The epidemiology of NNPDS was studied in four selected herds by Hanne Kongsted of the University of Copenhagen and co-authors there and at the Technical University of Denmark.

In a paper in BMC Veterinary Research, they explain that NNPDS is a recently emerged syndrome, characterised by diarrhoea within the first week of life, which is unresponsive to antibiotics and not associated with known pathogens. The aetiology behind the syndrome is unknown, and specific risk factors predisposing piglets to develop NNPDS also remain to be determined.

The researchers evaluated a total of 941 newborn piglets from 86 litters for five consecutive days. The study evaluated sow- and piglet-level risk factors for developing NNPDS and described the epidemiologic characteristics within four herds previously diagnosed with the syndrome. NNPDS was defined as diarrhoea at any time-point during the second to fifth day of life.

NNPDS was observed in a total of 60 per cent (range: 39 to 89 per cent) of first-parity piglets and 36 per cent (range: 19 to 65 per cent) of piglets born by mature sows.

Overall, 26 per cent of piglets had liquid faeces on the day of birth. Approximately half of these piglets developed NNPDS. In the majority of cases (50 to 70 per cent of cases within herds), symptoms started on the second or third day of life.

Piglets in Herd 1 had 12.8 times higher probability of developing NNPDS than piglets in Herd 4. First-parity piglets had a 4.1 higher probability of developing NNPDS than piglets born by mature sows. Birth weight and faecal consistency on the day of birth were minor risk factors, each significant within one herd.

The most important factors associated with NNPDS were herd of origin and sow parity, according to Kongsted and colleagues. The reason for one of the herds experiencing a considerably more severe outbreak than the others was not explained by the factors addressed in this study.

The epidemiological pattern of diarrhoea varied considerably between herds, they noted, however, in all herds, first-parity piglets seemed predisposed to the condition. This association may be explained by an infectious background of the syndrome but further studies are needed to explain this association.

Reference

Kongsted H., N. Toft and J.P. Nielsen. 2014. Risk factors and epidemiological characteristics of new neonatal porcine diarrhoea syndrome in four Danish herds. BMC Veterinary Research. 10:151. doi:10.1186/1746-6148-10-151

August 2014