猪流感的免疫控制DBN02.ppt

疫苗的使用 流行期免疫接种 可缩短发病病程 可控制疾病的扩散 非流行时免疫接种 使猪群的免疫水平趋于一致 提高机体的免疫力（猪群的健康状况） 预防疾病的发生 减少猪群中病毒的排放 免疫计划简单 小猪 每头份2ml，两次免疫间隔3周 种猪免疫 配种前，或配种时，或分娩前 首次免疫每头份2ml，两次间隔3周 以后每年2次 SIV Significant Reduction in Viral Shedding Just a few years ago, the prevalence of the H3N2 based on blood testing of samples was less then 3%. Diagnosing SIV If a herd vaccinated against H1N1 has a flu outbreak, H3N2 should be suspected, particularly if sows develop high fevers. Otherwise, H2N2 and H1N1 cannot be differentiated based on clinical signs alone. Diagnosis at a lab is required so that producers can implement appropriate control measures. The most widely available method of diagnosing SIV is with a blood test, or serology, known as hemagglutination inhibition (HI). It takes a few days to perform these types of tests, which can differentiate between H1N1 and H3N2 antibodies. A positive HI test indicates exposure to swine influenza through natural exposure and, in young pigs, it may reflect maternal antibody to SIV. A positive result can also result from vaccination. Other types of tests detect antigens to SIV in tissues or secretions. One is the fluorescent antibody assay (FA); another is the immunohistochemistry test (IHC). Both FA and IHC can yield results within 24-48 hours. Producers and veterinarians need to ask the lab for additional testing to distinguish H1N1 from H3N2. Sample collection and handling is important to assure accurate results. It is best to ask the lab how it wants samples collected and sent. Generally, however, samples should be taken from acutely ill pigs with an elevated temperature. If too much time elapses between the time the flu erupts and samples are taken, the virus might not be present and the results could be erroneously negative. Managing SIV When an SIV outbreak occurs, the only treatment available is control of fever with aspirin or antipyretic drugs. If secondary bacterial infections develop, antibiotic treatment may be necessary. It also helps to reduc