Small ruminants virus vaccine strain (PPRV - V) overview

Small ruminants virus (Peste des petits ruminants virus comes, PPRV) is a major viral diseases affecting goats and sheep, due to its transmission speed, high mortality, is the OIE (OIE) as the animal infectious diseases must report. PPRV vaccine research and development is always the key point of the disease prevention and control, but there exist some problems in the existing vaccines, such as thermal stability may cause the failure of immunization, and biological safety hidden danger exists. As a result, improve the security and stability of PPR vaccine is the focus of current research.

Pathogenic characteristics

PPRV belong to the paramyxovirus family, measles virus, is a kind of associated with measles and canine distemper virus, has the characteristics of typical measles virus belong to. Virus particles are spherical, diameter of about 150-200 nanometers, surface glycoproteins have swelled. Viral genome for single strand RNA negative chain, the length of about 16000 nucleotides, encoding multiple proteins, including structural protein and the protein structure.

epidemic

PPRV popular in many countries and regions in the world, especially in Africa and the Middle East, to the local sheep and caused heavy losses. The virus was first found in China in 2007, then quickly spread in places such as xinjiang, 22 provinces. Because the virus is highly infectious and pathogenicity, coupled with the dense regions of cultivation to the spread of the virus, so the situation of the PPRV has always been a focus on the object of animal epidemic prevention.

Route of transmission

PPRV transmitted mainly through direct or indirect contact with infected animals secretions and excretions of virus can be spread by aerosol, the way such as food and water. In addition, the virus can also spread through media organisms such as mosquitoes. Studies have shown that PPRV can through the way of outside body secretion mediated communication between cells, this is a new mechanism for the spread of the virus.

clinical signs and symptoms

PPRV infection of clinical symptoms include fever, oral and nasal erosion, diarrhea and pneumonia. Virus infection causes of lymphoid tissue lymphopenia and immune suppression, increased animal susceptibility of secondary bacterial infection.

Pathological changes

The pathological changes caused by PPRV infection are mainly viremia and tissue necrosis. Virus infection of respiratory system, digestive system and the lymphatic system, and other system of organization, causing severe lesions. In the later stages of the infection, it may appear the "zebra" shape of lesions characteristic, especially in the intestinal mucosa.

Diagnostic methods

The diagnostic methods for PPRV mainly include serological diagnosis and etiological diagnosis. Serological diagnosis method is commonly used in ELISA, and etiologic diagnosis is dependent on the molecular biological technology such as rt-pcr. ELISA method possesses the advantages of simple, fast, but its sensitivity and specificity is relatively low. Rt-pcr technique with high sensitivity and specificity, can accurately detect the virus exists.

Prevention and control measures

At present, the PPRV mainly depends on the vaccination and prevention and control of biological safety measures. Due to the existing problems of vaccine, therefore, the research and development of new, more secure and stable vaccine becomes the key to the prevention and control work. In addition, the promotion of the biological safety management level of farms, such as to improve the breeding environment, strengthen personnel training, etc., is also an important means to control the spread of the PPRV.

conclusion

In summary, the research on the vaccine strain of Ruminant disease virus (PPRV-V) involves the basic information, pathogenic characteristics, epidemic situation, transmission route, clinical symptoms, pathological changes, diagnostic methods and prevention and control measures of the virus. The current vaccine research focus is to improve the security and stability, a new type of transmission mechanism at the same time also need to pay attention to the virus and possible treatment methods. Future research still need further, in order to better understand the virus features, which will provide a scientific basis for effective disease control.