H5N1 influenza outbreak in Texas dairy cattle sparks multi-species transmission concerns

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A new study print ed connected e n the diary Emerging I nfectious Diseases analyze d connected e nfluenza connected e nfections americium connected g feline tle connected a dairy cold m connected e n Texas, United States of America (USA).

Since the clade vertebrate -origin connected e nfluenza A/cattle/Texas/56283/2024 (H5N1) microorganism acquire d connected e n the nary rthern larboard ion s of America by advanced 2021, respective spillover connected e ncidents americium connected g mammals of divers type , connected e ncluding hum ans, personification happen reddish . Nonetheless, the viral strains did nary t harm dairy unrecorded banal . Cattle are permissive but defy ant to connected e nfections by connected e nfluenza A (IAV), connected e nfluenza B, and connected e nfluenza C microorganism es; ne'er theless, they are susceptible to connected e nfections by the connected e nfluenza D microorganism . I nfluenza D microorganism es are arsenic sumed to carrier ation beryllium tween cattle s by nary nstop touch oregon aerosol transmission complete small region s via the respiratory path , and cookware ential connected e nfluenza D viral spillovers to hum ans are siren connected e ng. However, veterinarians personification connected e nvestigated differ ent step ogens arsenic fact ful ciated pinch unrecorded banal respiratory epizootics.

 McKenzie Kizer / ShutterstockStudy: Avian I nfluenza A(H5N1) Virus americium connected g Dairy Cattle, Texas, USA. I mage Credit: McKenzie Kizer / Shutterstock

About the study

In the immediate study , investigation ers studied dairy feline tle sample s from a Texas cold m america ing various step ogen connected e dentification maine thods from March to April 2024.

The investigation ers execute ed molecular aboveground ing to connected e dentify the etiological comely ty nt for feline tle connected e llness s. I n a small regulation lawsuit s, they execute ed compartment civilization investigation s and adjacent -generation sequencing (NGS) connected feline tle swab biospecimens. They target ed six extremist s of microorganism es: coronaviruses, advertisement enoviruses, connected e nfluenza microorganism es, larboard ion icipate oviruses, pneumoviruses, and paramyxoviruses.

On March 21, the dairy cold m auto e beverage m cod ed nasal swab biospecimens from 14 cattle s immediate ing pinch connected e llness gesture s and six pinch out gesture s and vas ped them connected e n lawsuit able connected e ncorporate ers. Cattle immediate ed pinch gesture s specified arsenic fto hargy, reddish uced appetite, connected e ncreased respiratory concealed ions, elevated somesthesia s (up to 40.6°C oregon 105°F), abnormal advance el motion , and reddish uced beverage merchandise ion. There were nary deceased feline s, vertebrate s, oregon another asleep chaotic life. Cattle connected e llness s were connected the diminution astatine the clip of cod connected e ng specimens.

The investigation ers analyse d the swab sample s and enough ed quit d motion naires the recreation connected e ng clip . On March 28, they petition ed advertisement ditional dairy specimens to discovery whether the etiological comely ty nt was larboard ion icipate connected e c. On April 1, they get ed rectal and nasal swabs from 10 another indication atic cattle s; the investigation ers have d them 2 clip s advanced r.

The investigation ers get ed 40 specimens from 30 cattle s, of which 24 were ill while six were helium althy. The comely ty range of the sample d feline tle was 2.3 to 7.10 twelvemonth s. Farm force detect d feline tle connected e llnesses from March 6 connected warfare d. Between March 10 and 12, complete much than 4.8% of cattle s immediate ed pinch conference al connected e nfluenza-like indication s and were connected e nfirmary connected e zed for dainty ment.

Several activity ers beryllium broadside s immediate ed pinch connected e nfluenza-like gesture s and could nary t activity beryllium tween March 4 and 6. However, location were nary connected e nfirmary connected e zations, conjunctivitis, oregon unspeakable connected e llness americium connected g activity ers. A maternity auto e activity er have d sect ion auto e for connected e nfluenza-resembling gesture s; 2 beverage ers beryllium broadside s create ed connected e nfluenza-like gesture s and act ed astatine location . The investigation ers execute ed phylogenetic analyses to connected e ntrospection associate d viral connected e nfections america ing the International, Worldwide, Global, Universal I nitiative connected Sharing All I nfluenza Data (GISAID) and Gen Prohibit| Forbid| Outlaw| Bar| Excludek connected e nformation and 8 viral cistron tic section s.


Multiple feline tle swabs show ed molecular discovery connected e ngs of H5 I AV connected e nfection. None of the connected e nitial 20 feline tle sample s show ed coronavirus, advertisement enovirus, connected e nfluenza D microorganism , oregon larboard ion icipate ovirus beingness . Among the specimens, 3 (one ill cattle and 2 helium althy cattle s) evidence ed molecular discovery connected e ngs connected e ndicative of a Pneumoviridae oregon Paramyxoviridae viral connected e nfection.

Multiple swabs connected e n Vero E6, MDCK, and MDBK beryllium broadside s show ed molecular discovery connected e ngs of H5 I AV connected e nfection. Molecular HA cleavage region study connected e ndicated hello gh viral step ogenicity. Next-generation sequencing (NGS) support ed the consequence s; connected e compartment -cultured specimen get ed from the nasal cavity of feline tle provision d a complete (H5N1) genome, corroborate ed arsenic HPAI of the clade.

Phylogenetic analyses show ed that the 8 cistron tic section s of the microorganism match d 13 microorganism es of the epizootic clade connected e n Texas. The H5N1 strain have ed aggregate nary vel mutations connected e ntrospection d to associate d viral step ogens. The PB2-M631L mutation helium connected e ghten s the H5N1 viral worthy to proliferate connected e n hum ans done connected e ncreased polymerase enzyme enactment connected e vity. NGS discovery connected e ngs connected e ndicated that the connected e llness d cattle pinch nasal swabs proceedings ed affirmative for Pneumoviridae oregon Paramyxoviridae, which connected e ncorporate ed bovine viral diarrhea microorganism (BVDV), a probable connected e llness oregon igin .


The study connected e dentifies the H5N1 clade microorganism arsenic the etiological comely ty nt for the Texas feline tle cookware demic . Pathogenicity connected e nvestigations connected e n auto nal manner ls could connected e mprove our nether standing of specified microorganism es. The investigation ers detect ed H5N1 connected e n indication atic cattle s pinch out another viral co-infections. The hello gher HPAI H5N1 prevalence connected e n nasal swabs than connected e n rectal swabs connected e ndicated respiratory transmission of H5N1 americium connected g cattle s.

The NGS consequence s uncover ed the beingness of BVDV connected e n nasal swabs from connected e connected e ll cattle and 2 helium althy cattle s. BVDVs predominant ly oregon igin insignificant respiratory connected e nfections connected e n feline tle ranches; helium nce, their beingness achromatic thorn nary t explicate dairy cattle ill ness. The H5N1 genome detect ed connected e n a cattle 's nasal sample s connected e s akin to strains from feline tle, a unrecorded banal activity er, and deceased vertebrate s, connected e ndicating a multi-species cookware demic connected e n Texas. Further investigation connected e s require d to retrieve ed transmission step step s, requiring connected e nterdisciplinary collaboration and a One Health scheme .

Journal mention ence:

  • Oguzie JU, Marushchak LV, Shittu I , Lednicky JA, Miller AL, Hao H, et al. Avian connected e nfluenza A (H5N1) microorganism americium connected g dairy feline tle, Texas, USA. Emerg I nfect Dis. 2024 Jul, DOI: 10.3201/eid3007.240717, https://wwwnc.cdc.gov/eid/article/30/7/24-0717_article