A pathogen
Swine flu pathogen, virus is more for the sivs spherical shape, generally, diameter 80 ~ 120 nm. Posterior capsule, there are many 2.see anticlinal membrane glycoprotein, namely the bumps and ashdod, fiber were columnar of hemagglutinin (HA), mushrooms, or the neuraminidase enzyme (n.) and film making or on the yankees lipoprotein M2. HA and making sure influenza virus subtype as the main basis and strain. HA in appropriate conditions, the erythrocyte aggregation in some animals infected with recognition process of adsorption target cells. Making can make the virus in red blood cells from red blood cells, also can make the virus from infected cells.
Second, the epidemiology
The main transmission way swine flu pig is between the direct contact with the nose nose, the air is mainly transmitted, appear more temperature changes in the outbreak of time, such as the late spring, the weather changed and the cold winter.
A transmission is one of the significant characteristic of the sivs. In the process of influenza irus infection, HA on recognition and adsorption cell receptor action, it is a major determinant of host specificity. Influenza viruses are two receptor alpha 2: saliva acid (SA galacitiol alpha 2 - Gal) and saliva acid alpha 2,6-dimethylphenyl galacitiol (SA alpha lysine, exists in different Gal) or gastrointestinal tract epithelial cells of the host. People on SA respiratory epithelium cells Gal receptor alpha lysine, while the intestinal epithelium cells waterfowl SA alpha 2 - existing Gal receptors, pig respiratory epithelial cells of the influenza virus exist two receptor alpha 2 - Gal SA SA and alpha 2,6-dimethylphenyl Gal. Thus, it is a pig, pigs, the common person flu virus, is susceptible hosts influenza virus gene recombinant or with "mixer and influenza virus strains produced new popular" incubation, has important public health significance. In Europe, Asia and the USA, occasionally from people in the airways or lungs to pig flu virus, also from pig to H9N2 viruses in poultry. Kaufman m etc from death in 1988, the primary viral pneumonia in women from a pig viruses, the women were H1N1 has participated in the exhibition of pigs. Olsen etc, since January 2005 Canadian pigs have been isolated H3N2 flu virus, except the man is making significant genetic, these viruses and 1998 U.S. pigs in the virus appears similar/classical pig/avian influenza virus strains of restructuring. Recently, the emergence of a new strain of H3N1 sivs, pedigree analysis shows that it can separate strains from H3N2 Turkey obtained from people, HA gene H1N1 separation plant gene, making obtained from the current sivs won the gene. This H3N1 sivs antigen and Turkey viruses. The lung injury and infected pigs has hinted H3N1 sivs outflow of nose in pigs in the spread of infection and potential. Myers etc. [5] research shows that the pig occupational exposure greatly increases the risk of infection sivs staff. ZhangMei [6] of hebei province as pig population (H1N1) the influenza virus serological survey research results show that the crowd is healthy pigs influenza virus infection, from the age of increase with age, have gradually increasing positive of antibody of trend, During the same period to meat company harvesting serum, 2 has 226 positive of antibody positive, pigs, 0.88% for existing in pig (H1N1) influenza virus. Therefore, the authors put forward to strengthen monitoring of pig, who make warning signs. LiuJiHu on 16 in anhui province, raising and commercial farms were slaughtered pigs dot collection of random sampling, and the corresponding nasal serum samples of cotton swab 2588 samples, results show that in the range, the monitoring and slaughtered pigs are scattered pig has not been detected H5 subtype antibody. 64 thousand six hundred portions serum sample size of pig farms have 11 67 sample to detect H5 flu antibody positive field, subtype of 17.19% (11), the positive / 64 percent from the field detection antibody positive samples, ~ 50% for 4.15% (67 / thousand six hundred. From the antibody positive cotton swabs samples of nasal antigen did not detect a virus. Anhui multiple scale farm that were H5 subtype antibody positive pig.
The pig and poultry from that of the influenza virus spread across species to have multiple reports, but all these viruses were lack of human-to-human transmission of the key ability. Subtype H5N1 bird flu virus in the body of the poisonous force strong in lung tissue extreme copy, make human body to produce too much for a long time, but the cytokines on influenza virus cells and the precise situation or there is still a lot of questions. Although pigs to include subtype H5N1 bird flu virus, several kinds of virus subtypes are predisposition, but obviously have a prevent the virus infected pigs important barrier. Bird flu virus in pig body can be frequently made with, but no evidence that, in 1957 and 1968 pandemic strains produced with the H5N1 strain or in all poultry virus or other infectious virus to play a certain role. Therefore, some scholars believe that pigs influenza virus spread across species of itself to cause the person flu pandemic influenza virus, animals must pass significant genetic variation (the most still unknown) in the crowd to settle in.
Third, both at home and abroad present popular sivs
At present, SI has covered the americas, Asia, Africa, Europe all over the world, in recent years, Japan, South Korea, the United States, is that H1N2 subtype strain H1N1 and the restructuring of the product; H3N2 Different regions of China pigs in SI, as well as H3N2 subtypes H1N1 and other subtypes. From Spain Maldonado northern and eastern 100 not immune SI pig, with 600 serum collected test H1N1 HI, and H1N2 subtypes of antibody H3N2, and the results showed that the pig and 76.3% 83% was at least 1 subtypes of pigs in the sivs antibody, 600 was H1N2 serum antibodies, H3N2 H1N1 and 109 (18.2) respectively, 60 (10%) and 41 (6.8%. China is the largest country in the world, in recent years, raising pig industry in China from the traditional family raise progressively to scale the development direction, due to its size, the breeding density feeding, high stress caused by many factors, easily outbreak of disease of SI etc, serious threat to China and the continuous and steady development and the development of animal. In some provinces and cities and pigs, the existence of the survey shows that the SI of guangxi as part GaoYongRui: municipal (county) pigs were swine flu serological survey, in 12 municipal (county) acquisition of 1000 serum, 10 municipal (county) detection H3N2, 257 portions serum antibodies in H3N2 antibody positive, average rate 25.17%. YangDeSheng survey results are widely distributed in fujian province swine flu. KangWenBiao etc, enzyme immunosorbent test (ELISA) in gansu 13 city and state of health of 188 17 pig pig serum and the other a serum swine flu (H3N2 serum antibodies), average rate 27.89%. From the above data that has been in the sivs exist in pigs.
Four, the sivs diagnosis
(a) serodiagnostic serodiagnostic technology is qualitative diagnosis, conventional subtypes SI identification method, the most practical indeed have erythrocyte aggregation (HA) experiments, the erythrocyte aggregation inhibition (HI) experiments, neuraminidase enzyme inhibition (NI) experiments, AGAR immune diffusion method (AGP), indirect ELISA, antigen capture ELISA, etc.
(2) molecular diagnosis of traditional methods, demanding conducted directly grind beast molecular diagnosis of early rapid and identify research. XiaXiangRong such as the establishment of the influenza virus TaqM reverse transcriptase PCR, an influenza virus, used to detect the nucleoprotein (NP) RNA, NP influenza virus's most conservative genes. This can be detected and the birds, mammals influenza virus samples for the acquisition of the bronchi, the sample and lung tissue, wipe provides higher detection sensitivity, rapid detection, and other test samples from the samples as subtype diagnosis and removed the viral nucleic acid sequence analysis on.
Five, SI vaccine research
(a) the virus was used on the market at present is inactivated vaccine SI unit, and have with H3N2 H1N1 double price, this kind of vaccine was already in Europe countries, such as Intervet commercially supply of End - Imugen) FLUence (paintings and End - 2 (Microsol paintings Diluvac FLUence Forte). Heinen etc compared the vaccine pigs and natural immune effect, the pig pig found vaccine in the short-term poison poison attack, and natural infection is fully protect, pig analysis indicates that the vaccine produced the same or higher swine serum HI, viruses and antibody specificity IgG ribonucleoprotein and antibody, but the nasal mucosa IgA and lymphocyte proliferation reaction, which may explain lower immune after the state protection. Currently the commercialization of influenza inactivated vaccine to prevent swine flu though pig plays an important role in vision, but the source and alien virus cannot provide effective protection, thus to effectively control inactivated vaccine in KangYuanXing changeful sivs pigs and the infection.
(2) the unit vaccine subunits vaccine is through physical and chemical methods or genetic engineering major pathogens means to gain the protein and immune a vaccine, it can effectively avoid using the pathogens to produce vaccines biological safety risk, and is helpful to improve the vaccines effective compositions of concentration, purity, and develop more and more united vaccine. Mainly includes:
(1) gene engineering seedlings: use baculovirus expression system used for making proteins and HA, domestic SIVA expressed immune Swine / / HeNan / 703/2001 (H3N2) making gene.
(2) DNA vaccines: pig influenza virus infection (HA) and making alone or with cytokine gene (interleukin - 6, gamma interferon, etc.) after cloning genes encoding series to eukaryotic expression plasmid, then recombinant DNA plasmid into the cell, through the endogenous expression and to the immune system produces induction host specificity, protective immune response, and this is the so-called DNA vaccines. Recently, by express Tompkins influenza virus M2 common sequence of DNA vaccines immunization mice, induce antibody specificity and M2 deadly poison attack has protection. At first, then M2DNA vaccine with the reorganization of adenovirus expressing M2, strengthen and improve the immunity and influenza virus and handed the antibody response M2 * T cells, and produce A reaction, experimental results show that M2DNA vaccine inoculation and strengthen early, can avoid to fatal influenza A (H5N1) attack produces broad-spectrum include protection.
(3) live vaccine is used for the carrier, including people adenovirus vector 5 type, type, viral pig pig pseudo hydrophobic virus (PRV), baculovirus etc. Tian sivs will be the restructuring of the false rabies virus HA rPRV (HA) - in mice inoculated immune, three weeks after produced HI antibody, after 28 d, use immune 105TCID50 of heterologous sivs nasal attack in the rat poison, not separate from the immune to attack in the lungs, only form observed slightly damaged. The restructuring of the artifacts that express HA protects mice against rabies virus strain of heterologous attack.
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