United States: A detailed investigation on a large number of water samples collected from all the 50 states of America from the middle of May to July revealed presence of the H5N1 bird flu but this was peculiar with regions with population of farming animals.
The avian flu virus affected U.S. poultry and herds of dairy cows for which there were fears that the virus could mutate and spread among people.
As reported by the HealthDay, the tests which were done on the wastewaters between May 12 and July 13 are comforting and implies that the virus is still focused on animals.
Out of 41 states that tested for flu viruses in wastewater, nine states detected sites with the H5N1 virus in samples, the CDC said.
Nevertheless, “the nine States with H5 detections in wastewater included seven States with an HPAI A[H5N1]–infected herd reported during this period and one additional State with an infected herd reported before this period,” the agency said in its Morbidity and Mortality Weekly Report journal on September 19, 2012.
Those nine states include California, Colorado, Idaho, Iowa, Michigan, Minnesota, North Carolina, South Dakota and Texas.
Up to date, only 14 cases of human infection with H5N1 have been recorded; usually presenting minor ailment; almost all cases reported involving people in direct contact with the affected animals, in this case dairy farm workers.
In the new wastewater report, two of these nine states, namely Colorado and Michigan, confirmed the human cases of HPAI A(H5N1) virus infection during the period mentioned,” said the team of authors led by Souci Louis of the CDC, an investigator at the Epidemic Intelligence Service.
In many of these states further investigations into the sources of the outbreaks, which probably include animal related circumstances, such as those linked to milk production, were conducted.
Yet, the researchers noted that wastewater testing is still not definitive about the source of virus because, although the presence of influenza viruses in wastewater can be proven, the researchers also said that the current method cannot differentiate whether it is from human or animal origin.
The same team also searched for other strains of influenza A viruses (of which H5N1 is only a sub-type). A viruses or seasonal human flu are associated with the flu.
The report found that during the early summer, 11 sites in the four states which is califronia, Illiionois , Kansas and Oregon which reported the high levels of the influenza A virus, which indicating the regular flu which was being passed around between the people there.
“None of these four states reported H5 human influenza cases nor did they report nay confirmed cases in the livestock herds or the poultry within their sewer or counties during this time Louis team noted that.