Etiology of acute respiratory disease in fattening pigs in Finland

Abstract

BackgroundThe objective of our study was to clinically and etiologically investigate acute outbreaks of respiratory disease in Finland. Our study also aimed to evaluate the clinical use of various methods in diagnosing respiratory infections under field conditions and to describe the antimicrobial resistance profile of the main bacterial pathogen(s) found during the study.MethodsA total of 20 case herds having finishing pigs showing acute respiratory symptoms and eight control herds showing no clinical signs suggesting of respiratory problems were enrolled in the study. Researchers visited each herd twice, examining and bleeding 20 pigs per herd. In addition, nasal swab samples were taken from 20 pigs and three pigs per case herd were necropsied during the first visit. Serology was used to detect Actinobacillus pleuropneumoniae (APP), swine influenza virus (SIV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine respiratory coronavirus (PRCV) and Mycoplasma hyopneumoniae antibodies. Polymerase chain reaction (PCR) was used to investigate the presence of porcine circovirus type 2 (PCV2) in serum and SIV in the nasal and lung samples. Pathology and bacteriology, including antimicrobial resistance determination, were performed on lung samples obtained from the field necropsies.ResultsAccording to the pathology and bacteriology of the lung samples, APP and Ascaris suum were the main causes of respiratory outbreaks in 14 and three herds respectively, while the clinical signs in three other herds had a miscellaneous etiology. SIV, APP and PCV2 caused concurrent infections in certain herds but they were detected serologically or with PCR also in control herds, suggesting possible subclinical infections. APP was isolated from 16 (80%) case herds. Marked resistance was observed against tetracycline for APP, some resistance was detected against trimethoprim/sulfamethoxazole, ampicillin and penicillin, and no resistance against florfenicol, enrofloxacin, tulathromycin or tiamulin was found. Serology, even from paired serum samples, gave inconclusive results for acute APP infection diagnosis.ConclusionsAPP was the most common cause for acute respiratory outbreaks in our study. SIV, A. suum, PCV2 and certain opportunistic bacteria were also detected during the outbreaks; however, viral pathogens appeared less important than bacteria. Necropsies supplemented with microbiology were the most efficient diagnostic methods in characterizing the studied outbreaks.

Antimicrobial susceptibility of pathogenic bacteria isolated from swine lungs

“…Porcine respiratory disease complex (PRDC) is a syndrome caused by mixed viral (porcine respiratory and reproductive syndrome virus, porcine circovirus type 2, porcine coronavirus) and bacterial pathogens (Actinobacillus pleuropneumoniae, Pasteurella multocida, Mycoplasma hyopneumoniae, Streptococcus suis, Eschericha coli) (M. HAIMI-HAKALA & al. [1]). In many cases it is difficult to say what is the primary pathogen and which one acts as a predisposing agent for other infections or as a secondary infection (E. THACKER & al.…”

“…In other studies (M. HAIMI-HAKALA & al. [1]; Z. KUCEROVA [16])A. pleuropneumoniae strains were resistant to tetracycline and penicillin, and sensitive to florfenicol. Streptococcal strains were sensitive to penicillin (A. de JONG & al.…”

Herd-level risk factors for chronic pleurisy in finishing pigs: a case-control study

“…Controversial results have been previously reported regarding serology and pleurisy registered in meat inspection [2,13,8,24]. In case of endemic disease, serology might not be the most useful tool in diagnosis or at least paired samples are needed [25]. Also, the timing of the infection remains unknown in our study, as we are dealing with endemic disease.…”

A Systematic Review Analyzing the Prevalence and Circulation of Influenza Viruses in Swine Population Worldwide

“…Europe Belgium H1N1, H1N2, H3N2 None [179][180][181] Denmark H1N1, H1N2, H3N2 None [182][183][184] United Kingdom H1N1, H1N2, H3N2, A(H1N1)pdm09, H1N7 IBV, ICV [185][186][187][188][189][190][191][192] Finland H1N1, H1N2, H3N2, A(H1N1)pdm09 None [193,194] France H1N1, H1N2, H3N2, A(H1N1)pdm09 None [195][196][197][198][199] Germany H1N1, H1N2, H3N2, A(H1N1)pdm09 None [200][201][202][203] Greece H1N1, H1N2, H3N2, A(H1N1)pdm09 None [204] Italy H1N1, H1N2, H3N2, A(H1N1)pdm09 IDV [205][206][207][208][209][210][211][212][213][214][215][216][217] Spain H1N1, H1N2, H3N2 None [218][219][220][221] Netherlands H1N1, H1N2, H3N2 None [222] Norway A(H1N1)pdm09 None [223][224]…”

“…Later, the first A(H1N1)pdm09 virus in Finnish swine was detected in November 2009 [193]. Three more swine were identified with IAV antibodies during May 2011-January 2014 which was due to a past exposure to IAV [194].…”