Commonground
Senior Moderator
THIS IS AN OFFICIAL NH DHHS HEALTH ALERT
Distributed by the NH Health Alert Network
DHHS.Health.Alert@dhhs.nh.gov
January 16, 2025, 1700 EDT (5:00 PM EDT)
NH-HAN 202501161
H5N1 Avian Influenza Update
Key Points and Recommendations:
• Review the Background Information below, and be aware that a CDC HAN
released on 1/16/25 outlines one strategy for early identification of human H5N1
infections.
• Almost all of the initial patients with H5N1 infections had an identified exposure to
infected birds or animals and presented with mild symptoms, including
conjunctivitis as the most commonly reported symptom (see NEJM article).
• Ask any patient presenting with signs or symptoms of influenza (including
conjunctivitis) about exposure to sick or dying animals (including wild birds,
poultry, or livestock). For any person with compatible signs/symptoms AND who
reports a relevant exposure history:
– Isolate the patient and wear appropriate PPE per CDC infection control
guidance
– Notify NH Division of Public Health Services (DPHS) immediately by
calling 603-271-4496 (after hours 603-271-5300)
– Collect the recommended conjunctival and/or respiratory specimens for
influenza virus testing, including expedited subtyping at our NH Public
Health Laboratories (PHL)
– Initiate empiric antiviral treatment and do not delay treatment while
awaiting laboratory results
• Because H5N1 has not been identified in dairy cattle or people in New England,
and there have been no recent detections in NH poultry flocks, the risk of
unidentified H5N1 human infection in NH is very low. Therefore, NH DPHS is
currently requesting clinical specimens from the following patients be sent to the
NH PHL for subtyping:
– Any patients (hospitalized or outpatient) who have undergone testing and
subtyping (e.g., on a BioFire panel) and test positive for influenza A, but
negative for H3 or H1
– Severely ill patients hospitalized in the ICU for influenza, even without a
known exposure history to sick animals
NH DHHS-DPH
NH-HAN #202501161 H5N1 Avian Influenza Update Page 2
Background Information
Influenza A virus subtype H5N1 has been circulating in wild migratory bird populations in
the U.S. since December 2021, which has led to introductions and outbreaks in
commercial and backyard poultry flocks and mammals. In March 2024, H5N1 was
introduced into U.S. dairy cattle and has since been spreading between dairy cattle
farms causing more than 925 outbreaks in 16 different states. There have been no
H5N1 outbreaks identified in dairy cattle or commercial poultry flocks in New England,
but H5N1 has been identified sporadically in backyard poultry flocks, including in NH
most recently in January 2023.
Due to increasing human exposures to infected animals, there have been an increasing
number of human infections, primarily due to occupational exposures to infected poultry
and dairy cattle. There have been 67 total human infections reported so far in the U.S.
since 2024, including one death. Most of the human infections have been mild, including
people presenting with only signs/symptoms of conjunctivitis (see NEJM article), but
severe disease has been reported (see NEJM Case Report and CDC media statement).
There is no current evidence of human-to-human transmission, but the more that virus
circulates in bird and mammal populations, the greater the risk for virus adaptation for
human transmission. Therefore, in an attempt to eliminate H5N1 from dairy cattle and
reduce human and animal exposures, the USDA is implementing a National Milk Test
Strategy, which the NH dairy program will begin to implement at the beginning of
February 2025.
For Additional Information:
https://www.cdc.gov/bird-flu/index.html
https://www.cdc.gov/bird-flu/hcp/clinicians-evaluating-patients/index.html
https://www.dhhs.nh.gov/sites/g/files/ehbemt476/files/documents2/han-h5n1-avian-influenza-update.pdf
Distributed by the NH Health Alert Network
DHHS.Health.Alert@dhhs.nh.gov
January 16, 2025, 1700 EDT (5:00 PM EDT)
NH-HAN 202501161
H5N1 Avian Influenza Update
Key Points and Recommendations:
• Review the Background Information below, and be aware that a CDC HAN
released on 1/16/25 outlines one strategy for early identification of human H5N1
infections.
• Almost all of the initial patients with H5N1 infections had an identified exposure to
infected birds or animals and presented with mild symptoms, including
conjunctivitis as the most commonly reported symptom (see NEJM article).
• Ask any patient presenting with signs or symptoms of influenza (including
conjunctivitis) about exposure to sick or dying animals (including wild birds,
poultry, or livestock). For any person with compatible signs/symptoms AND who
reports a relevant exposure history:
– Isolate the patient and wear appropriate PPE per CDC infection control
guidance
– Notify NH Division of Public Health Services (DPHS) immediately by
calling 603-271-4496 (after hours 603-271-5300)
– Collect the recommended conjunctival and/or respiratory specimens for
influenza virus testing, including expedited subtyping at our NH Public
Health Laboratories (PHL)
– Initiate empiric antiviral treatment and do not delay treatment while
awaiting laboratory results
• Because H5N1 has not been identified in dairy cattle or people in New England,
and there have been no recent detections in NH poultry flocks, the risk of
unidentified H5N1 human infection in NH is very low. Therefore, NH DPHS is
currently requesting clinical specimens from the following patients be sent to the
NH PHL for subtyping:
– Any patients (hospitalized or outpatient) who have undergone testing and
subtyping (e.g., on a BioFire panel) and test positive for influenza A, but
negative for H3 or H1
– Severely ill patients hospitalized in the ICU for influenza, even without a
known exposure history to sick animals
NH DHHS-DPH
NH-HAN #202501161 H5N1 Avian Influenza Update Page 2
Background Information
Influenza A virus subtype H5N1 has been circulating in wild migratory bird populations in
the U.S. since December 2021, which has led to introductions and outbreaks in
commercial and backyard poultry flocks and mammals. In March 2024, H5N1 was
introduced into U.S. dairy cattle and has since been spreading between dairy cattle
farms causing more than 925 outbreaks in 16 different states. There have been no
H5N1 outbreaks identified in dairy cattle or commercial poultry flocks in New England,
but H5N1 has been identified sporadically in backyard poultry flocks, including in NH
most recently in January 2023.
Due to increasing human exposures to infected animals, there have been an increasing
number of human infections, primarily due to occupational exposures to infected poultry
and dairy cattle. There have been 67 total human infections reported so far in the U.S.
since 2024, including one death. Most of the human infections have been mild, including
people presenting with only signs/symptoms of conjunctivitis (see NEJM article), but
severe disease has been reported (see NEJM Case Report and CDC media statement).
There is no current evidence of human-to-human transmission, but the more that virus
circulates in bird and mammal populations, the greater the risk for virus adaptation for
human transmission. Therefore, in an attempt to eliminate H5N1 from dairy cattle and
reduce human and animal exposures, the USDA is implementing a National Milk Test
Strategy, which the NH dairy program will begin to implement at the beginning of
February 2025.
For Additional Information:
https://www.cdc.gov/bird-flu/index.html
https://www.cdc.gov/bird-flu/hcp/clinicians-evaluating-patients/index.html
https://www.dhhs.nh.gov/sites/g/files/ehbemt476/files/documents2/han-h5n1-avian-influenza-update.pdf