The form of the H1N1 swine influenza is a descendant of the strain that caused the influenza pandemic of 1918. And the persistence in pigs, descendants of the 1918 virus was also circulating in humans through the 20th century, contributing to the normal seasonal epidemics of influenza. However, direct transmission from pigs to humans is rare, with only 12 cases in the United States since 2005. However, the maintenance of strains of influenza in pigs after these strains were removed from the human population could be a reservoir where swine influenza viruses can persist, alongside emerging reinfect humans once the immunity of Man of these strains declined.
Swine influenza has been reported several times as a zoonosis in humans, usually with limited distribution, often with a wide distribution. Outbreaks are common in swine, causing significant economic losses in industry, primarily by causing delays in growth and time to market. For example, this disease costs the meat industry on the UK £ 65 million each year. l man once immunity to these human stem down.
1918 pandemic in humans
Flu pandemic in 1918 was associated with human flu and the H1N1 in pigs appears, which reflects a zoonosis May, from pigs to humans or from humans to swine. Although it is not certain in which direction the virus has been transferred, some data suggest that in this case, the pigs took the man's disease. For example, swine influenza has been identified as a new pig disease in 1918, after the first large outbreaks of influenza in people. Although a recent phylogenetic analysis of more recent strains of influenza in humans, birds, pigs and 1918 suggests that the outbreak in humans following a reassortment in a mammal, the precise origin of the strain 1918 remains uncertain.
1976 U.S. outbreak
On 5 February, 1976, the United States of an army recruit at Fort Dix said he felt tired and weak. He died the next day, and four of his comrades were hospitalized. Two weeks after his death, health officials announced that the death was caused by a new strain of swine influenza. Strain, a variant of H1N1, is known as A / New Jersey/1976 (H1N1). It was detected only from January 19 to February 9 and has not spread beyond Fort Dix.
This new strain appears to be closely linked to the strain involved in the influenza pandemic of 1918. In addition, increased surveillance has found that another strain circulating in the United States: A/Victoria/75 (H3N2) spread simultaneously, also caused the disease and continued until March . Alarmed public health agreed measures shall be taken to avoid a major pandemic, and called on President Gerald Ford that anyone in the United States be vaccinated against the disease.
The vaccination program was plagued by delays and public relations problems. On 1 October 1976, the vaccination program began in October and 11, about 40 million people, approximately 24% of the population, had received vaccinations of swine influenza. The same day, three elderly people died shortly after receiving their vaccines against swine influenza and there was a media outcry linking death to immunization, despite the lack of evidence. According to science writer Patrick Di Justo, however, when the truth was known - that the dead are not found to be related to the vaccine - it was too late. "The government has long feared mass panic over swine flu - now they feared mass panic on the swine flu vaccine." This is a setback for the program.
There were reports of Guillain-Barré syndrome, a paralyzing neuromuscular disorder, which affects some people who had received vaccinations of swine influenza. This syndrome is a rare side effect of vaccines against influenza modern, with a frequency of about one case per million vaccinations. Accordingly, Di Justo says that "the public has refused to trust a government operated health program who killed the elderly and disabled young people." In total, less than 33% of the population were vaccinated at the end of 1976. The national program of vaccination against influenza has been arrested on 16 December.
Overall, there were approximately 500 cases of Guillain-Barré syndrome (GBS), resulting in the death of severe pulmonary complications for 25 people, which, according to Dr. P. Haber, were probably caused by an immunopathological reaction to the vaccine in 1976. Other vaccines against influenza are not linked to GBS, but caution is advised for some people, especially those with a history of GBS. However, as noted by a participant in the program of vaccination, the vaccine killed more Americans that the disease did.
1988 zoonosis
In September 1988 a virus of swine influenza killed one woman and other infections. 32-years, Barbara Ann saucissons was eight months pregnant when she and her husband, Ed, fell ill after visiting the barn at a funfair in Walworth County, Wisconsin. Barbara died eight days later, after developing pneumonia. The only pathogen was identified a strain of H1N1 influenza virus. Doctors are able to induce labor and to offer a girl in good health before his death. Her husband recovered from his symptoms.
ILI was widespread among pigs at the fair. 76% of exhibitors from 25 pigs aged 9 to 19 positive tests for antibodies to SIV, but no serious diseases have been detected in this group. Further studies suggested between one and three health personnel who have been in contact with the patient a mild flu like illness with antibody evidence of infection with swine influenza. However, there is no community outbreak.
|
