LP248181-2 Influenza virus A & B & Respiratory syncytial virus RNA panel Influenza viruses A and B are single-stranded RNA enveloped viruses belonging to the Orthomyxoviridae family. The symptoms of infection of Influenza A and B include fever, cough, sore throat, rhinorrhea, nasal congestion, headache, myalgia and malaise.Influenza epidemics, also known as seasonal flu, occur annually and are the most common emerging infection among humans. These epidemics have major medical impacts, but they are generally not fatal except in certain groups such as the elderly. Pandemics, on the other hand, happen once every few decades on average.Sep 1, 2023 · Based on NCHS mortality surveillance data available on August 31, 2023, 6.5% of the deaths that occurred during the week ending August 26, 2023 (week 34), were due to pneumonia, influenza, and/or COVID-19 (PIC). This percentage is above the epidemic threshold of 5.5% for this week. Table 2: Available FDA-Cleared Rapid Influenza Diagnostic Tests (Antigen Detection Only) 1. These tests provide results in 10-15 minutes and differentiate between influenza A and B. Available FDA cleared tests as of August 2020.*The BD Veritor™ System for Rapid Detection of SARS-CoV-2 & Flu A+B is intended for the in vitro, simultaneous qualitative detection and differentiation of SARS-CoV-2 nucleocapsid antigen and/or influenza A and B nucleoprotein antigens directly from anterior nasal swab samples taken from individuals who are suspected of a viral respiratory infection consistent with COVID-19 by a healthcare ... The flu is an infection of the nose, throat, and lungs. It spreads easily from person to person. This article discusses influenza types A and B. A type of influenza A infection due to the H1N1 influenza strain is commonly called the swine flu. Alternative NamesRapid Molecular Assay [influenza viral RNA or nucleic acid detection] A and B. NP 5 swab, nasal swab. 15-30 minutes 6. Yes/No 6. Immunofluorescence, Direct (DFA) or Indirect (IFA) Florescent Antibody Staining [antigen detection] A and B. NP 4 swab or wash, bronchial wash, nasal or endotracheal aspirate. 1-4 hours.There are three types of flu viruses: A, B, and C. Type A and B cause the annual influenza epidemics that have up to 20% of the population sniffling, aching, coughing, and running high... Jan 10, 2020 · Types Symptoms Comparison Treatment Prevention Outlook There are four types of influenza virus. Influenza A is the most common, followed by influenza B. Both are highly contagious, and... (SARS-CoV-2) (Coronavirus disease [COVID-19]), influenza virus types A and B, and respiratory syncytial virus, multiplex amplified probe technique Influenza/RSV and COVID-19 0240U Infectious disease (viral respiratory tract infection), pathogen-specific RNA, 3 targets (severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2], influenza A ... The four main types of Type A and B influenza viruses that are most likely to spread and make people sick during the upcoming flu season are the targets of seasonal influenza (flu) vaccines. All of the available flu vaccinations in the United States offer protection against the influenza A(H1), A(H3), B/Yamagata, and B/Victoria lineage viruses.fever* or feeling feverish/chills. cough. sore throat. runny or stuffy nose. muscle or body aches. headaches. fatigue (tiredness) some people may have vomiting and diarrhea, though this is more common in children than adults. *It’s important to note that not everyone with flu will have a fever.Performance characteristics for influenza A and B were established during February through March 2011 when influenza viruses A/California/7/2009 (2009 H1N1), A/Perth/16/2009 (H3N2), and B/Brisbane/60/2008 (Victoria-Like) were the predominant influenza viruses in circulation according to the Morbidity and Mortality WeeklyFlu viruses are of four main types: A, B, C and D. Human influenza type A and B viruses are mainly responsible for the “flu season,” or seasonal influenza epidemics almost every winter in the United States. Type A influenza: This is the cause of most flu cases. It is the only influenza virus causing flu pandemics (a large number of flu ... Influenza (flu) is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and lungs. Some people, such as people 65 years and older, young children, and people with certain health conditions, are at higher risk of serious flu complications. There are two main types of influenza (flu) viruses: types A and B.Influenza A and B: A(H1), A(H1)pdm09, A(H3) SARS-CoV-2, Adenovirus, Coronavirus 229E, Coronavirus HKU1, Coronavirus NL63, Coronavirus OC43, Human Metapneumovirus, Human Rhinovirus/Enterovirus, Parainfluenza Virus 1, Parainfluenza Virus 2, Parainfluenza Virus 3, Parainfluenza Virus 4, Respiratory Syncytial Virus: NPS: Approximately 45 minutes ...*The BD Veritor™ System for Rapid Detection of SARS-CoV-2 & Flu A+B is intended for the in vitro, simultaneous qualitative detection and differentiation of SARS-CoV-2 nucleocapsid antigen and/or influenza A and B nucleoprotein antigens directly from anterior nasal swab samples taken from individuals who are suspected of a viral respiratory infection consistent with COVID-19 by a healthcare ... Mar 10, 2020 · Objectives Timely implementation of influenza infection control and treatment can significantly reduce the impact on Hospital resources and patient management when demand is at peak. Turnaround times of Laboratory based screening tests for the diagnosis of influenza may have an impact on the implementation of infection control measures and treatment. In this study the objectives included ... Viral transport medium acceptable for collection of influenza specimens in 1 mL or 3 mL volumes can be used to transport swabs for COVID-19 testing. For swabs in saline: OP, NP or anterior nasal swabs may be placed in 1 to 3 mL of sterile saline (0.85 to 0.9%) in a sterile screw cap container.Print. The Centers for Disease Control and Prevention (CDC) recognizes that school administrators, teachers, staff, and parents are concerned about influenza (flu), particularly its effects on children. Educators and staff can help slow the spread of respiratory illnesses, including flu. On this page, you will find information on preventing the ...The flu is caused by an influenza virus. Most people get the flu when they breathe in tiny airborne droplets from the coughs or sneezes of someone who has the flu. You can also catch the flu if you touch something with the virus on it, and then touch your mouth, nose, or eyes. People often confuse colds and flu.Nationally, flu activity during the 2021-2022 season began to increase in November and remained elevated until mid-June with two different waves of influenza A (H3N2) virus activity occurring; the first peaked in late December 2021, and the second in April 2022. Prior to the emergence of SARS-CoV-2, flu activity would most commonly begin to ...Jan 10, 2020 · Types Symptoms Comparison Treatment Prevention Outlook There are four types of influenza virus. Influenza A is the most common, followed by influenza B. Both are highly contagious, and... Influenza (flu) is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and lungs. Some people, such as people 65 years and older, young children, and people with certain health conditions, are at higher risk of serious flu complications. There are two main types of influenza (flu) viruses: types A and B.Jan 12, 2023 · Nationally, flu activity during the 2021-2022 season began to increase in November and remained elevated until mid-June with two different waves of influenza A (H3N2) virus activity occurring; the first peaked in late December 2021, and the second in April 2022. Prior to the emergence of SARS-CoV-2, flu activity would most commonly begin to ... Results are for the identification and differentiation of RNA from SARS-CoV-2, Influenza A, Influenza B and RSV. Limitations This assay is intended for use only under the Food and Drug Administration's Emergency Use Authorization.Jan 12, 2023 · There are 4 types of influenza viruses, types A, B, C and D. Influenza A and B viruses circulate and cause seasonal epidemics of disease. Influenza A viruses are further classified into subtypes according to the combinations of the hemagglutinin (HA) and the neuraminidase (NA), the proteins on the surface of the virus. Currently circulating in ... The US is only about three months into the 2019–2020 flu season, and the illness has already left its mark—but it's a little different this year. According to the Centers for Disease Control ...Yes, for some people. There are three flu vaccines that are preferentially recommended for people 65 years and older. These are Fluzone High-Dose Quadrivalent vaccine, Flublok Quadrivalent recombinant flu vaccine and Fluad Quadrivalent adjuvanted flu vaccine . This recommendation was based on a review of available studies which suggests that ... H1N1 flu is a subtype of influenza A. Subtypes of influenza A are categorized based on two proteins on the surface of the virus, hemagglutinin (H) and neuraminidase (N). There are many H and N subtypes, and each one is numbered. All H and N flu subtypes are influenza A viruses. Each influenza subtype has many different strains of influenza virus.Similarities: Both COVID-19 and flu can have varying degrees of symptoms, ranging from no symptoms (asymptomatic) to severe symptoms. Common symptoms that COVID-19 and flu share include: Fever or feeling feverish/having chills. Cough. Shortness of breath or difficulty breathing.Information for the 2023-2024 Flu Season Thursday, August 17, 2023. CDC Reports Two Human Infections with Flu Viruses From Pigs Friday, August 4, 2023. H5N1 Bird Flu Found in Polish Domestic Cats Friday, July 21, 2023. Influenza Risk Assessment Tool (IRAT) Thursday, July 6, 2023. Virus Descriptions and Report Summaries Tuesday, July 4, 2023.The flu is an infection of the nose, throat, and lungs. It spreads easily from person to person. This article discusses influenza types A and B. A type of influenza A infection due to the H1N1 influenza strain is commonly called the swine flu. Alternative NamesOct 16, 2020 · This instructional video reviews the items included in the McKesson Consult® Flu Test Kit and provides an overview of step-by-step instructions for using this test kit. The flu is an infection of the nose, throat, and lungs. It spreads easily from person to person. This article discusses influenza types A and B. A type of influenza A infection due to the H1N1 influenza strain is commonly called the swine flu. Alternative Names Influenza, commonly known as " the flu ", is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These symptoms begin from one to four days after exposure to the virus (typically two days) and last for about 2–8 days.*The BD Veritor™ System for Rapid Detection of SARS-CoV-2 & Flu A+B is intended for the in vitro, simultaneous qualitative detection and differentiation of SARS-CoV-2 nucleocapsid antigen and/or influenza A and B nucleoprotein antigens directly from anterior nasal swab samples taken from individuals who are suspected of a viral respiratory infection consistent with COVID-19 by a healthcare ...For Influenza, the test demonstrated a positive percent agreement of 83.3% (Flu A) and 80% (Flu B) and a negative percent agreement of 97.5% (Flu A) and 95.3% (Flu B) versus RT-PCR, based on ...Jan 12, 2023 · Nationally, flu activity during the 2021-2022 season began to increase in November and remained elevated until mid-June with two different waves of influenza A (H3N2) virus activity occurring; the first peaked in late December 2021, and the second in April 2022. Prior to the emergence of SARS-CoV-2, flu activity would most commonly begin to ... Nov 14, 2022 · The CDC Influenza SARS-CoV-2 (Flu SC2) Multiplex Assay is a real-time reverse-transcription polymerase chain reaction (rRT-PCR) laboratory test that can simultaneously detect and differentiate between influenza A, influenza B, and SARS-CoV-2 in upper or lower respiratory specimens. The test is a highly accurate, nucleic acid-based diagnostic ... Rapid influenza diagnostic tests (RIDTs) detect influenza viral antigens in respiratory tract specimens. Available RIDTS detect and differentiate between type influenza A and B viruses, but do not specifically identify or differentiate subtypes of influenza A viruses. RIDTs are not recommended for use in hospitalized patients with suspected ... The last time the state saw a significant wave of influenza B was in 2019, when 12,950 cases of influenza B were recorded. In 2020, 720 notifications of influenza B were made. There were 57 in ...The four main types of Type A and B influenza viruses that are most likely to spread and make people sick during the upcoming flu season are the targets of seasonal influenza (flu) vaccines. All of the available flu vaccinations in the United States offer protection against the influenza A(H1), A(H3), B/Yamagata, and B/Victoria lineage viruses.Follow recommended infection prevention and control measures1. SARS-CoV-2 Testing. Test for SARS-CoV-2 by nucleic acid detection 2. , 3 ; OR if not available, by SARS-CoV-2 antigen detection assay. 5. a) If SARS-CoV-2 Test result is positive, administer supportive care. If the patient is at high risk for progression to severe COVID-19 ... Influenza — commonly known as the flu — is a respiratory infection caused by flu viruses. There are three main types of influenza: A, B, and C. Types A and B are similar, but influenza B can ...Jun 22, 2023 · Influenza A is the most common type of influenza virus that causes the seasonal flu. Influenza A viruses are classified by subtypes based on surface proteins hemagglutinin (H) and neuraminidase (N). The viruses are named for the combination of proteins, such as A (H1N1) or A (H3N2). Influenza B. May 28, 2009 · Influenza A viruses infect a range of mammalian (e.g. pigs and horses) and avian species, whereas type B and C infections are largely restricted to humans. Only types A and B cause human disease of any concern. All of the currently identified 16 HA and 9 NA subtypes of influenza A viruses are maintained in wild, aquatic bird populations. Mayo Clinic offers flu shots in Arizona, Florida and Minnesota. Your health care provider will conduct a physical exam, look for signs and symptoms of flu, and possibly order a test that detects influenza viruses. During times when flu is widespread, you may not need to be tested for it. Your health care provider may diagnose you based on your ...The flu is caused by an influenza virus. Most people get the flu when they breathe in tiny airborne droplets from the coughs or sneezes of someone who has the flu. You can also catch the flu if you touch something with the virus on it, and then touch your mouth, nose, or eyes. People often confuse colds and flu.Oct 15, 2019 · The four types of influenza are A, B, C, and D. Types A and B are widespread during most winters in the United States. Type C is milder than types A or B and does not spread as easily. Type D ... Influenza (flu) is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and lungs. Some people, such as people 65 years and older, young children, and people with certain health conditions, are at higher risk of serious flu complications. There are two main types of influenza (flu) viruses: types A and B.1. INTRODUCTION. Influenza outbreaks are seen every year during the colder months of the year. Until now, four influenza pandemics have been reported, including the H1N1 (1918), the H2N2 (1957), the H3N2 (1967) and the H1N1 pandemic in 2009. 1 In addition, seasonal flu is reporting in different countries every year.Oct 25, 2021 · During the 2020-2021 flu season, there was very low circulation of seasonal flu viruses. During September 27, 2020–May 22, 2021 in the United States, 1,899 (0.2%) of 1,081,671 clinical samples tested were positive for an influenza virus (713 [37.5%] influenza A and 1,186 [62.5%] influenza B). During that same period, public health ... (SARS-CoV-2) (Coronavirus disease [COVID-19]), influenza virus types A and B, and respiratory syncytial virus, multiplex amplified probe technique Influenza/RSV and COVID-19 0240U Infectious disease (viral respiratory tract infection), pathogen-specific RNA, 3 targets (severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2], influenza A ... May 18, 2021 · H1N1 flu is a subtype of influenza A. Subtypes of influenza A are categorized based on two proteins on the surface of the virus, hemagglutinin (H) and neuraminidase (N). There are many H and N subtypes, and each one is numbered. All H and N flu subtypes are influenza A viruses. Each influenza subtype has many different strains of influenza virus. Influenza (the flu) is a viral infection that causes symptoms like fever and chills, sneezing, coughing and a sore throat. The flu can be serious for some people, but if you are otherwise fit and healthy you usually don’t need to see a doctor. There is a vaccine available for the flu, and it’s recommended that everyone over the age of 6 ...As fears of a "tripledemic" die down, health officials say they are seeing an uptick of a particular strain of the flu: influenza B. According to data from the Centers for Disease Control and ...Influenza A viruses infect a range of mammalian (e.g. pigs and horses) and avian species, whereas type B and C infections are largely restricted to humans. Only types A and B cause human disease of any concern. All of the currently identified 16 HA and 9 NA subtypes of influenza A viruses are maintained in wild, aquatic bird populations.Influenza A viruses infect a range of mammalian (e.g. pigs and horses) and avian species, whereas type B and C infections are largely restricted to humans. Only types A and B cause human disease of any concern. All of the currently identified 16 HA and 9 NA subtypes of influenza A viruses are maintained in wild, aquatic bird populations.Influenza B almost exclusively infects humans and is less common than influenza A. Flu type B also mutates about two to three times more slowly than influenza A. Because humans are the natural host of influenza B, pandemics generally do not occur with influenza B viruses. 22. Although scientists can classify and monitor the different types of ... Jun 22, 2023 · Influenza A is the most common type of influenza virus that causes the seasonal flu. Influenza A viruses are classified by subtypes based on surface proteins hemagglutinin (H) and neuraminidase (N). The viruses are named for the combination of proteins, such as A (H1N1) or A (H3N2). Influenza B. Background. Rapid influenza diagnostic tests (RIDTs) are immunoassays that can identify the presence of influenza A and B viral nucleoprotein antigens in respiratory specimens, and display the result in a qualitative way (positive vs. negative) (1). In the United States, a number of RIDTs are commercially available.The Flu SC2 Multiplex Assay and similar panels identify co-infections or alternative causes of influenza-like and COVID-19–like illnesses. The Flu SC2 Multiplex Assay can enable collection of critical data on influenza A and B viruses and SARS-CoV-2, as well as the prevalence of co-infection among these respiratory viruses.Nov 7, 2022 · A healthcare professional may be able to test for COVID-19, the flu and RSV at the same visit. Abbott offers several diagnostic tools to aid in fast, reliable respiratory virus testing. From our ID-NOW™ rapid system to the Alinity m Resp-4-Plex to the Panbio COVID-19/Flu A&B Rapid Panel test*, we are equipping clinicians with tools to ... Room temperature (15°C to 30°C/59°F to 86°F) Internal controls. Positive and negative included. External controls. Positive and negative included. PPA* (versus an FDA-cleared influenza A and B molecular assay) A: 81.5%, B: 80.9%. NPA* (versus an FDA-cleared influenza A and B molecular assay) A: 97.8%, B: 99.1%. There are two main types of influenza viruses: types A and B. Both type A and B influenza viruses regularly spread in people and are responsible for seasonal flu each year. WHAT IS THE The influenza A and B virus genomes each comprise eight negative-sense, single-stranded viral RNA (vRNA) segments, while influenza C virus has a seven-segment genome. (See Table 1.) The eight segments of influenza A and B viruses (and the seven segments of influenza C virus) are numbered in order of decreasing length.Influenza (flu) is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and lungs. Some people, such as people 65 years and older, young children, and people with certain health conditions, are at higher risk of serious flu complications. There are two main types of influenza (flu) viruses: types A and B.(SARS-CoV-2) (Coronavirus disease [COVID-19]), influenza virus types A and B, and respiratory syncytial virus, multiplex amplified probe technique Influenza/RSV and COVID-19 0240U Infectious disease (viral respiratory tract infection), pathogen-specific RNA, 3 targets (severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2], influenza A ...Results are for the identification and differentiation of RNA from SARS-CoV-2, Influenza A, Influenza B and RSV. Limitations This assay is intended for use only under the Food and Drug Administration's Emergency Use Authorization.For influenza A and influenza B viruses, selective amplification of target nucleic acid from the sample is achieved by the use of target-specific forward and reverse Yes. There are tests that will check for seasonal influenza A and B viruses and SARS-CoV-2, the virus that causes COVID-19. Testing for these viruses at the same time gives public health officials important information about how flu and COVID-19 are spreading and what prevention steps people should take.Dec 3, 2020 · Influenza A and B infect humans each flu season and are both highly contagious. While treatment and prevention are the same, flu B tends to be less common. Search sneezing. sore throat. fever. headache. fatigue. chills. body aches. Sometimes, influenza A symptoms may resolve on their own. However, if symptoms persist for more than a week without improvement ...Nationally, flu activity during the 2021-2022 season began to increase in November and remained elevated until mid-June with two different waves of influenza A (H3N2) virus activity occurring; the first peaked in late December 2021, and the second in April 2022. Prior to the emergence of SARS-CoV-2, flu activity would most commonly begin to ...Minjun et al. also evaluated a one-step quadruplex rRT-PCR assay to detect and differentiate SARS-CoV-2 ORF1ab and N genes, influenza type A and B. Primers targeting the matrix protein gene and the neuraminidase gene were designed to enable the detection of influenza A and B viral RNA . The assay’s performance was assessed using 312 clinical ...Follow recommended infection prevention and control measures1. SARS-CoV-2 Testing. Test for SARS-CoV-2 by nucleic acid detection 2. , 3 ; OR if not available, by SARS-CoV-2 antigen detection assay. 5. a) If SARS-CoV-2 Test result is positive, administer supportive care. If the patient is at high risk for progression to severe COVID-19 ...Jan 10, 2020 · Types Symptoms Comparison Treatment Prevention Outlook There are four types of influenza virus. Influenza A is the most common, followed by influenza B. Both are highly contagious, and... Flu Treatment. If you get sick with flu, influenza antiviral drugs may be a treatment option. Antiviral drugs work best when started early, such as one to two days after your flu symptoms begin. Check with your doctor promptly if you are at higher risk of serious flu complications and you get flu symptoms .
Waner JL, Todd, SI, Shalaby H, et al. Comparison of Directigen FLU-A with viral isolation and direct immunofluorescence for the rapid detection and identification of influenza A virus. J Clin Microbiol. 1991; 29(3):479-482. 2037665. Burnett
Follow recommended infection prevention and control measures1. SARS-CoV-2 Testing. Test for SARS-CoV-2 by nucleic acid detection 2. , 3 ; OR if not available, by SARS-CoV-2 antigen detection assay. 5. a) If SARS-CoV-2 Test result is positive, administer supportive care. If the patient is at high risk for progression to severe COVID-19 ...A healthcare professional may be able to test for COVID-19, the flu and RSV at the same visit. Abbott offers several diagnostic tools to aid in fast, reliable respiratory virus testing. From our ID-NOW™ rapid system to the Alinity m Resp-4-Plex to the Panbio COVID-19/Flu A&B Rapid Panel test*, we are equipping clinicians with tools to ...LP248181-2 Influenza virus A & B & Respiratory syncytial virus RNA panel Influenza viruses A and B are single-stranded RNA enveloped viruses belonging to the Orthomyxoviridae family. The symptoms of infection of Influenza A and B include fever, cough, sore throat, rhinorrhea, nasal congestion, headache, myalgia and malaise. People who are sick with flu often feel some or all of these symptoms: Fever*/feeling feverish or chills. Cough. Sore throat. Runny or stuffy nose. Muscle or body aches. Headaches. Fatigue (tiredness) Some people may have vomiting and diarrhea, though this is more common in children than adults.Flu symptoms for both A and B tend to appear in progression, beginning with a sudden onset of fever. Other early symptoms include: Dry cough Runny nose Sore throat Body aches Headache Fatigue When young children acquire influenza, they may experience nausea, vomiting, or diarrhea in addition to respiratory symptoms.Influenza, commonly known as " the flu ", is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These symptoms begin from one to four days after exposure to the virus (typically two days) and last for about 2–8 days.The CDC Influenza SARS-CoV-2 (Flu SC2) Multiplex Assay is a real-time reverse-transcription polymerase chain reaction (rRT-PCR) laboratory test that can simultaneously detect and differentiate between influenza A, influenza B, and SARS-CoV-2 in upper or lower respiratory specimens. The test is a highly accurate, nucleic acid-based diagnostic ...(SARS-CoV-2) (Coronavirus disease [COVID-19]), influenza virus types A and B, and respiratory syncytial virus, multiplex amplified probe technique Influenza/RSV and COVID-19 0240U Infectious disease (viral respiratory tract infection), pathogen-specific RNA, 3 targets (severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2], influenza A ... A healthcare professional may be able to test for COVID-19, the flu and RSV at the same visit. Abbott offers several diagnostic tools to aid in fast, reliable respiratory virus testing. From our ID-NOW™ rapid system to the Alinity m Resp-4-Plex to the Panbio COVID-19/Flu A&B Rapid Panel test*, we are equipping clinicians with tools to ...There are three types of flu viruses: A, B, and C. Type A and B cause the annual influenza epidemics that have up to 20% of the population sniffling, aching, coughing, and running high...Minjun et al. also evaluated a one-step quadruplex rRT-PCR assay to detect and differentiate SARS-CoV-2 ORF1ab and N genes, influenza type A and B. Primers targeting the matrix protein gene and the neuraminidase gene were designed to enable the detection of influenza A and B viral RNA . The assay’s performance was assessed using 312 clinical ...Waner JL, Todd, SI, Shalaby H, et al. Comparison of Directigen FLU-A with viral isolation and direct immunofluorescence for the rapid detection and identification of influenza A virus. J Clin Microbiol. 1991; 29(3):479-482. 2037665 H1N1 flu is a subtype of influenza A. Subtypes of influenza A are categorized based on two proteins on the surface of the virus, hemagglutinin (H) and neuraminidase (N). There are many H and N subtypes, and each one is numbered. All H and N flu subtypes are influenza A viruses. Each influenza subtype has many different strains of influenza virus..