Avian influenza kills 17,000 elephant seals in Argentina
Professor Dr. Salah Mahdi Hassan / Consultant and expert in poultry health and production
A new study published in Nature Communications on 13/11/2024 investigated the outbreak of the highly pathogenic avian influenza virus (HPAI H5N1) in marine mammals, specifically elephant seals, along the coast of Argentina from 2022 to 2023. It highlights the alarming spread of the virus among marine mammals and its link to outbreaks in other countries in South America.
The new study showed that the avian influenza virus caused the death of more than 17,000 elephant seals in one year in Argentina, with breeding seal groups being the most affected, killing 95% of seal pups in 2023. The researchers also showed evidence of increased adaptation of H5N1 among mammals and its spread from seabirds to shorebirds.
The research indicated that the virus spread along the coasts of Peru and Chile between 2022 and 2023, and is transmitted by porpoises, dolphins and other marine mammals. In June 2023, the virus spread south into Chile, eventually reaching other South American coasts. Since October 2023, it has caused record mortality rates in southern elephant seals (Mirounga leonina) in the Península Valdés in central Patagonia, Argentina. It is worth noting that this site in Argentina is a UNESCO World Heritage Site, and is of global importance for the conservation of marine wildlife. The outbreak has affected breeding numbers, with at least 35 deaths of adult and subadult seals recorded in the area. The study found that “the die-offs have led to major changes in the social structure of elephant seals, with mature alpha males gradually being replaced by less mature and mature males and a rapid decline in the number of breeding females. The peak in elephant seal pup mortality occurred between September and October 10, 2023. The study suggests that seal populations will experience an unusually low birth rate in 2024, even if the majority of adult females survive the virus infection.
Currently, no infected elephant seals have been identified in the new breeding season, although the study noted that males and females have abandoned their colonies, likely due to the spread of the infection.
In addition, the researchers uncovered evidence of the evolution of a new, highly virulent H5N1 avian influenza virus (HPAI 2.3.4.4b) for marine mammals, with genetic mutations that may have enhanced its ability to infect mammals while retaining its ability to infect birds. The genome data provide The viral strain in this study provides evidence of the evolution of a new strain of HPAI H5N1 Clade 2.3.4.4b marine mammals that has spread to seals in several South American countries, revealing that genetic mutations have occurred in this virus that have enabled it to infect mammals while also retaining the ability to spread to birds.
The researchers identified the H5N1 HPAI viruses in Argentina as belonging to the B3.2 genotype out of 11 virus sequences analyzed. The study also indicated that the B3.2 viruses that spread from North America to South America had a reorganized genotype with four segments of the highly pathogenic Eurasian H5 lineage (PA, HA, NA, and MP) as well as four segments of the low-pathogenic avian influenza viruses of the North American lineage (PB2, PB1, NP, and NS). Therefore, this study showed that within this biological series of the virus, there appears to be mixing between poultry viruses in Argentina with viruses from other regions as well as viruses present in wild birds, indicating that there is frequent movement of the virus across national borders and its spread between wild birds and poultry. A quantitative analysis conducted by the researchers showed that the H5N1 HPAI virus has been transmitted nearly four times from wild birds to marine mammals along the Pacific coast of South America. The study also noted transmission from marine mammals to shorebirds and humans in Chile. Four terns (shorebirds) were reported to be infected with a virus isolated from wild birds in Chile, confirming four independent cases of marine mammal-to-bird transmission. It also appears that human and sanderling viruses, which are part of the marine mammal virus family, are spreading independently of marine mammals. This conclusion is supported by the presence of genetic mutations in PB2 that coincide with adaptation to mammal tissues, in viruses in the marine mammal virus family. The study warned that the genetic mutation in the virus that leads to increased adaptation to mammals is a “potential public health concern.” The researchers called for comprehensive strategies that take into account the links between human, animal and environmental health, as well as protecting biodiversity, promoting sustainable practices, and improving global capacity to address emerging infectious diseases.
The last question of this article is what is the future of the situation in our Iraqi reality in light of the presence of many subtypes of avian influenza viruses, including H5N1, the last report of which in Iraq dates back to the current year 2024 when seagulls were infected in Dokan Dam, and the presence of the H9N2 virus, which is said to have caused and is causing many outbreaks of disease in broilers and layers. It is necessary to point out the H5N8 subtype that was present in Iraq in the years 2017-2018 and caused huge losses in broilers and layers. In addition to all this data is the random and extensive use of avian influenza vaccines for both H5N1 and H9N2, and the presence of different types and forms of these dangerous vaccines, especially those mixed with the Newcastle vaccine?? Noting that there are many international studies that indicate that the bird flu virus works to suppress the immune response to the Newcastle vaccine, and what confirms this is the high incidence of Newcastle in Iraq and in a field image that is strange from the previous image of Newcastle, which means a complete wipeout of immunity in poultry raised in Iraq??? Just to remind veterinarians that the Iraqi field has been endemic with Newcastle for many years, and therefore Newcastle cannot work in well-vaccinated flocks. What the Nahrain Veterinary Network displays of pictures of Newcastle cases, which the reader can accept when Newcastle infections occur in America, France, Britain or Australia?? Where Newcastle is not present and therefore the vaccine is not used?? And therefore the Newcastle virus can do its work as in the pictures of the Nahrain Veterinary Network, but in Iraq the matter is very different. Iraq was one of the countries where it was difficult to diagnose Newcastle except after a very thorough examination of both the digestive tract and the respiratory tract, and it may require a brain examination.. Today, Newcastle is one of the easiest diseases to diagnose??? The dangerous thing that works to continue the danger to poultry and then public health is the introduction of the combined vaccines of the subtype (H5N1 + H9N2 + Newcastle strain seventh generation)?? And I do not know how such a vaccine was allowed in Iraq?? Today, all global research and reports warn, as you saw in the research above, of the danger of reorganization between H5N1 viruses and H9N2 viruses, which produced H5N1 viruses with a high epidemic and multiple infections for poultry and livestock, including humans. Therefore, a serious pause is necessary to understand the reality of the situation and an accurate analysis of the correct field reality.. We cannot stand idly by in the face of an imminent danger looming over Iraq in the near future?? Frankly, I do not know who to appeal to?? We were hoping for the advisory body in the General Secretariat of the Council of Ministers to provide assistance and correct some The tracks, but my hope is in the net.
Finally, the poultry sector cannot be without a governing and controlling reference if what is required is a sustainable Iraqi poultry industry that Iraqi food security depends on without commercial fraud and providing the imported under the name of the local.
Reference : Massive outbreak of Influenza A H5N1 in elephant seals at Peninsula Valdes,
Argentina: increased evidence for mammal-to-mammal transmission
