Leptospirosis strain a potential killer

Press, 29 August 1984, Page 2

Leptospirosis strain a potential killer

pa iNeison The Health Department confirmed yesterday that a strain of leptospirosis discovered in Nelson deer herds is potentially a killer in humans. Research by two veterinarians in Nelson has identified three strains of leptospirosis in wild and farmed deer in the province. Two of the strains are common to cattle and pigs but the third. Leptospirosis copenhageni, is the first reported evidence of this strain in domestic stock in New Zealand. “There is no doubt that this particular serovar strain has much more serious reactions in humans than other types,” said the department’s deputy director (occupational health), Dr John Stoke, yesterday.

Those affected would be more likely to develop jaundice and bleeding disorders associated with the disease. In other parts of the world deaths had been recorded, he said. Dr Stoke could not say whether Leptospirosis copenhageni had caused any deaths in New Zealand without checking mortality records. However, he did check Health Department records over the last five years and found that six blood tests had given a positive reaction to this strain of the disease. In five of the cases the tests also showed a reaction to other strains of Leptospirosis which Dr Stoke said was consistent with the department’s experience of a cross-strain infection.

Only one case of the six

reacted to the copenhageni strain alone. The sample came from a person near Blenheim, he said. The copenhageni strain was well known in the northern hemisphere, where it was once known as tunnel workers’ disease, Dr Stoke said. The ailment was frequently contracted by tunnel workers from contact with rat urine. Veterinary researchers are experimenting with vaccines for deer but are not hopeful of a quick solution. At present there is no leptospirosis vaccination for deer. Instead scientists are experimenting with the vaccine used on dairy cattle with the aim of eventually being able to license it for use in deer.