Cryptosporidium, one of many bugs that can cause diarrhoea, dehydration and death in calves and vomiting and diarrhoea in humans, is the target of a seasonal study.

Children particularly may be infected, and cryptosporidium affects many other mammals.

However, a new effective antibiotic has recently become available.

Cattle producers throughout the New England, north west and parts of the Hunter are invited to participate in the study.

Free testing, funded by the McGarvie Smith Institute, will be offered to identify the cause of scouring in young calves, and where cryptosporidium is identified, Hunter New England Health and the Australian Centre for Agricultural Health and Safety will investigate the potential for people to become infected through contact.

"We would be particularly grateful for producers’ assistance if cryptosporidium has been diagnosed on their properties before," NSW Department of Primary Industries (DPI) senior regional animal health manager, Belinda Walker, said.

"This is an important study, in which we hope to identify some of the risk factors for becoming infected, for both calves and humans, so that future infections may be prevented."

The duration of the study will be dependent on the "crypto season" but will probably run from July 2008 to April 2009.

"DPI will also try to determine the factors affecting the severity of the disease in calves, and why it appears to affect calves on some farms and not others," she said.

The study area covers the Rural Lands Protection Board Districts of Moree, Narrabri, Northern Slopes (Warialda), Northern New England (Glen Innes and Tenterfield), Armidale and Tamworth, Gloucester, Scone and Maitland.

Although drought will have reduced the level of environmental contamination, in many areas where moisture remains such as in watercourses, areas around dams and troughs, it is likely that viable oocysts (eggs) of cryptosporidium are still present.

"Scouring in calves is more common in wet conditions and recent rains may allow these to infect stock, particularly if we continue to get moisture through into spring," Dr Walker said.

A vet will need to confirm that cryptosporidium is causing scours before the new antibiotic can be prescribed, as a number of different bacteria and viruses may also cause diarrhoea, including rotavirus, E.coli, yersinia, salmonella and coccidiosis.

"Producers can assist with this research by arranging a prompt visit by their Rural Lands Protection Board District or private vet if their calves show signs of scouring," Dr Walker said.

Contact Dr Belinda Walker, Gunnedah, (02) 6741 8363.