Jan 16, 2025 · Most influenza tests ordered in clinical settings do not distinguish avian influenza A(H5) viruses from seasonal influenza A viruses; a positive result simply confirms influenza A virus infection. Therefore, using tests that identify the seasonal influenza A virus subtype will help identify whether infection with a seasonal influenza A virus is ...

LOCS message. On January 16, 2025, the U.S. Centers for Disease Control and Prevention (CDC) issued a Health Alert Network (HAN) Health Advisory following sporadic human infections with avian influenza A(H5N1) viruses amid high levels of seasonal influenza activity. CDC recommends a shortened timeline for subtyping all influenza A specimens among hospitalized patients and increasing efforts at ...

Sep 18, 2024 · Influenza A viruses are divided into subtypes based on two proteins on the surface of the virus: hemagglutinin (H) and neuraminidase (N). There are 18 different hemagglutinin subtypes and 11 different neuraminidase subtypes (H1 …

Dec 20, 2024 · All known subtypes of influenza A viruses can infect birds, except subtypes A (H17N10) and A (H18N11), which have only been found in bats. Only two influenza A virus subtypes A (H1N1)pdm09, and A (H3N2), are currently circulating among people.

Jan 16, 2025 · The CDC recommends that this subtyping occur as soon as possible following admission — ideally within 24 hours — to determine whether the virus is a seasonal influenza A subtype (i.e. A[H1] and A[H3]) or a novel influenza A virus, such as avian influenza A H5N1.

Dec 26, 2024 · CDC compared the influenza gene segments from each specimen with A(H5N1) virus sequences from dairy cows, wild birds, poultry and other human cases in the U.S. and Canada. The genomes of the virus (A/Louisiana/12/2024) from each clinical specimen are publicly posted in GISAID (EPI_ISL_19634827 and EPI_ISL_19634828) and GenBank …

Jan 17, 2025 · Positive specimens by type/subtype : Influenza A: 1,719 (98.0%) 18,704 (97.1%) ... by the California Department of Public Health and occurred in a child less than 18 years old with no known contact with influenza A(H5N1) virus-infected animals or humans. ... Influenza Virus Characterization. CDC performs genetic and antigenic characterization ...

May 8, 2024 · CDC is actively looking at multiple flu indicators to monitor for novel flu viruses like A (H5N1), including looking for spread of the virus to, or among, people nationwide. CDC is committed to providing timely and transparent information on unusual flu activity.

Data from public health laboratories are used to monitor the proportion of circulating influenza viruses that belong to each influenza subtype/lineage. ... (H5N1) situation" † When an influenza virus that normally circulates in swine (but not people) is detected in a person, it is called a "variant" influenza virus. Most human infections with ...

Dec 30, 2024 · One subtype of bird flu, caused by avian influenza A (H5) virus, is spreading worldwide in wild birds and causing sporadic outbreaks in U.S. poultry and dairy cows. In addition to spreading to an increasing number of mammals, H5 bird …