Епізоотологічний моніторинг цирковірусної, парвовірусної інфекцій і репродуктивно-респіраторного синдрому свиней на території Південно-Східного регіону України

Abstract

Porcine circovirus infection (PCV), parvovirus infection of pigs (PVIS), porcine reproductive and respiratory syndrome (PRRS) at the present time, according to the productive serological monitoring in various countries, including the Russian Federation, are very widespread in pig breeding industrial enterprises. The aim of this study was to conduct serological monitoring for PCV, PVIS and PRRS in the Udmurt Republic taking into account a certain age factor when these diseases begin to appear and develop. Contamination of pig population aged from 28 to 120 days was determined above 50%, indicating that the virus is circulating widely in the study age group of animals. It was found that the level of PCV seropositivity was 49.1%, PRRS level - 47.5%, PVIS varied about 36.3%. During the study of different types of pathological materials in the polymerase chain reaction (PCR) viral antigens on PCV and PRRS were revealed, which indicates the associated form of the disease in group of weaning piglets. The most common epizootiological and economic problem in modern small-scale pig breeding is reproductive and neonatal infections of pigs (RNIP). RNIP are mixed viral-bacterial infectious diseases. The main feature of these infections is damage to genital organs of animals resulting in reproductive disorders in sows and buds, as well as reduction in viability of newborn piglets caused by immunodeficiency and depletion from various pneumoniae enteritis. Insufficient knowledge about the nature of zoonotic RNIP and underestimation of their significance for pig breeding have led to their unprecedented spread in the last decade. The zoonotic RNIP in pig farms of Ukraine currently have a viral-bacterial etiology. Traditional approaches to epizootic regulation of these polyetiological infections are ineffective and can not provide a sustainable disease-free status of the Ukrainian pig breeding for zoonotic RNIP. This gives a reason to consider these infectious diseases as emergent. The international experience in issues of elimination of the hotbeds of emergent diseases of polyetiological origin, shows that the development of a plan for antiepizootic measures individually for each farm proves effective. Our analysis of the latest scientific publications shows that reproductive respiratory syndrome, circovirus and parvovirus infection of pigs are considered to be among the viral diseases of economical significance for the industrial pig breeding along with the classical swine fever and Aujeszky's disease. According to the serological monitoring conducted in various countries, including Ukraine, the CVIP are widespread in pig farms of the industrial type. The circovirus infection manifests itself clinically in piglets 2-3 weeks after weaning. Rejection of food, shortness of breath, fever, exhaustion, lag in growth, increased mesenteric lymph nodes, pallor or yellowness of skin shave been observed in sick animals. Among piglets of 7-15 weeks of age, the circovirus infection is manifested as a syndrome of post weaning multiple systemic exhaustion. According to foreign researchers, the incidence in piglets is at the level of 5-10%, sometimes up to 50-70%, and the mortality level reaches 70-80%. The aim of our study was to carry out serological monitoring of CVIP, PVIP and PRRS on the territory of Kharkiv, Zaporizha and Poltava regions of Ukraine, taking into account the factor of age when these diseases begin to manifest itself and spread. A total of 1684 blood samples from pigs of all ages were investigated. Serological blood tests for CVIP and PRRS were conducted with the use of LIA method, for parvovirus infection by the, detection of HIT viral genetic material - by the PCR method of Narvak system. The virological examinations of the clinical and pathological material were carried out according to generally accepted methods using the transfilled lines of cell cultures PK-15, Mark-145. Manifestation of CPE with subsequent identification of the viruses in the immunofluorescence (RIF) reaction using the immunoperoxidase method on the cultural monosharm, HIT (AD, CSF, CVIP-2, PRRS) were also studied. The research was conducted in the P.I. Verbitsky scientific and educational laboratory of genetic-molecular research methods at the Department of Epizootology and Veterinary Management of the KhDZVA. We found that the level of seropositivity of pigs for CVIP was 51.4%, for PRRS 45.8%, while PVIP varies within 34.8%. In the study of various types of pathological materials in the polymerase chain reaction, the viral antigens of the CVIP and PRRS have been detected. This indicates the associated form of the disease in piglets in the growing group.