Bird Flu Linked to Bird Markets, Fish Farms, Weather Patterns

Bird flu can produce a critical epidemic. Researchers are trying to nail down the sources for past bird flu epidemics. They have found that many originate in bird markets. Meanwhile, some flu attacks arelinked to weather patterns.

Bird flu and bird markets

Research from Colorado State University and the Shantou University Medical College confirmed in 2013 that many Avian Influenza Viruses (AIVs) originate from live bird markets and farms in China. In other words, bird flu often comes from from farmed chickens.

The researchers collected and analyzed six years of investigative data to determine the predominant vector (source) for Avian Influenza Viruses. The researchers found 13 different subtypes of influenza viruses that have originated from ten poultry species among poultry farms, wholesaling and marketplaces.

Their sample collection numbered an amazing 42,646 samples over that six year period. The virus subtypes found among these samples included AIV1 through AIV13, and Avian Paramyxovirus-type-1 (APMV-1).

The research concluded that the farming and selling of birds trapped in cages is incubating and transmitting these dangerous pandemic viruses to humans.

This has been a predominant risk among China because of the sheer number of contacts between people and infected birds through these marketplaces. These live animal marketplaces, in other words, act more than an exchange of animals: They provide a foundation for the spreading of viruses.

Avian flu and fish farms

In another recent study, this funded by the U.S. National Institutes of Health, researchers conducted a monthly sampling of chickens along with ducks and quail among live bird markets in the Southern China region. The sampling and analysis continued over a four-year period.

This study also found the 13 subtypes of AIV among the live bird markets. This study also confirmed that the chickens are the primary vector for the transmission of the virus, rather than the ducks and quail as assumed.

The bottom line is that both studies confirmed that the biggest vector of the Avian Influenza Virus is the farming and trading of live chickens.

This virus vector reminds us of the ongoing viral decimation taking place against the Wild Pacific Salmon and Wild Atlantic Salmon.

In this case, fish farms are being suspected as being the most likely vector for viral infections such as the Haematopoietic Necrosis Virus (IHNV). IHNV and associated viruses are now infecting the Wild Atlantic Salmon throughout the U.S. Northeast and Canadian waters, and the Wild Pacific Salmon of the Northwest.

Research has confirmed that IHNV may be associated with salmon lice that can accumulate in fish farms.

Another more recent study found that the antibiotics used to treat fish in fish farms are producing antibiotic-resistant bacteria not only among the fish within the farms, but these hardy bacteria are spreading to surrounding waters. A recent Spanish study from the University of Malaga studied four fish farms and their surrounding waters and came to the conclusion that:

“Significant differences in antibiotic resistance incidence were also detected among the four fish farms due probably to different approaches in farm management and the more or less frequent use of antibiotics. Antibiotic-resistant and multi-resistant strains isolated constitute an environmental reservoir directly involved in the seafood chain and might represent a public health concern.”

Is nature trying to tell us something about animal farming – removing animals from their natural habitats and penning them up in close proximity – where they can harbor deadly viral and bacterial infections?

Flu epidemics and weather patterns

Researchers from Columbia University’s Department of Environmental Health Sciences found that the last four influenza pandemics – of 1918, 1957, 1968, and 2009 – were related to a Pacific Ocean weather pattern called La Niña.

All of these influenza outbreaks were preceded by the La Niña weather pattern, characterized by cooler than normal ocean surface temperatures along the central Pacific Ocean.

This condition, translated from Spanish to mean “the child,” can last about five months, and often begins in the spring or summer months.

The La Nina pattern differs from the typical pattern of the El Niño Southern Oscillation – the predominant pattern. This La Nina cooling of ocean temperatures facilitates stronger storms, and a variety of atmospheric changes. La Nina often occurs every three or four years, but this is not consistent.

The La Nina pattern changes the migration patterns of migratory birds, along with that of their offspring. This, the researchers suggest, brings certain birds together with domestic animals – where the influenza virus can mutate.

The essential step is the mutation of bird flu viruses into a virus contagious to humans. This mutation step is known to occur through domestic animals – typically animals raised for slaughter such as pigs or chickens. The incubation of the virus within these domestic animals allows the virus to become transmittable to humans.

The researchers confirmed this as they stated:

“Changes in the phase of the El Niño-Southern Oscillation have been shown to alter the migration, stopover time, fitness, and interspecies mixing of migratory birds, and consequently, likely affect their mixing with domestic animals.”

REFERENCES:

Pepin KM, Wang J, Webb CT, Smith GJ, Poss M, Hudson PJ, Hong W, Zhu H, Riley S, Guan Y. Multiannual patterns of influenza A transmission in Chinese live bird market systems. Influenza Other Respi Viruses. 2013 Jan;7(1):97-107.

Pepin KM, Wang J, Webb CT, Hoeting JA, Poss M, Hudson PJ, Hong W, Zhu H, Guan Y, Riley S. Anticipating the prevalence of avian influenza in live-bird markets. PLoS One. 2013;8(2):e56157.

Jakob E, Barker DE, Garver KA. Vector potential of the salmon louse Lepeophtheirus salmonis in the transmission of infectious haematopoietic necrosis virus (IHNV). Dis Aquat Organ. 2011 Dec 6;97(2):155-65.

Labella A, Gennari M, Ghidini V, Trento I, Manfrin A, Borrego JJ, Lleo MM. High incidence of antibiotic multi-resistant bacteria in coastal areas dedicated to fish farming. Mar Pollut Bull. 2013 Mar 18.

Shaman J, Lipsitch M. The El Nino-Southern Oscillation (ENSO)-pandemic Influenza connection: Coincident or causal? Proc Natl Acad Sci U S A. 2012 Jan 17.