Field Station for Epidemiology, University of Veterinary Medicine Hannover, Foundation, Buescheler Street 9, Bakum, D-49456, Germany.
Acta Vet Scand. 2013 Jun 3;55(1):44. doi: 10.1186/1751-0147-55-44.
In recent years, the occurrence and the relevance of Mycoplasma hyopneumoniae infections in suckling pigs has been examined in several studies. Whereas most of these studies were focused on sole prevalence estimation within different age groups, follow-up of infected piglets or assessment of pathological findings, none of the studies included a detailed analysis of individual and environmental risk factors. Therefore, the aim of the present study was to investigate the frequency of M. hyopneumoniae infections in suckling pigs of endemically infected herds and to identify individual risk factors potentially influencing the infection status of suckling pigs at the age of weaning.
The animal level prevalence of M. hyopneumoniae infections in suckling pigs examined in three conventional pig breeding herds was 3.6% (41/1127) at the time of weaning. A prevalence of 1.2% was found in the same pigs at the end of their nursery period. In a multivariable Poisson regression model it was found that incidence rate ratios (IRR) for suckling pigs are significantly lower than 1 when teeth grinding was conducted (IRR: 0.10). Moreover, high temperatures in the piglet nest during the first two weeks of life (occasionally >40°C) were associated with a decrease of the probability of an infection (IRR: 0.23-0.40). Contrary, the application of PCV2 vaccines to piglets was associated with an increased infection risk (IRR: 9.72).
Since single infected piglets are supposed to act as initiators for the transmission of this pathogen in nursery and fattening pigs, the elimination of the risk factors described in this study should help to reduce the incidence rate of M. hyopneumoniae infections and thereby might contribute to a reduced probability of high prevalences in older pigs.
近年来，支原体肺炎感染在哺乳仔猪中的发生和相关性已在多项研究中进行了研究。虽然这些研究大多集中在不同年龄段的单一患病率估计、感染仔猪的随访或对病理发现的评估上，但没有一项研究包括对个体和环境危险因素的详细分析。因此，本研究的目的是调查地方性感染猪群中哺乳仔猪支原体肺炎感染的频率，并确定可能影响仔猪断奶时感染状态的个体危险因素。
在三个常规猪养殖群中，对 1127 头哺乳仔猪进行检查，发现支原体肺炎感染的动物水平患病率为断奶时的 3.6%（41/1127）。在同一批猪中，在保育期末期发现患病率为 1.2%。在多变量泊松回归模型中发现，磨牙时仔猪的发病率比（IRR）明显低于 1（IRR：0.10）。此外，仔猪生命的头两周中猪窝内的高温（偶尔>40°C）与感染概率降低有关（IRR：0.23-0.40）。相反，向仔猪接种 PCV2 疫苗与感染风险增加相关（IRR：9.72）。
由于单个感染的仔猪被认为是在保育和育肥猪中传播这种病原体的启动因素，因此消除本研究中描述的危险因素应有助于降低支原体肺炎感染的发病率，从而可能降低大龄猪高患病率的概率。
