Tweet
[bolding is mine]
Health Care Providers
JULY 8, 2025ESPAÑOL KEY POINTS
Overview of recommendations
Clinicians should consider the possibility of HPAI A(H5N1) virus infection in patients showing signs or symptoms of acute respiratory illness or conjunctivitis who also have relevant exposure history. This includes patients who:
For patients who meet the above criteria, clinicians should:
Testing for other potential causes of acute respiratory illness should also be considered depending upon the local activity of circulating respiratory pathogens, including SARS-CoV-2.
Infection prevention and control
Standard, contact, and airborne precautions with eye protection (e.g. goggles or face shield) are recommended for patients presenting for medical care or evaluation who have illness consistent with influenza and recent exposure to birds or other animals potentially infected with HPAI A(H5N1) virus.
Antiviral Treatment
Specific dosage recommendations for treatment by age group are available at Influenza Antiviral Medications: Summary for Clinicians. Physicians should consult the manufacturer's package insert for dosing, limitations of populations studied, contraindications, and adverse effects. Outpatients
Outpatients meeting epidemiologic exposure criteria who develop signs and symptoms consistent with HPAI A(H5N1) virus infection, including acute respiratory illness or conjunctivitis, should be referred for prompt medical evaluation, testing, and empiric treatment with oseltamivir (twice daily x 5 days) as soon as possible. Clinical benefit is greatest when antiviral treatment is administered early, especially within 48 hours of illness onset. Empiric antiviral treatment can be started before test results are available and after 48 hours of symptom onset.
Asymptomatic persons with bird or other animal exposures who test positive for influenza A(H5N1) virus should be offered oseltamivir treatment (twice daily x 5 days), unless already receiving oseltamivir post-exposure prophylaxis (see details below).
Hospitalized patients
Hospitalized patients meeting epidemiologic exposure criteria with signs and symptoms consistent with HPAI A(H5N1) virus infection, including acute respiratory illness or conjunctivitis, regardless of time since illness onset, are recommended to initiate antiviral treatment with oral or enterically administered oseltamivir (twice daily x 5 days) as soon as possible. Antiviral treatment should not be delayed while waiting for influenza testing results. Clinicians should consult a hospital pharmacist regarding adjustment of antiviral dosing for patients with acute kidney injury or kidney failure.
Detailed guidance on dosing and treatment duration, including consideration of combination antiviral treatment, is available at Interim Guidance of the Use of Antiviral Medications for the Treatment of Human Infection with Novel Influenza A Viruses Associated with Severe Human Disease. The optimal duration and dosing of antiviral treatment are uncertain for severe or complicated influenza. Treatment regimens might need to be altered to fit the clinical circumstances. Longer duration of treatment e.g., 10 days) should be considered for severely ill hospitalized patients with influenza A(H5N1) virus infection. Combination antiviral treatment (e.g., oseltamivir and baloxavir) can be considered for hospitalized patients. Any questions regarding arranging testing for antiviral resistance, combination antiviral treatment dosing, or regarding appropriate clinical management if antiviral resistance is a concern, should be directed to the CDC Influenza Division for consultation with a medical officer via the CDC Emergency Operations Center (770-488-7100).
Asymptomatic persons with bird or other animal exposures who test positive for influenza A(H5) virus
Asymptomatic persons exposed to animals known or suspected to be infected with HPAI A(H5N1) virus who reported not wearing recommended PPE or who experienced a PPE breach in recommended PPE and who tested positive for influenza A(H5) virus should be offered oseltamivir treatment (standard dose is twice daily x 5 days) (unless already receiving oseltamivir post-exposure prophylaxis).
Monitoring and Antiviral Post-exposure Prophylaxis of Close Contacts of Persons with HPAI A(H5N1) virus infection
Recommendations for monitoring and antiviral PEP of close contacts of infected people (e.g., household contacts of a case patient, healthcare personnel with unprotected exposures to a case patient) are different from those that apply to people who meet bird or other animal exposure criteria. Post-exposure prophylaxis of close contacts of a person with HPAI A(H5N1) virus infection is recommended as soon as possible with oseltamivir twice daily (treatment dosing) for 5 days as soon as possible instead of the once daily oseltamivir PEP dosing for seasonal influenza. Detailed guidance is available at Interim Guidance on Follow-up of Close Contacts of Persons Infected with Novel Influenza A Viruses and Use of Antiviral Medications for Chemoprophylaxis.
Antiviral Post-exposure Prophylaxis (PEP) of Persons with Animal Exposures
Considerations for Antiviral PEP of asymptomatic persons with exposures to animals infected with HPAI A(H5N1) virus For people who properly used recommended PPE
Antiviral PEP is not routinely recommended for asymptomatic persons who properly used (including when taking off) recommended PPE and experienced no breaches while handling sick or potentially infected birds or other sick or dead animals or decontaminating infected environments (including animal disposal). For people who meet the epidemiologic exposure criteria
Antiviral PEP with oseltamivir can be considered for any person meeting epidemiologic exposure criteria. Decisions to initiate antiviral PEP should be based on clinical judgment, with consideration given to the person's underlying health (e.g., pregnancy, chronic medical conditions), the type of exposure, duration of exposure, time since exposure, and known infection status of the birds or animals the person was exposed to.
Antiviral PEP is not an alternative for use of appropriate PPE and engineering and administrative controls, and receipt of PEP should not be contingent upon acceptance of and participation in influenza testing.
When feasible, offer oral oseltamivir for post-exposure prophylaxis (PEP) and avian influenza A(H5) virus testing as soon as possible to asymptomatic individuals who experienced high risk of exposure to A(H5N1) virus. Antiviral Post-exposure Prophylaxis Dosing
If oseltamivir PEP is initiated for A(H5N1), oseltamivir treatment dosing (one dose twice daily) is recommended instead of antiviral post-exposure prophylaxis dosing (once daily) for seasonal influenza. If exposure was time-limited and not ongoing, five days of medication (one dose twice daily) from the last known exposure is recommended.
Oseltamivir PEP [twice daily x 5 days (treatment dosing)]can be given to asymptomatic persons who experienced high risk of exposure (without using recommend PPE) to animals confirmed to be infected or highly suspected to be infected with HPAI A(H5N1) virus.
Longer duration of oseltamivir PEP (e.g., twice daily for 10 days) can be given for ongoing high risk of exposure (e.g., inadequate PPE) to animals confirmed to be infected or highly suspected to be infected with HPAI A(H5N1) virus.
Vaccination
No human vaccines for prevention of influenza A(H5N1) virus infection are currently commercially available in the United States. Seasonal influenza vaccines do not provide specific protection against human infection with HPAI A(H5N1) viruses.
Interim Risk Categories by Exposure
Categories of individual risk for influenza A(H5N1) virus infection by setting and exposure, including exposure to infected poultry or dairy cows, contaminated animal products, and other suspected infected peri-domestic animals.
Last updated: November 7, 2024
This tableA provides a framework for epidemiologic assessment of individual risk for highly pathogenic avian influenza (HPAI) A(H5N1) virus infection amidst the ongoing U.S. outbreak of HPAI A(H5N1) viruses in poultry and dairy cows. CDC considers the current risk to the U.S. public from HPAI A(H5N1) viruses to be low; however, persons with exposure to infected animals, or contaminated materials, including raw cow's milk, are at higher risk for HPAI A(H5N1) virus infection and should take recommended precautions, including using recommended personal protective equipment. This table is intended for use by public health practitioners to help determine how best to prioritize monitoring and investigation efforts among higher risk persons when resources are limited. In summary, among groups exposed to HPAI A(H5N1) viruses, the highest risk for HPAI A(H5N1) virus infection is from close, direct, unprotected contact with animals with confirmed or suspected HPAI A(H5N1) virus infection or their environments and exposure to contaminated raw cow's milk from infected cows or other products made from contaminated raw cow's milk.
While data are still being gathered on the current outbreak, current risk assessments are based on expert opinion and supported by historical case examples from the literature. As additional data are gathered from the response, these assessments will be refined, and the risk category associated with some exposures may change.
High risk of exposure
...continued. https://www.cdc.gov/bird-flu/hcp/cli...treatment.html
Health Care Providers
JULY 8, 2025ESPAÑOL KEY POINTS
- Clinicians should consider the possibility of highly pathogenic avian influenza (HPAI) A(H5N1) virus infection in patients showing signs or symptoms of acute respiratory illness or conjunctivitis, and who have relevant exposure history.
- Patients with relevant exposure histories who also develop signs and symptoms consistent with HPAI A(H5N1) virus infection, including acute respiratory illness or conjunctivitis, should be referred for prompt medical evaluation, testing, and empiric initiation of antiviral treatment with oseltamivir (standard dose is twice daily x 5 days) as soon as possible.
- Antiviral post-exposure prophylaxis (PEP) with oseltamivir can be considered as soon as possible for any asymptomatic person meeting epidemiologic exposure criteria (e.g., household contacts of cases or other persons with high-risk exposures).
Overview of recommendations
Clinicians should consider the possibility of HPAI A(H5N1) virus infection in patients showing signs or symptoms of acute respiratory illness or conjunctivitis who also have relevant exposure history. This includes patients who:
- Have had unprotected contact (without using recommended respiratory and eye protection) with potentially infected sick or dead birds, livestock, or other animals, or with secretions or other materials like animal bedding that were contaminated or potentially contaminated, within 10 days before symptom onset (e.g., handling, milking, feeding, and providing care for, as well as slaughtering, defeathering, butchering, culling, preparing for consumption or consuming uncooked or undercooked food or related uncooked food products, including unpasteurized (raw) milk or other unpasteurized dairy products) outdoors or indoors, including in a confined space.
- Had direct contact with water or surfaces contaminated with feces, unpasteurized (raw) milk or unpasteurized dairy products, or parts (carcasses, internal organs, etc.) of potentially infected animals.
For patients who meet the above criteria, clinicians should:
- Contact the state public health department to arrange testing for influenza A(H5N1) virus.
- Collect respiratory specimens (visit recommendations below) utilizing recommended personal protective equipment (PPE).
- Start empiric antiviral treatment with oseltamivir (more information below).
- Encourage the patient to isolate at home away from their household members and not go to work or school until it is determined they do not have HPAI A(H5N1) virus infection.
Testing for other potential causes of acute respiratory illness should also be considered depending upon the local activity of circulating respiratory pathogens, including SARS-CoV-2.
Infection prevention and control
Standard, contact, and airborne precautions with eye protection (e.g. goggles or face shield) are recommended for patients presenting for medical care or evaluation who have illness consistent with influenza and recent exposure to birds or other animals potentially infected with HPAI A(H5N1) virus.
Antiviral Treatment
Specific dosage recommendations for treatment by age group are available at Influenza Antiviral Medications: Summary for Clinicians. Physicians should consult the manufacturer's package insert for dosing, limitations of populations studied, contraindications, and adverse effects. Outpatients
Outpatients meeting epidemiologic exposure criteria who develop signs and symptoms consistent with HPAI A(H5N1) virus infection, including acute respiratory illness or conjunctivitis, should be referred for prompt medical evaluation, testing, and empiric treatment with oseltamivir (twice daily x 5 days) as soon as possible. Clinical benefit is greatest when antiviral treatment is administered early, especially within 48 hours of illness onset. Empiric antiviral treatment can be started before test results are available and after 48 hours of symptom onset.
Asymptomatic persons with bird or other animal exposures who test positive for influenza A(H5N1) virus should be offered oseltamivir treatment (twice daily x 5 days), unless already receiving oseltamivir post-exposure prophylaxis (see details below).
Hospitalized patients
Hospitalized patients meeting epidemiologic exposure criteria with signs and symptoms consistent with HPAI A(H5N1) virus infection, including acute respiratory illness or conjunctivitis, regardless of time since illness onset, are recommended to initiate antiviral treatment with oral or enterically administered oseltamivir (twice daily x 5 days) as soon as possible. Antiviral treatment should not be delayed while waiting for influenza testing results. Clinicians should consult a hospital pharmacist regarding adjustment of antiviral dosing for patients with acute kidney injury or kidney failure.
Detailed guidance on dosing and treatment duration, including consideration of combination antiviral treatment, is available at Interim Guidance of the Use of Antiviral Medications for the Treatment of Human Infection with Novel Influenza A Viruses Associated with Severe Human Disease. The optimal duration and dosing of antiviral treatment are uncertain for severe or complicated influenza. Treatment regimens might need to be altered to fit the clinical circumstances. Longer duration of treatment e.g., 10 days) should be considered for severely ill hospitalized patients with influenza A(H5N1) virus infection. Combination antiviral treatment (e.g., oseltamivir and baloxavir) can be considered for hospitalized patients. Any questions regarding arranging testing for antiviral resistance, combination antiviral treatment dosing, or regarding appropriate clinical management if antiviral resistance is a concern, should be directed to the CDC Influenza Division for consultation with a medical officer via the CDC Emergency Operations Center (770-488-7100).
Asymptomatic persons with bird or other animal exposures who test positive for influenza A(H5) virus
Asymptomatic persons exposed to animals known or suspected to be infected with HPAI A(H5N1) virus who reported not wearing recommended PPE or who experienced a PPE breach in recommended PPE and who tested positive for influenza A(H5) virus should be offered oseltamivir treatment (standard dose is twice daily x 5 days) (unless already receiving oseltamivir post-exposure prophylaxis).
- Exposed asymptomatic persons who test positive for influenza A(H5) virus should wear a facemask when in close contact with others and should continue to be actively monitored for signs and symptoms of acute respiratory illness or conjunctivitis for 10 days after testing A(H5) virus positive.
- Any exposed person who tested positive for influenza A(H5) virus while asymptomatic and who develops signs or symptoms of acute respiratory illness or conjunctivitis while receiving oseltamivir for treatment or post-exposure prophylaxis, should be isolated, and tested again for A(H5) virus. If testing is negative for influenza A(H5) virus, testing for other respiratory pathogens can be considered.
- Repeat testing is recommended to rule out initial A(H5) virus test positivity as a result of viral contamination, such as from an environmental exposure, that did not progress to infection [i.e., repeat testing yields a negative A(H5) virus result] and to allow for evaluation of development of antiviral resistance during treatment/prophylaxis if repeat testing is still positive for A(H5) virus.
Monitoring and Antiviral Post-exposure Prophylaxis of Close Contacts of Persons with HPAI A(H5N1) virus infection
Recommendations for monitoring and antiviral PEP of close contacts of infected people (e.g., household contacts of a case patient, healthcare personnel with unprotected exposures to a case patient) are different from those that apply to people who meet bird or other animal exposure criteria. Post-exposure prophylaxis of close contacts of a person with HPAI A(H5N1) virus infection is recommended as soon as possible with oseltamivir twice daily (treatment dosing) for 5 days as soon as possible instead of the once daily oseltamivir PEP dosing for seasonal influenza. Detailed guidance is available at Interim Guidance on Follow-up of Close Contacts of Persons Infected with Novel Influenza A Viruses and Use of Antiviral Medications for Chemoprophylaxis.
Antiviral Post-exposure Prophylaxis (PEP) of Persons with Animal Exposures
Considerations for Antiviral PEP of asymptomatic persons with exposures to animals infected with HPAI A(H5N1) virus For people who properly used recommended PPE
Antiviral PEP is not routinely recommended for asymptomatic persons who properly used (including when taking off) recommended PPE and experienced no breaches while handling sick or potentially infected birds or other sick or dead animals or decontaminating infected environments (including animal disposal). For people who meet the epidemiologic exposure criteria
Antiviral PEP with oseltamivir can be considered for any person meeting epidemiologic exposure criteria. Decisions to initiate antiviral PEP should be based on clinical judgment, with consideration given to the person's underlying health (e.g., pregnancy, chronic medical conditions), the type of exposure, duration of exposure, time since exposure, and known infection status of the birds or animals the person was exposed to.
Antiviral PEP is not an alternative for use of appropriate PPE and engineering and administrative controls, and receipt of PEP should not be contingent upon acceptance of and participation in influenza testing.
When feasible, offer oral oseltamivir for post-exposure prophylaxis (PEP) and avian influenza A(H5) virus testing as soon as possible to asymptomatic individuals who experienced high risk of exposure to A(H5N1) virus. Antiviral Post-exposure Prophylaxis Dosing
If oseltamivir PEP is initiated for A(H5N1), oseltamivir treatment dosing (one dose twice daily) is recommended instead of antiviral post-exposure prophylaxis dosing (once daily) for seasonal influenza. If exposure was time-limited and not ongoing, five days of medication (one dose twice daily) from the last known exposure is recommended.
Oseltamivir PEP [twice daily x 5 days (treatment dosing)]can be given to asymptomatic persons who experienced high risk of exposure (without using recommend PPE) to animals confirmed to be infected or highly suspected to be infected with HPAI A(H5N1) virus.
Longer duration of oseltamivir PEP (e.g., twice daily for 10 days) can be given for ongoing high risk of exposure (e.g., inadequate PPE) to animals confirmed to be infected or highly suspected to be infected with HPAI A(H5N1) virus.
Vaccination
No human vaccines for prevention of influenza A(H5N1) virus infection are currently commercially available in the United States. Seasonal influenza vaccines do not provide specific protection against human infection with HPAI A(H5N1) viruses.
Interim Risk Categories by Exposure
Categories of individual risk for influenza A(H5N1) virus infection by setting and exposure, including exposure to infected poultry or dairy cows, contaminated animal products, and other suspected infected peri-domestic animals.
Last updated: November 7, 2024
This tableA provides a framework for epidemiologic assessment of individual risk for highly pathogenic avian influenza (HPAI) A(H5N1) virus infection amidst the ongoing U.S. outbreak of HPAI A(H5N1) viruses in poultry and dairy cows. CDC considers the current risk to the U.S. public from HPAI A(H5N1) viruses to be low; however, persons with exposure to infected animals, or contaminated materials, including raw cow's milk, are at higher risk for HPAI A(H5N1) virus infection and should take recommended precautions, including using recommended personal protective equipment. This table is intended for use by public health practitioners to help determine how best to prioritize monitoring and investigation efforts among higher risk persons when resources are limited. In summary, among groups exposed to HPAI A(H5N1) viruses, the highest risk for HPAI A(H5N1) virus infection is from close, direct, unprotected contact with animals with confirmed or suspected HPAI A(H5N1) virus infection or their environments and exposure to contaminated raw cow's milk from infected cows or other products made from contaminated raw cow's milk.
While data are still being gathered on the current outbreak, current risk assessments are based on expert opinion and supported by historical case examples from the literature. As additional data are gathered from the response, these assessments will be refined, and the risk category associated with some exposures may change.
High risk of exposure
...continued. https://www.cdc.gov/bird-flu/hcp/cli...treatment.html