Michigan - Human cases of H5N1 2024 (2 cases)

[sharon sanders]

hat tip Michael Coston


First case of influenza A (H5) detected in Michigan resident

https://content.govdelivery.com/attachments/MIDHHS/2024/05/22/file_attachments/2886512/Influenza%20A%20Detection.pdf

[Pathfinder]

First case of influenza A (H5) detected in Michigan resident

May 22, 2024

The Michigan Department of Health and Human Services (MDHHS) is announcing the first case of influenza A (H5) virus identified in a Michigan farmworker who had regular exposure to livestock infected with influenza A (H5). This follows extensive public heath actions over the course of the last few months by the state of Michigan to allow farmworkers to monitor and notify local public health officials should they have symptoms. According to the Centers for Disease Control (CDC), the risk to the public remains low; the Michigan farmworker diagnosed with influenza A (H5) had mild symptoms and has recovered. To protect farm and farmworker privacy, additional details are not being provided.

The virus has been circulating in dairy and poultry farms across the U.S. this spring, and state and local public health officials have been closely monitoring for human cases, which can occur sporadically in individuals with close contact to ill animals. This virus has been associated with the ongoing multistate outbreak of influenza A (H5N1). As such, it is not unexpected that comprehensive testing identified a human infection. Information to date suggests this is a sporadic infection, with no associated ongoing spread person-to-person.

“Michigan has led a swift public health response, and we have been tracking this situation closely since influenza A (H5N1) was detected in poultry and dairy herds in Michigan. Farmworkers who have been exposed to impacted animals have been asked to report even mild symptoms, and testing for the virus has been made available,” said Dr. Natasha Bagdasarian, chief medical executive. “The current health risk to the general public remains low. This virus is being closely monitored, and we have not seen signs of sustained human-to-human transmission at this point. This is exactly how public health is meant to work, in early detection and monitoring of new and emerging illnesses.”

MDHHS and local health departments continue to work closely with the Michigan Department of Agriculture and Rural Development (MDARD), farms and workers to conduct monitoring of the health of people exposed to ill animals.

“Since the first detection of influenza A (H5N1) in dairy cattle on March 29, Michigan has prioritized both the animal and human health aspects of this disease outbreak. Today’s news underscores the continued importance of limiting nonessential farm visits, including farm tours and field trips, as well as the use of personal protective equipment when working with livestock,” said MDARD Director Tim Boring.

MDARD continues to implement a proactive, science-based approach to mitigating the spread of influenza A (H5N1). Michigan's response to influenza A (H5N1) has been a one-health approach, working with federal, state and local partners to address animal and public health concerns rapidly. Three U.S. Department of Agriculture (USDA) emergency management teams have been on the ground assisting MDARD in day-to-day responses at all impacted poultry facilities statewide. An epidemiological team from USDA is also deployed to further assist in tracing and testing within dairy herds to be able to provide real-time information.

Director Boring has taken proactive actions by signing an "Determination of Extraordinary Emergency" order Wednesday, May 1, which further protects Michigan's poultry and livestock industries from the ongoing threat of influenza A (H5N1). Michigan's order enhances USDA's federal order, which was issued Wednesday, April 24.

MDARD has identified both dairy and poultry farms that have tested positive for influenza A (H5N1) in several Michigan counties. Risk is not limited to those geographies as additional detections may be possible.

MDHHS recommends seasonal flu vaccination for people working on poultry or dairy farms. It will not prevent infection with avian influenza viruses, but it can reduce the risk of coinfection with avian and flu viruses.

Since 2022, there have been two previous human cases related to bird and dairy exposure in the U.S. -- one in Colorado in 2022 and one in Texas in 2024.

For more information, visit Michigan.gov/InfluenzaA.

###

https://www.michigan.gov/mdhhs/insid...za-a-detection

[sharon sanders]

Thanks Pathfinder for expanding that link.

[sharon sanders]

Please see:

FluTrackers 2016+ Global H5N1 Human Cases List

Michigan - Avian flu in mammals and livestock 2024

Michigan: 2022-2024 Avian flu in poultry

Michigan - Avian influenza in wild birds 2024

Michigan: Determination of Extraordinary Emergency HPAI Risk Reduction & Response May 1, 2024. (...effective Wednesday, May 8, 2024). Department Of Agriculture And Rural Development

[Treyfish]

Michigan farmworker diagnosed with bird flu, becoming 2nd US case tied to cows
On Wednesday, May 22, 2024, Michigan health officials said a farmworker has been diagnosed with bird flu, the second human case connected to an outbreak in U.S. dairy cows. (Cynthia Goldsmith, Jackie Katz/CDC via AP)Read More
BY MIKE STOBBE AND JONEL ALECCIA
Updated 3:38 PM EDT, May 22, 2024
Share
NEW YORK (AP) — A Michigan dairy worker has been diagnosed with bird flu — the second human case associated with an outbreak in U.S. dairy cows.

The patient had mild eye symptoms and has recovered, U.S. and Michigan health officials said in announcing the case Wednesday. The worker had been in contact with cows presumed to be infected, and the risk to the public remains low, officials said.

A nasal swab from the person tested negative for the virus, but an eye swab tested positive, “indicating an eye infection,” the U.S. Centers for Disease Control and Prevention said in a statement…

https://apnews.com/article/bird-flu-cows-michigan-farmworker-cacf56984b328ff2b2f94883b20f5272

[Treyfish]

Michigan reports H5 avian flu in dairy farm worker


Lisa Schnirring


12 minutes ago.

The Michigan Department of Health and Human Services (MDHHS) today announced an H5 avian flu case in a Michigan farm worker who had regular exposure to infected livestock, marking the third human case in the United States and the second related to the H5N1 outbreaks in dairy cattle. Patient recovered after mild symptoms


In a statement, MDHHS said the identification of the case came after the state's ongoing public health actions allowed farm workers to monitor and notify health officials if they develop symptoms.

Officials didn't detail the patient's symptoms, but said they were mild and that the farm worker has recovered. The earlier patient from a Texas farm also had a mild illness, which consisted of conjunctivitis.

Natasha Bagdasarian, MD, MPH, chief medical executive at the MDHHS, said, "Michigan has led a swift public health response, and we have been tracking this situation closely since influenza A (H5N1) was detected in poultry and dairy herds in Michigan. Farmworkers who have been exposed to impacted animals have been asked to report even mild symptoms, and testing for the virus has been made available."

CDC weighs in on test results and current risk

Also in a statement today, the Centers for Disease Control and Prevention (CDC) said a nasal swab for the worker tested negative for H5 influenza at the state lab in Michigan, but an eye swab shipped to the CDC for testing was positive, suggesting an eye infection, similar to the Texas patient.

The CDC's lab is one of a few where can eye specimens can be used with the CDC's H5 test. The CDC also retested the nasal specimen, which was negative for the virus. Further subtyping is underway pending genetic sequencing.

Sequencing of the virus from the clinical specimen is underway and will be made available within 1 to 2 days if successful. Additional genetic analysis will look for any changes to the virus that could alter the agency’s risk assessment. For now, the…

https://www.cidrap.umn.edu/avian-influenza-bird-flu/michigan-reports-h5-avian-flu-dairy-farm-worker

[sharon sanders]

From:
"Media (CDC)" <sohco@CDC.GOV>
To: <MMWR-MEDIA@LISTSERV.CDC.GOV>
Subject: CDC Reports Second Human Case of H5 Bird Flu Tied to Dairy Cow Outbreak
Date: May 22, 2024 3:30 PM



Press Release

For Immediate Release
Wednesday, May 22, 2024

Contact: CDC Media Relations
(404) 639-3286          





CDC Reports Second Human Case of H5 Bird Flu Tied to Dairy Cow Outbreak

CDC’s Risk Assessment for the General Public Remains Low



May 22, 2024 -- A human case of highly pathogenic avian influenza (HPAI) A(H5) (“H5 bird flu”) virus infection in the United States has been identified in the state of Michigan. This is the second case associated with an ongoing multistate outbreak of A(H5N1) in dairy cows.[i] As with the case in Texas, the individual is a worker on a dairy farm where H5N1 virus has been identified in cows. While a nasal swab from the person tested negative for influenza in Michigan, an eye swab from the patient was shipped to CDC and tested positive for influenza A(H5) virus, indicating an eye infection. Similar to the Texas case, the patient only reported eye symptoms. CDC has been watching influenza surveillance systems closely, particularly in affected states, and there has been no sign of unusual influenza activity in people, including in syndromic surveillance.



Based on the information available, this infection does not change CDC’s current H5N1 bird flu human health risk assessment for the U.S. general public, which the agency considers to be low. However, this development underscores the importance of recommended precautions in people with exposure to infected or potentially infected animals. People with close or prolonged, unprotected exposures to infected birds or other animals (including livestock), or to environments contaminated by infected birds or other animals, are at greater risk of infection.



Case Background



A dairy worker who was being monitored because of their work exposure to H5N1-infected cattle reported symptoms to local health officials. Two specimens were collected from the patient. An upper respiratory tract specimen collected from the worker's nose was negative for influenza virus at the state health department laboratory. The eye specimen was sent to CDC for testing because it is one of a few labs where those specimens can be used with the CDC A(H5) test. The specimen was received by CDC and testing results confirmed A(H5) virus infection. The nasal specimen was retested at CDC and confirmed to be negative for influenza. The state was then notified of the results. The designation of the influenza virus neuraminidase (the N in the subtype) is pending genetic sequencing at CDC. Attempts to sequence the virus in the clinical specimen are underway and will be made available within 1-2 days if successful. Additional genetic analysis will look for any changes to the virus that could alter the agency’s risk assessment.



Conjunctivitis (eye infection) has been associated with previous human infections with avian influenza A viruses and is part of the current CDC case definition for A(H5N1) surveillance. While it’s not known exactly how eye infections result from avian influenza exposures, it may be from contamination of the eye(s), potentially with a splash of contaminated fluid, or touching the eye(s) with something contaminated with A(H5N1) virus, such as a hand. High levels of A(H5N1) virus have been found in unpasteurized milk from H5N1-infected cows.



CDC Activities



This case was detected through the state’s implementation of CDC’s recommended monitoring and testing strategies in exposed persons. In addition to enhanced and targeted surveillance, CDC also has:

• Held numerous weekly engagements with state and local HDs around increasing their preparedness posture
• Updated interim recommendations for worker protection to include those who work with dairy cows
• Issued a Health Alert Notice (HAN) on identification of human infection and recommendations for investigations/response
• Held a call with states asking them to move from preparedness to readiness
• Updated interim recommendations for worker protection to include those who work in slaughterhouses
• Conducted numerous calls with groups representing farmworkers
• Asked states to furnish PPE for farmworkers
• Announced incentives for workers who participate in public health research efforts into the outbreak
• Asked states to work with clinical labs to increase submissions of positive influenza virus samples to public health labs for subtyping

Given the high levels of A(H5N1) virus in raw milk from infected cows, and the extent of the spread of this virus in dairy cows, similar additional human cases could be identified. Sporadic human infections with no ongoing spread will not change the CDC risk assessment for the U.S. general public, which CDC considers to be low.



CDC Recommendations

• People should avoid close, long, or unprotected exposures to sick or dead animals, including wild birds, poultry, other domesticated birds, and other wild or domesticated animals (including cows).
• People should also avoid unprotected exposures to animal poop, bedding (litter), unpasteurized (“raw”) milk, or materials that have been touched by, or close to, birds or other animals with suspected or confirmed A(H5N1) virus.
• CDC has interim recommendations for prevention, monitoring, and public health investigations of A(H5N1) virus infections in people. CDC also has updated recommendations for worker protection and use of personal protective equipment (PPE).
• Following these recommendations is central to reducing a person’s risk and containing the overall public health risk.

More information is available on the CDC website at https://www.cdc.gov/flu/avianflu/avian-flu-summary.htm.



[1] first human case of A(H5N1) bird flu in the United States linked to an outbreak in dairy cows was also the first likely case of human infection with A(H5N1) from a cow globally. This was reported on April 1, 2024. The person reported eye redness as their only symptom, consistent with conjunctivitis, and recovered. Learn more about this case in a letter published in the New England Journal of Medicine titled Highly Pathogenic Avian Influenza A(H5N1) Virus Infection in a Dairy Farm Worker. The April 1 case was actually the second human case of A(H5N1) reported in the United States. The first human case of A(H5N1) bird flu in the United States was reported in 2022 in a person in Colorado who had direct exposure to poultry and who was involved in depopulating poultry with presumptive A(H5N1) bird flu. The 2022 human case was not related to dairy cattle. The person only reported fatigue without any other symptoms and recovered. Learn more at U.S. Case of Human Avian Influenza A(H5) Virus Reported.

[Pathfinder]

Health officials explain human-contracted bird flu, say to take precautions

By Riley Connell
Published: May. 23, 2024 at 4:19 PM CST|Updated: 15 hours ago

LANSING, Mich. (WILX) -
...
The Michigan Department of Health and Human Services said a male farm worker is confirmed to have contracted highly pathogenic avian influenza, commonly known as bird flu, or H5N1. Although the patient’s specific location within the state was not released, officials said he has already recovered without the help of medication.

Chief Medical Executive Dr. Natasha Bagdasarian said the farm worker’s primary symptom was a “grainy feeling” in his eyes. The human contraction of a disease named after its aggressive spread among flocks of birds might come as a surprise to members of the public but not to Bagdasarian.

“We’ve tested a total of 35 individuals here in Michigan, and that’s more than any other state in the country, and when you look for something, you often find it,” she said.
...
“So, we do recommend both personal protective equipment as well as symptom monitoring and letting us know if anyone gets sick on a farm,” she told News 10. “Now, as for the general public, the risk remains low.”
...

https://www.wilx.com/2024/05/23/health-officials-explain-human-contracted-bird-flu-say-take-precautions/

[sharon sanders]

Technical Update: Summary Analysis of the Genetic Sequence of a Highly Pathogenic Avian Influenza A(H5N1) Virus Identified in a Human in Michigan


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Updated May 24, 2024

This is a technical summary of an analysis of the genomic sequence of the virus identified in the Michigan case of highly pathogenic avian influenza (HPAI) A(H5N1) virus infection. This analysis supports the conclusion that the overall risk to the general public associated with the ongoing HPAI A(H5N1) outbreak has not changed and remains low at this time. The genome of the virus identified from the patient in Michigan (A/Michigan/90/2024) is publicly posted in GISAID (EPI_ISL_19162802) and has been submitted to GenBank.

May 24, 2024 – CDC has sequenced the influenza virus genome identified in a conjunctival specimen collected from the person in Michigan who was identified to be infected with HPAI A(H5N1) virus and compared each gene segment with HPAI A(H5N1) sequences from cows, wild birds and poultry and the first human case in Texas. The virus HA was identified as clade 2.3.4.4b with each individual gene segment closely related to genotype B3.13 viruses detected in dairy cows available from USDA testing. No amino acid changes were identified in the HA gene sequence from the Michigan patient specimen compared to the HA sequence from the case in Texas and only minor changes were identified when compared to sequences from cows. These data indicate viruses detected in both cows and the two human cases maintain primarily avian genetic characteristics and lack changes that would make them better adapted to infect or transmit between humans. The genome of the human virus from Michigan did not have the PB2 E627K change detected in the virus from the Texas case, but had one notable change (PB2 M631L) compared to the Texas case that is known to be associated with viral adaptation to mammalian hosts, and which has been detected in 99% of dairy cow sequences but only sporadically in birds[i]. This change has been identified as resulting in enhancement of virus replication and disease severity in mice during studies with avian influenza A(H10N7) viruses[ii]. The remainder of the genome of A/Michigan/90/2024 was closely related to sequences detected in infected dairy cows and strongly suggests direct cow-to-human transmission. Further, there are no markers known to be associated with influenza antiviral resistance found in the virus sequences from the Michigan specimen and the virus is very closely related to two existing HPAI A(H5N1) candidate vaccine viruses that are already available to manufacturers, and which could be used to make vaccine if needed. Overall, the genetic analysis of the HPAI A(H5N1) virus detected in a human in Michigan supports CDC’s conclusion that the human health risk currently remains low. More details of this and other viruses characterized in association with the dairy cow outbreak are available in a previous technical summary.

[i] Thao-Quyen Nguyen, Carl Hutter, Alexey Markin, Megan Thomas, Kristina Lantz, Mary Lea Killian, Garrett M. Janzen, Sriram Vijendran, Sanket Wagle, Blake Inderski, Drew R. Magstadt, Ganwu Li, Diego G. Diel, Elisha Anna Frye, Kiril M. Dimitrov, Amy K. Swinford, Alexis C. Thompson, Kevin R. Snevik, David L. Suarez, Erica Spackman, Steven M. Lakin, Sara C. Ahola, Kammy R. Johnson, Amy L. Baker, Suelee Robbe-Austerman, Mia Kim Torchetti, Tavis K. Anderson Emergence and interstate spread of highly pathogenic avian influenza A(H5N1) in dairy cattle bioRxiv 2024.05.01.591751; doi: https://doi.org/10.1101/2024.05.01.591751

[ii]Zhang X, Xu G, Wang C, Jiang M, Gao W, Wang M, Sun H, Sun Y, Chang KC, Liu J, Pu J. Enhanced pathogenicity and neurotropism of mouse-adapted H10N7 influenza virus are mediated by novel PB2 and NA mutations. J Gen Virol. 2017 Jun;98(6):1185-1195. doi: 10.1099/jgv.0.000770. Epub 2017 Jun 8. PMID: 28597818.

Last Reviewed: May 24, 2024

https://www.cdc.gov/flu/avianflu/spotlights/2023-2024/h5n1-technical-update-may-24-2024.html

[Treyfish]

BREAKING NEWS A third U.S. farm worker infected with bird flu is the first to experience respiratory symptoms

• By Helen Branswell May 30, 2024 BRENDAN SMIALOWSKI/
• A-third human case of H5 bird flu tied to the ongoing U.S. outbreak in cattle has been detected in a farm worker in Michigan, state health authorities confirmed on Thursday.

The unnamed individual worked on a dairy farm and was in close contact with infected cows, the state health department said in a statement. The farm involved is different from the one where an earlier human case was detected last week.

https://www.statnews.com/2024/05/30/bird-flu-third-case-human-infection-caused-respiratory-symptoms/

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Please see:

US - Third farm worker infected with H5 (presumed H5N1), 2nd case in Michigan - May 30, 2024

[Pathfinder]

CDC A(H5N1) Bird Flu Response Update, July 19, 2024
...
In this week’s Spotlight, we include the key findings from the recent Michigan-led study that tested the blood of farmworkers from two dairy farms that experienced an outbreak of highly pathogenic avian influenza A(H5N1) virus among cattle. The study looked for antibodies that would indicate infection with the virus. None of the blood samples collected from people who had been exposed to infected dairy cows showed H5N1 antibodies. This is an important finding because it suggests that asymptomatic infections in people are not occurring and provides support to the current testing approach – i.e., collecting samples from symptomatic people who have been exposed to sick animals.
...
Among other activities previously reported in past spotlights and still ongoing, recent highlights of CDC's response to this include:

• Reporting the preliminary results of the Michigan-led seroprevalence investigation. CDC analyzed sera (blood) collected from people who were exposed to dairy cattle infected with highly pathogenic avian influenza (HPAI) A(H5N1) clade 2.3.4.4b viruses causing outbreaks among animals in the United States. These blood samples were collected as part of a type of study called a seroprevalence study. Seroprevalence studies test people’s blood for antibodies (an immune response) specific to a pathogen of interest, in this case HPAI A(H5N1). These studies can tell us whether someone has been previously infected.
  • Blood samples were collected in June 2024 from 35 people who work on dairies in Michigan with herds that were confirmed positive for HPAI A(H5N1) virus.
    • Study participants were from multiple counties and had different roles on affected farms, but most worked with sick cows directly and fewer than half reported using masks or goggles.
  • These samples were tested for antibodies against an avian influenza A(H5N1) clade 2.3.4.4b virus and a seasonal influenza virus (control virus) to measure antibodies.
    • Specimens were tested by two methods: microneutralization and hemagglutination inhibition (HI) assays.
  • None of these 35 people showed neutralizing or HI antibodies (a sign of prior infection) specific to avian influenza A(H5N1) virus.
  • Many of the people had neutralizing antibodies to seasonal flu.
    • The detection of antibodies to seasonal flu suggests that, not unexpectedly, participants in the study had been previously infected or vaccinated with seasonal influenza viruses and were able to generate an immune response.
  • The lack of antibodies to avian influenza A(H5N1) virus suggests these people were not previously infected with an avian influenza A(H5N1) influenza virus.
  • These data are consistent with other data demonstrating the seroprevalence to HPAI A(H5N1), even among workers with known exposures, is low.
  • Additional data are necessary to fully understand the occupational risks of exposure to the currently circulating avian influenza A(H5N1) viruses.
  • The Michigan Department of Health and Human Services is continuing the study and working with CDC to analyze the data and prepare a manuscript for peer-review publication once complete

...

https://www.cdc.gov/bird-flu/spotlights/h5n1-response-07192024.html

[Pathfinder]

Notes from the Field: Health Monitoring, Testing, and Case Identification Among Persons Exposed to Influenza A(H5N1) — Michigan, 2024


Weekly / July 25, 2024 / 73(29);656–658


Joseph Coyle, MPH¹; Natasha Bagdasarian, MD¹; Seth Eckel, MPH¹; Jeremy Kuo, MPH¹; Mary Grace Stobierski, DVM¹; James Barber, MPH¹; Megan Weinberg, PhD¹; Fatema Mamou, MPH¹; Sarah Lyon-Callo, PhD¹; Michigan Local Health Departments; Bureau of Laboratories; Bureau of Infectious Disease Prevention Investigation Team (VIEW AUTHOR AFFILIATIONS)

...
Summary


What is already known about this topic?

Highly pathogenic avian influenza (HPAI) A(H5N1) virus has been detected in wild birds and mammals, poultry, and commercial dairy facilities in the United States. A human case in a Texas dairy worker was reported in April 2024.

What is added by this report?

As of May 23, 2024, Michigan had the largest number of affected dairy and poultry facilities linked to the HPAI A(H5N1) outbreak. Active symptom monitoring and testing of exposed workers led to detection of the second and third known dairy-associated HPAI A(H5N1) cases in 2024.

What are the implications for public health practice?

The current risk to the public from HPAI A(H5N1) viruses is low; however, continued symptom monitoring and testing are critical to characterizing genetic or epidemiological changes that might alter the risk assessment.


On March 25, 2024, a Texas dairy farm detected highly pathogenic avian influenza (HPAI) A(H5N1) virus in cows. The outbreak widely spread after interstate cow movement. During March 25–June 17, animals at a total of 102 dairy farms in 12 states, 24 commercial poultry flocks in five states, and multiple backyard flocks tested positive for HPAI A(H5N1) (1,2). This report describes response activities in Michigan, which led to detection of the second and third human cases related to the 2024 HPAI A(H5N1) outbreak. The activity was reviewed by the Michigan Department of Health and Human Services, deemed not research, and was conducted consistent with applicable federal law, state, and departmental policy.*


Investigation and Outcomes


Infected cows from Texas resulted in introduction of HPAI A(H5N1) virus in a Michigan dairy, detected on March 29. As of May 29, a total of 23 Michigan dairies in 10 counties are known to be affected (1). Michigan’s first affected commercial poultry facility was confirmed on April 2; currently, seven affected poultry facilities in four counties have been identified (2). HPAI A(H5N1) virus has also been detected in a backyard flock, pigeons, foxes, cats, opossums, and a racoon in Michigan. Whole genome sequencing results suggest that, since March 2024, all sequenced isolates have ancestral Texas origins (3).

Monitoring of Dairy Workers


Among the 23 affected dairies, 306 persons exposed to affected cows were identified. Lists of exposed persons were obtained by public health officials from 20 (87%) affected dairies. Workers at 12 (60%) of those dairies were enrolled in text-based daily symptom monitoring,^† and workers at eight (40%) farms were monitored through a farm point of contact. Because it could be unclear when workers’ exposures to cows ended, some workers were monitored for >50 days.

Twenty (6.5%) exposed workers reported symptoms and were tested for influenza A(H5) virus infection. Among persons who received real-time reverse transcription–polymerase chain reaction testing,^§ one received a positive test result from a conjunctival swab, similar to the case of HPAI A(H5N1) reported from a dairy worker in Texas (4). Before the onset of mild unilateral conjunctivitis, the patient reported direct ocular exposure to raw, unpasteurized milk from an affected cow. A second worker from a different dairy farm experienced respiratory symptoms after close contact with sick cows and received a positive A(H5) virus test result from a nasopharyngeal swab. In both instances, public health officials rapidly collected patient specimens, which tested positive for HPAI A(H5N1). Neither worker was severely ill, neither required hospitalization, and no household or work contacts reported being ill. Both workers wore some personal protective equipment (PPE), but neither wore a mask or respirator.

Monitoring of Poultry Workers


Among seven affected commercial poultry facilities, 857 persons exposed to affected birds were identified. Lists of exposed persons were obtained from all facilities. Workers from four facilities were directly enrolled in text-based daily symptom monitoring, and workers from three facilities were monitored through a farm point of contact who reported results to public health officials. Eighteen (2.1%) symptomatic persons were identified and tested; all test results were negative for influenza A(H5).

Monitoring of Other Exposed Persons


Federal and state employees who responded to affected farms were also observed for symptoms, as were persons with exposure to HPAI A(H5N1) virus–infected animals (domestic or wild) or humans. Overall, 125 such persons were monitored, and 15 (12%) reported symptoms, 14 of whom received negative influenza A(H5) test results.


Preliminary Conclusions and Actions


Among 1,288 Michigan residents who were monitored for signs and symptoms after potential HPAI A(H5N1) virus exposure, 53 (4.1%) reported signs and symptoms, 52 of whom received testing for influenza A(H5). Two dairy workers received positive test results (3.8% of all persons tested, <1% of all monitored dairy workers).

Although the risk for HPAI A(H5N1) virus to the public remains low, novel influenza A viruses such as A(H5N1) have pandemic potential. Therefore, it is critical to notify persons with exposure to infected animals, provide education and access to PPE,^¶ monitor signs and symptoms, test specimens collected from any exposed person with signs and symptoms, and make antivirals available to symptomatic persons as soon as possible.**

Although the percentage of workers who regularly used PPE is not known, the human cases associated with dairy farms in Texas and Michigan demonstrate the potential value of PPE, including eye and respiratory protection, especially on affected farms (4,5). The cases identified to date have resulted in mild illness, which might not have been detected without the collaboration of state officials and the engagement of farms and workers. Streamlined, nonintrusive approaches to monitoring, such as the text-message monitoring used in Michigan, might encourage participation and subsequent testing. A One Health^†† approach including collaboration with agriculture departments, farms, and workers is crucial to successful public health response.

...

https://www.cdc.gov/mmwr/volumes/73/wr/mm7329a4.htm?s_cid=mm7329a4_w