updated news.

On March 27, 2023, the National Health Commission of the People's Republic of China notified the WHO of one confirmed human infection with an avian influenza A(H3N8) virus. The patient was a 56-year-old female from Guangdong province. She was hospitalized for severe pneumonia and died on March 16, 2023. A study published on August 9, 2023, confirmed the first known human death after infection with the avian influenza (A/H3N8) virus.

As of June 12, 2023, and since 1998, a total of 112 laboratory-confirmed cases of human infection with avian influenza A(H9N2) viruses have been reported in China.

Human Bird Flu India

Thiruvananthapuram's Health Minister confirmed a bird flu infection in Trivandrum Azhur Gram Panchayat in southern India in January 2023.

Human Bird Flu Vietnam

On October 17, 2022, the Vietnam Central Institute of Hygiene and Epidemiology reported positive influenza A(H5) results in a specimen from a 5-year-old female patient in Phu Tho. Since 2003, Vietnam has recorded 127 influenza A(H5) infection cases.

Human Bird Flu Ukraine

Local media reported a bird flu outbreak at a poultry farm in the village of Velyka Oleksandrivka in the Kherson region of Ukraine on March 19, 2023. Eighteen people were hospitalized, two of whom died. Reuters reported previous bird flu cases in January 2023.

Human Bird Flu United Kingdom

The U.K. Health Services Agency (UKHSA) confirmed in July 2023 that 15 human cases of influenza A(H5N1) clade 2.3.4.4b virus have been reported globally officially since December 2021.

Human Bird Flu United States

Human influenza A H5N1 2.3.4.4b infections globally were reported in 2022-2023. Available epidemiological and virological evidence currently suggests that influenza A(H5) viruses have not acquired the ability to sustain transmission among humans. As of July 2023, more than 6,500 people in 52 jurisdictions have been monitored since 2022, and only one human case has been identified. In addition, more than 160 people showed symptoms and were subsequently tested for novel influenza A viruses (Swine flu). On April 28, 2022, the state of Colorado reported the first influenza A (H5) virus infection in Montrose County. The CDC says this 'Colorado patient is the first human detection of any influenza A(H5) virus in the U.S. since 2016. In addition, the CDC publishes Past Reported Global Human Cases with Highly Pathogenic Avian Influenza A(H5N1) (HPAI H5N1) by Country, 1997-2022. As of 2022, the WHO posted the cumulative number of confirmed human cases of avian influenza A(H5N1) reported (2003-2022).

In addition, the CDC published Dispatch Volume 29, Number 6 (June 2023), confirming among 4,000 persons exposed to infected birds, 

Bird Flu Caribbean 

Prensa Latina reported on February 7, 2023, Cuba's National Center for Animal Health confirmed the presence of bird flu in wild birds at the Havana Zoological Garden in Plaza de la Revolucion municipality. On November 28, 2022, it confirmed its initial HAPI outbreak.

Bird Flu Central America

On January 18, 2023, the WHO stated that the Ecuador case was the first human infection caused by the avian influenza A(H5) virus in Latin America and the Caribbean. As of February 2023, countries such as Belize, Honduras, Mexico, and Panama have recently confirmed HAPI cases.

Bird Flu Europe

The European Centre for Disease Prevention and Control (ECDC) reported Between December 2022 and March 2023, the HPAI A(H5N1) virus, clade 2.3.4.4b, was reported in Europe in domestic (522) and wild (1,138) birds over 24 countries, and in sea birds, mainly in gull species and particularly in black-headed gulls (France, Belgium, the Netherlands, and Italy). The close genetic relationship among viruses collected from black-headed gulls suggests a southward spread of the virus. Moreover, the genetic analyses indicate that the virus persisted in Europe in residential wild birds during and after the summer months. On June 26, 2023, the European Centre for Disease Prevention and Control (ECDC) published Enhanced Surveillance of severe avian influenza virus infections in the EU/EEA hospital settings.

Bird Flu France

The French Ministry of Agriculture reduced the nationwide bird flu alert level from high to moderate on March 14, 2023. However, "Since May 4, 2023, 21 HAPI outbreaks have been detected in south-western France, mostly among ducks," the ministry stated. European officials agreed in 2022 to implement a poultry vaccination strategy in France with ducks.

Bird Flu Japan

On January 27, 2023, seven new outbreaks of H5N1 were reported in Japan: Otsu-City 1, Sousa-City 1, Sera-Town 5, and Maebashi-city 2. As a result, 49 cases and 34 deaths were reported among domestic birds, and 716,416 birds were culled.

Bird Flu Spain

On November 4, 2022, public health authorities in Spain reported the detection of influenza A(H5N1) in two poultry workers on a single farm. However, no evidence of human-to-human transmission of the influenza A(H5N1) virus in this event has been identified.

Spanish researchers reported in Eurosurveillance on January 19, 2023, the first known HAPI A(H5N1) outbreak in farmed mink in the Galicia region. The new variant puts bird flu in "uncharted territory," says Wendy Puryear, a virologist at Tufts University in Massachusetts, on January 24, 2023.

Bird Flu South America

The PAHO issued an epidemiological alert in 2023 in response to the increased detection of avian influenza outbreaks in birds in ten countries in the Americas. As of 2023, birds, mammals, and humans infected with HAPI were confirmed in Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela, and Uruguay. The overall risk to human health associated with the ongoing A(H5N1) outbreak in wild birds and poultry has not changed and remains low.

In November 2023, Brazil's Ministry of Agriculture and Livestock extended the declaration of an animal health emergency for 180 more days across the Country due to the identification of outbreaks of the highly pathogenic H5N1 avian influenza virus, mainly in wild birds. 

The CDC addendum to Technical Report: Highly Pathogenic Avian Influenza A(H5N1) Viruses published on April 17, 2023, summarizes the case and the genomic analysis of the virus from the first H5N1 infection reported in a human in Chile. On March 29, 2023, the Chilean Ministry of Health notified the WHO of a laboratory-confirmed case of human infection caused by the avian influenza A(H5) virus in the Region of the Americas. This is the first human infection with avian influenza A(H5) virus reported in Chile and the third reported in the Region of the Americas to date. 

MercoPress reported on May 22, 2023, that  Paraguay's National Animal Health and Quality Service confirmed three H5 outbreaks in the Chaco region in the northwest, involving backyard birds.

Bird Flu United Kingdom

The U.K. Health Security Agency (UKHSA) published new guidance (fourth update) regarding the risk assessment of avian influenza A(H5N1) on January 31, 2023. The risk of influenza A(H5N1) infection in U.K. residents within the U.K. is very low. On October 17, 2022, the U.K. declared an Avian Influenza Prevention Zone, making it a legal requirement for all bird keepers to follow strict biosecurity measures.

Bird Flu in Mammals 2023

Mammalian bird flu news is posted at this link.

Bird Flu Vaccines

Avian influenza (bird flu) vaccines are listed on this web page.