Skip to main content

From North to South: #Transmission #Dynamics of #H1N1pdm09 Swine #Influenza A Viruses in #Italy

Image
By G.M.

Abstract

The influenza A H1N1pdm09 virus continues to be a significant pathogen, posing potential risks to both animal and human health due to its zoonotic potential. Italy, which has one of the largest swine populations in Europe, plays a crucial role in monitoring the evolution of influenza viruses in livestock. This study aims to address the existing knowledge gaps regarding the genetic diversity and transmission dynamics of H1N1pdm09 circulating in Italian swine populations. Utilizing whole genome sequencing and dynamic modeling, we conducted a comprehensive analysis of virus samples collected from swine farms across Italy. Our results reveal that multiple independent viral introductions have occurred into the country, with most cases resulting in self-limited infections and limited onward transmission. However, six distinct transmission clusters were identified, suggesting instances of sustained viral spread. These clusters were found across multiple regions of Italy, highlighting the broad geographic distribution of virus lineages. Our findings indicate that while many introductions led to localized containment, certain virus lineages were able to spread within specific regions of Italy. Through a detailed examination of selective pressures, we observed that most viral genes are under strong purifying selection in both swine and human hosts, as reflected by dN/dS ratios well below 1. The hemagglutinin (HA) gene exhibited a notably higher dN/dS ratio in swine (~0.28) compared to humans (~0.22), indicating slightly relaxed selection in swine. In contrast, other genes, such as neuraminidase (NA) and non-structural protein (NS), showed similarly strong purifying selection across both hosts. These results reflect a general trend of selective pressures affecting multiple viral components, rather than emphasizing specific genes. Our study emphasizes the importance of ongoing genomic surveillance in detecting viral circulation and mitigating risks to both animal and public health. Italy's efforts contribute significantly to global influenza monitoring and highlight the importance of a One Health approach that integrates human, animal, and environmental health. These findings provide essential data to inform public health policies and enhance preparedness against future zoonotic influenza outbreaks.

Source: BioRxIV, https://www.biorxiv.org/content/10.1101/2024.12.12.628126v1?rss=1 

_____

Labels:

Comments

Post a Comment

Popular posts from this blog

#Neuroinvasive #Oropouche virus in a patient with #HIV from extra-Amazonian #Brazil

By G.M.
{Excerpt} A novel reassortant Oropouche virus (OROV) lineage (with medium [M], large [L], and small [S] RNA segments : M1L2S2) has driven Brazil's largest and most geographically widespread OROV epidemic , expanding beyond the endemic Amazon basin to establish local transmission across multiple Brazilian states and other previously unaffected Latin American countries . The rapid spread of this lineage underscores its evolutionary potential and reinforces its significance as a public health threat .1 Similar to chikungunya and Zika viruses, expanding arboviruses can exhibit unexpected clinical and epidemiological shifts , including vertical transmissions , neuroinvasive effects, and potentially fatal outcomes.2–4 Although OROV typically causes self-limited febrile illness, accumulating clinical and experimental evidence suggests neurotropic potential .5 This Correspondence describes the first confirmed case of neuroinvasive OROV infection caused by the emergent M1L2S2 lineage in ext...
Post a Comment
Read more »

Stability of #influenza viruses in the #milk of #cows and #sheep

By G.M.
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...
Post a Comment
Read more »

#Evidence of #Viremia in Dairy #Cows Naturally Infected with #Influenza A {#H5N1} Virus, #California, #USA

By G.M.
Abstract We confirmed influenza A virus (IAV) by PCR in serum from 18 cows on 3 affected dairy farms in California, USA . Our findings indicate the presence of viremia and might help explain IAV transmission dynamics and shedding patterns in cows. An understanding of those dynamics could enable development of IAV mitigation strategies. Source: US Centers for Disease Control and Prevention,  https://wwwnc.cdc.gov/eid/article/31/7/25-0134_article ____
Post a Comment
Read more »