ETIDIOH - NEW

Abstract In late 2023, H5N1 high pathogenicity avian influenza (HPAIV) started circulating in dairy cattle in the USA . High viral titres were detected in milk from infected cows , raising concerns about onwards human infections . Although pasteurisation was shown to effectively inactivate influenza viruses in milk, unpasteurised milk still poses a risk of infection, both from occupational exposure in dairies and from the consumption of raw milk. We therefore assessed how long influenza viruses could remain infectious for in milk without heat inactivation. We examined the stability of a panel of influenza viruses in milk , including a contemporary H5N1 HPAIV and a variety of other influenza A and D viruses. We incubated viruses in cows' milk under laboratory conditions : at room temperature to simulate exposure in dairies and at 4°C to simulate exposure to refrigerated raw milk. Following an isolated report of H5N1 viral RNA being detected in milk from a sheep in the UK , we also c...

Abstract Highly pathogenic avian influenza viruses (HPAIV) of subtype H5N1 (clade 2.3.4.4b) have crossed the species barrier and caused a mastitis-like infection in dairy cows . The high levels of infectious virus found in the milk raised considerable concerns about the safety of raw milk products . This study examined the effect of temperature and pH on the stability of HPAIV and low-pathogenic avian influenza viruses (LPAIV). We found that H5N1 HPAIV remained infectious in milk at 4 degrees Celsius for four weeks , with slow decreases at 21 degrees Celsius, and complete inactivation at 37 degrees Celsius after four weeks . H5N1 LPAIV was stable at 50 degrees Celsius for 30 minutes but inactivated at higher temperatures (55 degrees Celsius for 10 minutes, 60 degrees Celsius for 1 minute, or 72 degrees Celsius for 30 seconds). At pH levels between 6 and 10 , the virus remained stable but was partially inactivated at pH 5.0 and completely inactivated at pH 4.0. During yogurt production,...

Abstract The recent spillover events of highly pathogenic avian influenza (HPAI) A(H5N1) clade 2.3.4.4b to dairy cattle , and high viral shedding in the milk from infected animals, has created concern that milk and dairy products could be a route for human infection . It has been demonstrated that pasteurization is effective in inactivating A(H5N1) in milk. However, multiple dairy products are made with unpasteurized but thermised milk . The aim of this study was to examine whether some conditions commonly used for thermisation are effective against inactivation of A(H5N1) in whole milk. For this purpose, we artificially inoculated whole raw cow milk with 6.5 log10 EID50 A(H5N1) and heated for 15 seconds at 60°C, 63°C and 66°C , the viral infectivity was tested using embryonated chicken eggs. We observed over 4 and 5 log10 reduction in viral infectivity at 60°C and 63°C, respectively. The viral infectivity was reduced to below the detection limit at 66°C. We also calculated the D-value...

Abstract The spillover of highly pathogenic avian influenza H5N1 into dairy cattle has raised concerns over the safety of fluid milk . While no human foodborne infection has been reported , this strain has infected dozens of people and milk from infected cows is known to be infectious by ingestion in multiple other species. Investigation into the public health threat of this outbreak is critical . This study uses quantitative risk assessment (QRA) models to represent the United States raw and pasteurized fluid milk supply chains to estimate the risk of human infection from consumption of fluid cow's milk. These models were parameterized with literature emerging from this outbreak, then employed to estimate the H5N1 infection risk and evaluate multiple potential interventions aimed at reducing this risk. The median (5th, 95th percentiles) probabilities of infection per 240-mL serving of pasteurized, farmstore-purchased raw, or retail-purchased raw milk were 5.68E-15 (1.77E-16, 2.98E...

Abstract The spillover of highly pathogenic avian influenza (HPAI) H5N1 virus to dairy cows and shedding of high amounts of infectious virus in milk raised public health concerns. Here, we evaluated the decay and thermal stability spectrum of HPAI H5N1 virus in raw milk. For the decay studies , HPAI H5N1 positive raw milk was incubated at different temperatures and viral titers and the thermal death time D-values were estimated. We then heat treated HPAI H5N1 virus positive milk following different thermal conditions including pasteurization and thermization conditions. Efficient inactivation of the virus was observed in all tested conditions, except for thermization at 50C 10 min . Utilizing a submerged coil system with temperature ramp up times that resemble commercial pasteurizers, we showed that the virus was rapidly inactivated by pasteurization and most thermization conditions . These results provide important insights on the food safety measures utilized in the dairy industry. S...

Abstract Following reports of HPAI H5N1 infections of dairy cattle in the United States (US) in March 2024, we established a Pan-Canadian Milk network to monitor retail milk in Canada. Milk samples from across Canada that had previously tested negative for influenza A virus (IAV) RNA were tested for the presence of anti-IAV nucleoprotein (NP) antibodies , as an indicator of past infection of dairy cattle. None of the 109 milk samples tested had evidence of anti-IAV NP antibodies. This is consistent with previous findings from our academic group as well as others including federal testing initiatives that have not found any IAV RNA in milk. Although not surprising given that no cases of H5N1 in cattle have been reported in Canada to date, this work further supports that the extensive outbreak in dairy cattle in the US has not extended northward into Canada, and the integrity of the Canadian milk supply remains intact. Source: MedRxIV,  https://www.medrxiv.org/content/10.1101/2025.01...

Abstract In late 2023 an H5N1 lineage of high pathogenicity avian influenza virus (HPAIV) began circulating in American dairy cattle.  Concerningly, high titres of virus were detected in cows’ milk , raising the concern that milk could be a route of human infection . Cows’ milk is typically pasteurised to render it safe for human consumption, but the effectiveness of pasteurisation on influenza viruses in milk was uncertain . To assess this, here we evaluate heat inactivation in milk for a panel of different influenza viruses. This includes human and avian influenza A viruses (IAVs), an influenza D virus that naturally infects cattle, and recombinant IAVs carrying contemporary avian or bovine H5N1 glycoproteins . At pasteurisation temperatures of 63 °C and 72 °C , we find that viral infectivity is rapidly lost and becomes undetectable before the times recommended for pasteurisation ( 30 minutes and 15 seconds, respectively ). We then show that an H5N1 HPAIV in milk is effectively i...

WASHINGTON, January 17, 2025—As part of its ongoing, multi-faceted efforts to combat the spread of highly pathogenic avian influenza (HPAI), USDA’s Animal and Plant Health Inspection Service (APHIS) today is updating its policy for pre-slaughter surveillance to enhance testing of turkey flocks in affected states .  In late December 2024, APHIS became aware of a genetic link between turkeys potentially infected with HPAI H5N1, virus detected in raw pet food, and an infected household cat . Out of an abundance of caution, and to remove a potential avenue for ongoing disease spread as well as to bolster consumer and trading partner confidence, APHIS collaborated with state animal health officials and the poultry industry to update its guidance for existing pre-slaughter surveillance steps to further ensure that affected poultry does not enter the food system. APHIS will continue to report confirmed HPAI detections to the World Organisation for Animal Health and on the APHIS website (m...

January 17, 2025 The U.S. Food and Drug Administration has determined that it is necessary for manufacturers of cat and dog foods who are covered by the FDA Food Safety Modernization Act Preventive Controls for Animal Food (PCAF) rule and using uncooked or unpasteurized materials derived from poultry or cattle (e.g., uncooked meat, unpasteurized milk or unpasteurized eggs) to reanalyze their food safety plans to include Highly Pathogenic Avian Influenza virus (specifically H5N1) as a known or reasonably foreseeable hazard .  Furthermore, the FDA is issuing this update to ensure that cat and dog food manufacturers are aware of information about the new H5N1 hazard associated with their pet food products, which is an additional reason that manufacturers must conduct a reanalysis of their food safety plans. The FDA is tracking cases of H5N1 in domestic and wild cats in California, Colorado, Oregon and Washington State that are associated with eating contaminated food products.  S...

Abstract The recent outbreak of highly pathogenic avian influenza (HPAI) in dairy cows has created public health concerns about the potential of consumers being exposed to live virus from commercial dairy products. Previous studies support that pasteurization effectively inactivates avian influenza in milk and an earlier retail milk survey showed viral RNA, but no live virus could be detected in the dairy products tested. Because of the variety of products and processing methods in which milk is used, additional product testing was conducted to determine if HPAI viral RNA could be detected in retail dairy samples, and for positive samples by quantitative real-time RT-PCR (qRT-PCR) further testing for the presence of live virus. Revised protocols were developed to extract RNA from solid dairy products including cheese and butter . The solid dairy product was mechanically liquified with garnet and zirconium beads in a bead beater diluted 1–4 with BHI media. This preprocessing step was su...

The Oregon Department of Agriculture (ODA) is alerting pet owners that samples of Northwest Naturals brand 2lb Turkey Recipe raw & frozen pet food tested positive for a H5N1 strain of the Highly Pathogenic Avian Influenza (HPAI) virus .  Testing conducted by the U.S. Department of Agriculture’s (USDA) National Veterinary Services Laboratories (NVSL) and the Oregon Veterinary Diagnostic Laboratory (ODVL) at Oregon State University confirmed a house cat in Washington County contracted H5N1 and died after consuming the raw frozen pet food .  Tests confirmed a genetic match between the virus in the raw and frozen pet food and the infected cat. “We are confident that this cat contracted H5N1 by eating the Northwest Naturals raw and frozen pet food ,” said ODA State Veterinarian Dr. Ryan Scholz.  “This cat was strictly an indoor cat ; it was not exposed to the virus in its environment, and results from the genome sequencing confirmed that the virus recovered from the raw pe...

Assessment based on data as of 18 November 2024   12 December 2024  Key points   At the present time , based on available information , FAO-WHO-WOAH assess the global public health risk of influenza A(H5N1) viruses to be low , while the risk of infection for occupationally exposed persons is low to moderate depending on the risk mitigation measures in place and the local avian influenza epidemiological situation.  Transmission between animals continues to occur and, to date, a growing yet still limited number of human infections are being reported.  Although additional human infections associated with exposure to infected animals or contaminated environments are expected to occur, the overall public health impact of such infections at a global level, at the present time, is minor .  This risk assessment from FAO, WHO, and WOAH updates the assessment of the risk of zoonotic transmission (for example, animal to human) considering additional information made a...

In an update on the mutating virus - known as H5N1 – Dr. Madhur Dhingra from the Food and Agriculture Organization, FAO, said that it had “spilled over into wildlife”.  More than 500 bird species have been infected along with at least 70 mammalian species , including the endangered California condor and polar bears .  In regions that are heavily reliant on poultry as a primary source of protein, the FAO medic insisted that avian influenza “poses a serious threat to food and nutrition security”. Economic damage Dr Dhingra warned that hundreds of millions of people’s livelihoods have been affected by the virus – an economic burden on farmers that could prevent them from investing in adequate biosafety measures. Following the emergence of H5N1 influenza virus in dairy cattle , the WHO has joined calls for strengthened surveillance and biosecurity on farms, to keep animals and people safe. The UN health agency said that in 2024, 76 people have been infected with the H5 avian influ...

 {Excerpt} (Xinhua) 13:20, December 17, 2024 LOS ANGELES, Dec. 16 (Xinhua) -- The U.S. state of California has recalled raw milk produced and packaged by Valley Milk Simply Bottled , a local dairy company based in Stanislaus County, due to detection of bird flu virus . The recall order came following the detection of Influenza-A H5N1 (bird flu) virus in samples taken from a raw milk bulk tank at the Valley Milk Simply Bottled dairy farm , said the California Department of Food and Agriculture (CDFA) in a release. The order applies to all "Valley Milk Simply Bottled Raw Cow Milk" and "DESI Milk Raw Cow Milk" distributed in quart, half-gallon, and one-gallon plastic jugs with a code date marked on the container of DEC 23 2024 through DEC 30 2024. CDFA urged consumers not to consume any product remaining in their refrigerators. No illnesses have been reported in the state yet. (...) Source: People's Daily,  http://en.people.cn/n3/2024/1217/c90000-20254910.html   __...

Abstract Highly pathogenic avian influenza (HPAI) viruses with H5 hemagglutinin (HA) genes (clade 2.3.4.4b) are causing an ongoing panzootic in wild birds . Circulation of these viruses is associated with spillover infections in multiple species of mammals , including a large, unprecedented outbreak in American dairy cattle . With limited testing of dairy herds, there is an unmet need for genomic surveillance . Infected cattle can shed high amounts of HPAI H5N1 viruses in milk , allowing detection in pasteurized retail dairy samples. Over a 2-month sampling period in one Midwestern city , we obtained dairy products processed in 20 different states . Here we demonstrate that a tiled-amplicon sequencing approach produced over 90% genome coverage at greater than 20x depth from 5 of 13 viral RNA positive samples. A combination of RT-qPCR testing and sequencing from retail dairy prod- ucts can be a useful component of a One Health framework for responding to the avian influenza outbreak in ...