Re: Fifty years of leptospirosis research in New Zealand: a perspective.

The article which appeared in the Jubilee Issue of the New Zealand Veterinary Journal (Marshall and Manktelow 2002) reviewed one of this country's most important zoonotic diseases. I wish to add three important references concerning its first recognition in livestock and humans in New Zealand. The first field cases of leptospirosis in calves due to Leptospira pomona (now L. interrogans serovar pomona) were confirmed in November 1951 on farms in Westland, not in Northland in 1953 as stated in the review. The seminal year for leptospirosis research was 1951 not 1953. Simultaneously, the association with human disease in New Zealand was also recognized and confirmed (Bruere 1952; Kirschner et al 1952). In that year there was a mini-epidemic of cases in Westland involving both calves and humans. It was fortuitous at the time that Kirschner had established methods for the diagnosis of leptospirosis at Otago Medical School. Despite obvious clinical signs, laboratory diagnosis of leptospirosis was not confirmed at Wallaceville (New Zealand's only animal diagnostic station available to veterinarians in 1951) because of logistic impossibilities in both transport and sample preservation. From calf sera collected in Koiterangi (now renamed Kowhitirangi) in Westland in November 1951, Kirschner confirmed my diagnosis of leptospirosis ...